[Xastir] Xastir Map Chooser and wget

[Tom Russo]

On Sat, Nov 28, 2009 at 10:47:45AM -0800, we recorded a bogon-computron collision of the <ki6tyv at arrl.net> flavor, containing:
> 
> Strangely, the station placements are inaccurate on the terraserver maps --
> off by about 10 km, and placing my home station, among others, in San
> Francisco Bay! 

Is your screen and Xastir window very large, by any chance?

The .geo code in xastir is not very robust actually.  It assumes that when it
asks a server for a map of a certain area that it gets it, and then stretches
the image it gets on the assumption that it's gotten exactly what it asks.

Turns out that terraserver will serve up a truncated image if you ask for one
that covers too many pixels.  This map will cover a much smaller area than your
xastir window, but will be stretched to cover the window by xastir, which 
has no idea that it got something other than what it asked for.  Stations 
plotted over this incorrectly-stretched map will look like they're in the 
wrong place, but it's the *map* that's wrong.

I found this out on a machine with a 1600 pixel wide monitor when trying to
use Xastir stretched out to the whole width of the screen.  I found that 
limiting my Xastir window to 1200 pixels made sure that terraserver never 
returned partial maps.  I didn't experiment with very many widths between 1200
and 1600 to find the sweet spot of maximum width and no truncated images.

If your window is smaller than 1200 pixels, then of course this is probably
not your issue.
-- 
Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236        http://kevan.org/brain.cgi?DDTNM
  In some cultures what I do would be considered normal. 
                                  -- Ineffective daily affirmation