[aprssig] Aerial Photos (Terraserver) and findU

[Larry Cerney]

Steve,

I tried it and it works great!  Most mapping show my location two houses
away, but this script and geo file nailed my house and showed my car in the
driveway.  Too cool!

Thanks 
Larry
K0ANI

"The only reason for time is so that everything doesn't happen at once." 
--Albert Einstein 
-----Original Message-----
From: aprssig-bounces at lists.tapr.org [mailto:aprssig-bounces at lists.tapr.org]
On Behalf Of Steve Dimse
Sent: Saturday, November 13, 2004 11:02 PM
To: 'TAPR APRS Mailing List'
Subject: [aprssig] Aerial Photos (Terraserver) and findU

I was finally able to lay off the pain pills long enough to get some work
done!

Here is a script to grab Terraserver tiles and return an image with a geo
file.
This works as other geo file cgi's I've done, the cgi returns the geo file,
the
image is placed in a temp file referenced by the geo file. And as with other
geo
scripts, this can be used in any cgi with a geo parameter. For example:

http://www.findu.com/cgi-bin/plot.cgi?call=*&geo=http://mm.aprs.net/terra.cg
i?
call=k4hg|scale=1

The center of the image (and in this case it means the point occurs in the
center tile, not at the exact center of the image) is specified wither with
a
callsign or a lat/lon pair:

http://www.findu.com/cgi-bin/plot.cgi?call=*&geo=http://mm.aprs.net/terra.cg
i?
lat=24.67|lon=-81.5|scale=64

scale is meters-per-pixel, values accepted by terraserver are 1, 2, 4, 8,
16,
32, and 64.

So far this only returns a 600x600 image, I'll be expanding it to make it
work
at other sizes.

The tiles are cached on findU, so the first time you load a particular
lat/lon
and scale, it will take longer (about 8 seconds), after that it only takes a
a
second to render the map. At some point I'll have to start pruning the cache
based on the last time a tile was used, but of course after the first reload
it
again will be in the cache.

Please give this a good workout and let me know how it works...

Steve K4HG

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