[aprssig] Balloon Tracking Question

[David Dobbins]

Hi Ted, info the group.

I would recommend you contact Ron K6RPT who has been doing some recent
balloon launches near San Jose, shooting for record altitude payloads. While
several recent flights have been less than successful, he knows his stuff
and will be a good source of info for your group. One tracker he has been
using is the Beeline, which has GPS, TNC, and TX all built into one nice
little package and associated li-poly battery. I'm using the same
configuration. It's light weight and compact. I have an external BNC on the
capsule and use one of several 19" whips with similar BNC and seems to work
just fine.

In regards to tracking, I would recommend, in addition to your VX8 solution,
someone running one of the APRS clients in mobile environment and equipped
with maps for visual representation. The VX8, or a TH-D72, will serve you
best as you get closer to the package for recovery, and walk right up to it.

Here are some links:
Beeline tracker:
http://www.bigredbee.com/beelinegps.htm

One of my flight summaries. It highlights use of mobile APRS client UI-View.
Having this available helps to determine the LZ after plotting the LAUNCH
and BURST objects manually. The LZ will likely be along the same bearing
from a line drawn from LAUNCH through BURST. Distance can vary based on
package weight and parachute size but generally is about 1/2 the flight
distance between the first two points. Knowing the LZ, it's possible to to
drive to the area and watch the descent. I did one a couple years ago near
Boise where we were 50 yards from the actual LZ and missed "capturing" the
payload in the back of truck because of a lousy irrigation canal that forced
a slight detour.
http://nwaprs.info/balloontracking.htm

I strongly recommend a backup; cellular or another APRS tracker.

Here's another flight summary:
http://nwaprs.info/balloons.htm

While I'm on the subject of ballooning, my group in Spokane is planning an
April 16 launch from Ritzville WA. We'll be using a 2kg balloon and capsule
with a pair of trackers and cameras. We'll post more info on our (UC)
website http://nearspace.us as time permits.

At a recent meeting, the suggestion came up how cool it would be to promote
a high altitude balloon launch day this summer. We've set our date for a
Saturday in July (it's not on my digital calendar.... I think July 9th or
16th. A group in Utah will coordinate with us, and if others would like to
continue this we'll get something on the Yahoo balloon groups page as well.

Best wishes on your project.

Dave K7GPS

Message: 1
Date: Fri, 25 Feb 2011 11:44:15 -0800
From: "Ted11" <tedlists at hullar.com>
Subject: [aprssig] Balloon tracking questions
To: "'TAPR APRS Mailing List'" <aprssig at tapr.org>
Message-ID: <024c01cbd524$62f0d380$28d27a80$@hullar.com>
Content-Type: text/plain;       charset="us-ascii"

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
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