NASA Planetary Data Systems Standards and Architecture and NASAVIEW, a utility for viewing
all NASA data products.

==== Mike Martin, JPL
NASAView and DataSlate

About 10 years ago, I helped to develop a program called IMDISP.  The idea was
to use it to sell CD-ROM technology.  What a success that has been (joke). 
Seriously, I think that it did help a lot to sell the technology to management
and to users.

One exciting thing for me was to walk into a room where Jerry McFaul was
sitting with two geologists who had never before been able to access their
own data. They always had to go to someone else on a mainframe or whatever.  
IMDISP gave them the opportunity to view their data on their own machines
any time, any way they wanted. 

NASAView

PDS has now produced over 500 CD-ROM titles.  That is about 75% of the total
Planetary digital archive, at least the data that needs to be available to the

science community.  What does a librarian do when they get a PDS CD-ROM in 
the mail.  The data is raw format and possibly in a format specific to a
particular 
platform. 

There are tools.  IMDISP still goes out on our image volumes, Image4PDS was 
developed for Macintosh users.  But it has been kind of embarrassing.
Since people have started using GUIs, IMDISP has begun to look hard to use.

When you put this software on a disc, you have to tell people how to use it.
So you have to have a completely separate set of documentation for each
program you distribute.  You never have time to do a good job of the 
documentation.   So I've been very unsatisfied by the help we have
been able to provide to users.

Our sponsor at NASA headquarters wanted to process some Jupiter data.  He
could not get into the files.  So he became an advocate for a new tools.

I hope NASAView will view any NASA data set by 2000.

Solution:
Cross-platform
Simple display
Export data for use with user software.

Many scientists would just like to write out a GIF or PCX.

Functionality:

We spent six months evaluating cross platform user interfaces.  What a
disaster.  Open interface was $6,000.  It had lots of widgets, many of which
didn't work.  If your enterprise is committed to Open Interface, it could be 
successful.  It has an excellent interface for designing GUIs.  So we ended 
up using XVT as our cross platform development environment.

Below XVT, there is the  Object Access Library (OAL).  All our NASA discs are 
described with ODL (object description language) labels which define the
format and provide metadata for the data products.  The data is described
in terms of objects and the OAL is a library to access these objects.  To open
and read an image three calls are needed, label=OAParseLabelFile(filename);
image=OAGETIMAGE(label);  buf=OAREADIMAGE(image) 

L3 ("L cubed") is the bottom level, written in C.

Everything that we can distribute to people, there will be pointers to it from
the 
SIGCAT home page.

XVT has a couple of weeks of learning curve.  You have to learn events.  It
generates the application for you on all platforms.  NASAView currently works
on Mac and UNIX the Windows version has problems associated with the 16-bit
architecture
of the PC.

Issues and Plans:

Currently, the program is a memory hog.   To make it useful on small
computers, 
we'll need to do some disc caching.  Photoshop does a good job of this, if you

have enough hard disk space.  Palette handing is a real problem.  Mapping 256 
gray levels to 16 grays sucks.  Windows 16-bit has severe problems.  It wants 
local addresses, but for a big image you need a FAR address. For now, we will 
just do 32-bit apps.

XVT is not cheap, $2K to $5K per platform.

Add gif writer code.
Add limited stretching, cut and paste
Add non-image routines
Add plug-in filter capability (a la Photoshop)

Photoshop has a very sophisticated plug-in kit.  

Q: What do you mean?

There is a PDS plug-in for Photoshop.  When you put this in the directory,
it installs itself.  Then you can retrieve PDS files into Photoshop.


DataSlate came out of ScriptX.  Object-oriented tool from Kalieda, which
went down the tubes in December.  The objects in ScriptX are really neat.  The
object knows what it can do.

So, to organize data sets for unsophisticated users, we do not have tools
available.   Thumbnails and text search are the tools of the future. 
Thumbnails 
have become metadata.  That's where we are headed.  You want to have a tool 
that you can use, throw away.

Java-based for portability and internet access.  This offered an elegance
unseen before.  The Java White Paper you can get off the net is the best I
have ever seen.  It convinced me to buy stock in Sun.

CASDE - Consortium for the Application of Space Data to Education.

We really think that we can't just work with the raw data.  It needs to be
nicely
packaged into a registered, orderly structure we call DataStruct.

The initial interface turned out to be too busy.  We want this slate to be a
personal thing.  For a kid, it should be their slate. The goal is to
personalize this.  

A magnifying glass tool, actually a little window that lets you see the
topographic information underneath.  You know kids are going to get a lot
more excited if they can see their house, if they can see their school.  You
can trace the route from the school to your house.  The golf courses really
show up in the LandSat photos.

We will use a quad-tree architecture.  We are fitting the data in to spatial
bins.  There will be some fraction of a degree.  1 degree per pixel, down to
1/16 degree per picture and below.  So we are using the same architecture as
USGS.  

DataSlate issues:

Slight differences between Mac and Windows.  These development kits are free
from SUN.

Windows95 or PowerMac support initially, with MacOS and Windows 3.1 coming.

Performance of applets vs compiled code.

Plans:
- complete alpha version by July 96
- evaluate performance and test in schools


There are no pointers in Java, which I think is wonderful.

You may be aware of the products from Small Blue Planet. They have a set of
three CDS. They have this nice window view, where you can see into one data
set from another.

Q: Performance of applets versus compiled code?

My data distribution lab is working on this.  stargate.jpl.nasa.gov/ddl
Whatever we are developing we keep pretty current on there.

Q: Several times you mentioned the use of children using it.  I've been
contending at the survey that we would be getting more use if we could make
data more publicly available.  But I am having a hard time selling that to
people.

We are distributing USGS data. We took the Hazards disc and loaded it
into WebCat.  WebCat is an automatic process that can be used to build a
simple WWW catalog.  SDSU has access now to Alert. CASDE will provide
testimonial material.  What we need to do is work on those intermediary tools.

Q: How will you handle multivolume discs?

We will be taking software routines out of a NASA program called Plato which
is designed to handle multiple discs.  If possible, don't mess with
multivolume when you design your volumes. Put browse and the data on every
disc.



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