ARISSat-1

One aspect of amateur radio that I've long been interested in, but hadn't pursued is amateur satellites. In early August, ARISSat-1 was deployed from the International Space Station. This satellite consists of a 145MHz FM downlink, a 435MHz/145MHz linear transponder, 145MHz CW beacons, and 145MHz BPSK-1000 telemetry. For more information on ARISSat-1, check out the website here. If you wish to attempt to receive it's signals, time is limited as the satellite's orbit is rapidly decaying and it's expected to re-enter the atmosphere in January or February 2012.

Around the time that ARISSat-1 was deployed, I purchased an Arrow 2m/70cm handheld satellite yagi to use with my FT-817ND for both terrestrial VHF/UHF operation and amateur satellites. The Arrow satellite antenna is a combination 7 element 70cm yagi and 3 element 2m yagi. More information on the antenna can be found at Arrow Antennas.

The Arrow Antenna, with only the 2m elements, attached mounted on a camera tripod.

On the evening of August 17th, I went out into the courtyard behind my apartment building to record a pass of ARISSat-1. I used the Arrow with my FT-817ND. The antenna was held in my hand as I tracked the pass across the sky and the radio was around my neck. I recorded the audio with my iPhone (using the mic on the included headphones - no direct connection).

The Arrow Antenna and FT-817ND

In order to track the satellite, I used the excellent iPad/iPhone app HamSat.

HamSat HD on the iPad

For this pass, I would start pointing the antenna towards the northwest and move east through the pass.

Map View of HamSat HD on the iPad tracking ARISSat-1

Shortly after 8pm on August 17th, I acquired the FM downlink signal and was able to receive the audio for about 7 minutes before the satellite was out of range. Below is the audio recorded from the pass.

ARISSat-1 Pass 8/17/11 by stoetze4

At Acquisition of Signal (AoS), the satellite was transmitting an SSTV image from one of it's onboard cameras. Following the completion of this transmission, the satellite transmitted it's identification and greeting messages followed by satellite status and more greeting messages. An SSTV image follows that, then another identification, more greetings, satellite status, another SSTV image, and so on until Loss of Signal (LoS).

I decoded the SSTV images simply by holding a microphone up to my computer speaker and using the iPad app SSTV. The following two images were decoded, both taken by the satellite's onboard cameras:

First image

 

 

Second image

This was my first attempt at receiving transmissions from an amateur satellite. I hope to continue to dabble in amateur satellites in the future. As mentioned before, ARISSat-1's orbit is rapidly decaying and it won't be with us for much longer. Act now if you wish to attempt to receive the satellite's signals.