[aprssig] Re: FindU Maps Quirky

Jason Winningham jdw at eng.uah.edu
Mon Feb 7 07:29:25 EST 2005


Besides the datum conversion there's also the simple issue of 
resolution.  A map of the entire CONUS doesn't necessarily need the 
resolution/accuracy that a map of a considerably smaller area does.  If 
it did have that resolution it would be computationally expensive to 
render.

For example, I've been working with US-wide maps from the National 
Atlas and NOAA.  Even though there are obvious accuracy issues when you 
get in close, these maps are reasonably sized (5 to 100Mb each) and can 
be drawn fairly quickly.  TIGER maps, on the other hand, are quite a 
bit more accurate, but to get a nationwide map would require more 
gigabytes of storage than my laptop has available and my APRS client 
would take a long time to render it all - so long that the computer 
doesn't have time for things like drawing any APRS stations on the map.

Freely available data that is fairly accurate is out there, but what 
may be missing is an engine to render that data into appropriate maps.

-Jason
kg4wsv





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