From: anne@cco.caltech.edu (Anneliese Lilje)
Newsgroups: comp.infosystems.gis
Subject: Re: where to get USGS DEMs
Date: 26 Jan 1993 21:55:35 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: sandman.caltech.edu

In article <9301261552.AA12425@crdokokl> "Alan H. Rea" <ahrea@CRDOKOKL.CR.USGS.GOV> writes:
>
>meets those agencies' needs.  If my memory serves me well, the current
>level of basic-mapping funding will not result in full digital
>coverage of the US at 1:24,000 scale until well into the next century.
>Because of the high demand for broad digital coverage, they have decided
>to emphasize digital production of 1:100,000-scale products, which can
>be finished much sooner.

What is the source of the "High demand for broad digital coverage"? I am
really curious. As a scienctist, there is very very little need for 
this type of coverage in the scientific arena in Geology. Which is
why I am curious as to what geological applications are being met by
funding (the USGS)
these 1:100,000 scale maps and not the 1:24,000 maps (which are
used routinely in every University I have been associated with or 
visited).

>There are ways, however, to speed up the process for the particular quads
>requested by several agencies, not just one), the reality is that if
>you want a specific quad in some time frame shorter than 3 or 4 years,
>you are best off to enter a cooperative agreement with NMD to produce
>the data you need.  If you are a state agency, NMD may have matching funds
>to help with the costs.  For example, I'm told that the state share for
>producing a 1:24,000 Digital Orthophotoquad is $400 per quarter-quad.
>Considering that a by-product of that is also a DEM, that's a pretty good
>deal.

I can produce the digital equivalent of the USGS 1:24,000 maps in 2 weeks
working by myself at a leisurely pace (while also doing other things :-)).
I have found that the way around the USGS bottleneck is simply to "roll
my own". Yo see, there are a lot of people like me who need the present
USGS data in a digital form. 

>As for the practicality of putting all the USGS public domain digital
>data up for ftp, there are some efforts underway to provide access to
>_some_ data sets via WAIS.  As someone else pointed out, the data
>storage requirements are a bit of a problem, and I suppose network
>performance may become an issue.  There are political issues, too,
>like job security for people who currently distribute data, and
>complaints about USGS "competing with the private sector."  All in

GAG. My tax dollars at work. There are some MONSTER ftp sites on the
internet already that are much broader and larger than what would 
be needed for map distribution. WAIS is a good idea. 

>think.  In fact, there is nothing to stop a university or other agency
>from buying all the digital products for their state and providing
>public access.  It may be a more manageable problem on a state level.

Well, being from California, which is being stripped down to the bare walls
for money, it is not possible or reasonable to expect a research institute
to provide such a service. This is what the tax dollars that go to the 
USGS should be for.

>I calculated it would cost about $6000 to buy all the currently
>available data for Oklahoma.  (That figure includes all available
>1:24K and 1:100K DEMs, DLGs, and CD-ROM TIGER files.)

But again. For California for example, the digital data is insufficient
for almost everything. DLG's do not contain topo lines in many places
and DEM's are neither of sufficient resolution for many purposes AND many
of them contain ERRONEOUS data. (Read bad Quality Control!).
>
>Now for a short disclaimer: I work for a different division in USGS,
>and I am not involved at all in the map production business.  I am a

Your comments on the USGS mapping projects are appreciated (Whether or not
you work for the mapping agency). But as a hard core end user, the reality
of getting reasonable digital data is not good. At least that has
been my experience and the experience of my collegues.

anne
Newsgroups: comp.infosystems.gis