[amsat-bb] Re: ISS and APRS with a TT3+ ?

Robert Bruninga bruninga at usna.edu
Fri Jan 30 10:58:20 PST 2009

> Is there a way to set up my TT3+ to send APRS to the ISS ?

Generally, unattended one-way tracking devices are discouraged
from the packet satellites and the ISS to limit uncontrollable
QRM...  Live Operator operations, contacts, messages, and QSO's
are preferred.

There are of course, exceptions, for example, one year we
tracked a Ham driver of a vehicle delivering goods over Ice
rivers in Northern Canada above the arctic circle.  There was a
scientific expedition to Mongolia this year and we wanted to
send along a tiny tracker with WX station attached but could not
get it ready in time.  Then there was the student project of a
remote WX station on a ski-pole in Antarctica, and an Igloo WX
station by an experiment also in the arctic circle..

Then of course are the student experiments that might want to
demonstrate remote environmental data from a remote device (we
ran one for a week 2 years ago at the 5W level) to quantify the
link reliability (1 packet every 2 minutes).

In general, if you think your experiment is suitable, then we
recommend a routine long term packet period using 5W at about
one packet per 2 minutes.  This gives you about 3 good chances
at one packet per pass.  But also include in your packet, some
contact information.  Such as your email address.  Exceptions to
the email requirement could be:

1) if your callsign (on the device using a different SSID) is
also permanently maintaining a presence on APRS somewhere, they
you can be contacted that way, since any APRS message to that
callsign will be delivered to all of your other callsign
stations too.

2)if you maintain a forwarding email address @amsat.org (for
satellite operations or @arrl.net for terrestrial operations).

PATH: you should use is VIA ARISS, since when PCSAT-1 is
operational (there will be a period in Feb maybe) it also
supports that path, so you get 12 passes a day, not just 6.

Hope that helps.

For more info on APRS via ISS please see:

And read the User Service Agreement for packet operations via
PCSAT-1.  This applies to PCSAT, but could also apply to packet
operations via the ISS digipeater also on the same channel

We continue to encourage more AX.25 digipeater satellites on
145.825 to serve as a continuing worldwide CQ, Contact and Data
channel for remote operations.

Bob, Wb4APR

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