January or February ISS Digital “Ham Video” Commissioning Possible
The digital Amateur Radio TV (DATV) “Ham Video” project delivered to the International Space Station last summer could be up and running in a month or two. Amateur Radio on the International Space Station-Europe (ARISS-Europe) Chairman Gaston Bertels, ON4WF, said in a late-December project update that the January-February 2014 time frame “seems a reasonable guess for the Ham Video commissioning.” Initial plans called for commissioning the 2.4 GHz Ham Video system last October, but Bertels said ISS flight rules regarding ARISS activities, which already cover VHF and UHF, needed to be updated for S band.
“Writing flight rules and having them verified, accepted and signed by all parties involved is a process that takes time,” he said. “ARISS matters have low priority among the countless activities [aboard] the International Space Station. Unforeseen events, such as the recent failing of a cooling system, evidently caused further delay.” US Astronaut Mike Hopkins, KF5LJG, is scheduled to handle the tasks involved with getting the S Band Ham Video DATV setup on the air from the Columbus Laboratory, where it has been in storage.
Last September, the European Space Agency (ESA) and ARISS conducted experimental testing and simulations. Bertels says commissioning the Ham Video transmitter involves configurations using two antennas, four frequencies, and two symbol rates.
Signals transmitted during commissioning will be received by the Matera ground station in southern Italy. During the commissioning period, the Ham Video transmitter will transmit continuously for several days or even weeks, Bertels said.
“This will allow ground stations to test their equipment and to provide useful information concerning the efficiency of the transmitter.” The commissioning transmissions will be carried out with the Ham TV camera turned off, but Bertels said the “blank” transmissions will provide the necessary digital video broadcasting — satellite (DVB-S) protocol signal.
Receiving the DATV signal will be a greater challenge, Bertels has said, adding that DATV decoding should be possible for a ground station equipped with a 1.2 meter dish, when the ISS is within a range of about 800 to 1000 kilometers.” This would limit the DATV reception window to about 3 or 4 minutes during a favorable pass. Once operational, the Ham Video transmitter will be used for ARISS educational contacts with schools in Europe. There are no immediate plans to deploy downlink video for ARISS contacts with US schools, in part because no North American ground stations have been planned.
ARISS-EU says a “simple station” might consist of a helix-fed parabola dish, a low-noise downconverter (such as a High Sierra Microwave Model 2400 or Kuhne Electronic KU LNC 23 TM, or AliExpress HD LNBF), a DVB-S receiver on a computer card (such as the Techno Trend S2-1600), and the free Tutioune software developed by Jean Pierre Courjaud, F6DZP.
With this setup, Ham Video from the ISS can be received, decoded and viewed on a computer display. The Tutioune software graphically displays received signal characteristics and can save data to a file for forwarding to ARISS for analysis. — ARISS-Europe Chair Gaston Bertels, ON4WF