Subject: RE: [amsat-bb] The need for telemetry data -or what
Question: Are you proposing that all future satellites should send telemetry on the APRS frequency to make this system work?
Yes, no and maybe. The Global APRS network is there, the ground stations are there and listening, and it works. But even satellites that are not on the APRS satellite frequencies can be injected into the system as long as there are ground stations willing to tune their stations to the other satellites frequency for the duration of a pass. Once it is received, it does not matter what frquency it came in on, once it goes into the global APRS packet system, they all look the same.
I think the only limitation is that the telemetry must be an AX.25 packet...
Bob, WB4APR
Stefan
From: "Robert Bruninga" bruninga@usna.edu Reply-To: bruninga@usna.edu To: "'Stefan Wagener'" stefan_wagener@hotmail.com,
Subject: RE: [amsat-bb] The need for telemetry data -or what
happened to
FO-29- Date: Tue, 1 May 2007 11:03:55 -0400
...One key component of failure analysis is the availability of data, especially telemetry.
My question is, can the satellite user community at large come up with a system that allows the routine capturing of satellite telemetry? Is there a role that AMSAT can play? What would it take?
All of the APRS satellites (PCSAT-1, PCSAT2, ANDE and RAFT)
use
AX.25 and beacon their telemetry around the world. Any telemetry packets, heard by any station that is on the
internet,
feeds the packets live into the global APRS internet. Not
only
does this make it available to anyone at any time, but the
data
is also archived and is available in graphical form over any date period.
For example, Simple URL's can be constructed to access and
plot
any of the telemetry parameters. See this WEB page:
http://www.ew.usna.edu/~bruninga/andeTemps.html
And look at the source code. You will see that each plot is simply a URL constructed to access the correct period of data, and to select the range of values and the labels. This way, this
data
can be incorporated into any application. Thanks to the work
fof
K4HG, Steve Dimese and the FINDU system.
This is all hands-off, fully automated, and routine. Not
only
does it work for the satellites, but it can also plot all of this same data for ANY KPC-3+ TNC that is sending periodic telemetry packets anywhere in the world on any APRS
frequency.
For example, this simple URL will plot the telemetry for ANY KPC-3+ TNC on the air. This one is my local digipeater:
http://www.findu.com/cgi-bin/tele2.cgi?call=wb4apr-1&last=240
Just change the ULR callsign to your TNC's callsign (if it is tramnsmitting its 5 channel telemetry beacons on any APRS frequency) and you will see it show up here. This is a fantastic system for quick-and-dirty experiments, since the global collection and plotting is already done.
Bob, WB4APR