[Xastir] Trail refresh speed for fast movers

[Darren Long]

Hi all,

I've been pottering with gnuradio and gr-air-modes for ADS-B decoding
with my USRP and got fed up with running Google Earth for viewing
aircraft tracks, so I've bodged together a feed into Xastir.  It is
working quite nicely.

There are some pics here:
http://g0hww.blogspot.co.uk/2012/06/very-dirty-hack-to-feed-ads-b-data-from.html

I've noticed that when I'm receiving new positions for a fast moving
aircraft, Xastir shows a dense sequence of position icons for quite a
while before condensing them into an extension of the trail, although if
I nudge the map view a bit, then the trail extends immediately and the
historic position icons go away, leaving only the latest as expected. 

My bodged feed does produce dupes of reports, as it dumps  all aircraft
that are in the  database which were seen in the last 10 seconds, every
5 secs into Xastir, but I guess Xastir dedupes inbound traffic anyway,
so it seems to be a drawing matter rather than a position update issue.

Are there any tweaks that I can make to speed this up?  I don't mind
taking a higher CPU hit from Xastir, as it is way less resource hungry
than Google Earth.

I'm using fairly recent Xastir source from cvs.

Cheers,

Darren, G0HWW