Real-time GPS Vector Display

[James Cameron]

G'day from Australia,

Summary: 

(a) given a vector file, how to find the x/y limits?
(b) what constitutes a minimum Grass installation?
(c) is the sequence planned workable?
(d) has anyone done this sort of thing?

Details:

I wish to display in real-time vectors derived from a GPS, hopefully
about once a second.  So far, of the options I've explored, GRASS has
the smallest memory footprint, and memory is my primary limit.  Both
chip memory and disk space.

The unit being used to display the information is a 486/33 laptop with
just 8Mb of memory.  d.mon has a RSS of 964k and a VSZ of 2Mb when asked
to draw a Grass vector file.

Other options I've looked into are GPS visualisation software in the
http://freshmeat.net/ application index, xcircuit due to the ease of use
of the keyboard zooming, and a custom-written application.

So using Grass I would expect to have the GPS data logging process save
the vectors in v.in.ascii format, process them into a binary vector,
find the x/y limits, define a region for display (g.region?), then
d.vect the data onto screen.  Perhaps with a "site" drawn for the
current position.

What program is best to use to find the x/y limits of a vector file?

Since disk space is very low (100Mb disk with Linux already taking up
a fair amount of it), I will need to install as little of Grass as
possible.  I'm certain I can use "strace" to find out what the programs
actually read in normal operation, so that I can make sure I include
the critical files; but is there a list somewhere?

I notice already that programs appear to have a wrapper that activates
a real program after checking that it is accessible.

I'm very interested in hearing from anybody who has done this before.

(Thank you for reading this far ... the task at hand is plotting the
coverage of a utility truck as it is driven over a field containing
a few hundred emus and their freshly laid eggs.  The eggs are dark
green and very hard to spot in the foliage, and there are no landmarks
to make it easy to prove that we have driven over the search area
properly.  http://quozl.netrek.org/pictures/ may help.)

-- 
James Cameron    mailto:quozl at us.netrek.org     http://quozl.netrek.org/