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Peter's Challenge

Peter's data analysis challenge has brought to focus in my mind the fact
that we, the satellite user community, are overly reliant on the limited
resources of the command team for information.  Their primary focus must
always remain on maintaining the health of AO-40.  Following an unexpected
event, especially one involving orbit changes, the first two priorities are
power budget and orbit determination.  With the NORAD element sets off by
over 65 minutes at perigee earlier in the week, it was imperative that the
correct orbit be determined as quickly as possible.  I can only imagine the
wailing and finger pointing that would have occurred if the satellite had
been "lost" because the command team was spending their time on ATOS data

I think we have the capability to develop additional data analysis capacity
outside the command team.  I envision a group where different people are
analyzing specific parts of the telemetry data that interest them.  For
example, one person might want to analyze attitude data and provide more
frequent or predicted alon/alat tables.  Others may have an interest in
power, thermal, or RF systems behavior.  This "data analysis group"  would
be available to provide more information and explanations of how the
satellite's systems are operating without placing additional demands on the
command team. There are other benefits as well.  With more people looking at
the data, trends and unusual events are more likely to be noticed.  This
information could then be fed back to the command team for their
consideration and planning.  Finally, as we expand the pool of people with
data analysis experience we are also developing needed skills that will be
required of future command stations.

Several things will be needed to make this work in addition to the people
willing to do the analysis:

1.  Archive of all available telemetry
2.  Detailed manual of AO-40 systems
3.  Commands planned for uplinking to AO-40
4.  Actual commands loaded on AO-40

The first item is already available due to the fine efforts of Paul Willmott
and the ground stations who regularly contribute their telemetry files to
the archive.

The second item I suspect exists but is not readily available.  While a lot
of information is scattered about on the web, most of it is too generalized
for use in data analysis.  Full schematics, drawings, pictures, and
functional descriptions are needed to really be able to understand what the
data is telling you.  Obviously a few things would need editing out of a
publicly released "engineering notebook" of AO-40 systems.  Command uplink
freqs and the master reset sequence are two that immediately come to mind.

The third and fourth items are also essential to any attempt at data
analysis.  Particularly when analyzing unexpected events.  I suspect the
information already exists in the form of communications between the command
stations.  Since the goal of this entire effort is to reduce the workload on
the command stations, providing this information must be done in a way that
doesn't put additional burdens on them.  If, as I suspect, the command team
emails proposed uplinks and confirmations internally, perhaps they could
also be emailed to a mailing list.  Ideally the list would be available for
subscription by anyone but only the command stations would be allowed to
post messages.  For example, the only public information regarding the final
ATOS gassing schedule that I've been able to find is below.

"Since everything went so well, the computer onboard AO-40 was commanded to
initiate 2h "burns" starting around apogee on orbit 297 for the next three

The first 2-hour burn stopped at Orbit 297 MA 142, which is 2001 Jun 23 0154
utc. Again, all telemetry is looking good and we may soon expand to 4h
"burns" and possibly increase the thrust level as well."

"Since orbit #302 the ammonia stopped flowing and the pressure indicators in
the telemetry show no more pressure in the motor and in the ammonia tanks,
while the perigee is much higher than anticipated."

The missing piece is what ATOS was commanded to do after the second and
third 2h burns.  Without that it is hard to determine from the telemetry the
difference between the expected and unexpected results.

I hope everyone will consider and add to my suggestion in the constructive
spirit in which it is offered.  My intent is not to be critical of anyone or
any group.  My hope is that a team and process can evolve which is
beneficial to everyone.


----- Original Message -----
From: "Peter Guelzow" <peter.guelzow@arcormail.de>
To: "Amsat-Bb" <amsat-bb@AMSAT.Org>
Sent: Saturday, July 07, 2001 16:27 PM
Subject: Re: [amsat-bb] IHU-2 Telemetry availability?

> > When the S2 beacon was turned off during the arcject burns, the IHU-2
> > collecting telemetry to be downloaded by the command team.  Will this,
or is
> > this telemetry available in the archives?
> Yes, all the telemetry which is available to the command team
> is also available for everyone in the archive.
> Hmm.. does anybody know another satellite were this is the case?
> I suggest some on this board reconstruct exactly what happened
> and tells us the real thing within the next 24 hours...
> 73s Peter DB2OS
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org

Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
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