HAM TV is a project that allows in the international program ARISS of make broadcasts audio / video from the International Space Station (ISS) on amateur radio bands for contacts with schools, with the aim of sharing the experiences of the astronauts during their stay in Space. An ambitious project started in 2009 and developed over the years to follow up the implementation of a group of volunteer amateur radio operators of AMSAT Italia in collaboration with the European Space Agency (ESA), which it approved, supported and financed the experiment entrusted to the company Kayser Italy in Livorno the realization of the transmitting station of the Columbus module aboard the International Space Station (ISS) and with the participation of a group of companies, including the ARCol WG (Amateur Radio on Columbus Working Group). Precious collaboration of Italian astronaut Paolo Nespoli, IZ0PA, who heard of the project HAM TV, we has enthusiastically supported AMSAT Italia in ESA, as we have seen engaged in educational activities of “contact school “when he was on the ISS in 2010 and 2011. In the pre-launch phase, the transmitter “payload”, after being subjected to rigorous ESA test applied to take a trip to the space with a carrier-cargo and for commissioning in service onboard of the ISS, it was launched 3 August 2013 with the Japanese HTV-4 cargo vessel, successfully reaching the International Space Station (ISS). At that time the astronaut Luca Parmitano was on board the ISS, who transferred the transmitter from the Japanese cargo at the Columbus module. The first transmissions of HAM TV were made in 2014 from the base station in Earth orbit with the ASI (Italian Space Agency) at the Centro of Geodesia Spaziale (CGS) in Matera (Italy), the grouns station is equipped with a great satellite dish. On 8 March at 13:29 UTC of the same year, it was transmitted from space the first DVB-S tramsmission in the amateur band, great emotion and satisfaction among the control room operators, when acquired the signal successfully of HAM TV, sent to Earth by the Columbus module of the International Space Station, decoding systems began to play on the monitor images and audio from the NASA astronaut Michael S. Hopkins, KF5LJG on the ISS, the signal is received successfully, also by the station IK1SLD of Casale Monferrato and of the station at Kayser Italy in Livorno , both configured in the experiment and include a system of small satellite dishes, in turn, they sent the video transmitted from the ISS streaming TV on the website BATC.TV. To allow processing of the video signal received at Earth stations in their configuration utilized Laptop computers and dedicated programs. In April of that year, at 18:23 UTC, the final test of the experiment was performed in which participated four stations: G4KLB, F6DZP, IK1SLD and that of Kayser Italia, the Japanese astronaut Wakata Koiki, KC5ZTA Commander of the ISS, he completed the HAM TV experiment of simulating the same procedures for contact schools of ARISS program, of which the result was more than satisfactory. The transmitter, for the purposes for which it was designed and built, operates on the frequency 2,422 GHz and 2.437 GHz in Downlink (the data transfer from the station in orbit to Earth station) and on the Contigency frequency of 2.369 GHz and 2.395 GHz, the DVB-S (Digital Video Broadcasting-Satellite) transmits the signal video with camera turned off, without tables PMT (Program Map Table), without content “blank transmission” where the received signal is used for technical tests, to optimize the configuration of ground stations, it provides significant data that allow power measurement signal – analog signal / noise – digital signal / noise – error / correction report – validation of the transport stream received. Also, the transmitter operates at a speed of 1.3 Ms/s or 2.0 Ms/s, with the possibility of forward error correction of a digital broadcast through the FEC (Forward Error Correction) of ½, value that indicates how many of the transmitted bits are used to correct any errors in reception. The flow of video data of a single channel digital (video PID) has a value of 256 and for the flow of the audio data of a single channel digital (Audio PID) has a value of 257. The ARISS antennas 41 and 43 installed in the Columbus module, have an approximate RF output power of 10 watts, finally, the video camera provided by NASA is a Canon XF-305. The project HAM TV is a great leap forward in terms of technology for space communications for amateur radio, an excellent result obtained by an all-Italian team, which has experience in the field of technical-scientific and operational planning, matured in the field Telecommunications, Space and Technology. The Association AMSAT Italy for many years been involved in amateur via Satellite, in radio contact on the whole national territory under the ARISS educational program with schools and the International Space Station, the transmission permitted in voice mode in the band VHF, but with the commissioning of the transmitter DATV (Digital Amateur Television) called “Ham Video”, installed in the Columbus module of the ISS, is possible to transmit from the Space, in addition on the voice, also the video of the astronauts and the environment where they live and work. The HAM TV system is capable of transmitting other pre-recorded video up to 24 hours a day to allow ground stations tuning. Today, the amateur radio stations are able to receive the live images transmitted from Space to Earth, using a parable commercial, a “converter” to convert the amateur band of 2.4 GHz on which it transmits and pass on a commercial decoder to see the images on monitor. Thanks to AMSAT Italy is born the Amateur Live TV from the International Space Station.
Source: AMSAT Italia
Photo Credit: AMSAT Italia