udmap updates the index maps used for web display of helicorders and spectrograms. 
Given a list of SCN's and their lat/lon's, GIF basemaps are read, points are plotted 
on them and they are written out as GIF files.  Additionally, a file is written 
containing the html snippets required to click on the index map and link elsewhere.
This is one of a suite of routines needed to automatically keep the web pages 
up-to-date.  Others are:

stalist - Queries all the waveservers and the calsta.db file to build a 
          text file of all served channels.
current_chans.pl - Perlscript to find info about channels for one helicorder 
                   or spectrogram process.
udmap - 

heli_htm.pl - Perlscript to build html for a set of helicorder pages.



Jim Luetgert  07/23/02