HamTV Project to Open “A New Era” for ARISS
The Amateur Radio on the International Space Station (ARISS) program hopes that an Amateur Radio digital TV system will be up and running aboard the International Space Station by later this year. A project initiated by AMSAT-Italy, HamTV would provide one-way video and audio from the ISS to complement the FM radio voice link used for ARISS school group radio contacts. According to an overview paper drafted by ARISS-Europe Chairman Gaston Bertels, ON4WF, a DATV downlink on S-Band (2.4 GHz) is under development to place aboard the ISS Columbus module in August. Columbus already sports the necessary antenna. As a debate between the merits of analog versus digital TV aboard the ISS continued, Bertels says, the digital system got a big boost from Italian astronaut Paolo Nespoli, IZØPA, who had conducted ARISS school contacts in 2010 and 2011, when he was aboard the ISS.
“At the initiative of AMSAT Italy, an Italian manufacturer, Kayser Italia, presented a project for an Amateur Radio DATV transmitter to ESA’s [European Space Agency] educational services,” Bertels explains in his paper. ESA accepted the proposal in 2012 and contracted with Kayser Italia to develop and manufacture a 10 W EIRP “Ham Video” DATV transmitter for S-Band.
NASA will provide a Canon XF-305 camera for the system. The equipment is slated to deploy to the ISS on a Japan Space Agency resupply vehicle. Receiving the DATV signal will be the greater challenge, Bertels says.
“Receiving DATV signals from Columbus will be far more demanding than receiving VHF or UHF,” he notes in his overview paper. “A careful study of the link budget, conducted by Piero Tognolatti, IØKPT, shows 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 km.” He points out that this would limit the DATV reception window to about 3 or 4 minutes during a favorable pass. “ISS tracking will be far more demanding than it is for receiving VHF signals,” he added.
According to Bertels, Kayser Italia is to provide five ground stations for siting in Europe. These will be “chained” to provide overlapping video reception. The British Amateur Television Club (BATC) will provide a central server site to receive ground-station video and make it available via the Internet. “It is hoped that amateurs will support other ground station ‘chains’ in other countries, as multiple stations are needed to provide up to 15 minutes of video in support of school contacts,” Bertels explains in his paper. He says ARISS anticipates that similar chains of ground stations will be set up on other continents, to expand the system’s flexibility. “Ham Video transmissions will not be limited to school contacts,” Bertels says, but could include automated transmission of recorded video.
“A new era opens for Amateur Radio on the International Space Station,” Bertels concludes. — Thanks to AMSAT News Service; Kayser Italia