From fitsbits-request  Fri Jul  7 05:56:17 1995
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	["594" "" "6" "July" "1995" "22:29:22" "GMT" "Andrew J. P. Maclean" "a.maclean at uws.edu.au" "<3tho42$45g at ob1.uws.EDU.AU>" "23" "WIndows FITS Table reader" "^From:" nil nil "7" "1995070622:29:22" "WIndows FITS Table reader" (number " " mark "     Andrew J. P. Macl Jul  6   23/594   " thread-indent "\"WIndows FITS Table reader\"\n") nil]
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From: "Andrew J. P. Maclean" <a.maclean at uws.edu.au>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: WIndows FITS Table reader
Date: 6 Jul 1995 22:29:22 GMT

Does anyone know if there is a FITS Table reader that 
runs in Widows 3.1 or Win95 available?

-- 
+----------------------------------+---------------------------
----+
|  Andrew J. P. Maclean            |                           
    |
|  University Planner              |                           
    |
|  University of Western Sydney    |  Ph:     +61 (02) 678 7848 
   |
|  PO Box 1000, St Marys, NSW 2760 |  Fax:    +61 (02) 678 7804 
   |
|  Australia                       |  e-mail: 
a.maclean at uws.edu.au |
+----------------------------------+---------------------------
----+

From fitsbits-request  Fri Jul 14 14:24:33 1995
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	["628" "Fri" "14" "July" "1995" "14:24:15" "-0400" "William Pence" "pence at tetra.gsfc.nasa.gov" "<199507141824.OAA26730 at tetra.gsfc.nasa.gov>" "20" "re: FITSIO  V4.0" "^From:" nil nil "7" "1995071418:24:15" "FITSIO  V4.0" (number " " mark "     William Pence     Jul 14   20/628   " thread-indent "\"re: FITSIO  V4.0\"\n") nil]
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To: fitsbits at fits.cv.nrao.edu
Cc: pence at tetra.gsfc.nasa.gov
Subject: re: FITSIO  V4.0
Date: Fri, 14 Jul 1995 14:24:15 -0400

A couple bugs have been reported and fixed in the version 4.0 of the
FITSIO software that was announced here on 26 June.  One of the
problems is potentially serious and could affect programs which have
more than 1 FITS file open at one time.  Anyone using versions 4.01
thru 4.03 of FITSIO should replace it with the latest V4.04 version.
As before, this can be obtained on the WWW at URL:

     http://heasarc.gsfc.nasa.gov/docs/software/fitsio/fitsio.html
 
 or via anonymous ftp from:
 
     legacy.gsfc.nasa.gov in the /software/fitsio directory.
 
Sorry for the inconvenience.

William Pence
pence at tetra.gsfc.nasa.gov.
 

From fitsbits-request  Sun Jul 30 15:36:00 1995
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	["1167" "" "28" "July" "1995" "17:26:25" "GMT" "Mike Fitzgibbon" "fitz at argus.lpl.arizona.edu" "<3vb6k1$icm at news.ccit.arizona.edu>" "38" "Re: FITSVIEW Header Problem" "^From:" nil nil "7" "1995072817:26:25" "FITSVIEW Header Problem" (number " " mark "     Mike Fitzgibbon   Jul 28   38/1167  " thread-indent "\"Re: FITSVIEW Header Problem\"\n") "<3v9s7a$p3f at crl9.crl.com>"]
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From: fitz at argus.lpl.arizona.edu (Mike Fitzgibbon)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: FITSVIEW Header Problem
Date: 28 Jul 1995 17:26:25 GMT

In article <3v9s7a$p3f at crl9.crl.com>, atherton at crl.com says...
...
>
>     "FITShead::valid_check:Invalid FITS (no SIMPLE = T)"
>
... but ...
>
>SIMPLE  = T
>BITPIX  = 16
>NAXIS   = 3
>NAXIS1  = 384
>NAXIS2  = 576
>NAXIS3  = 1
>BZERO   = 0.000000E+000         
>BSCALE  = 1.000000E+000
>ORIGIN  = UC Santa Barbara Remote Access Telescope
>TELESCOP= Celestron C-14 w/ Photometrics 576x384 CCD
>DATE-OBS= 20/02/95
>TIME-OBS= 20:38
>RA      =  .9616
>DEC     =  81.61
>Comment = Exposure :=  5sec
>COMMENT = Filter Wheel #1: EMPTY
>COMMENT = Filter Wheel #2: EMPTY
>END
...

Well the problem seems to be that "buggy" software is generating these FITS 
files.  According to the format definition, (see Astron. Astrophys. Suppl. 
Ser. 44, (1981) pp363-370, "FITS: A Flexible Image Transport System" by D.C. 
Wells, E.W. Greisen, and R.H. Harten), a logical variable (e.g. SIMPLE) has a 
value of T or F in column 30.  This header put the logical value in column 11.
Also of note is that integer and real values should be right justified in 
columns 11-30 and character variables should have a single quote in column 11 
with the ending quote no earlier that column 20.

From fitsbits-request  Mon Jul 31 07:54:52 1995
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	["1526" "" "29" "July" "1995" "20:18:29" "-0700" "Dave Atherton" "atherton at crl.com" "<3vetm5$h9e at crl13.crl.com>" "29" "Re: FITSVIEW Header Problem" "^From:" nil nil "7" "1995073003:18:29" "FITSVIEW Header Problem" (number " " mark "     Dave Atherton     Jul 29   29/1526  " thread-indent "\"Re: FITSVIEW Header Problem\"\n") "<3vb6k1$icm at news.ccit.arizona.edu>"]
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From: atherton at crl.com (Dave Atherton)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: FITSVIEW Header Problem
Date: 29 Jul 1995 20:18:29 -0700

Mike Fitzgibbon (fitz at argus.lpl.arizona.edu) wrote:
: Well the problem seems to be that "buggy" software is generating these FITS 
: files.  According to the format definition, (see Astron. Astrophys. Suppl. 
: Ser. 44, (1981) pp363-370, "FITS: A Flexible Image Transport System" by D.C. 
: Wells, E.W. Greisen, and R.H. Harten), a logical variable (e.g. SIMPLE) has a 
: value of T or F in column 30.  This header put the logical value in column 11.
: Also of note is that integer and real values should be right justified in 
: columns 11-30 and character variables should have a single quote in column 11 
: with the ending quote no earlier that column 20.

Thanks for all the help from those who responded on Usenet and via email. 
I've succeeded in using DOS DEBUG to touch-up 2 files well enough to get
FITSView to read them.  Now, with this experience and the NOST FITS manual
in hand, I am prepared to touch-up a few more and chat intelligently with
the originator of the problematic files. 

In case anyone is interested, FITSView 0.4.0 required the "T" to be in 
column 30 but was unconcerned about the character strings not being in 
quotes.

-Dave
  ---------------------------------------------------------------------
 | Dave Atherton - Work: cara25 at email.mot.com - Home: atherton at crl.com |
 | Christian Radio Pipeline Page:  http://www.crl.com/~atherton/       |
 | "There's a fine line between participation and mockery." - S. Adams |
  ---------------------------------------------------------------------

From fitsbits-request  Tue Aug  1 08:22:41 1995
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	["1310" "Sat" "29" "July" "1995" "00:57:59" "GMT" "Stan Voynick" "svoynick at netcom.com" "<svoynickDCGDCn.63z at netcom.com>" "40" "Re: FITSVIEW Header Problem" "^From:" nil nil "7" "1995072900:57:59" "FITSVIEW Header Problem" (number " " mark "     Stan Voynick      Jul 29   40/1310  " thread-indent "\"Re: FITSVIEW Header Problem\"\n") "<3v9s7a$p3f at crl9.crl.com>"]
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content-length: 1308
From: svoynick at netcom.com (Stan Voynick)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: FITSVIEW Header Problem
Date: Sat, 29 Jul 1995 00:57:59 GMT

In article <3v9s7a$p3f at crl9.crl.com>, Dave Atherton <atherton at crl.com> wrote:
>I have used FITSVIEW 0.4.0 to view image files from several different
>sources but am having difficulty with the files from a particular
>automated telescope.
>
>     ..............
>
>When I inspected the header, I found the "SIMPLE = T" and found that the
>header contained 80-column records with no newlines...just like one
>would expect.  There's evidently something else about that header that
>it doesn't like.
>
>     ..................
>
>A file that I tested was JATILA01.ZIP.  Unzipping produced 2 *.FTS files
>which I renamed to *.FIT.  Below is a listing of the header and first
>line of image data from JATILA01.FIT (with a newline inserted after
>every 80 chars for readability).  Can somebody suggest what part of this
>header might be bothering FITSVIEW?
>
>SIMPLE  = T

If this is reproduced accurately, then the "T" is not in the correct 
column.  From the FITS standard:

==================== Start Quote ======================

5.3.2.2  Logical Variable

If the value is a logical constant, it shall appear as a T or F 
in column 30.

==================== End Quote ========================

Maybe try to manually go in and fix up a file and see if it works...

                             - Stan Voynick -

From fitsbits-request  Tue Aug  1 08:58:44 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["1875" "Tue" "1" "August" "1995" "08:58:32" "EDT" "Bill Cotton" "bcotton at gorilla.cv.nrao.edu" "<9508011258.AA03234 at gorilla.cv.nrao.edu>" "52" "Re: FITSVIEW Header Problem" "^From:" nil nil "8" "1995080112:58:32" "FITSVIEW Header Problem" (number " " mark "     Bill Cotton       Aug  1   52/1875  " thread-indent "\"Re: FITSVIEW Header Problem\"\n") "<svoynickDCGDCn.63z at netcom.com>"]
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From: bcotton at gorilla.cv.nrao.edu (Bill Cotton)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu, svoynick at netcom.com (Stan Voynick)
Subject: Re: FITSVIEW Header Problem
Date: Tue, 1 Aug 95 08:58:32 EDT

Stan Voynick writes:

>>In article <3v9s7a$p3f at crl9.crl.com>, Dave Atherton <atherton at crl.com> wrote:
>>I have used FITSVIEW 0.4.0 to view image files from several different
>>sources but am having difficulty with the files from a particular
>>automated telescope.
>>
>>     ..............
>>
>>When I inspected the header, I found the "SIMPLE = T" and found that the
>>header contained 80-column records with no newlines...just like one
>>would expect.  There's evidently something else about that header that
>>it doesn't like.
>>
>>     ..................
>>
>>A file that I tested was JATILA01.ZIP.  Unzipping produced 2 *.FTS files
>>which I renamed to *.FIT.  Below is a listing of the header and first
>>line of image data from JATILA01.FIT (with a newline inserted after
>>every 80 chars for readability).  Can somebody suggest what part of this
>>header might be bothering FITSVIEW?
>>
>>SIMPLE  = T
>
>If this is reproduced accurately, then the "T" is not in the correct 
>column.  From the FITS standard:
>
>==================== Start Quote ======================
>
>5.3.2.2  Logical Variable
>
>If the value is a logical constant, it shall appear as a T or F 
>in column 30.
>
>==================== End Quote ========================
>
>Maybe try to manually go in and fix up a file and see if it works...
>
>                             - Stan Voynick -

   FITSview takes a rather strict interpretation of the FITS rules for
the SIMPLE= T keyword as it has to use this to distinguish FITS files
from others; thus the "T" must be in column 30.  The interpretation of
other keywords is somewhat more relaxed even though the FITS rules are
that the "required" keywords shall be in a fixed format.  FITSview
ignores keywords that it doesn't need to interprete the image.
Editing the file to put the "T" in the correct column should fix the
problem. 

Bill Cotton

From fitsbits-request  Wed Aug  2 21:49:18 1995
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	["834" "" "31" "July" "1995" "06:51:03" "GMT" "Michael Olberg" "olberg at nain.oso.chalmers.se" "<3vhugn$cbn at nyheter.chalmers.se>" "17" "Re: FITSVIEW Header Problem" "^From:" nil nil "7" "1995073106:51:03" "FITSVIEW Header Problem" (number " " mark "     Michael Olberg    Jul 31   17/834   " thread-indent "\"Re: FITSVIEW Header Problem\"\n") "<3vetm5$h9e at crl13.crl.com>"]
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From: olberg at nain.oso.chalmers.se (Michael Olberg)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: FITSVIEW Header Problem
Date: 31 Jul 1995 06:51:03 GMT

Dave Atherton (atherton at crl.com) wrote:
: Thanks for all the help from those who responded on Usenet and via email. 
: I've succeeded in using DOS DEBUG to touch-up 2 files well enough to get
: FITSView to read them.  Now, with this experience and the NOST FITS manual

Just as a hint: I have at times used emacs (or any of its clones) to edit
FITS files, it is one of the few editors who happily work on binary files
as well. Might be less awkward to use for some of you than DEBUG.

-- 
---------------------------------------------------------------------------
Michael Olberg                      | e-mail: olberg at oso.chalmers.se
Onsala Space Observatory            | tel:    +46-31-7725507
S-43992 Onsala, SWEDEN              | fax:    +46-31-7725590
-------------------- This quote left blank intentionally ------------------

From fitsbits-request  Fri Aug  4 05:41:41 1995
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	["1014" "" "3" "August" "1995" "13:25:35" "GMT" "Ralph P. Pass" "rppass at tasc.com" "<3vqiof$gmu at hazel.Read.TASC.COM>" "30" "FITS 'extensions'" "^From:" nil nil "8" "1995080313:25:35" "FITS 'extensions'" (number " " mark "     Ralph P. Pass     Aug  3   30/1014  " thread-indent "\"FITS 'extensions'\"\n") nil]
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From: rppass at tasc.com (Ralph P. Pass)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: FITS 'extensions'
Date: 3 Aug 1995 13:25:35 GMT

I have looked at some of the FITS files that are generated by various
CCD camera interface programs.  I notices many non-defined 
(non-standard??) parameters.  While the FITS document allows for this
should we not standardize them so that at least we know what the
parameters mean and what form they are??

For example, I have seen UT and TIME-OBS for the time.  I have seen
the values after these labels being in single quotes. I have seen
them in the form with colons (:) separating the hours minutes seconds
and with slashes (/).

It is apparent that the FITS format is flexible but has grown into a 
non-standard.  

I, of course, would like to suggest a set of unofficial standards for
many of the extensions I have seen (just to try to control the 
proliferation).  Of course, getting the software suppliers to change to 
these suggestions might prove to be difficult.

On the other hand, how about FITS having a set of defined 'unofficial' 
extensions??

Just some thoughts

Ralph Pass
rppass at tasc.com

a

From fitsbits-request  Fri Aug  4 10:05:00 1995
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	["2065" "Fri" "4" "August" "1995" "10:04:53" "-0400" "Mike Corcoran" "corcoran at barnegat.gsfc.nasa.gov" "<199508041404.KAA02283 at barnegat.gsfc.nasa.gov>" "58" "Re: FITS 'extensions'" "^From:" nil nil "8" "1995080414:04:53" "FITS 'extensions'" (number " " mark "     Mike Corcoran     Aug  4   58/2065  " thread-indent "\"Re: FITS 'extensions'\"\n") nil]
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content-length: 2063
From: Mike Corcoran <corcoran at barnegat.gsfc.nasa.gov>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu, rppass at tasc.com
Subject: Re: FITS 'extensions'
Date: Fri, 4 Aug 1995 10:04:53 -0400

Ralph Pass writes:

> 
> I have looked at some of the FITS files that are generated by various
> CCD camera interface programs.  I notices many non-defined 
> (non-standard??) parameters.  While the FITS document allows for this
> should we not standardize them so that at least we know what the
> parameters mean and what form they are??
> 
> For example, I have seen UT and TIME-OBS for the time.  I have seen
> the values after these labels being in single quotes. I have seen
> them in the form with colons (:) separating the hours minutes seconds
> and with slashes (/).
> 
> It is apparent that the FITS format is flexible but has grown into a 
> non-standard.  
> 
> I, of course, would like to suggest a set of unofficial standards for
> many of the extensions I have seen (just to try to control the 
> proliferation).  Of course, getting the software suppliers to change to 
> these suggestions might prove to be difficult.
> 
> On the other hand, how about FITS having a set of defined 'unofficial' 
> extensions??
> 
> Just some thoughts
> 
> Ralph Pass
> rppass at tasc.com

The High Energy Astrophysics Science Archive Research Center (HEASARC)
at GSFC came to a similar conclusion.  The HEASARC has the
responsibility of archiving data from space-based high energy astronomy
missions.  We've adopted FITS as our archiving format, but we soon
realized that non-conventional usages made analyzing the data a real
pain. To help remedy this we've tried to promote some conventions.  You
can get more information about these conventions from the web page

http://heasarc.gsfc.nasa.gov/docs/heasarc/ofwg/ofwg_intro.html

for more information about the conventions we've recommended.  

best regards

Mike Corcoran

********************************************************************************
Dr. Michael F. Corcoran
High Energy Astrophysics Science Archive Research Center
Goddard Space Flight Center
Greenbelt, MD 20771
corcoran at barnegat.gsfc.nasa.gov
LHEAVX::CORCORAN
********************************************************************************

From fitsbits-request  Fri Aug  4 19:12:43 1995
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	["379" "" "4" "August" "1995" "15:33:05" "GMT" "keith at msmri.med.ubc.ca" "keith at msmri.med.ubc.ca" "<3vtejh$mg at nntp.ucs.ubc.ca>" "16" "Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080415:33:05" "Saving 100GB of data for 15 years cheaply" (number " " mark "     keith at msmri.med.u Aug  4   16/379   " thread-indent "\"Saving 100GB of data for 15 years cheaply\"\n") nil]
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Reply-To: keith at msmri.med.ubc.ca (Keith S Cover)
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From: keith at msmri.med.ubc.ca
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Saving 100GB of data for 15 years cheaply
Date: 4 Aug 1995 15:33:05 GMT

Please post replies to sci.data.formats.

I need to save several hundred gigabytes of medical imaging data on a cheap 
reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
This is cheap but is only good for about 1 year.  Does anyone have any better
suggestions?

Thanks in advance.

Keith S Cover
Physics, UBC
Vancouver, Canada
keith at msmri.med.ubc.ca

From fitsbits-request  Sat Aug  5 09:45:15 1995
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	["603" "" "4" "August" "1995" "19:23:05" "GMT" "Christopher Michael Jones" "cjones at ccserver.uoregon.edu" "<3vts2p$4j0 at pith.uoregon.edu>" "16" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080419:23:05" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Christopher Micha Aug  4   16/603   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<3vtejh$mg at nntp.ucs.ubc.ca>"]
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From: cjones at ccserver.uoregon.edu (Christopher Michael Jones)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 4 Aug 1995 19:23:05 GMT

keith at msmri.med.ubc.ca wrote:
: Please post replies to sci.data.formats.

: I need to save several hundred gigabytes of medical imaging data on a cheap 
: reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
: This is cheap but is only good for about 1 year.  Does anyone have any 
: better suggestions?

: Thanks in advance.

I'm not sure hom much getting a CD-ROM made would cost but that could be 
an option.  You could try distributing chunks of it over the internet for 
people to save for you :-).  Or you could wait about a while and put the 
data on 10 or 7 Gig DVD's.

From fitsbits-request  Sat Aug  5 11:21:27 1995
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	["1673" "" "5" "August" "1995" "14:33:34" "GMT" "Tom Potter" "tdp at ix.netcom.com" "<3vvvfu$a1e at ixnews6.ix.netcom.com>" "37" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080514:33:34" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Tom Potter        Aug  5   37/1673  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") nil]
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From: tdp at ix.netcom.com (Tom Potter )
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 5 Aug 1995 14:33:34 GMT

In <mancini-0508951513050001 at usx121.maxlab.lu.se> mancini at maxlab.lu.se (Derrick C. Mancini) writes: 

>
>In article <3vts2p$4j0 at pith.uoregon.edu>, cjones at ccserver.uoregon.edu
>(Christopher Michael Jones) wrote:
>>keith at msmri.med.ubc.ca wrote:
>>: I need to save several hundred gigabytes of medical imaging data on a cheap 
>>: reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
>>: This is cheap but is only good for about 1 year.  Does anyone have any 
>>: better suggestions?
>>I'm not sure hom much getting a CD-ROM made would cost but that could be 
>>an option. 
>
>CD-ROM blanks will be slow to write, but are cheap (about $20 each) and
>will hold about 700K.  They also have the advantage of being readable on
>a large number of machines, provided you put things into a readily accessible
>format.  You could also maintain an index CD.  Write times are slow compared
>to a hard drive, but should be better than the tape.  Backup should be good
>for 10 years, I think.  I would guess that price per gigabyte per year of
>storage would be competitive with tapes.  The CD-ROM writable drives can
>be had for as little as $2000.
>
>-- 
>Dr. Derrick C. Mancini
>MAXLab, Lund University         Advance Photon Source, ANL
>Box 118, Ole Romers Vag 1       9700 S. Cass Avenue - APS/431
>S-221 00, Lund, Sweden          Argonne, IL, USA  60439
>Tel: +46 46 222 3355            Tel: +1 708 252 0147
>FAX: +46 46 222 4710            FAX: +1 708 252 3222
>Email: mancini at maxlab.lu.se     Email: mancini at aps.anl.gov
>

CD's hold about 700 MEGABYTES of data, uncompressed.
They can hold at least two times this if the data is compressed ( Zipped ).

From fitsbits-request  Sun Aug  6 02:45:54 1995
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	["788" "" "4" "August" "1995" "19:53:13" "GMT" "Andy Loughe" "afl at cdc.noaa.gov" "<3vttr9$8r2 at lace.Colorado.EDU>" "26" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080419:53:13" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Andy Loughe       Aug  4   26/788   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<3vtejh$mg at nntp.ucs.ubc.ca>"]
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From: afl at cdc.noaa.gov (Andy Loughe)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 4 Aug 1995 19:53:13 GMT

In article <3vtejh$mg at nntp.ucs.ubc.ca>, keith at msmri.med.ubc.ca writes:
|> Please post replies to sci.data.formats.
|> 
|> I need to save several hundred gigabytes of medical imaging data on a cheap 
|> reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
|> This is cheap but is only good for about 1 year.  Does anyone have any better
|> suggestions?
|> 
|> Thanks in advance.
|> 
|> Keith S Cover
|> Physics, UBC
|> Vancouver, Canada
|> keith at msmri.med.ubc.ca
|> 

What about a small optical drive with removable disks?

-- 

Andrew F. Loughe                        email: afl at cdc.noaa.gov
University of Colorado, CIRES           voice: (303) 492-0707
Campus Box 449                            fax: (303) 497-7013
Boulder, CO  80309-0449   USA                

From fitsbits-request  Mon Aug  7 09:37:10 1995
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	["3197" "" "7" "August" "1995" "11:24:58" "GMT" "Ralph Martin" "ralf at mail.ast.cam.ac.uk" "<404t6a$fme at lyra.csx.cam.ac.uk>" "49" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080711:24:58" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Ralph Martin      Aug  7   49/3197  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<404l2e$40v at anarchy.io.com>"]
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From: ralf at mail.ast.cam.ac.uk (Ralph Martin)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 7 Aug 1995 11:24:58 GMT

The question of how to store digital information for long periods of
time is worth a hard look because there are already a number of
archives in astronomy which have had to ask the same question. Our archive
of telescope data was started in 1984 and originally used 1600 bpi nine track 
tape. The later computers had 6250 bpi nine track, then Exabyte and now DAT
tapes. By the beginning of last year we had some 7000 nine track tapes which
used about 60-70 square metres of floor space. More importantly we found
out that these kind of nine track tapes, which were mostly held in sealed 
canisters, were an immense fire risk. There are records of a test done
by the fire brigade at the Rutherford Laboratory. A few hundred of
these tapes were put into a former bomb store and a lighted rag thrown in.
A few minutes later, the fire was going so fiercely that it bent the
door lintel which was made of reinforced concrete. The brigade doused the blaze
with water but the fire restarted because the canisters provided their
own oxygen and the cooled outer shell protected the still hot inner core.
It took the fire crew serious amounts of foam to extinguish
the blaze. We thus had to choose what medium we were going to transfer
all this past data onto and it is here that the various options come into
play. How often do you want to reaccess the data? If it rare then
Exabyte will do the job but if you want to do it lots of times, the
Exabyte drive wear the tape. (This has something to do with the angle
that the tape makes with the reading heads). We asked around what was our
best option was and we decided to copy onto DAT tapes rather than CD-Rom
because a) DAT decks are cheap. b) DAT tapes are cheap c) It didn't
need any extra software effort to our derchiving software. I'm prepared
to believe that the choice could be made differently but the issue boils
down to what is going to be around for the next 10-15 years and I'd
say that DAT, Exabyte (maybe) and CD-Rom all have lifetimes of that
order. I now have two cabinets full of DATs and a spare room of 65 square
metres with students in it rather than tapes. The problem will probably
return in 10-15 years by which time I'll have the 'gone fishing' sign
over my door. The DAT's are being accessed regularly and so far we haven't
had any problems. Since we now dearchive the equivalent of nearly a full
telescope of data every year, it's important for it to be right. 
The DAT's are also considerably quicker than Exabytes when it comes
to reading FITS formatted tapes (which are the de facto standard in
astronomy) because Exabytes are hopeless at reading tape marks. Tape marks
occur after every FITS file on a tape....
The correspondent who wrote about optical storage is also correct
as the 10,000 Schmidt plates in our plate library and 150,000 glass plates
in our plate archive (some of which are well over a century old)
illustrate.
-- 
Ralph Martin                            Internet:      ralf at ast.cam.ac.uk
Royal Greenwich Observatory             Telephone:     UK+ 01223-374000
Cambridge CB3 0EZ                       ISDN:          UK+ 01223-328028
United Kingdom                          ISDN:          UK+ 01223-328087

From fitsbits-request  Mon Aug  7 21:56:59 1995
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	["654" "" "5" "August" "1995" "16:30:09" "-0700" "Ron Wickersham" "rjw at crl.com" "<400uu1$qqo at crl5.crl.com>" "24" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080523:30:09" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Ron Wickersham    Aug  5   24/654   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<3vtejh$mg at nntp.ucs.ubc.ca>"]
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From: rjw at crl.com (Ron Wickersham)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 5 Aug 1995 16:30:09 -0700

Please elaborate on the 8mm Exabyte storage lifetime.  I thought that tape
would be good for the fifteen year requirement stated.  Do others report 
the Exabyte system only reliable for 1 year?

-ron wickersham
rjw at crl.com

keith at msmri.med.ubc.ca 
wrote: : Please post replies to sci.data.formats.

: I need to save several hundred gigabytes of medical imaging data on a cheap 
: reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
: This is cheap but is only good for about 1 year.  Does anyone have any better
: suggestions?

: Thanks in advance.

: Keith S Cover
: Physics, UBC
: Vancouver, Canada
: keith at msmri.med.ubc.ca

From fitsbits-request  Tue Aug  8 09:56:33 1995
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	["657" "Mon" "7" "August" "1995" "17:13:03" "GMT" "susan cassidy" "susanc at ssd3450.sandiegoca.attgis.com" "<DCyAHr.A0r at lcpd2.SanDiegoCA.ATTGIS.COM>" "17" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080717:13:03" "Saving 100GB of data for 15 years cheaply" (number " " mark "     susan cassidy     Aug  7   17/657   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<404t6a$fme at lyra.csx.cam.ac.uk>"]
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From: susanc at ssd3450.SanDiegoCA.ATTGIS.COM (susan cassidy)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: Mon, 7 Aug 1995 17:13:03 GMT

I would be reluctant to count on any form of magnetic tape lasting for 15
years.  When I visited the U.S. Geological Survey office where they 
process the data from space probes, they told us they had problems with
tapes distintegrating that had data that had not yet been processed.
Also, the reliability of tape is very dependent on the environmental
conditions.

One other factor is that anything like 8mm Exabyte tapes may not be
around (the drives/software to read them) 15 years from now.  They
did not exist 15 years ago.  I think the CD/ROM idea is probably
a better approach for now.

-- 
Susan Cassidy
email: susan.cassidy at sandiegoca.attgis.com

From fitsbits-request  Tue Aug  8 13:11:43 1995
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	["1389" "" "8" "August" "1995" "13:34:11" "GMT" "Martin Leese" "mleese at hudson.cs.unb.ca" "<407p4j$ms2 at sol.sun.csd.unb.ca>" "28" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080813:34:11" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Martin Leese      Aug  8   28/1389  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<406st6$8le at gwis2.circ.gwu.edu>"]
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Reply-To: MLeese at atlantic.cs.unb.ca
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From: mleese at hudson.CS.unb.ca (Martin Leese - OMG)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 8 Aug 1995 13:34:11 GMT

On 8 Aug 1995 01:32:22 -0400 Scott Fearing (sfearing at gwis2.circ.gwu.edu) wrote:
>> 	I should warn you of a potential danger of CD storage: CD 'rot'.
>> Apparently, the aluminum can oxidize under the plastic protective covering 
>> and data can be lost.  This is appearing on CDs as well as laserdiscs, 
>> but I assume it does not happen to the special gold plated discs that come 
>> out on the audiophile pressings.  There are discussions of this from time 
>> to time on rec.video.laserdisc.

Laserdiscs are made in two halves and then glued together.  There are
problems with the glue eating the aluminum layer - disc rot - but the 
glue was changed many years ago.  It takes years for the Laserdisc to 
rot, so we are currently reaping the "benefits" of a past mistake.

Audio CDs and CD-ROMs are not made in two halves so there is no glue.
There was a problem many years ago with acid from the cheap cardboard
sleeves of promo CDs attacking the aluminium. There was also a problem
many years ago with the ink used to print onto the CD.  Both of these 
problems are long gone.

Regards,
Martin
E-mail: mleese at atlantic.cs.unb.ca
WWW:    http://www.omg.unb.ca/~mleese/
________________________________________________________________________
 Want to know how Ambisonics can improve the sound of your LPs and CDs?
  See the Ambisonic Surround Sound FAQ.  Details on my WWW Home page.

From fitsbits-request  Tue Aug  8 16:01:36 1995
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	["1461" "" "8" "August" "1995" "10:56:29" "-0400" "Ben Weiner" "bweiner at electron.rutgers.edu" "<407tut$21e at electron.rutgers.edu>" "30" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080814:56:29" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Ben Weiner        Aug  8   30/1461  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<406st6$8le at gwis2.circ.gwu.edu>"]
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From: bweiner at electron.rutgers.edu (Ben Weiner)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 8 Aug 1995 10:56:29 -0400

sfearing at gwis2.circ.gwu.edu (Scott Fearing) writes:

>	I should warn you of a potential danger of CD storage: CD 'rot'.
>Apparently, the aluminum can oxidize under the plastic protective covering 
>and data can be lost.  This is appearing on CDs as well as laserdiscs, 
>but I assume it does not happen to the special gold plated discs that come 
>out on the audiophile pressings.  There are discussions of this from time 
>to time on rec.video.laserdisc.

Uh.  This sounds like an urban legend.  Or one of those audiophile stories.
If aluminum oxidizes, it forms, natch, aluminum oxide, which is clear.
In fact first-surface aluminized mirrors always form a thin layer of
clear aluminum oxide on the top, which is not bad, but good - aluminum
oxide is less reactive than raw aluminum, so it prevents tarnish.

This is not to in any way endorse claims that CDs are permanent.

But I believe that in 15 years your CDs will probably still be good.
Also, I believe that in 15 years you will be able to find a CD(ROM)
player.  I can barely read nine-track tapes now, and in a couple of
years I expect it would be a real pain in the ass finding a nine-track
drive.  Some of the tapes will be less than 10 years old then, yet
unreadable.  (Fortunately, there's nothing important on them.)  I
expect the situation to be better with Exabytes and even better with
DATs.  But still ...

-- 
History / has a stutter / it says / w-w-w-w-watch out!           - the mekons

From fitsbits-request  Wed Aug  9 06:43:07 1995
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	["2258" "Tue" "8" "August" "1995" "17:42:05" "GMT" "Mitchell R. Grunes" "grunes at news.nrl.navy.mil" "<grunes.302.807903725 at news.nrl.navy.mil>" "45" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080817:42:05" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Mitchell R. Grune Aug  8   45/2258  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<407tut$21e at electron.rutgers.edu>"]
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Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 2256
From: grunes at news.nrl.navy.mil (Mitchell R Grunes)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: Tue, 8 Aug 1995 17:42:05 GMT

1.  Why not leave put the data on those 1 year lifetime (but high
capacity) tapes, but re-copy it every 5 or 6 months?  Since it would only 
take a few tapes, and you could copy one overnight, it really wouldn't 
take much of your time.  If you are paranoid, add an extra layer of 
error detection and/or correction coding, keep the last version's tape 
around in case an error happens, and I would think you could make it work.

This isn't based on extended experience--it just seems reasonable.

Re-copying needs to be done even with 9 tracks, though less often.  With
any media.  

2.  About your old 9 tracks.  How could they burn in sealed containers?
Surely there is a simple solution to this problem?  Inert gas?

3.  Since no one liked my idea of film, I've an even better idea.  
Print it all out in hex, on acid free paper.  When you need it, use a 
scanner.  Let's see: two characters/byte, about 100 characters/line 
and 60 lines/page...now that's a REAL fire hazard.  Compact, too.
                             (-:

4.  I've tried to think up a solution to a somewhat similar problem, and 
wasn't real happy with any of the solutions.  My personal solution mostly 
followed #1 above, because the tape drives were already around, whereas we 
would have to buy a CD recorder, and it would have taken ALOT of CDs--a lot 
of time and energy to deal with.

5.  For really long term storage, one would have to buy extra tape
drives, and computers to put them in, and a few decades of spare
parts.  I really wish libraries would keep a few old computers around,
of every conceivable common design, to make sure people could read
old media.  Would you believe that most scientific labs would now have
trouble reading 9 tracks?  It's not very sexy, but the need to read
old media (in spite of the errors) is going to be a very real problem.
What would you do if someone handed you an old TRS-80 audio tape with 
data on which the fate of the world (or at least your personal future) 
depended?
-------------------------------------------------------------------------
  Opinions are mine alone.
  I am not a "Real Programmer".  I only program in the Real World.
  Mitchell R Grunes (grunes at nrlvax.nrl.navy.mil)
  AlliedSignal Technical Services Corp.

From fitsbits-request  Wed Aug  9 07:01:43 1995
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	["1944" "" "8" "August" "1995" "18:23:06" "GMT" "Steve Allen" "sla at umbra.ucolick.org" "<408a2a$h50 at darkstar.UCSC.EDU>" "37" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080818:23:06" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Steve Allen       Aug  8   37/1944  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<40778p$rd9 at noao.edu>"]
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References: <3vtejh$mg at nntp.ucs.ubc.ca> <grunes.301.807838315 at news.nrl.navy.mil> <DCyvv2.LqH at midway.uchicago.edu> <40778p$rd9 at noao.edu>
Newsgroups: sci.astro.fits
content-length: 1942
From: sla at umbra.ucolick.org (Steve Allen)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 8 Aug 1995 18:23:06 GMT

Note that I have restricted this to sci.astro.fits only, as it
is not relevant to any of the other original newsgroups.

In article <40778p$rd9 at noao.edu>, Rob Seaman  <seaman at noao.edu> wrote:
>Another way to address this problem is to write larger files onto the
>tapes - and thus fewer tape marks.  FITS image extensions (and other
>FITS extensions) allow a good way to do this by concatenating multiple
>images into a single large file.

But in the instance of non-IMAGE extensions how would it be possible
to determine the relationships between the various different kinds of
HDUs?  I suspect that this would be an excellent application for
the <A HREF="http://acadia.gsfc.nasa.gov/convert/group.html">
FITS Grouping Convention </A> which was proposed last year.

>any single image in the archive is accessible in under 10 minutes.  Not
>exactly what I'd call "online", but quite acceptable for our purposes.
>In addition, multiple retrievals are much more likely than single image
>retrievals due to the calibration data, multiple filters and exposures,
>and the initial seek time is shared between the entire list of images
>retrieved.

Again, the proposed FITS grouping extension seems to contain the necessary
structure to document the relationships between all such images stored
together.

I'm putting together specs for the Keck DEIMOS data storage, and as
a part of the data that comes out of that we think we will be generating
FITS tables that describe the slitlet configurations.  We're planning on
embedding the FITS grouping convention keywords (which are simple to
add and unobtrusive to a FITS reader that does not care about them).
--  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --
Steve Allen          UCO/Lick Observatory       Santa Cruz, CA 95064
sla at ucolick.org      Voice: +1 408 459 3046     FAX: +1 408 454 9863
Notice:  The ucolick.org domain has just changed from being lick.ucsc.edu

From fitsbits-request  Wed Aug  9 08:57:20 1995
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	["1409" "Sat" "5" "August" "1995" "14:13:05" "GMT" "Derrick C. Mancini" "mancini at maxlab.lu.se" "<mancini-0508951513050001 at usx121.maxlab.lu.se>" "29" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080514:13:05" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Derrick C. Mancin Aug  5   29/1409  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<3vts2p$4j0 at pith.uoregon.edu>"]
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content-length: 1407
From: mancini at maxlab.lu.se (Derrick C. Mancini)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: Sat, 5 Aug 1995 14:13:05 GMT

In article <3vts2p$4j0 at pith.uoregon.edu>, cjones at ccserver.uoregon.edu
(Christopher Michael Jones) wrote:
>keith at msmri.med.ubc.ca wrote:
>: I need to save several hundred gigabytes of medical imaging data on a cheap 
>: reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
>: This is cheap but is only good for about 1 year.  Does anyone have any 
>: better suggestions?
>I'm not sure hom much getting a CD-ROM made would cost but that could be 
>an option. 

CD-ROM blanks will be slow to write, but are cheap (about $20 each) and
will hold about 700K.  They also have the advantage of being readable on
a large number of machines, provided you put things into a readily accessible
format.  You could also maintain an index CD.  Write times are slow compared
to a hard drive, but should be better than the tape.  Backup should be good
for 10 years, I think.  I would guess that price per gigabyte per year of
storage would be competitive with tapes.  The CD-ROM writable drives can
be had for as little as $2000.

-- 
Dr. Derrick C. Mancini
MAXLab, Lund University         Advance Photon Source, ANL
Box 118, Ole Romers Vag 1       9700 S. Cass Avenue - APS/431
S-221 00, Lund, Sweden          Argonne, IL, USA  60439
Tel: +46 46 222 3355            Tel: +1 708 252 0147
FAX: +46 46 222 4710            FAX: +1 708 252 3222
Email: mancini at maxlab.lu.se     Email: mancini at aps.anl.gov

From fitsbits-request  Wed Aug  9 13:03:39 1995
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	["1585" "" "9" "August" "1995" "13:07:45" "GMT" "Mitchell R. Grunes" "grunes at news.nrl.navy.mil" "<grunes.305.0 at news.nrl.navy.mil>" "33" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080913:07:45" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Mitchell R. Grune Aug  9   33/1585  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<409gdi$2qrq at yuma.ACNS.ColoState.EDU>"]
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Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 1583
From: grunes at news.nrl.navy.mil (Mitchell R Grunes)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 9 Aug 1995 13:07:45 GMT

In article <409gdi$2qrq at yuma.ACNS.ColoState.EDU> dean at phobos.cira.colostate.edu writes:
>  CD Recorders would be my vote. I am currently using a Pinnicle Recorder
>to make 650Mb CD-ROMs...
>
>  The CD that I am making with the Pinnicle do have problems. Some CD-ROMs
> will not read them. It is not a problem for us, because all the CD we
> make work on our CD-ROMs on our Window NT system. However, there have been
> some people reporting that their DOS machines with a CD-ROM wil not see the
> disk in the drive.

Could other people give their experiences on this, with the Pinnicle
and with other drives?  Does anyone know whether it is an issue of:

(1) Format.  Windows NT file systems may be unreadable to DOS
    boxes.  In fact, Some new DOS file systems will be unreadable to
    old DOS's, and any compressed file system (e.g., Stacker) will be 
    unreadable if you aren't using the same compression system.

(2) Reliability.  I suppose it is possible that some/all CD writers
    (or some/all brands of blank disks) do a borderline job, producing 
    disks that are just barely readable by some drives, not readable by 
    others.  Kind of like writing 360 KB floppies on 1.2 MB drives.

If the latter is true, it would make a big difference to those
of us who might otherwise consider buying a CD-ROM writer.
-------------------------------------------------------------------------
  Opinions are mine alone.
  I am not a "Real Programmer".  I only program in the Real World.
  Mitchell R Grunes (grunes at nrlvax.nrl.navy.mil)
  AlliedSignal Technical Services Corp.

From fitsbits-request  Wed Aug  9 14:19:29 1995
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	["623" "Wed" "9" "August" "1995" "13:39:37" "GMT" "Doug McDonald" "mcdonald at aries.scs.uiuc.edu" "<mcdonald.1605.3028BA99 at aries.scs.uiuc.edu>" "15" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080913:39:37" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Doug McDonald     Aug  9   15/623   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<mancini-0908951129210001 at usx121.maxlab.lu.se>"]
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Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 621
From: mcdonald at aries.scs.uiuc.edu (Doug McDonald)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: Wed, 9 Aug 1995 13:39:37 GMT

In article <mancini-0908951129210001 at usx121.maxlab.lu.se> mancini at maxlab.lu.se (Derrick C. Mancini) writes:

>>        I should warn you of a potential danger of CD storage: CD 'rot'.
>>Apparently, the aluminum can oxidize under the plastic protective covering 
>>and data can be lost.

Actually, the data can be recovered from a CD anyway. The overcoat can be 
stripped and the metal completely removed with acid. Then recoat.
Or the uncoated disk can be played like a record, mechanically, with
a simple low-resolution AFM of the "beetle" type. In fact, uncoated CDs
are used as tests for these gizmos.

Doug McDonald 

From fitsbits-request  Wed Aug  9 15:42:12 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["644" "" "9" "August" "1995" "14:13:18" "GMT" "Mitchell R. Grunes" "grunes at news.nrl.navy.mil" "<grunes.306.0 at news.nrl.navy.mil>" "15" "QIC Tape Lifetimes? was: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080914:13:18" "QIC Tape Lifetimes? was: Saving 100GB of data for 15 years cheaply" (number " " mark "     Mitchell R. Grune Aug  9   15/644   " thread-indent "\"QIC Tape Lifetimes? was: Saving 100GB of data for 15 years cheaply\"\n") "<mcdonald.1605.3028BA99 at aries.scs.uiuc.edu>"]
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References: <3vvvfu$a1e at ixnews6.ix.netcom.com> <404au3$jlh at itchy.itsnet.com> <406st6$8le at gwis2.circ.gwu.edu> <mancini-0908951129210001 at usx121.maxlab.lu.se> <mcdonald.1605.3028BA99 at aries.scs.uiuc.edu>
Newsgroups: sci.data.formats,sci.image.processing,sci.astro.fits,comp.sys.ibm.pc.hardware.storage
content-length: 642
From: grunes at news.nrl.navy.mil (Mitchell R Grunes)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: QIC Tape Lifetimes? was: Saving 100GB of data for 15 years cheaply
Date: 9 Aug 1995 14:13:18 GMT

As long as we are on the subject of tape lifetimes, what is the lifetime
of QIC family tapes, such as the ones rated at (compressed) capacities
of 250 MB, 350 MB, and 700 MB?

Also, does one extend the # of uses (usually rated at 3-5 back-ups, due
to the large number of passes required to handle multiple tracks with
one head) of these tapes if they are commercially pre-formatted? 
-------------------------------------------------------------------------
  Opinions are mine alone.
  I am not a "Real Programmer".  I only program in the Real World.
  Mitchell R Grunes (grunes at nrlvax.nrl.navy.mil)
  AlliedSignal Technical Services Corp.

From fitsbits-request  Wed Aug  9 15:50:38 1995
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	["624" "" "9" "August" "1995" "14:20:14" "GMT" "Dennis Ward" "dward at comet.ucar.edu" "<40ag6u$b9q at ncar.ucar.edu>" "27" "FITS to TIFF conversion?" "^From:" nil nil "8" "1995080914:20:14" "FITS to TIFF conversion?" (number " " mark "     Dennis Ward       Aug  9   27/624   " thread-indent "\"FITS to TIFF conversion?\"\n") nil]
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content-length: 622
From: Dennis Ward <dward at comet.ucar.edu>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: FITS to TIFF conversion?
Date: 9 Aug 1995 14:20:14 GMT

I am looking for software that will allow me to convert 
FITS image files to TIFF, TARGA or any other 24-bit 
graphics format.

The conversion software MUST run on a PC (either DOS or 
Windows).

Thanks in advance.

Clear Skies!

Dennis L. Ward              Internet:  dward at comet.ucar.edu
Multimedia Author/Programmer  
UCAR/COMET
PO BOX 3000                 Phone:           (303) 497-8345
Boulder, Co. 80307-3000     FAX:             (303) 497-8491
WWW HomePage:     
http://adder.colorado.edu/~ward/DLW/dlw.html   

We are all in the gutter, but some of us are looking at the 
stars.
                -- Oscar Wilde

From fitsbits-request  Wed Aug  9 16:32:17 1995
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From: jack at itsnet.com (Jack Hudler)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: Mon, 07 Aug 1995 06:12:23 GMT

tdp at ix.netcom.com (Tom Potter ) wrote:

>In <mancini-0508951513050001 at usx121.maxlab.lu.se> mancini at maxlab.lu.se (Derrick C. Mancini) writes: 

>>
>>In article <3vts2p$4j0 at pith.uoregon.edu>, cjones at ccserver.uoregon.edu
>>(Christopher Michael Jones) wrote:
>>>keith at msmri.med.ubc.ca wrote:
>>>: I need to save several hundred gigabytes of medical imaging data on a cheap 
>>>: reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
>>>: This is cheap but is only good for about 1 year.  Does anyone have any 
>>>: better suggestions?

>CD's hold about 700 MEGABYTES of data, uncompressed.
>They can hold at least two times this if the data is compressed ( Zipped ).

If you find the right software (Young Minds comes to mind :-) ), and
if your not worried about losses in the image, you could write
the data in raw CD data... in this case a CD can hold 1.2 to 1.6 gig.
The final amount would depend on the amount of correction information
you supply with the image. A CD has a huge overhead for the correction
logic.

From fitsbits-request  Wed Aug  9 22:25:29 1995
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	["1435" "" "7" "August" "1995" "09:06:22" "GMT" "Edwin Strickland" "EdStrick at io.com" "<404l2e$40v at anarchy.io.com>" "29" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080709:06:22" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Edwin Strickland  Aug  7   29/1435  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<3vtejh$mg at nntp.ucs.ubc.ca>"]
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content-length: 1433
From: EdStrick at io.com (Edwin Strickland)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 7 Aug 1995 09:06:22 GMT

In article <3vtejh$mg at nntp.ucs.ubc.ca>,    keith at msmri.med.ubc.ca says...
>
>Please post replies to sci.data.formats.
>
>I need to save several hundred gigabytes of medical imaging data on a 
cheap >reliable media.  We are currently saving the data to 10GB 8mm 
Exabyte tapes >This is cheap but is only good for about 1 year.  Does 
anyone have any better suggestions?

CD-ROM recorders mail order for $1,599 US dollars, and I see prices 
of "less than" $8. for recordable CDs (when ordered in large quantity --
hundreds?).  Recordable CD's are supposed to be as stable as factor-
pressed ones, or so I think I've been told.  This is "decades" of shelf
life.  I doubt you can do better, especially since it is a medium that
will be supported for a couple decades, at least.  When they have high-
density recordable CD's (several gig, instead of 640 meg) switch to that.

---------------------------------------------------------------------
Edwin L. Strickland III                       Image Processor/Analyst
Austin, Tx.                          Planetary, Geologist (esp. Mars)
Ed Strick  at  IO .com                       SF, Hard Fantasy, Classical
|                                         Music, Wild-Cat Species Fan
|                                                                   |
IO.com is Illuminati Online, of Steve Jackson Games << Shameless Plug
---------------------------------------------------------------------

From fitsbits-request  Wed Aug  9 23:25:26 1995
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	["729" "" "6" "August" "1995" "17:59:19" "+0200" "Paul Schlyter" "pausch at electra.saaf.se" "<402osn$q30 at electra.saaf.se>" "19" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080615:59:19" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Paul Schlyter     Aug  6   19/729   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<3vtejh$mg at nntp.ucs.ubc.ca>"]
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From: pausch at electra.saaf.se (Paul Schlyter)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 6 Aug 1995 17:59:19 +0200

In article <3vtejh$mg at nntp.ucs.ubc.ca>,  <keith at msmri.med.ubc.ca> wrote:
>Please post replies to sci.data.formats.
>
>I need to save several hundred gigabytes of medical imaging data on a cheap 
>reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
>This is cheap but is only good for about 1 year.  Does anyone have any better
>suggestions?

Since the data consists of images, why not try photographic plates or film?
That medium is known to be long-lasting and reliable.

-- 
----------------------------------------------------------------
Paul Schlyter,  Swedish Amateur Astronomer's Society (SAAF)
Nybrogatan 75 A,  S-114 40 Stockholm,  SWEDEN
e-mail:  pausch at saaf.se       paul.schlyter at ausys.se

From fitsbits-request  Thu Aug 10 00:48:34 1995
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	["1063" "" "9" "August" "1995" "15:56:48" "GMT" "Anthony J. Ferro" "tferro at merlin.la.asu.edu" "<40als0$f6k at news.ccit.arizona.edu>" "25" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080915:56:48" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Anthony J. Ferro  Aug  9   25/1063  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<mcdonald.1605.3028BA99 at aries.scs.uiuc.edu>"]
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content-length: 1061
From: tferro at merlin.la.asu.edu (Anthony J. Ferro)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 9 Aug 1995 15:56:48 GMT

  Just to pitch in a couple of items to this discussion:

  CD-R (recordable CD-ROM) is different than normal, manufactured CDs.
  The process is more photographic (the laser changes the reflectivity
  of the media), and isn't magnetic (MO).  With both CD and CD-R, the
  lifetimes aren't well established.  I think the claims are that CD-R
  might be around the 15-year timescale.  A well made normal CD should
  be much longer, 50-100 years.

  The problems someone was having with Pinnacle CD-Rs is mostly to do with
  differences in how people interpret the ISO 9660 standard, and which level
  they support.  If you stick to the level 1 (the wonderful 8.3 file names,
  etc), I've been able read disks on almost any computer.  When you go above
  that, you can have problems.  Some of these problems can be solved
  using other software, besides that shipped by Pinnacle.

---------
Anthony J. Ferro				aferro at as.arizona.edu
Steward Observatory, NICMOS Project		Ph:  (520) 621-8683
University of Arizona				FAX: (520) 621-1891	
Tucson, AZ 85721
---------

From fitsbits-request  Thu Aug 10 09:21:03 1995
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	["1262" "" "7" "August" "1995" "10:47:53" "-0700" "Stephen Walton" "swalton at galileo.csun.edu" "<405jk9$3vq at galileo.csun.edu>" "30" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080717:47:53" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Stephen Walton    Aug  7   30/1262  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<3vts2p$4j0 at pith.uoregon.edu>"]
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content-length: 1260
From: swalton at galileo.csun.edu (Stephen Walton)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 7 Aug 1995 10:47:53 -0700

In article <3vts2p$4j0 at pith.uoregon.edu>,
Christopher Michael Jones <cjones at ccserver.uoregon.edu> wrote:
>keith at msmri.med.ubc.ca wrote:
>: Please post replies to sci.data.formats.

OK.

>: I need to save several hundred gigabytes of medical imaging data on a cheap 
>: reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
>: This is cheap but is only good for about 1 year.

Wow, I had no idea Exabytes were good for such a short time.

>I'm not sure hom much getting a CD-ROM made would cost but that could be 
>an option.

CD-ROM recorders are down to about $2000, and the recordable media are
about $7.50 per disk.  These are write-once, and (of course) have the
advantage that any $1000 'multimedia' PC can read them.  This didn't
become a good option until recently, when 'multisession' recorders
made it possible to record data in multiple pieces.  Before that, at
least as far as I understand, you had to have a complete image of all
660 MB on a hard disk and record the CD in one pass.  We just bought a
Yamaha 4X CD-ROM recorder with the 'EasyPro for Windows' software but
haven't tried it out yet.
-- 
Stephen Walton, California State University, Northridge
"Be careful what you wish for;  you might get it."	swalton at csun.edu

From fitsbits-request  Thu Aug 10 10:05:14 1995
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	["828" "Mon" "7" "August" "1995" "23:31:55" "GMT" "Mitchell R. Grunes" "grunes at news.nrl.navy.mil" "<grunes.301.807838315 at news.nrl.navy.mil>" "22" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080723:31:55" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Mitchell R. Grune Aug  7   22/828   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<3vtejh$mg at nntp.ucs.ubc.ca>"]
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content-length: 826
From: grunes at news.nrl.navy.mil (Mitchell R Grunes)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: Mon, 7 Aug 1995 23:31:55 GMT

In article <3vtejh$mg at nntp.ucs.ubc.ca> keith at msmri.med.ubc.ca writes:
>I need to save several hundred gigabytes of medical imaging data on a cheap 
>reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
>This is cheap but is only good for about 1 year.  Does anyone have any better
>suggestions?

I guess saving imagery on film sounds ridiculous, doesn't it?  Surely
no one would do such a thing?

(-:

(Some films have fairly long lives, it's cheap, and it doesn't require 
specialized and soon-outdated hardware to read.  It's even obvious.)

-------------------------------------------------------------------------
  Opinions are mine alone.
  I am not a "Real Programmer".  I only program in the Real World.
  Mitchell R Grunes (grunes at nrlvax.nrl.navy.mil)
  AlliedSignal Technical Services Corp.

From fitsbits-request  Thu Aug 10 18:47:46 1995
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	["3085" "" "8" "August" "1995" "08:29:13" "GMT" "Rob Seaman" "seaman at noao.edu" "<40778p$rd9 at noao.edu>" "61" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080808:29:13" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Rob Seaman        Aug  8   61/3085  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<DCyvv2.LqH at midway.uchicago.edu>"]
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References: <3vtejh$mg at nntp.ucs.ubc.ca> <DCyAHr.A0r at lcpd2.SanDiegoCA.ATTGIS.COM> <grunes.301.807838315 at news.nrl.navy.mil> <DCyvv2.LqH at midway.uchicago.edu>
Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 3083
From: Rob Seaman <seaman at noao.edu>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 8 Aug 1995 08:29:13 GMT

In article <404t6a$fme at lyra.csx.cam.ac.uk> ralf at mail.ast.cam.ac.uk,
Ralph Martin writes:

> The DAT's are also considerably quicker than Exabytes when it comes
> to reading FITS formatted tapes (which are the de facto standard in
> astronomy) because Exabytes are hopeless at reading tape marks. Tape
> marks occur after every FITS file on a tape....

Another way to address this problem is to write larger files onto the
tapes - and thus fewer tape marks.  FITS image extensions (and other
FITS extensions) allow a good way to do this by concatenating multiple
images into a single large file.

The NOAO archive (http://iraf.noao.edu/~seaman/archive/archive.html)
multiplexes images from a half dozen or so of our telescopes on
Kitt Peak into FITS image extension files about 50 Mbytes in size.
These are taped onto duplicate exabyte 8505s (non-compressed) over
the network onto a central archive machine.  The software would just
as easily support DATs or other formats, but exabytes remain cheaper
per Gbyte.

With a capacity of 4.12 Gbytes (a very conservative choice amounting to
1.5M FITS records), this file size results in about 80 files per tape.
Combined with the much smaller tape marks on the 8505 drives compared
with the original 8200 drives, this small number of files means that
any single image in the archive is accessible in under 10 minutes.  Not
exactly what I'd call "online", but quite acceptable for our purposes.
In addition, multiple retrievals are much more likely than single image
retrievals due to the calibration data, multiple filters and exposures,
and the initial seek time is shared between the entire list of images
retrieved.

After a pair of tapes is full, active taping is shifted to a second
pair of drives and the tapes are FITS checksum verified.  The checksums
also provide a way to verify the readability of the tapes at a later
date (see ftp://iraf.noao.edu/misc/checksum/checksum.ps).  One copy
of each pair is shipped downtown, the other stays on the mountain
providing some disaster protection.

The tapes are stored in climate controlled computer labs in Tucson and
on Kitt Peak.  Note that climate control is important for blank media,
too.  Our tape handling procedures allow several days or weeks of
preconditioning in the mountain computer room before the blank tapes
are mounted in the drives - this allows the drives and media to
equilibrate thermally.

We also store the header catalog and the header/tape cross-index as
separate data products from the data tapes themselves.  This has obvious
advantages, but from the standpoint of simple survival of the data, the
biggest advantage is that the data can be easily recast onto new media,
perhaps reordering or regrouping the data into new tape or disk FITS
files, without actually having to read through and interpret the data.
This isn't a minor point with Tbyte size archives.  Recasting the data
will be required periodically no matter what the current medium - it's
only a question of how often.

Rob Seaman
seaman at noao.edu
National Optical Astronomy Observatories, Tucson

From fitsbits-request  Thu Aug 10 19:20:42 1995
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	["545" "" "8" "August" "1995" "01:32:22" "-0400" "Scott Fearing" "sfearing at gwis2.circ.gwu.edu" "<406st6$8le at gwis2.circ.gwu.edu>" "18" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080805:32:22" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Scott Fearing     Aug  8   18/545   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<404au3$jlh at itchy.itsnet.com>"]
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content-length: 543
From: sfearing at gwis2.circ.gwu.edu (Scott Fearing)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 8 Aug 1995 01:32:22 -0400

	I should warn you of a potential danger of CD storage: CD 'rot'.
Apparently, the aluminum can oxidize under the plastic protective covering 
and data can be lost.  This is appearing on CDs as well as laserdiscs, 
but I assume it does not happen to the special gold plated discs that come 
out on the audiophile pressings.  There are discussions of this from time 
to time on rec.video.laserdisc.

-- 
		Scott

Scott Fearing       <sfearing at gwis2.circ.gwu.edu>
National Symphony Orchestra and George Washington University:   Washington,DC

From fitsbits-request  Thu Aug 10 22:05:48 1995
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	["1351" "Tue" "8" "August" "1995" "00:54:37" "GMT" "Bradford Holden" "holden at oddjob.uchicago.edu" "<DCyvv2.LqH at midway.uchicago.edu>" "36" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080800:54:37" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Bradford Holden   Aug  8   36/1351  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<grunes.301.807838315 at news.nrl.navy.mil>"]
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From: holden at oddjob.uchicago.edu (Bradford Holden)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: Tue, 8 Aug 1995 00:54:37 GMT

In article <grunes.301.807838315 at news.nrl.navy.mil> grunes at news.nrl.navy.mil (Mitchell R Grunes) writes:
>In article <3vtejh$mg at nntp.ucs.ubc.ca> keith at msmri.med.ubc.ca writes:
>>I need to save several hundred gigabytes of medical imaging data on a cheap 
>>reliable media.  We are currently saving the data to 10GB 8mm Exabyte tapes.
>>This is cheap but is only good for about 1 year.  Does anyone have any better
>>suggestions?
>
>I guess saving imagery on film sounds ridiculous, doesn't it?  Surely
>no one would do such a thing?

Oddly enough large numbers of astronomers do this.
Film however, has some disadvantages.  It doesn't have a great dynamic range
(though fairly good for some of them) its not machine readable (unless you 
build a machine to do it), it has a nonlinear response, and its hard to make
good quality copies cheaply.  

>
>(-:
>
>(Some films have fairly long lives, it's cheap, and it doesn't require 
>specialized and soon-outdated hardware to read.  It's even obvious.)
>
>-------------------------------------------------------------------------
>  Opinions are mine alone.
>  I am not a "Real Programmer".  I only program in the Real World.
>  Mitchell R Grunes (grunes at nrlvax.nrl.navy.mil)
>  AlliedSignal Technical Services Corp.
>

-- 
Bradford "PROS is evil" Holden 

gradual student at the University of Chicago

From fitsbits-request  Fri Aug 11 02:43:20 1995
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	["967" "" "8" "August" "1995" "20:23:05" "GMT" "Martin Leese" "mleese at hudson.cs.unb.ca" "<408h39$m8p at sol.sun.csd.unb.ca>" "23" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080820:23:05" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Martin Leese      Aug  8   23/967   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<400uu1$qqo at crl5.crl.com>"]
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Reply-To: MLeese at atlantic.cs.unb.ca
Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 965
From: mleese at hudson.CS.unb.ca (Martin Leese - OMG)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 8 Aug 1995 20:23:05 GMT

On 5 Aug 1995 16:30:09 -0700 Ron Wickersham (rjw at crl.com) wrote:
>> Please elaborate on the 8mm Exabyte storage lifetime.  I thought that tape
>> would be good for the fifteen year requirement stated.  Do others report 
>> the Exabyte system only reliable for 1 year?

I used to help run an archive of seismic data using 300 GByte WORM
jukeboxes.  The data arrived on Exabytes and our experience was that
if an Exabyte is less that 1 year old you should be surprised if you
cannot read it.  If an Exabyte is more than 1 year old you should not 
be surprised if you cannot read.

Having said this, most Exabytes will read for many years, just don't
rely on it.

Regards,
Martin
E-mail: mleese at atlantic.cs.unb.ca
WWW:    http://www.omg.unb.ca/~mleese/
________________________________________________________________________
 Want to know how Ambisonics can improve the sound of your LPs and CDs?
  See the Ambisonic Surround Sound FAQ.  Details on my WWW Home page.

From fitsbits-request  Fri Aug 11 04:25:29 1995
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	["2048" "Tue" "8" "August" "1995" "22:40:19" "GMT" "Paul Carpenter" "paul at pcserv.demon.co.uk" "<807921619snz at pcserv.demon.co.uk>" "51" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080822:40:19" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Paul Carpenter    Aug  8   51/2048  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<grunes.302.807903725 at news.nrl.navy.mil>"]
	nil)
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References: <3vvvfu$a1e at ixnews6.ix.netcom.com> <404au3$jlh at itchy.itsnet.com> <406st6$8le at gwis2.circ.gwu.edu> <407tut$21e at electron.rutgers.edu> <grunes.302.807903725 at news.nrl.navy.mil>
Reply-To: paul at pcserv.demon.co.uk
Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 2046
From: Paul Carpenter <paul at pcserv.demon.co.uk>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: Tue, 08 Aug 95 22:40:19 GMT

grunes at news.nrl.navy.mil "Mitchell R Grunes" writes:
-1.  Why not leave put the data on those 1 year lifetime (but high
-capacity) tapes, but re-copy it every 5 or 6 months?  Since it would only 
-take a few tapes, and you could copy one overnight, it really wouldn't 
-take much of your time.....

-This isn't based on extended experience--it just seems reasonable.

AFAIR major banks, used to do this practise with their archives, to avoid tape 
ageing and stretch.. This was with old 9 track tapes and the like.

How many people create archives/backups of important data without a true 
verification pass, let alone a compatability test. Too often I hear of backups 
being no use because:-

	1/	Data was not checked after being written

	2/	Drive being used for storage was out of calibration so backup
		media only worked on that drive.

	3/	No non-compressed etc. copy of software to read backup was kept 
		in an even safer place(s), that was verified to work!.

-Re-copying needs to be done even with 9 tracks, though less often.  With
-any media.  

-2.  About your old 9 tracks.  How could they burn in sealed containers?
-Surely there is a simple solution to this problem?  Inert gas?

Tried filling an individual tape canister with inert gas, and ensuring that 
oxygen was not released from the plastics used :-)

-3....

In short whatever the archive/backup method used ensure it works and test that
archive/backup can actually be used at some point in the future. No system is
infallible, assess the archive/backups means/media/procedures/software/host to
suit your needs now and in N years time.

Keeping a system with spares for large archives may seem silly but in fact is
very practical as long as people are around who still know how to fix them or
run them.

=-------------------------------------------------
Paul Carpenter		| paul at pcserv.demon.co.uk
PC Services		| tel (44) 1734-463634
PO Box 2030, Reading	| fax (44) 1734-463423
RG4 8YW, UK		| 
Consulting for DSP, Image processing, Data Acquisition, System tuning & more..

From fitsbits-request  Fri Aug 11 06:28:52 1995
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	["851" "" "8" "August" "1995" "20:16:59" "GMT" "Martin Leese" "mleese at hudson.cs.unb.ca" "<408gnr$m8p at sol.sun.csd.unb.ca>" "20" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080820:16:59" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Martin Leese      Aug  8   20/851   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<grunes.302.807903725 at news.nrl.navy.mil>"]
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Reply-To: MLeese at atlantic.cs.unb.ca
Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 849
From: mleese at hudson.CS.unb.ca (Martin Leese - OMG)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 8 Aug 1995 20:16:59 GMT

On Tue, 8 Aug 1995 17:42:05 GMT Mitchell R Grunes (grunes at news.nrl.navy.mil) wrote:
...
>> 2.  About your old 9 tracks.  How could they burn in sealed containers?
>> Surely there is a simple solution to this problem?  Inert gas?

Presumably the sealed container heated up, heating up the tape inside
until it ignited.  (Incidentially, this is how fire spreads on a ship,
even through airtight steel bulkheads.)  I cannot see how inert gas 
would help.  Once the fire was going, you would have sealed canisters 
popping open all over the place.

Regards,
Martin
E-mail: mleese at atlantic.cs.unb.ca
WWW:    http://www.omg.unb.ca/~mleese/
________________________________________________________________________
 Want to know how Ambisonics can improve the sound of your LPs and CDs?
  See the Ambisonic Surround Sound FAQ.  Details on my WWW Home page.

From fitsbits-request  Fri Aug 11 12:06:31 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["617" "" "9" "August" "1995" "02:12:51" "GMT" "Adrian Whichello" "adrianw at cassius" "<4095j3$lfl at metro.ucc.su.OZ.AU>" "18" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080902:12:51" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Adrian Whichello  Aug  9   18/617   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<406st6$8le at gwis2.circ.gwu.edu>"]
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content-length: 615
From: adrianw at cassius (Adrian Whichello)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 9 Aug 1995 02:12:51 GMT

In article <406st6$8le at gwis2.circ.gwu.edu> sfearing at gwis2.circ.gwu.edu (Scott Fearing) writes:
>	I should warn you of a potential danger of CD storage: CD 'rot'.
>Apparently, the aluminum can oxidize under the plastic protective covering 
>and data can be lost.  This is appearing on CDs as well as laserdiscs, 
>but I assume it does not happen to the special gold plated discs that come 
>out on the audiophile pressings.  There are discussions of this from time 
>to time on rec.video.laserdisc.
>
>
>-- 
>		Scott

yeah, but can't you paint all around the edge of the CD with a special green
felt pen...

Adrian.

From fitsbits-request  Fri Aug 11 12:41:32 1995
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	["658" "" "9" "August" "1995" "05:17:38" "GMT" "dean at phobos.cira.colostate.edu" "dean at phobos.cira.colostate.edu" "<409gdi$2qrq at yuma.ACNS.ColoState.EDU>" "17" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080905:17:38" "Saving 100GB of data for 15 years cheaply" (number " " mark "     dean at phobos.cira. Aug  9   17/658   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<3vtejh$mg at nntp.ucs.ubc.ca>"]
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content-length: 656
From: dean at phobos.cira.colostate.edu
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 9 Aug 1995 05:17:38 GMT

  CD Recorders would be my vote. I am currently using a Pinnicle Recorder
to make 650Mb CD-ROMs. It take about 30 min to make, but some time is
 involved with preparing the directory tree. We use 3M blank disk which are
 about $11. However, I hear TDK blank disk are better and they cost about
 $7.50 a piece.

  The CD that I am making with the Pinnicle do have problems. Some CD-ROMs
 will not read them. It is not a problem for us, because all the CD we
 make work on our CD-ROMs on our Window NT system. However, there have been
 some people reporting that their DOS machines with a CD-ROM wil not see the
 disk in the drive.

  Kelly Dean
  CSU/CIRA

From fitsbits-request  Fri Aug 11 12:47:55 1995
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	["1828" "Wed" "9" "August" "1995" "09:29:21" "GMT" "Derrick C. Mancini" "mancini at maxlab.lu.se" "<mancini-0908951129210001 at usx121.maxlab.lu.se>" "34" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080909:29:21" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Derrick C. Mancin Aug  9   34/1828  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<406st6$8le at gwis2.circ.gwu.edu>"]
	nil)
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content-length: 1826
From: mancini at maxlab.lu.se (Derrick C. Mancini)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: Wed, 9 Aug 1995 09:29:21 GMT

In article <406st6$8le at gwis2.circ.gwu.edu>, sfearing at gwis2.circ.gwu.edu
(Scott Fearing) wrote:
>        I should warn you of a potential danger of CD storage: CD 'rot'.
>Apparently, the aluminum can oxidize under the plastic protective covering 
>and data can be lost.  This is appearing on CDs as well as laserdiscs, 
>but I assume it does not happen to the special gold plated discs that come 
>out on the audiophile pressings.  There are discussions of this from time 
>to time on rec.video.laserdisc.

I believe, Scott, that your comments may be only applicable to pressed CDs.
The writable CDs are a MO technology, I think.  I am not sure what they
use for reflective coat.   In properly manufactured CDs, the aluminum
should last for 15 years.  It is the presence of water and salts that
cause the damage.  I know I have never seen this effect on anything in my
CD collection, which started when CD's started, about 12 years (and a few
hundred CDs) ago.  By the same token, poor manufacture and improper storage
of tape is far more likely to fail than aluminum in CDs.  In either case,
you would be advised to store in a cool, dry place.  And make duplicates.

Another advantage of CDs is that they are a random access storage device,
which most tapes are not, and should have better ability to recover good
files if a particular sector or track were to go bad.  Many tape systems
will lose the whole tail of a tape from the point a defect is found.

-- 
Dr. Derrick C. Mancini
MAXLab, Lund University         Advance Photon Source, ANL
Box 118, Ole Romers Vag 1       9700 S. Cass Avenue - APS/431
S-221 00, Lund, Sweden          Argonne, IL, USA  60439
Tel: +46 46 222 3355            Tel: +1 708 252 0147
FAX: +46 46 222 4710            FAX: +1 708 252 3222
Email: mancini at maxlab.lu.se     Email: mancini at aps.anl.gov

From fitsbits-request  Fri Aug 11 19:42:53 1995
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	["1397" "Wed" "9" "August" "1995" "06:59:46" "GMT" "James Petts" "pettsj at visigoth.demon.co.uk" "<pettsj-0908950800400001 at visigoth.demon.co.uk>" "31" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080906:59:46" "Saving 100GB of data for 15 years cheaply" (number " " mark "     James Petts       Aug  9   31/1397  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<grunes.302.807903725 at news.nrl.navy.mil>"]
	nil)
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Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 1395
From: pettsj at visigoth.demon.co.uk (James Petts)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: Wed, 09 Aug 1995 06:59:46 GMT

In article <grunes.302.807903725 at news.nrl.navy.mil>,
grunes at news.nrl.navy.mil (Mitchell R Grunes) wrote:

> 3.  Since no one liked my idea of film, I've an even better idea.  
> Print it all out in hex, on acid free paper.  When you need it, use a 
> scanner.  Let's see: two characters/byte, about 100 characters/line 
> and 60 lines/page...now that's a REAL fire hazard.  Compact, too.

I came into this discussion late (i.e. this is the first message on
the subject I've seen), but what was the main objection to film.

If it is the stability of the film base, that can almost certainly be
addressed by storing the film in vacuum containers. If it is image
permanence that can be addressed by using metallic replacement in the
developed film, substituting gold for silver.

Both techniques have been used at Kodak Limited in England: when Domesday
Book was taken apart and rebound in 1985-1986 it was photographed and the
film treated as mentioned above. Accelerated ageing test show that the
film is expected to retain its image in essentially he same form for at
least 100 years. I can speak with the person who did it, and get more
information if required.

-- 
=== James Petts ===
In the world of CD-ROM, a horse will always be an herbivorous
quadruped, and there'll be endless examples to prove just that.
But that world will never tell you how it feels to ride a horse.
Or fall off it.

From fitsbits-request  Fri Aug 11 19:43:36 1995
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	["728" "" "9" "August" "1995" "20:45:57" "GMT" "Mark Overton" "mark at sdd.hp.com" "<40b6q5$59f at news.sdd.hp.com>" "20" "Re: QIC Tape Lifetimes? was: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995080920:45:57" "QIC Tape Lifetimes? was: Saving 100GB of data for 15 years cheaply" (number " " mark "     Mark Overton      Aug  9   20/728   " thread-indent "\"Re: QIC Tape Lifetimes? was: Saving 100GB of data for 15 years cheaply\"\n") "<grunes.306.0 at news.nrl.navy.mil>"]
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References: <3vvvfu$a1e at ixnews6.ix.netcom.com> <404au3$jlh at itchy.itsnet.com> <406st6$8le at gwis2.circ.gwu.edu> <mancini-0908951129210001 at usx121.maxlab.lu.se> <mcdonald.1605.3028BA99 at aries.scs.uiuc.edu> <grunes.306.0 at news.nrl.navy.mil>
Newsgroups: sci.data.formats,sci.image.processing,sci.astro.fits,comp.sys.ibm.pc.hardware.storage
content-length: 726
From: mark at sdd.hp.com (Mark Overton)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: QIC Tape Lifetimes? was: Saving 100GB of data for 15 years cheaply
Date: 9 Aug 1995 20:45:57 GMT

grunes at news.nrl.navy.mil (Mitchell R Grunes) writes:
> Also, does one extend the # of uses (usually rated at 3-5 back-ups, due
> to the large number of passes required to handle multiple tracks with
> one head) of these tapes if they are commercially pre-formatted? 

Only 3-5 backups?!

I asked a Colorado tech support person about this, who said that a tape
will last a year if used (weekly or daily or in rotation, I forget).

Our tapes are lasting a year, being used twice a week (ie, around
100 backups).

- Mark

------------------------------------------------------------------------------
Mark Overton,  Hewlett-Packard (San Diego Division),  mark at sdd.hp.com
"A hundred thousand lemmings can't be wrong." ... Unknown

From fitsbits-request  Sat Aug 12 01:42:08 1995
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	["899" "" "9" "August" "1995" "21:28:33" "-0400" "Mark Edward Schill" "gt7602b at prism.gatech.edu" "<40bnc1$fia at acmex.gatech.edu>" "20" "looking for fits viewer" "^From:" nil nil "8" "1995081001:28:33" "looking for fits viewer" (number " " mark "     Mark Edward Schil Aug  9   20/899   " thread-indent "\"looking for fits viewer\"\n") nil]
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From: gt7602b at prism.gatech.edu (Mark Edward Schill)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: looking for fits viewer
Date: 9 Aug 1995 21:28:33 -0400

	I am looking for a program that will allow me to view fits images.
I would like a program that would allow me to view the image and the
header silmutaneously. I would also like to have the option of saving the
image in either gif or jpg format so that the images can be readily
displayed. A program that would allow me to convert or create fits images
with interactive prompts or a template to facilitate the header
information would be ideal. I would like a program that will run on
Solaris Openwindows, but either Ibm or Macintosh programs will be gladly
accepted.

I appreciate any help that is given.
	
-- 
| Mark E. Schill                       |" Imagination is more        |
| Email: gt7602b at prism.gatech.edu      |  important than knowledge   |
|                                      |_______________-  A.Einstein |
| WWW: http://kelvin.physics.gatech.edu/sps/mschill   |______________|

From fitsbits-request  Sat Aug 12 14:29:41 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["1190" "" "10" "August" "1995" "10:42:24" "GMT" "Ralph Martin" "ralf at mail.ast.cam.ac.uk" "<40cnqg$p7m at lyra.csx.cam.ac.uk>" "32" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081010:42:24" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Ralph Martin      Aug 10   32/1190  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<40als0$f6k at news.ccit.arizona.edu>"]
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References: <mancini-0908951129210001 at usx121.maxlab.lu.se> <mcdonald.1605.3028BA99 at aries.scs.uiuc.edu> <40als0$f6k at news.ccit.arizona.edu>
Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 1188
From: ralf at mail.ast.cam.ac.uk (Ralph Martin)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 10 Aug 1995 10:42:24 GMT

I checked back in my records for systems that store terabytes of data. 
(1 terabyte =1000 Gigabytes = 1,000,000 Megabytes).
Optical Memory News, February 1991, Published Monthly by
Rothchild Consultants, ran an article about a device marketed by ICI
Imagedata which wrote to optical tape. In it they described a device made by a
firm called CREO which had the following capabilities.
1 Terabyte capacity per 12" reel.
Cost ' a few dollars per gigabyte'
Transfer Rate  up to 3 Megs/sec sustained.
Media Life 30 years in office environment
SCSI-2 interface
Search speed 68 sec max for full reel.
The last contact I had with them was some years ago but the address
of the suppliers was

ICI Imagedata
PO BOX 6 Shire Park
Bessemer Road
Welwyn Garden City
Hertfordshire AL7 1HD
Telephone 01707 323400
Fax 01707 337896.

I have no connection either business or private with the afore mentioned
firm.
-- 
Ralph Martin                            Internet:      ralf at ast.cam.ac.uk
Royal Greenwich Observatory             Telephone:     UK+ 01223-374000
Cambridge CB3 0EZ                       ISDN:          UK+ 01223-328028
United Kingdom                          ISDN:          UK+ 01223-328087

From fitsbits-request  Sat Aug 12 18:28:55 1995
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	["1518" "" "10" "August" "1995" "04:37:53" "GMT" "Rob Seaman" "seaman at noao.edu" "<40c2f1$6rp at noao.edu>" "33" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081004:37:53" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Rob Seaman        Aug 10   33/1518  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<grunes.305.0 at news.nrl.navy.mil>"]
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References: <3vtejh$mg at nntp.ucs.ubc.ca> <408h39$m8p at sol.sun.csd.unb.ca> <409gdi$2qrq at yuma.ACNS.ColoState.EDU> <grunes.305.0 at news.nrl.navy.mil>
Newsgroups: sci.astro.fits
content-length: 1516
From: Rob Seaman <seaman at noao.edu>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 10 Aug 1995 04:37:53 GMT

In article <408a2a$h50 at darkstar.UCSC.EDU> sla at umbra.ucolick.org,
Steve Allen writes:

> But in the instance of non-IMAGE extensions how would it be possible
> to determine the relationships between the various different kinds of
> HDUs?  I suspect that this would be an excellent application for
> the <A HREF="http://acadia.gsfc.nasa.gov/convert/group.html">
> FITS Grouping Convention </A> which was proposed last year.

Well, this applies to IMAGE extensions as well as other extensions.
One difficulty with archiving raw data is that not all members of a
given group are defined - typically not even acquired yet - when an image
is archived.  Archiving the group interrelationships as a separate FITS
object at some later time is attractive - although this will complement,
not replace, a catalog database.

The grouping convention relies on URLs (or URNs) to refer to group
members that are external to the current file.  It isn't obvious (to
me, anyway) how best to construct a URL that references a tape sitting
on a shelf.  Examples, anybody?

Note also that since the physical media will be replaced periodically,
and since a new medium will likely have different constraints on size,
the arrangement of the data into files and HDUs in those files is likely
to change.  It may be tricky to define groupings whose URLs (or whatever)
will remain valid through a recasting of the data.  This would be
preferable
to discarding and then regenerating the grouping extensions, however.

Rob Seaman
seaman at noao.edu

From fitsbits-request  Sun Aug 13 05:43:47 1995
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	["766" "" "10" "August" "1995" "16:39:33" "-0400" "Albert Hybl" "hybl at umbc.edu" "<40dqq5$20j at umbc7.umbc.edu>" "19" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081020:39:33" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Albert Hybl       Aug 10   19/766   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") nil]
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From: hybl at umbc.edu (Dr. Albert Hybl)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 10 Aug 1995 16:39:33 -0400

  Recently, a TV station reported that Dr. Uzasny Blazen, CEO of
The Black Hole Storage Devices Inc., announced that they are about
to start shipping a new device that promises to provide a near
infinite storage capacity.
  A reporter and a technician have been dispatched with a mobile
satellite dish to obtain an interview with him.  Their report
had not arrived in time for the 6 pm news.  Hopefully, it will
be available for the 11 pm news.
  In related news, an airline pilot reported seeing a building
collapse into a huge subterranean chasm.  The cavern is located
exactly where Dr. Blazen's factory should be.  The last report
broadcast from the station's traffic helicopter estimated that
the crater is expanding at about five feet per hour.

:-)
Albert

From fitsbits-request  Sun Aug 13 07:19:52 1995
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	["6823" "" "11" "August" "1995" "08:50" "EDT" "Barry M. Schlesinger" "bschlesinger at nssdca.gsfc.nasa.gov" "<11AUG199508503853 at nssdca.gsfc.nasa.gov>" "163" "Sources of FITS Information" "^From:" nil nil "8" "1995081112:50:00" "Sources of FITS Information" (number " " mark "     Barry M. Schlesin Aug 11  163/6823  " thread-indent "\"Sources of FITS Information\"\n") nil]
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From: bschlesinger at nssdca.gsfc.nasa.gov (Barry M. Schlesinger)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Sources of FITS Information
Date: 11 Aug 1995 08:50 EDT

		Sources of FITS Information 

Preface 	

This material on sources of Flexible Image Transport System (FITS)
information is posted and updated periodically by the FITS Support
Office at the NASA Goddard Space Flight Center (GSFC).  It discusses
where general FITS information, including some answers to frequently
asked questions, can be found, and provides sources for detailed
information on FITS software and documentation. Discussions are under 
way for addition of this material to the *.answers hierarchy; further 
developments are expected in about a month.  It is posted here in the
meantime. Followups are to sci.astro.fits. 

FITS Support Office

The FITS Support Office maintains a library of FITS information
accessible from http://www.gsfc.nasa.gov/astro.fits/fits_home.html or
ftp://nssdc.gsfc.nasa.gov/pub/fits/.  The material available includes

o	"Definition of FITS," a codification of FITS for the 
	NASA/Science Office of Standards and Technology (NOST),
	available in LaTeX, PostScript, and ASCII text 

o	"A User's Guide to FITS", published by the FITS Support Office, 
	in LaTex, and compressed and uncompressed PostScript 

o	Proposed revisions to the "Definition of FITS"covering the
	specification of units (text)

o	A current list of the extension type (structure) names
	registered with the International Astronomical Union FITS
	Working Group (IAUFWG) (text)

o	Rules for physical blocking on various media adopted by
	the IAUFWG, (text)  

In the same directory, but accessible directly via 
http://www.gsfc.nasa.gov/astro/fits/basics_info.html is the FITS
Basics and Information that used to be regularly posted to
sci.astro.fits and sci.data.formats under the heading of FITS Basics
and Information.  It continues to be revised to reflect current FITS
developments.  It contains the following material: 

o	An overview of FITS
o	A list of FITS documents  
o	A list of software packages that support FITS, 
		including FITS-image converters for various platforms
o	A list of on-line FITS resources
o	A description of the FITS Support Office 

The hypertext version provides links to many of the documents, 
software, and network locations listed.  The text version provides 
information on how to obtain some of this material.

Links from the Web page and subdirectories of the ftp directory 
contain
	
o	Software developed by the FITS Support Office.  

o	Error test files, primary HDUs useful for testing the ability
	of software designed to read FITS files to cope with files that 
	have errors or are non-standard.

Printed copies of the material in the FITS directory can be obtained
from the Coordinated Request and User Support Office (CRUSO):  

(Postal) Coordinated Request and User Support Office
         Code 633
	 National Space Science Data Center
	 NASA Goddard Space Flight Center
	 Greenbelt MD 20771 USA

(Electronic mail) request at nssdca.gsfc.nasa.gov

(Telephone)  +1-301-286-6695 8:00 A. M. - 4:30 P.M. U. S. Eastern Time
(-0500 from the last Sunday in October through the first Saturday in
April; -0400 the remainder of the year) 
	When no one is available, messages can be left on voice mail. 
(FAX) +1-301-286-1635

National Radio Astronomy Observatory (NRAO)

	A FITS Archive can be found at URL http://fits.cv.nrao.edu/ or 
at ftp://fits.cv.nrao.edu/fits, located at NRAO.  This machine supports a
WAIS server named nrao-fits which has an index of all of the
FITS-related text files in the archive; the file nrao-fits.src is
available at think.com and at
ftp://fits.cv.nrao.edu/fits/wais-sources/nrao-fits.src.  
	The documents subdirectory of the fits directory contains a
number of subdirectories.  The BINTABLE draft for Astronomy and
Astrophysics is, in various formats, in files bintable_aa.*. A
proposals subdirectory is reserved for detailed proposals currently
being considered by the FITS committees.  A drafts subdirectory
contains drafts of designs not yet submitted.  The wcs subdirectory
contains a draft of the current proposal for world coordinate system
conventions now under community review and earlier documents and
presentations on world coordinates. Other subdirectories include
sample FITS files -- both actual data files and files specially
constructed to test the ability of software to read all kinds of FITS
structures, some code for particular environments, pointers to other
code, and an archive of Usenet postings related to FITS. 
This machine supports a WAIS server named nrao-fits (URL
wais://fits.cv.nrao.edu/nrao-fits; also see
ftp://fits.cv.nrao.edu/fits/wais-sources/nrao-fits.src) which has an
index of all of the FITS-related text files in the archive. Some of
the more noteworthy materials in this archive are 

o	Drafts of proposed additions to the FITS standard and other 
	drafts that may in the future be formally proposed

o	Conventions specific to particular projects or disciplines

o	Some code for various environments and Usenet postings about 
	code

o	Sample data and special test files designed to measure the
        ability of a FITS reader to handle a wide variety of FITS files

o	Archives of traffic on FITS-related newsgroups and exploders

HEASARC
	The NASA/Goddard High Energy Astrophysics Science Archive
Research Center (HEASARC) Web server at 
http://heasarc.gsfc.nasa.gov/docs/heasarc/fits.html 
and the anonymous ftp access through
ftp://heasarc.gsfc.nasa.gov/fits_info/ provide FITS material.  HEASARC
has developed a the FITSIO package of software routines for easily
reading and writing FITS files, in FORTRAN with a C interface
available, portable to a wide variety of machines.  There is also the
FTOOLS collection of software tools and the VERIFITS FITS conformance
verifier. HEASARC software is available directly through
http://heasarc.gsfc.nasa.gov/docs/heasarc/tech_res_software.html or
ftp://heasarc.gsfc.nasa.gov/fits_info/software/ .

The HEASARC server also provides information from the OGIP/HEASARC
FITS Working Group, (HFWG) the internal legislative body on
FITS-related matters within the Office of Guest Investigator Programs
(OGIP) at NASA/GSFC, at
http://heasarc.gsfc.nasa.gov/heasarc/ofwg/ofwg_intro.html or
ftp://heasarc.gsfc.nasa.gov/fits_info/ . The HFWG has developed a
number of FITS conventions that are more specific than the
requirements of the FITS standards. Proposed conventions are
publicized to the FITS community as a whole, with the goal of
collaborative development of a set of conventions that will be
accepted throughout the community as well as within OGIP/HEASARC. 

Direct questions about this material to 
				Barry M. Schlesinger
				Coordinator,
				FITS Support Office

Electronic mail: fits at nssdca.gsfc.nasa.gov
Telephone:       +1-301-441-4205		

The FITS Support Office is operated under the guidance of the
NASA/GSFC Astrophysics Data Facility.

From fitsbits-request  Sun Aug 13 10:03:53 1995
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	["3293" "" "10" "August" "1995" "13:53:08" "GMT" "Art Munson" "artmuns at tape.com" "<40d304$hd2 at excalibur.edge.net>" "86" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081013:53:08" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Art Munson        Aug 10   86/3293  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<409gdi$2qrq at yuma.ACNS.ColoState.EDU>"]
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Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 3291
From: Art Munson <artmuns at tape.com>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 10 Aug 1995 13:53:08 GMT

If anyone would be interested in our latest prices on TDK CDR blanks, 
just let me know and I'll e-mail them to you. I'm also posting a recent
fax from TDK regarding longevity. 

Thanks

Art

Cassette House

http://www.tape.com/ch

dean at phobos.cira.colostate.edu wrote:
> We use 3M blank disk which are
> about $11. However, I hear TDK blank disk are better and they cost > about
> $7.50 a piece.
>
-------------------------------------------------------------------------

              T-TEC TDK-TECHNICAL EXCELLENCE CORNER

Topics:  Mix Magazine Article      

Compiled by Tom Izumi & Henry Dobashi

Number 4 - July, 1995

In MIX magazine (July 1995), an article purportedly comparing
cyanine to phthalocyanine-based CD-R by Steven St. Croix 
contained injurious comments about cyanine. Here is a summery
of our reactions.

What Mr. St. Croix says:  He speaks ill of many things about
cyanine-based CD-R, but most of his comments center on the liefspan
of cyanine-based CD-Rs.  He leads readers to believe that cyanine
CD-Rs are veritable time bombs, designed to self-destruct in as
little as five years, one year or even over the weekend.  The most
puzzling aspect of the article is that his conclusions are based on
secret data -- research that he refuses to make public.

TDK'S Reaction:  We are afraid that the readers may have serious
doubts about the longevity of our media.  It is our responsibility
to rebut.  You will see a two-page open letter in MIX, October
issue, showing our assertions as follows.

Discussions in our open letter:  We believe the writer may have
based many of his conclusions on data describing the performance of
raw cyanine dye which TDK does not use.  We will publish data that
demonstrates a big improvement in light resistivity, when metal-
stabilized cyanine dye is used.

We will share our aging test data, too.  The results demonstrate
our CD-R lasts at least 70 years when stored at 30 degrees C (86
degrees F).

We will also present our test results comparing the light fastness
of cyanine and phthalocyanine discs.  Even after 40 Mlux*h exposure
under Xenon test lamp, every parameter stays within spec for both
disc types.  This test indicates that both types of discs will last
10 years at least when left beside the windows with their dye side
up.

According to the test results mentioned above, phthalocyanine is
slightly more resistant to light than our metal-stabilized cyanine
formulation.  That's why phthalocyanine discs are specified at 100
years; ours at 70 years.

So why use cyanine?  The answer is compatibility with CD recorders
and long-term writability.  A graph will be published showing block
error rate (BLER) vs. write power, which compares our CD-R with a
typical phthalocyanine disc.  Our disc maintains its low BLER over
a broader range of laser power than phthalocyanine media.

This is significant because factory-fresh CD recorders may generate
higher or lower power output than the nominal manufacturer spec. 
Also, the laser ages over time and operation temperature may
fluctuate.  These factors may cause recording power to fluctuate.

Compatibility and long-term writability are the strongest and most
rational arguments for use of cyanine dye.  These arguments are
made very strongly in our open letter to MIX.

From fitsbits-request  Sun Aug 13 23:20:57 1995
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	["1935" "" "10" "August" "1995" "17:25:09" "GMT" "Glen Kilpatrick" "szkilpat at rocky.ucdavis.edu" "<40dfdl$67l at mark.ucdavis.edu>" "34" "Re: looking for fits viewer" "^From:" nil nil "8" "1995081017:25:09" "looking for fits viewer" (number " " mark "     Glen Kilpatrick   Aug 10   34/1935  " thread-indent "\"Re: looking for fits viewer\"\n") "<40bnc1$fia at acmex.gatech.edu>"]
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Organization: University of California, Davis
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content-length: 1933
From: szkilpat at rocky.ucdavis.edu (Glen Kilpatrick)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: looking for fits viewer
Date: 10 Aug 1995 17:25:09 GMT

Mark Edward Schill (gt7602b at prism.gatech.edu) wrote:
: 	I am looking for a program that will allow me to view fits images.
: I would like a program that would allow me to view the image and the
: header silmutaneously. I would also like to have the option of saving the
: image in either gif or jpg format so that the images can be readily
: displayed. A program that would allow me to convert or create fits images
: with interactive prompts or a template to facilitate the header
: information would be ideal. I would like a program that will run on
: Solaris Openwindows, but either Ibm or Macintosh programs will be gladly
: accepted.
: I appreciate any help that is given.

Try ftp://fits.cv.nrao.edu/fits/os-support/ms-windows/fitsview/ for a
WINdoze program.  It doesn't do everything you want (but then -what-
does everything -I- want? :), but it's a start.  Be warned that, while
I have no problems using the program, I sweated plenty when the
installation program -disabled- WIN 3.1 for me.  I suspect the problem
was a matter of too many program groups, but -whatever-, the solution
to re-enabling Windows was to find progman.ini, delete it, and rename
progman.bak (.bac?) to the former progman.ini, and then WIN worked.
The second attempt at installation (with fewer program groups :)
worked fine, and I'm now a Happy Camper.

--
---------------------------------------------------------------------
   ___                         | [A-Z] is for { Amendment Black Clipper
  /   \                        | Decryption Encryption Factor Gore Hacker
 |   ____                      | ITAR Judicial Kafkaesque Lincoln Munitions
  \___/  | /   Glen Kilpatrick | Numerical Ossifrage Privacy Q-Clearance RSA
         | \   <gkilpatrick at    | Squeamish Trustworthy Untrustworthy Vigenere
         |  \  ucdavis.edu>    | White XOR Yankee Zimmermann }, {:-(....
PGP Fingerprint Real Soon Now! ---------------------------------------

From fitsbits-request  Tue Aug 15 00:25:48 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["532" "" "14" "August" "1995" "16:48:03" "GMT" "Richard Ottolini" "stgprao at sugarland.unocal.com" "<40nuo3$1pa at unogate.unocal.com>" "9" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081416:48:03" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Richard Ottolini  Aug 14    9/532   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<404t6a$fme at lyra.csx.cam.ac.uk>"]
	nil)
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Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 530
From: stgprao at sugarland.unocal.COM (Richard Ottolini)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 14 Aug 1995 16:48:03 GMT

There was a nice review of the issue of digital archives in Scientific American
about a year ago.  Cost is not so much the issue as is recoverable formats
in a rapidly change technology.  If things aren't copied into the new formats
every few years, they could be lost.  Much like if a classical work wasn't
recopied by a medieval monk or Arab classicist, most books distintigrated
or were lost.  Much of early NASA planetary data is "lost" in the old formats.
And this doesn't even address the issue of physical media lifetimes.

From fitsbits-request  Tue Aug 15 02:11:01 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["621" "" "14" "August" "1995" "18:35:08" "GMT" "John Atwood" "atwoodj at ada.cs.orst.edu" "<40o50s$mej at engr.orst.edu>" "14" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081418:35:08" "Saving 100GB of data for 15 years cheaply" (number " " mark "     John Atwood       Aug 14   14/621   " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<Pine.SUN.3.91.950813123611.7702F-100000 at alexis>"]
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content-length: 619
From: atwoodj at ada.CS.ORST.EDU (John Atwood)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 14 Aug 1995 18:35:08 GMT

I'm surprised no one has mentioned Optical Tape.  The August issue of
IEEE Spectrum shows it as a medium with good characteristics.  The 
article says Sony, Philips, Storage Technonlogy, E-Systems EMAS, and Kodak
are "actively investigating optical tape".  One graph shows the capacity of
optical tape to be, in 1993, 27GB, in 1995, 50GB, in 1999, 100GB.

John
-- 
_________________________________________________________________
Office phone: 503-737-5583 (Batcheller 349);home: 503-757-8772
Office mail:  303 Dearborn Hall, OSU, Corvallis, OR  97331
_________________________________________________________________

From fitsbits-request  Tue Aug 15 20:48:04 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["383" "Tue" "15" "August" "1995" "07:50:33" "GMT" "Tim Atkinson" "Tim at npagroup.demon.co.uk" "<808473033snz at npagroup.demon.co.uk>" "10" "Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081507:50:33" "Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply" (number " " mark "     Tim Atkinson      Aug 15   10/383   " thread-indent "\"Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply\"\n") "<Pine.SUN.3.91.950814093927.8911C-100000-100000 at alexis>"]
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Reply-To: Tim at npagroup.demon.co.uk
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content-length: 381
From: Tim Atkinson <Tim at npagroup.demon.co.uk>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply
Date: Tue, 15 Aug 95 07:50:33 GMT

I upgraded to a Yamaha 4 speed writer from a Phillips CDD521 (original)
and found that hardly anything would read the disks the Yamaha produced.
 Reducing the Yamaha write speed to double speed from quad speed solved
this problem mostly, for some really old pre-multisession players, you
still have to write disks at single speed.  Don't know why but it works. 

--  Tim Atkinson

From fitsbits-request  Wed Aug 16 04:15:34 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["1671" "Mon" "14" "August" "1995" "16:19:47" "" "A. P. R. Cooper" "aprc at pcmail.nerc-bas.ac.uk" "<aprc.373.001054E6 at pcmail.nerc-bas.ac.uk>" "39" "Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data" "^From:" nil nil "8" "1995081416:19:47" "Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data" (number " " mark "     A. P. R. Cooper   Aug 14   39/1671  " thread-indent "\"Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data\"\n") "<Pine.SUN.3.91.950813123611.7702F-100000 at alexis>"]
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content-length: 1669
From: aprc at pcmail.nerc-bas.ac.uk (A P R Cooper)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data
Date: Mon, 14 Aug 1995 16:19:47

In article <Pine.SUN.3.91.950813123611.7702F-100000 at alexis> Jeff Bloch <jbloch at alexis> writes:
>Subject: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data
>From: Jeff Bloch <jbloch at alexis>
>Date: Sun, 13 Aug 1995 12:46:03 -0600

>We store 650MB of satellite data on a CD ROM every 5 days using a setup from
>Young Minds on a Sparcstation. We have over 100 CD volumes in the archive.
>All has been well for the last two years until Sun started shipping new 4x CD
>ROM readers from Toshiba with new workstations. Suddenly, 50% of our archive
>is unreadable by the new drives. Old drives (mostly Sony) continue to read
>the archive just fine. This has nothing to do with the ISSO standards. Young
>Minds has not quite fessed up to the problem yet, but there may be a hardware
>problem with the particular model of the Phillips writer that we have. 

Surely we're not talking about CD but CD-R here? They are different 
technologies, even though they are compatible.

>--------------------------------------------------------------------------
>Jeffrey Bloch                                   Office:     (505) 665-2568
>Astrophysics and Radiation Measurements Group   ALEXIS Soc: (505) 665-5975
>Los Alamos National Laboratory                  FAX:        (505) 665-4414
>Group NIS-2, Mail Stop D436                     e-mail:     jbloch at lanl.gov
>Los Alamos, NM 87545
>--------------------------------------------------------------------------

A. Paul R. Cooper
British Antarctic Survey
aprc at pcmail.nerc-bas.ac.uk

*****          Any opinions given here are my own,          *****
***** and not necessarily those of British Antarctic Survey *****

From fitsbits-request  Wed Aug 16 12:12:24 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["2212" "" "16" "August" "1995" "08:32:48" "+0800" "David Brooks" "daveb at perth.dialix.oz.au" "<40rebg$di2$1 at perth.DIALix.oz.au>" "49" "Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data" "^From:" nil nil "8" "1995081600:32:48" "Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data" (number " " mark "     David Brooks      Aug 16   49/2212  " thread-indent "\"Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data\"\n") "<aprc.373.001054E6 at pcmail.nerc-bas.ac.uk>"]
	nil)
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content-length: 2210
From: daveb at perth.DIALix.oz.au (David Brooks)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data
Date: 16 Aug 1995 08:32:48 +0800

aprc at pcmail.nerc-bas.ac.uk (A P R Cooper) writes:

>In article <Pine.SUN.3.91.950813123611.7702F-100000 at alexis> Jeff Bloch <jbloch at alexis> writes:
>>Subject: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data
>>From: Jeff Bloch <jbloch at alexis>
>>Date: Sun, 13 Aug 1995 12:46:03 -0600

>>We store 650MB of satellite data on a CD ROM every 5 days using a setup from
>>Young Minds on a Sparcstation. We have over 100 CD volumes in the archive.
>>All has been well for the last two years until Sun started shipping new 4x CD
>>ROM readers from Toshiba with new workstations. Suddenly, 50% of our archive
>>is unreadable by the new drives. Old drives (mostly Sony) continue to read
>>the archive just fine. This has nothing to do with the ISSO standards. Young
>>Minds has not quite fessed up to the problem yet, but there may be a hardware
>>problem with the particular model of the Phillips writer that we have. 

>Surely we're not talking about CD but CD-R here? They are different 
>technologies, even though they are compatible.

>>--------------------------------------------------------------------------
>>Jeffrey Bloch                                   Office:     (505) 665-2568
>>Astrophysics and Radiation Measurements Group   ALEXIS Soc: (505) 665-5975
>>Los Alamos National Laboratory                  FAX:        (505) 665-4414
>>Group NIS-2, Mail Stop D436                     e-mail:     jbloch at lanl.gov
>>Los Alamos, NM 87545
>>--------------------------------------------------------------------------

>A. Paul R. Cooper
>British Antarctic Survey
>aprc at pcmail.nerc-bas.ac.uk

>*****          Any opinions given here are my own,          *****
>***** and not necessarily those of British Antarctic Survey *****

I have encountered this problem also. A friend recently loaned me an 
archive on a Kodak CD-R. I found I could read it on my old 486 (2x 
drive), but not on the Pentium (4x drive).
The old drive is a Panasonic CR-562-B, the newer one came with a Sound 
Balster Discovery kit.

-- 
David R. Brooks <daveb at perth.DIALix.oz.au>    Tel/fax. +61 9 434 4280
PGP public key via finger or keyservers
Public key fingerprint:  20 8F 95 22 96 D6 1C 0B  3D 4D C3 D4 50 A1 C4 34 

From fitsbits-request  Thu Aug 17 03:08:34 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["7158" "" "15" "August" "1995" "16:36:26" "GMT" "Perry Greenfield" "perry at eclipse.stsci.edu" "<40qiea$bl2 at marvel.stsci.edu>" "141" "FITS Image Extension support in IRAF" "^From:" nil nil "8" "1995081516:36:26" "FITS Image Extension support in IRAF" (number " " mark "     Perry Greenfield  Aug 15  141/7158  " thread-indent "\"FITS Image Extension support in IRAF\"\n") nil]
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From: perry at eclipse.stsci.edu (Perry Greenfield)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: FITS Image Extension support in IRAF
Date: 15 Aug 1995 16:36:26 GMT

The Science Software Group (i.e., the STSDAS group) at the Space
Telescope Science Institute has been involved in a cooperative
effort with NOAO to modify the IRAF imio kernel to support the
FITS Image Extensions within IRAF as a native disk format. We
have tentatively settled on a specification for how we see the
interface working and have been implementing a kernel to this
specification. The implementation we come up with may be modified
as a result of comments from NOAO or may later be enhanced or
modified by NOAO before distribution as part of IRAF v2.11.
This posting is intended to serve the purpose of notifying the
FITS community about our intended use and interpretation of the
FITS format as well as solicit comments about its compliance with
the standard.

Before discussing the details, some brief background. The calibration
pipelines being developed for the two new instruments being installed
during the 97 servicing mission, STIS and NICMOS, will produce
significantly more datasets than are now being produced for the
existing instruments. This is a result of generating associated
data arrays for all science images that will contain data quality
and variance information. Furthermore, both instruments have modes
which produce multiple images for each observation (possibly more
than 50 for NICMOS). FITS Image Extensions have been chosen
as a means of reducing the number of file generated by combining
all the associated arrays for an observation into one file. The 
following issues have arisen in the design of the data files and
the ease in which a user may access an image contained in such
a file.

I) "INHERITANCE"

There are two aspects of the interface we are developing that relate
to issues with the FITS standard. The first deals with relation of
the keywords in the primary header to the extension images that
follow in the same file. This particular aspect engendered much
discussion and consideration. There is an intuitive expectation
among many that the Primary Header keywords should apply to all
extension headers, but in fact it seems that most FITS software
makes no such assumptions, i.e., all extension headers are treated
as independent of the Primary Header. The FITS standard makes no
explicit reference to this issue. After much discussion it was
decided to include a mechanism for Extension Header Units (here-
after EHU) to "inherit" Primary Header Unit (PHU) keywords. The
scheme  being adopted is that the EHU will inherit the PHU
keywords if it contains a line specifying "INHERIT=T". In the
absence of such a line (or if "INHERIT=F" exists) no inheritance
of PHU keywords will take place. In cases where the PHU and EHU
both contain the same keyword, the EHU value takes precedence.
If the EHU is propagated by the applications program to an output
FITS file, the inherited keywords will then appear in the new
EHU (or PHU if it is written as the Primary Unit).

An obvious problem with this scheme is in the effective duplication
of all PHU keywords in the output EHUs after one step of processing
or data reduction effectively defeating the usefulness of having
"global" keywords in the PHU so they wouldn't be repeated everywhere.
To avoid this needless replication, we have incorporated a mechanism
to override the inheritance when opening an Extension Unit. This
is accomplished by specifying an option as part of the filename/
extension selection specification. This is intended to be used
primarily by the applications programs that expect files in FITS
Image Extension format (e.g., the future STIS and NICMOS calibration
pipeline programs) and expect the "global" PHU keywords. In this
situation, we expect that the application program will disable
inheritance, read the PHU and EHU as separate entities, and
propagate them separately. The inheritance of keywords is accomplished
by the use of routines that search the EHU and PHU (in that order)
for a given keyword.

A possibility being considered (but certainly more difficult to
implement) is to use the output PHU to determine if the keyword
in the combined input PHU/EHU exists in the output PHU and has the
same value. If so then the keyword would not be written to the
output EHU. This scheme would also prevent the automatic duplication
of PHU keywords in output EHUs.

Since most FITS readers will have no knowledge about our local
convention regarding keyword inheritance, it will be important for us
(and any others for that matter) to ensure that all keywords that
would be reasonably expected to be useful for analysis be present
in the EHU even if they are the same for all Extensions. (This still
leaves a healthy number of keywords for the global header as far
as HST data products are concerned!)

II) EXTENSION NAMES

The second issue related to the FITS standard is the selection
of Image Extensions. The obvious and straightforward way to
specify an extension is to refer to it by number. The convention
we have adopted is to refer to the Primary Unit as extension 0,
and the first Extension Unit as 1. We have also adopted a naming
scheme so that Image Extensions can be referred to by name. For the
time being the name is defined by the combination of the values
of the EXTNAME and EXTVER keywords, if they exist (future enhancements
by NOAO may include more keywords as part of the naming scheme).
This naming convention is essentially identical to that proposed
in "A Hierarchical Grouping Convention for FITS" by Jennings et al.

The planned data products of the future instruments will incorporate
one or more "groups" of images into one FITS file. Such a group might
consist of a science image, data quality image, and error image. There
are occasions where multiple groups will be in the same file. Our
plan is to use EXTNAME to specify the image type and EXTVER to specify
the number in the sequence, e.g., SCIENCE,3 would specify the first
extension with EXTNAME=SCIENCE and EXTVER=3.

There are many more details involved in specifying the IRAF imio
interface for FITS image extensions, but they don't directly relate
to FITS issues. Anyone who is interested in those details can email
me for the specifics.

NULL IMAGES:

There is one last issue that does not involve the IRAF imio interface
directly but is related to planned HST data products and the FITS
standard. The data products plan to use "NULL" Data Units for two
distinct cases. For the first case, and intended to be used for all STIS
and NICMOS data, the Primary Data Unit will be a NULL array. This is
so that all the data products can be referred to by name, and a use of
either EXTNAME or EXTVER in the Primary Header Unit would clearly be
at odds with their definition. The second use of NULL arrays is when
certain data arrays, for example data quality arrays or error images,
will be filled with a constant value. In these cases it makes sense
to use a NULL array with a keyword in the EHU specifying the constant
value. The IRAF imio kernel will *not* automatically convert these
Extensions into constant arrays. It will be up to specific application
programs to interpret the meaning of these NULL images.

Perry Greenfield

From fitsbits-request  Thu Aug 17 06:47:25 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["741" "Mon" "14" "August" "1995" "03:56:46" "GMT" "Mark Calabretta" "mcalabre at atnf.csiro.au" "<DDA8An.GK9 at rp.CSIRO.AU>" "23" "Reference point for conic projections" "^From:" nil nil "8" "1995081403:56:46" "Reference point for conic projections" (number " " mark "     Mark Calabretta   Aug 14   23/741   " thread-indent "\"Reference point for conic projections\"\n") nil]
	nil)
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content-length: 739
From: mcalabre at atnf.csiro.au (Mark Calabretta)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Reference point for conic projections
Date: Mon, 14 Aug 1995 03:56:46 GMT

I would like to propose a change to the World Coordinate System (WCS)
proposal.  I believe it would be more useful if the reference point for
the conic projections was midway between the two standard parallels
rather than at the native pole.  This "midpoint" convention would allow
conic projections to be constructed with the reference point at the
centre of the image.

Is anyone currently using any of the conic projections defined in the WCS
draft?  Would anyone be inconvenienced if the reference point was changed
to be at the midpoint of the two standard parallels?  Are there any other
objections to the change?

Please respond by email to mcalabre at atnf.csiro.au.

---
Dr. Mark Calabretta
Australia Telescope National Facility

From fitsbits-request  Thu Aug 17 07:29:38 1995
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	["659" "" "16" "August" "1995" "09:40:37" "GMT" "William Sommerwerck" "williams at nwlink.com" "<40seel$hkh at alaska.nwlink.com>" "14" "Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081609:40:37" "Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply" (number " " mark "     William Sommerwer Aug 16   14/659   " thread-indent "\"Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply\"\n") "<808473033snz at npagroup.demon.co.uk>"]
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Newsgroups: sci.astro.fits,sci.data.formats,sci.astro,sci.physics.accelerators,sci.image.processing,sci.image.processing
content-length: 657
From: William Sommerwerck <williams at nwlink.com>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply
Date: 16 Aug 1995 09:40:37 GMT

Tim Atkinson <Tim at npagroup.demon.co.uk> wrote:

> I upgraded to a Yamaha 4X writer from a Phillips CDD521 (original)
> and found that hardly anything would read the disks the Yamaha produced.
> Reducing the Yamaha write speed to 2X speed solved this problem
> mostly, for some really old pre-multisession players, you still have
> to write disks at single speed. Don't know why but it works.

The faster the CD ROM turns, the more power the recorder's laser has
to put out to "burn" the disk. If it doesn't put out enough power,
the disk will be "underexposed" (that's not right, but I can't think
of a better analogy) and players won't be able to read it.

From dwells  Fri Aug 18 14:04:31 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["2797" "Fri" "18" "August" "1995" "15:33:30" "+0200" "Francois Ochsenbein" "francois at simbad.u-strasbg.fr" "<9508181804.AA00637 at fits.cv.nrao.edu>" "64" "Question on FITS keywords" "^Resent-Message-Id:" nil nil "8" "1995081813:33:30" "Question on FITS keywords" (number " " mark "     Francois Ochsenbe Aug 18   64/2797  " thread-indent "\"Question on FITS keywords\"\n") nil]
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Resent-To: fitsbits
From: francois at SIMBAD.u-strasbg.fr (Francois Ochsenbein)
Sender: fitsbits-request at fits.cv.nrao.edu
Apparently-To: fitsbits
Subject: Question on FITS keywords
Date: Fri, 18 Aug 95 15:33:30 +0200

I have just a questions raised by a problem in the order of the
FITS keywords in in TABLE extension (XTENSION= 'TABLE   '):
the header starts with

XTENSION= 'TABLE   '           / Ascii Table Extension
BITPIX  =                    8 / Character data
NAXIS   =                    2 / Simple 2-D matrix
NAXIS1  =                  242 / Number of bytes per record
NAXIS2  =                  137 / Number of records
PCOUNT  =                    0 / Get rid of random parameters
GCOUNT  =                    1 / Only one group (isn't it obvious?)
EXTNAME = 'table1.dat'         / Catalog of Bright Galaxies in Hydra I
EQUINOX =                 1950 / Equinox of coordinates
         ====================================================================
TFIELDS =                   48 / Number of data fields (columns)
TBCOL1  =  (etc )...

and the FITS Users Guide specifies in section 3.4.1 that the order must be

1. XTENSION= 'TABLE   '
2. BITPIX
3. NAXIS
4. NAXIS1
5. NAXIS2
6. PCOUNT
7. GCOUNT
8. TFIELDS

Does the Users Guide mean that exactly the 8 keywords must be consecutive
(without intermediate other keywords) or not ? In other words, does
the example conform or not to the standard, or should it be rewritten
XTENSION= 'TABLE   '           / Ascii Table Extension
BITPIX  =                    8 / Character data
NAXIS   =                    2 / Simple 2-D matrix
NAXIS1  =                  242 / Number of bytes per record
NAXIS2  =                  137 / Number of records
PCOUNT  =                    0 / Get rid of random parameters
GCOUNT  =                    1 / Only one group (isn't it obvious?)
TFIELDS =                   48 / Number of data fields (columns)
EXTNAME = 'table1.dat'         / Catalog of Bright Galaxies in Hydra I
EQUINOX =                 1950 / Equinox of coordinates
         ====================================================================
TBCOL1  =  (etc )...

Thank you for the expert's comments ...
Francois Ochsenbein / CDS Strasbourg
================================================================================

        _/_/_/_/_/_/ . . .             Centre de Donnees astronomiques de
      _/                               Strasbourg
     _/                                http://cdsweb.u-strasbg.fr/CDS.html
    _/        _/_/  _/_/_/             
   _/      _/      _/    _/            Francois Ochsenbein
    _/_/_/_/      _/    _/_/_/_/       Internet: francois at astro.u-strasbg.fr
         _/      _/    _/      _/         Phone: +33 88 35 84 11
          _/_/  _/_/_/        _/            Fax: +33 88 37 14 08
                             _/            Post: Observatoire Astronomique
                            _/                   11, rue de l'Universite
        . . . _/_/_/_/_/_/_/                     67000 STRASBOURG, France 

From fitsbits-request  Fri Aug 18 17:35:27 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["1078" "Fri" "18" "August" "1995" "17:35:20" "-0400" "William Pence" "pence at tetra.gsfc.nasa.gov" "<199508182135.RAA22316 at tetra.gsfc.nasa.gov>" "28" "Re: Question on FITS keywords" "^From:" nil nil "8" "1995081821:35:20" "Question on FITS keywords" (number " " mark "     William Pence     Aug 18   28/1078  " thread-indent "\"Re: Question on FITS keywords\"\n") nil]
	nil)
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From: William Pence <pence at tetra.gsfc.nasa.gov>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Cc: francois at SIMBAD.u-strasbg.fr, pence at tetra.gsfc.nasa.gov
Subject: Re: Question on FITS keywords
Date: Fri, 18 Aug 1995 17:35:20 -0400

Regarding Francois Ochsenbein's question about the order of the FITS
keywords in a TABLE extension, the A&A Suppl. Series paper (73, 365),
which defines the format of the TABLE extension, says that the 8
required keywords must be in order, *and* must be the first 8 keywords in
the file:

  "The first eight keywords (XTENSION through TFIELDS) *must* appear, and in 
   the order shown here."

Also, the BINTABLE definition paper, (in the March 22, 1995 issue of A&A) 
says:
  
  "The mandatory keywords XTENSION, BITPIX, NAXIS, NAXIS1, NAXIS2,
  PCOUNT, GCOUNT, and TFIELDS must be in order; other keywords 
  follow these in an arbitrary order."

While this does not unambiguously state that these 8 required keywords
must also be the first 8 keywords in the file, the statement that
"other keywords follow these" seems to strongly imply that the 8
keywords must appear before any other keywords.  Thus, I think the
example header with the EXTNAME and EQUINOX keywords appearing before
the TFIELDS keyword would not conform to the FITS standard.

-Bill Pence
 HEASARC/NASA

From fitsbits-request  Fri Aug 18 22:17:24 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["1024" "Sun" "13" "August" "1995" "12:46:03" "-0600" "Jeff Bloch" "jbloch at alexis" "<Pine.SUN.3.91.950813123611.7702F-100000 at alexis>" "26" "Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081318:46:03" "Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply" (number " " mark "     Jeff Bloch        Aug 13   26/1024  " thread-indent "\"Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply\"\n") nil]
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Newsgroups: sci.astro.fits,sci.data.formats,sci.astro,sci.physics.accelerators,sci.image.processing,sci.image.processing
content-length: 1022
From: Jeff Bloch <jbloch at alexis>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply
Date: Sun, 13 Aug 1995 12:46:03 -0600

We store 650MB of satellite data on a CD ROM every 5 days using a setup from
Young Minds on a Sparcstation. We have over 100 CD volumes in the archive.
All has been well for the last two years until Sun started shipping new 4x CD
ROM readers from Toshiba with new workstations. Suddenly, 50% of our archive
is unreadable by the new drives. Old drives (mostly Sony) continue to read
the archive just fine. This has nothing to do with the ISSO standards. Young
Minds has not quite fessed up to the problem yet, but there may be a hardware
problem with the particular model of the Phillips writer that we have. 

--------------------------------------------------------------------------
Jeffrey Bloch					Office:     (505) 665-2568
Astrophysics and Radiation Measurements Group	ALEXIS Soc: (505) 665-5975
Los Alamos National Laboratory			FAX:	    (505) 665-4414
Group NIS-2, Mail Stop D436			e-mail:	    jbloch at lanl.gov
Los Alamos, NM 87545
--------------------------------------------------------------------------

From fitsbits-request  Sun Aug 20 11:58:47 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["1581" "Mon" "14" "August" "1995" "09:47:07" "-0600" "Jeff Bloch" "jbloch at alexis" "<Pine.SUN.3.91.950814093927.8911C-100000-100000 at alexis>" "31" "Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081415:47:07" "Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply" (number " " mark "     Jeff Bloch        Aug 14   31/1581  " thread-indent "\"Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply\"\n") "<Pine.SUN.3.91.950813123611.7702F-100000 at alexis>"]
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Newsgroups: sci.astro.fits,sci.data.formats,sci.astro,sci.physics.accelerators,sci.image.processing,sci.image.processing
content-length: 1579
From: Jeff Bloch <jbloch at alexis>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Beware about CD ROM Data Longevity - Was Re: Saving 100GB of data for 15 years cheaply
Date: Mon, 14 Aug 1995 09:47:07 -0600

The folks here who did the CD ROM study pointed out to me that I made an
error in my message below. Toshiba 2X readers provided in new Sparcstations
exhibited the problem, and actually a Toshiba 4X reader did not exhibit 
the difficulty. The actual failure rate was 20% to 50% depending on the 
reader. We have both a Phillips "CDD 521 Upgraded" writer and an older 
"CDD 521" model. Disks written with the older model also show no 
difficulties with any drive, just ones written on the newer writer.

--------------------------------------------------------------------------
Jeffrey Bloch					Office:     (505) 665-2568
Astrophysics and Radiation Measurements Group	ALEXIS Soc: (505) 665-5975
Los Alamos National Laboratory			FAX:	    (505) 665-4414
Group NIS-2, Mail Stop D436			e-mail:	    jbloch at lanl.gov
Los Alamos, NM 87545
--------------------------------------------------------------------------

On Sun, 13 Aug 1995, Jeff Bloch wrote:

> 
> We store 650MB of satellite data on a CD ROM every 5 days using a setup from
> Young Minds on a Sparcstation. We have over 100 CD volumes in the archive.
> All has been well for the last two years until Sun started shipping new 4x CD
> ROM readers from Toshiba with new workstations. Suddenly, 50% of our archive
> is unreadable by the new drives. Old drives (mostly Sony) continue to read
> the archive just fine. This has nothing to do with the ISSO standards. Young
> Minds has not quite fessed up to the problem yet, but there may be a hardware
> problem with the particular model of the Phillips writer that we have. 
> 

From fitsbits-request  Sun Aug 20 14:54:38 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["2760" "" "17" "August" "1995" "19:31:28" "GMT" "Francois Ochsenbein" "francois at cdsxb6.nosubdomain.nodomain" "<4105eg$rri at apopi.u-strasbg.fr>" "62" "Order of FITS keywords in ASCII TABLE extension" "^From:" nil nil "8" "1995081719:31:28" "Order of FITS keywords in ASCII TABLE extension" (number " " mark "     Francois Ochsenbe Aug 17   62/2760  " thread-indent "\"Order of FITS keywords in ASCII TABLE extension\"\n") nil]
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Newsgroups: sci.astro.fits
content-length: 2758
From: francois at cdsxb6.NoSubdomain.NoDomain (Francois Ochsenbein)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Order of FITS keywords in ASCII TABLE extension
Date: 17 Aug 1995 19:31:28 GMT

I have just a questions raised by a problem in the order of the
FITS keywords in in TABLE extension (XTENSION= 'TABLE   '):
the header starts with

XTENSION= 'TABLE   '           / Ascii Table Extension
BITPIX  =                    8 / Character data
NAXIS   =                    2 / Simple 2-D matrix
NAXIS1  =                  242 / Number of bytes per record
NAXIS2  =                  137 / Number of records
PCOUNT  =                    0 / Get rid of random parameters
GCOUNT  =                    1 / Only one group (isn't it obvious?)
EXTNAME = 'table1.dat'         / Catalog of Bright Galaxies in Hydra I
EQUINOX =                 1950 / Equinox of coordinates
         ====================================================================
TFIELDS =                   48 / Number of data fields (columns)
TBCOL1  =  (etc )...

and the FITS Users Guide specifies in section 3.4.1 that the order must be

1. XTENSION= 'TABLE   ' 
2. BITPIX  
3. NAXIS   
4. NAXIS1  
5. NAXIS2  
6. PCOUNT  
7. GCOUNT  
8. TFIELDS 

Does the Users Guide mean that exactly the 8 keywords must be consecutive
(without intermediate other keywords) or not ? In other words, does
the example conform or not to the standard, or should it be rewritten
XTENSION= 'TABLE   '           / Ascii Table Extension
BITPIX  =                    8 / Character data
NAXIS   =                    2 / Simple 2-D matrix
NAXIS1  =                  242 / Number of bytes per record
NAXIS2  =                  137 / Number of records
PCOUNT  =                    0 / Get rid of random parameters
GCOUNT  =                    1 / Only one group (isn't it obvious?)
TFIELDS =                   48 / Number of data fields (columns)
EXTNAME = 'table1.dat'         / Catalog of Bright Galaxies in Hydra I
EQUINOX =                 1950 / Equinox of coordinates
         ====================================================================
TBCOL1  =  (etc )...

Thank you for the expert's comments ...
================================================================================

        _/_/_/_/_/_/ . . .             Centre de Donnees astronomiques de
      _/                               Strasbourg
     _/                                http://cdsweb.u-strasbg.fr/CDS.html
    _/        _/_/  _/_/_/
   _/      _/      _/    _/            Francois Ochsenbein
    _/_/_/_/      _/    _/_/_/_/       Internet: francois at astro.u-strasbg.fr
         _/      _/    _/      _/         Phone: +33 88 35 84 11
          _/_/  _/_/_/        _/            Fax: +33 88 37 14 08
                             _/            Post: Observatoire Astronomique
                            _/                   11, rue de l'Universite
        . . . _/_/_/_/_/_/_/                     67000 STRASBOURG, France

From fitsbits-request  Mon Aug 21 09:43:33 1995
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	["1013" "" "18" "August" "1995" "15:07:56" "GMT" "Guy Rixon" "gtr at ast.cam.ac.uk" "<412acc$tq at lyra.csx.cam.ac.uk>" "21" "Re: Saving 100GB of data for 15 years cheaply" "^From:" nil nil "8" "1995081815:07:56" "Saving 100GB of data for 15 years cheaply" (number " " mark "     Guy Rixon         Aug 18   21/1013  " thread-indent "\"Re: Saving 100GB of data for 15 years cheaply\"\n") "<pettsj-0908950800400001 at visigoth.demon.co.uk>"]
	nil)
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References: <3vvvfu$a1e at ixnews6.ix.netcom.com> <404au3$jlh at itchy.itsnet.com> <406st6$8le at gwis2.circ.gwu.edu> <407tut$21e at electron.rutgers.edu> <grunes.302.807903725 at news.nrl.navy.mil> <pettsj-0908950800400001 at visigoth.demon.co.uk>
Newsgroups: sci.data.formats,sci.astro,sci.image.processing,sci.astro.fits,sci.physics.accelerators
content-length: 1011
From: Guy Rixon <gtr at ast.cam.ac.uk>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: Saving 100GB of data for 15 years cheaply
Date: 18 Aug 1995 15:07:56 GMT

pettsj at visigoth.demon.co.uk (James Petts) wrote:
>In article <grunes.302.807903725 at news.nrl.navy.mil>,
>grunes at news.nrl.navy.mil (Mitchell R Grunes) wrote:
>
>> 3.  Since no one liked my idea of film, I've an even better idea.  
>> Print it all out in hex, on acid free paper.  When you need it, use a 
>> scanner.  Let's see: two characters/byte, about 100 characters/line 
>> and 60 lines/page...now that's a REAL fire hazard.  Compact, too.
>
>I came into this discussion late (i.e. this is the first message on
>the subject I've seen), but what was the main objection to film.
[Suggestions for safe storage of film deleted]

The point about film is that you can't do all the analysis of the images you
want to without re-digitizing the data and that's an inherently lossy process.
We're talking about science data here, of course.  If the pictures were held
for their aesthetic value, or if they were, say, medical images that could be
analyzed by looking at them on a light-box, then film would be ideal.

From fitsbits-request  Mon Aug 21 13:33:24 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["667" "" "18" "August" "1995" "22:09:13" "GMT" "Joe Heafner" "heafnerj at mercury.interpath.net" "<413329$p2s at redstone.interpath.net>" "16" "IMDISP under OS/2????" "^From:" nil nil "8" "1995081822:09:13" "IMDISP under OS/2????" (number " " mark "     Joe Heafner       Aug 18   16/667   " thread-indent "\"IMDISP under OS/2????\"\n") nil]
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content-length: 665
From: heafnerj at mercury.interpath.net (Joe Heafner - Astronomer)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: IMDISP under OS/2????
Date: 18 Aug 1995 22:09:13 GMT

Can anyone give me any tips in using IMDISP under OS/2 Warp? I've tried 
it and while it doesn't generate any error messages, I can't seem to 
actually SEE the image! What am I doing wrong?

				Joe

--
	*************************************************************
	*     Paul J. Heafner, Astronomy and Physics Instructor     *
	*       Work:(704)327-7000, x.246 Home:(704)328-9425        *
	* HEAFNERJ at MERCURY.INTERPATH.NET   HEAFNER_PJ at ALICE.LRC.EDU *
        *                   HEAFNERJ at ECSVAX.UNCECS.EDU              *
        *                    Proud user of OS/2 Warp!               *
        *************************************************************

From fitsbits-request  Mon Aug 21 20:55:44 1995
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	["991" "" "21" "August" "1995" "09:57:29" "GMT" "Hartmut Frommert" "phfrom at nyx.uni-konstanz.de" "<phfrom.1131.0 at nyx.uni-konstanz.de>" "16" "FITS viewer for OS/2 Warp ?" "^From:" nil nil "8" "1995082109:57:29" "FITS viewer for OS/2 Warp ?" (number " " mark "     Hartmut Frommert  Aug 21   16/991   " thread-indent "\"FITS viewer for OS/2 Warp ?\"\n") nil]
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Newsgroups: sci.astro.fits
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From: phfrom at nyx.uni-konstanz.de (Hartmut Frommert)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: FITS viewer for OS/2 Warp ?
Date: 21 Aug 1995 09:57:29 GMT

Is there a fits viewer for native OS/2 Warp ?  I have ViewFits which is fine 
under OS/2 2.1 but crashes under Warp, and I know that IMDISP runs in a Dos
session of Warp, but certainly would like a native 32bit PM app more ..
                               | OS/2 vs. NT: Better Half than Not Testified
  Hartmut Frommert             | Warp 3.0 vs. 95:   Cheaper, Smaller, Faster
  <phfrom at nyx.uni-konstanz.de> |                    and finally, it exists..
----------- Get astronomical and space gifs via anon ftp from: -------------
ftp.seds.org; explorer.arc.nasa.gov: /pub/SPACE/GIF; jplinfo.jpl.nasa.gov  |
garbo.uwasa.fi:/pc/gif*; ftp.fce.vutbr.cz; ftp.univ-rennes1.fr; ftp.bdl.fr |
HST: marvel.stsci.edu:/pubinfo/gif; ftp.cnam.fr; crux.astr.ua.edu| Updates |
Clementine: clementine.s1.gov; images.jsc.nasa.gov (no more ftp) | welcome |
- More in SEDS' Astro FTP List:  ftp://ftp.seds.org/faq/astroftp.txt

The SL9 crash was just a heavenly celebration of Apollo 11 25th anniversary!

From fitsbits-request  Tue Aug 22 12:48:42 1995
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	["5218" "Tue" "22" "August" "1995" "12:22:00" "-0400" "William Pence" "pence at tetra.gsfc.nasa.gov" "<199508221622.MAA23921 at tetra.gsfc.nasa.gov>" "106" "Re: FITS Image Extension support in IRAF" "^From:" nil nil "8" "1995082216:22:00" "FITS Image Extension support in IRAF" (number " " mark "     William Pence     Aug 22  106/5218  " thread-indent "\"Re: FITS Image Extension support in IRAF\"\n") nil]
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From: William Pence <pence at tetra.gsfc.nasa.gov>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Cc: perry at eclipse.stsci.edu, pence at tetra.gsfc.nasa.gov
Subject: Re: FITS Image Extension support in IRAF
Date: Tue, 22 Aug 1995 12:22:00 -0400

I have 4 suggested changes or additions to the proposed STScI local
FITS convention for the INHERIT keyword (posted by Perry Greenfield on
17 Aug).  As it stands, I think the proposal is  too general or vague,
and could cause inappropriate keywords to be inherited in some cases
which could confuse users and possibly lead to incorrect results from
the analysis of FITS files using this convention.

Here are the suggested changes to the proposal:

  1)  The required keywords in the PHU shall never be inherited.

  2)  The PHU must have NAXIS = 0 for any keywords to be inherited.

  3)  If software modifies the value of an inherited keyword, that new
      keyword is simply added to the EHU, and the value of the keyword
      in the PHU is not changed.

  4)  Any COMMENT, HISTORY, or blank keywords in the PHU shall not be
      inherited.

The following sections describe why I think the above restrictions
are needed.

1.  Inheritance of the required PHU keywords:  

There could be problems if the required FITS keywords are inherited
from the primary header unit (PHU).  Clearly the SIMPLE keyword must
never be inherited.  If the primary array has NAXIS = 3 and the
extension has NAXIS = 2, then the extension must not inherit the NAXIS3
keyword from the PHU.  Also, it should be forbidden to have an
extension header unit (EHU) with just the following keywords:

XTENSION= 'IMAGE   '
INHERIT =                 T
END

with the expectation that the other required keywords would be
inherited from the PHU.  (This would violate the requirements for a
FITS conforming extension in any case).  All of these potential
problems can be avoided simply by restricting the inheritance proposal
to state that the following required or reserved PHU keywords shall
never be inherited:  SIMPLE, NAXIS, NAXISn, EXTEND, PCOUNT, GCOUNT, and
END.

2.  Inheritance of inappropriate PHU keywords by an Image extension:

If the primary array is not null (NAXIS != 0) then there may be
keywords in the PHU that should not be inherited.  For instance, the
BSCALE, BZERO, DATAMIN, and DATAMAX keywords might well only apply to
the primary array.  One solution to this problem would be to ensure
that these keywords are always repeated in each EHU, so they will never
be inherited, but due to negligence or ignorance users may forget to do
this, potentially leading to disasterous results when analyzing the
FITS file.  There is a subtle pitfall here, too, in that often the
absence of a keyword is used to imply a default value.  BSCALE and
BZERO for example should be assumed to have values of 1.0 and 0.0 if
not present in the EHU, and one should presumably not inherit the value
from the PHU in this case.  This also applies to the CROTA2 WCS keyword
which should be assumed to be 0.0 if not present in the EHU.  I think
the cleanest solution to this class of problems would be to restrict
the inherit convention to only apply in cases where the PHU has NAXIS =
0.  If NAXIS != 0, then the PHU keywords would not be inherited even if
the EHU has the INHERIT= T keyword.  If the PHU does have NAXIS = 0,
then it is safer to assume that any keywords may be inherited.

3.  Inheritance of inappropriate PHU keywords by a Table extension:

The same problems described above in (2) also apply to TABLE or
BINTABLE extensions, only more so. There are whole classes of PHU
keywords which would be illegal to inherit into tables such as the WCS
keywords, BSCALE, BZERO, BLANK, etc.  Any implementation of this scheme
would need to filter out these keywords before inheriting them to a
table extension.  However, this would not catch any user-defined
keywords which only apply to a primary array and are meaningless, or
confusing in the context of a table extension.  One could of course
restrict this proposal to only apply to IMAGE extensions, but this
would be inconsistant since the arguments in favor of this proposal
apply just as well to tables as they do to images.  As in case (2), I
think the simplest solution to these sorts of problems is to restrict
the inheritance convention to only apply if the PHU has NAXIS = 0.  By
doing this, then it is less likely that there would be keywords in
the PHU that would be forbidden in a table.

4.  Modification of inherited keywords:  

If a program opens a particular EHU and inherits some keywords from the
PHU, what should it do if it needs to modify the values of some of the
inherited keywords?  I think it would be too dangerous to directly
modify the value in the PHU because of the unknown effect this would
have on any other EHU which may inherit this same keyword.  So I think
the software should simply add this modified keyword value to the EHU,
thus overriding the value in the PHU.  If the software really needs to
modify (or delete) the PHU keyword value then it should be required to
physically open the PHU and make the modification directly.

5.  Are HISTORY, COMMENT and blank keywords inherited?  This is not a
major problem, but the proposal should state how these keywords should
be treated.  I would think these keywords should not be inherited, but
there may be cases where it would be desireable.

 Bill Pence
 HEASARC/NASA/GSFC
 pence at tetra.gsfc.nasa.gov

From fitsbits-request  Wed Aug 23 08:57:12 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["619" "" "22" "August" "1995" "08:54" "EDT" "Barry M. Schlesinger" "bschlesinger at nssdca.gsfc.nasa.gov" "<22AUG199508543192 at nssdca.gsfc.nasa.gov>" "20" "Re: FITS viewer for DECWindows?" "^From:" nil nil "8" "1995082212:54:00" "FITS viewer for DECWindows?" (number " " mark "     Barry M. Schlesin Aug 22   20/619   " thread-indent "\"Re: FITS viewer for DECWindows?\"\n") "<4190f9$626 at gap.cco.caltech.edu>"]
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References: <4190f9$626 at gap.cco.caltech.edu>
Newsgroups: sci.astro.fits
content-length: 617
From: bschlesinger at nssdca.gsfc.nasa.gov (Barry M. Schlesinger)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: FITS viewer for DECWindows?
Date: 22 Aug 1995 08:54 EDT

In article <4190f9$626 at gap.cco.caltech.edu>, carl at SOL1.GPS.CALTECH.EDU writes...
>Anybody out there got a FITS viewer that runs under X-Windows?  

The Sources of FITS Information posting, which on our system has not 
expired, points out a number of sites where information about software 
to read FITS files may be obtained.  For locations where it has
expired already, more general information about FITS and network
references can be found at 
http://www.gsfc.nasa.gov/astro/fits/basics_info.html
or
ftp://nssdc.gsfc.nasa.gov/pub/fits/basics_info.txt

				Barry Schlesinger
				FITS Support Office
				GSFC/ADF

From fitsbits-request  Thu Aug 24 18:21:32 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["1016" "" "21" "August" "1995" "04:01:45" "GMT" "Carl J. Lydick" "carl at sol1.gps.caltech.edu" "<4190f9$626 at gap.cco.caltech.edu>" "19" "FITS viewer for DECWindows?" "^From:" nil nil "8" "1995082104:01:45" "FITS viewer for DECWindows?" (number " " mark "     Carl J. Lydick    Aug 21   19/1016  " thread-indent "\"FITS viewer for DECWindows?\"\n") nil]
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Newsgroups: sci.astro.fits
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From: carl at SOL1.GPS.CALTECH.EDU (Carl J Lydick)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: FITS viewer for DECWindows?
Date: 21 Aug 1995 04:01:45 GMT

Anybody out there got a FITS viewer that runs under X-Windows?  Source code for
such a beast would be very helpful to me in writing some software here.  I only
need something that will handle a FITS file with:

SIMPLE  =                    T / Conformance to FITS                            
BITPIX  =                   16 / Bits per pixel in data file                    
NAXIS   =                    2 / Number of dimensions in data file              

Thanks in advance.
--------------------------------------------------------------------------------
Carl J Lydick | INTERnet: CARL at SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL

Disclaimer:  Hey, I understand VAXen and VMS.  That's what I get paid for.  My
understanding of astronomy is purely at the amateur level (or below).  So
unless what I'm saying is directly related to VAX/VMS, don't hold me or my
organization responsible for it.  If it IS related to VAX/VMS, you can try to
hold me responsible for it, but my organization had nothing to do with it.

From fitsbits-request  Sat Aug 26 10:15:10 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["596" "" "24" "August" "1995" "22:57:25" "GMT" "Rob Seaman" "seaman at noao.edu" "<41j04l$66r at noao.edu>" "19" "FITS checksum proposal" "^From:" nil nil "8" "1995082422:57:25" "FITS checksum proposal" (number " " mark "     Rob Seaman        Aug 24   19/596   " thread-indent "\"FITS checksum proposal\"\n") nil]
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Newsgroups: sci.astro.fits
content-length: 594
From: seaman at noao.edu (Rob Seaman)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: FITS checksum proposal
Date: 24 Aug 1995 22:57:25 GMT

A new draft of the FITS checksum proposal is available from:
 
    ftp://iraf.noao.edu/misc/checksum/checksum.ps
 
A README file and example data and code may be retrieved from the same
directory.
 
The major change from earlier drafts is that the unsigned integer value
of the DATASUM keyword is no longer ASCII encoded.  Various suggestions
from Barry Schlesinger and Arnold Rots have improved the document.
 
Rob Seaman, Bill Pence

-- 
seaman at noao.edu, http://iraf.noao.edu/~seaman
NOAO, 950 N Cherry Ave, Tucson AZ 85719, 520-318-8248
PGP: 98 8D 8B 49 74 9A 41 88  3A 43 87 54 51 BF 30 4B

From fitsbits-request  Tue Aug 29 00:00:42 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["2459" "" "25" "August" "1995" "15:51" "EDT" "Barry M. Schlesinger" "bschlesinger at nssdca.gsfc.nasa.gov" "<25AUG199515513160 at nssdca.gsfc.nasa.gov>" "51" "Re: FITS Image Extension support in IRAF" "^From:" nil nil "8" "1995082519:51:00" "FITS Image Extension support in IRAF" (number " " mark "     Barry M. Schlesin Aug 25   51/2459  " thread-indent "\"Re: FITS Image Extension support in IRAF\"\n") "<199508221622.MAA23921 at tetra.gsfc.nasa.gov>"]
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Newsgroups: sci.astro.fits
content-length: 2457
From: bschlesinger at nssdca.gsfc.nasa.gov (Barry M. Schlesinger)
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: FITS Image Extension support in IRAF
Date: 25 Aug 1995 15:51 EDT

In article <199508221622.MAA23921 at tetra.gsfc.nasa.gov>, William Pence <pence at tetra.gsfc.nasa.gov> writes...
>I have 4 suggested changes or additions to the proposed STScI local
>FITS convention for the INHERIT keyword (posted by Perry Greenfield on
>17 Aug).  As it stands, I think the proposal is  too general or vague,
>and could cause inappropriate keywords to be inherited in some cases
>which could confuse users and possibly lead to incorrect results from
>the analysis of FITS files using this convention.
> 

The general issue raised here, that of which header keywords are 
inherited, is an important one, not just the question of the
particular solution suggested.  The proposal needs to define more
precisely which keywords in the header are inherited and which are
not. 

More generally, it is important in the context of this discussion to
remember that individual FITS HDUs may be copied from one file to
another.  That possibility is one reason why most FITS software treats 
extensions independently.  Although the rule stated in the Generalized
Extensions Paper states only that keywords in the primary header are
not permitted to announce the presence of a particular kind of
extension, in general, it is not advisable to have keywords in the
primary header that mandate the structure or content of the extensions
in the file, since there is no requirement to copy the extensions 
along with the primary header.  EXTEND = T, for example means only that extensions *may*
be present, not necessarily that they are.  The discussion in the
proposal about maintaining information in the extensions, 

>> Since most FITS readers will have no knowledge about our local
>> convention regarding keyword inheritance, it will be important for us
>> (and any others for that matter) to ensure that all keywords that
>> would be reasonably expected to be useful for analysis be present
>> in the EHU even if they are the same for all Extensions. (This still
>> leaves a healthy number of keywords for the global header as far
>> as HST data products are concerned!)

also applies to the case where the extension is moved from one file to
another by software that does not recognize the inheritance
convention. 

Perhaps the best use of inheritance would be to express information 
that is relevant to a set of HDUs considered together but not of 
particular interest when only one is read.

				Barry Schlesinger
				FITS Support Office
				GSFC/ADF

From fitsbits-request  Tue Aug 29 11:54:09 1995
X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil]
	["2105" "Tue" "29" "August" "1995" "11:54:02" "-0400" "RANDY THOMPSON" "RTHOMPSON at iuedac.gsfc.nasa.gov" "<950829115402.2900012b at iuedac.gsfc.nasa.gov>" "35" "RE: FITS Image Extension support in IRAF" "^From:" nil nil "8" "1995082915:54:02" "FITS Image Extension support in IRAF" (number " " mark "     RANDY THOMPSON    Aug 29   35/2105  " thread-indent "\"RE: FITS Image Extension support in IRAF\"\n") nil]
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To: fitsbits at fits.cv.nrao.edu
Cc: RTHOMPSON at iuedac.gsfc.nasa.gov
Subject: RE: FITS Image Extension support in IRAF
Date: Tue, 29 Aug 1995 11:54:02 -0400 (EDT)

   I think the issue of inheritance is important, and the question 
of how to keep data sets connected with the data descriptions has become 
more involved with the addition of FITS extensions and FITS readers which 
separate extensions into separate files. The adoption of the Image
extension may have made separating FITS extensions into separate FITS files 
more feasible since the Image extension header format is so similiar to that
of a primary header. It needs to be emphasized however that the issue 
of inheritance is not specific to the Image extension but applies equally 
to all the existing FITS extensions. For this reason, I think it's important 
that new conventions do not change the interpretation of existing FITS 
files. Obviously LOCAL conventions should not impact other projects, but
IRAF users will undoubtedly want to read FITS files from other 
institutions.
    Our project adopted the policy of storing all but the required
extension header keywords in the primary header. In the most complicated 
file format, we use a primary HDU containing a 2-dimensional image, followed
by a Binary table extension, followed by two Image extensions. All the data
in the file pertains to one observation. It did not seem necessary to us 
to repeat all the observational and processing history information (roughly
400 keywords) in each of the extension headers. The FILENAME keyword
included in the extension headers provides (some) information about the 
individual data sets and does afford a way to keep data sets connected if 
they are written to separate files. 
    In retrospect, particularly in view of the discussions on inheritance, 
perhaps we should have considered a different format for the IUE archive 
in which more information is stored in the individual extension headers. 
Unfortunately, I think its too late for us to change, and because FITS
files like ours exist, it may not be valid to make assumptions about 
how primary header information should or should not be inherited by the 
extensions when newly-defined keywords (such as INHERIT = T) are not 
present. 

From fitsbits-request  Wed Aug 30 02:57:44 1995
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	["2275" "Wed" "30" "August" "1995" "09:01:45" "+0200" "Lucio Chiappetti" "lucio at ifctr.mi.cnr.it" "<Pine.3.89.9508300851.A23428-0100000 at poseidon.ifctr.mi.cnr.it>" "47" "Re: FITS Image Extension support in IRAF" "^From:" nil nil "8" "1995083007:01:45" "FITS Image Extension support in IRAF" (number " " mark "     Lucio Chiappetti  Aug 30   47/2275  " thread-indent "\"Re: FITS Image Extension support in IRAF\"\n") "<25AUG199515513160 at nssdca.gsfc.nasa.gov>"]
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From: Lucio Chiappetti <lucio at ifctr.mi.cnr.it>
Sender: fitsbits-request at fits.cv.nrao.edu
To: fitsbits at fits.cv.nrao.edu
Subject: Re: FITS Image Extension support in IRAF
Date: Wed, 30 Aug 1995 09:01:45 +0200 (MET DST)

On 25 Aug 1995, Barry M. Schlesinger wrote:

> The general issue raised here, that of which header keywords are 
> inherited, is an important one, ....
  [...]
> 
> More generally, it is important in the context of this discussion to
> remember that individual FITS HDUs may be copied from one file to
> another.  That possibility is one reason why most FITS software treats 
> extensions independently.  Although the rule stated in the Generalized
> Extensions Paper states ...

Uh, my apologies to everybody, but I remain constantly puzzled by the
emphasis on the ACTUAL USAGE of multi-extension files. It is clear to me 
why the "general extension" mechanism was invented that way (to allow the 
basic "image" files to coexist with new extensions), but it appears it 
did not have a widespread usage until binary tables came out. 

And even then I cannot understand why the majority of the cases (95 % ? 
or more ?) cannot be handled either :

  - as independent "image" files (i.e. primary HDU only)

  - as independent "single table" files (i.e. a primary HDU without data
    array, and ONLY another ONE HDU with a BINTABLE)

I do not understand what are the reasons for having more tables in the 
same file (and not separate files). There is no significant gain in space 
(an argument which might perhaps be relevant for a DATA EXCHANGE format), 
and there is complication in the reading/analysis software.
This is particularly true if the tables collated together are of 
miscellaneous nature and format.

I could PERHAPS find some sense for IMAGE extensions (the 5% or less 
missing above) where all extensions are of the same and simple nature and 
layout, and only in the case the extensions are of "ancillary" nature 
w.r.t. the primary data array (like the case of the "epsilons" for IUE).

---------------------------------------------------------------------------- 
Lucio Chiappetti - IFCTR/CNR     | Ma te' vugl' da' quost avis a ti' Orsign  
via Bassini 15 - I-20133 Milano  | Buttet rabios intant te se' pisnign       
Internet: LUCIO at IFCTR.MI.CNR.IT  |                                           
Decnet:   IFCTR::LUCIO           |             (Rabisch, II 46, 119-120)     
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