Ham Video - EST and Simulations

HamTV Bulletin 2 - September 10, 2013

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.

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