[aprssig] Balloon tracking questions

[Ted11]

Hi everyone, 

I've gotten involved with a high-altitude balloon project, and could use
some advice.  An undergraduate atmospheric science group from my university
(UC Davis, in Davis, California) had its first launch last April.  The
tracking and recovery effort, although successful, was a little touch and
go, and ultimately relied on GPS data provided by the meteorological
instrument package.  The primary cell-phone based tracking method failed.  

So, this time around, I've offered to implement a better tracking strategy.
I'm planning to use an APRS based tracker setup.  I'm familiar with the
Byonics and Argent tracker/radio/GPS offerings, and understand the need for
a high-altitude GPS.  What I'm a little less familiar with are best
practices for power supplies and antennas.  I did a few searches (including
the APRSSIG archive, but didn't come up with a lot of good information, so I
thought I'd ask the group.  

Questions:

1.  Is there a dedicated balloon tracking list I should be sending my
questions to?

2.  Any recommendations for GPS, radio, and tracker combinations?  Any
particular combinations that do not work well together?

3.  What is the best approach for power?  I'm concerned about the extreme
low temperatures, especially in light of some of the recent failures I've
read about.

4.  What do you recommend for antennas, both on the balloon and on the
ground?  I've got a VX-8DR I will be attaching to a roof mount antenna on
the tracking vehicle, but wonder if there is a better approach to match
balloon and receiver antennas. 

Thanks for the help. 

Ted
KE6ROS