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"Ham Video” Transmitter is Now Aboard the ISS

08/23/2013

A Japanese cargo spacecraft has delivered an Amateur Radio on the International Space Station (ARISS) digital TV transmitter to the ISS. The equipment arrived August 9 and is being stored in the space station’s Columbus module. Gear includes the transmitter, power supply, NASA-provided Canon XF-305 camera, and antenna cables, reports ARISS-Europe Chair Gaston Bertels, ON4WF, who says the DATV transmitter is being dubbed “Ham Video.”

“Installation will be done by US astronaut Michael Hopkins, KF5LJG, who has been trained for the commissioning of the Amateur Radio digital video equipment,” Bertels said in a report posted on the ARISS-EU website. The gear will be commissioned this fall, possibly at the end of October, when there are favorable passes over Italy. “[T]he test transmissions for the commissioning of the onboard equipment will be received by the ground station of the Centro di Geodesia Spaziale of the Italian Space Agency” in Southern Italy,” Bertels explained.

Commissioning will involve a series of tests that will be performed over the course of three or four orbits. Bertels says it’s possible that the transmitter will send a continuous signal between commissioning steps, offering Amateur Radio ground stations a chance to test and tune their receiving equipment. “The transmissions will be performed in automatic mode, without requiring crew time,” Bertels said. “The camera, which runs on a battery, will not be used, and the ground stations will receive a black image.” The 10 W EIRP S-band (2.4 GHz) Ham Video transmitter will use one of the L/S-band “patch” antennas installed on the Columbus module.

A preliminary “Experiment Sequence Test” (EST) is planned for August 28-29 involving ARISS ground station IK1SLD in Northern Italy. “IK1SLD, an ARISS telebridge station often used for educational ARISS school contacts on VHF, has been upgraded for S-band reception,” Bertels pointed out.

Italian manufacturer, Kayser Italia has delivered a 1.2 meter dish, a down converter and precision tracking motors, all part of the ESA-funded equipment. “For the EST, the station will receive a DATV signal from a local, low-power S-band test transmitter,” said Bertels. The decoded signal will be streamed over the web to the British Amateur Television Club server, to which BATC has offered ARISS free access. ESA investigators will evaluate reception via the streaming video. “The test transmissions at IK1SLD will cover the different frequencies and symbol rates available on the Ham Video transmitter,” Bertels said.

Receiving the DATV signal will be the greater challenge, Bertels says. “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 said in an overview paper on the project. He says 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 in Europe.

Once the Ham Video transmitter becomes operational, it 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.

Amateur Radio gear has been deployed in several locations of the sprawling ISS, which includes several modules. Two multiband, multimode transceivers are located in the Russian Zvezda Service Module. Additional VHF and UHF transceivers are operational in the ESA Columbus module. Several operational modes are automated for use by ground stations. In addition to VHF and UHF FM voice, modes include packet and SSTV (downlink only). The ARISS stations offer Amateur Radio a permanent presence in space for the worldwide ham radio community. — Thanks to ARISS-EU Chair Gaston Bertels, ON4WF; ARISS-EU; Kayser Italia

 

 



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