ARLA/CLUSTER: Video Radioamadoristico - Testes e simulações na ISS

[João Costa > CT1FBF]

Ham Video - EST and Simulations

Ham Video Commissioning preparation is progressing.

An EST (Experiment Sequence Test) has been performed 28-29 August and
Simulations tests were done 5-6 September 2013.

The EST consisted of a series of tests, mainly of the ground segment.

For the Commissioning, the VLBI (Very Long Baseline Interferometry)
station of the Italian Space Agency (ASI), located near Matera,
southern Italy, will be used for receiving the DATV signals from the
ISS.

For the EST, the IK1SLD ground station, situated at Casale Monferrato,
northern Italy was used. IK1SLD is one of the ARISS telebridge
stations, fully equiped for VHF and UHF. It was recently upgraded for
S-band with a 1.2m dish, feed, downconverter and precision tracking
motors.

For the EST, a very low power transmitter, installed in the shack,
generated signals on the Ham Video frequencies, transmitting a DATV
recording at 1.3 and 2.0 MS/s and FEC ½. The DATV signal was received
and decoded by the IK1SLD station and webstreamed to the BATC server.

B.USOC (Belgian User Support and Operations Center – ESA) conducted
operations. B.USOC and EAC (European Astronaut Center – Cologne,
Germany) specialists operated from Livorno at Kayser Itallia's
laboratory, where a Ham Video unit, the so-called EBB (Elegant
BreadBox), is operational. Parties involved were interconnected per
teleconference.
At Casale Monferrato, Claudio Ariotti IK1SLD and Piero Tognolatti
I0KPT produced, received and webstreamed the signals in the different
configurations as requested by B.USOC. ESA and ARISS observers
participated to the EST teleconference. After debriefing, the EST was
declared successful.

Simulations were done differently. B.USOC supervised from their
offices in Brussels and ARISS responsibles Piero Tognolatti I0KPT and
Jean Pierre Courjaud F6DZP operated from home. The simulations were
done in the Columbus mockup at EAC, where a non operational Ham Video
model is installed. This box is used for astronaut training on Ham
Video.

A KuPS power supply was also used, as well as a camera similar to the
one onboard Columbus in space. Ham Video transmissions were simulated
in the different configurations (frequencies and symbol rates). A view
of operations in the Columbus mockup was webstreamed to the
participants. ARISS operators simulated reception as if thery were at
the Matera ground station, taking into account expected timing between
AOS and LOS. They signaled AOS and requested “crew“ at EAC to transmit
in different configurations, according a pre-determined scenario. At
LOS, the test stopped and results were commented.

Four “passes” were simulated this way, using both ARISS antennas. An
important goal of the simulations was to check the efficiency of
communications between ground and “crew”. Commands were initiated by
ARISS operators (supposedly from Matera), received at B.USOC, relayed
to the Columbus Control Center at Oberpfaffenhofen near Munich and
uplinked to “crew” by EUROCOM. The European ISS Control Center is
called Col-CC and its spacecraft communicator's call sign is EUROCOM.
The Simulations were conducted successfully and lessons were learned
for gaining time on transmitting commands. This is important
considering the limited 8 minutes contact time during real
Commissioning.

ARISS proposed to use our VHF uplink capabilities to “crew” for the
Commissioning. This was not acceptable with regard to ESA's
commissioning protocol.

Presently, ISS pass predictions for Matera are computed for several
weeks starting mid October, The Matera VLBI activities are to be taken
into account for determining usable passes. Four passes will be needed
to fullfil the Commissioning requirements.

Ham Video Commissioning activities will be decided by ESA and NASA ISS
Operations. Hopefully the Commissioning will be planned during
Expedition 37. We will keep you informed.

73,

Gaston Bertels – ON4WF
ARISS-Europe chairman

P.S: Ham TV Bulletins are available at www.ariss-eu.org