[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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