It’s time to get ready for ARISSat-1
A few weeks remain before the planned July deployment of ARISSat-1 from the ISS.
 ARISSat-1 Here are some reminders to help you get your station ready for ARISSat-1 operation.
145.950 MHz FM Downlink:
FM transmissions will cycle between a voice ID as RS01S, select telemetry values, 24 international greeting messages in 15 languages and SSTV images. One of the messages will be a conversation between Yuri Gagarin and ground control. See the next news item for pointers to get your station ready to receive the SSTV images.
435 MHz – 145 MHz Linear Transponder:
The linear transponder will operate in Mode U/V (70 cm Up, 2m Down).
It is an 16 KHz wide inverting passband and the convention will be to TX LSB on the 435 MHz uplink and RX USB on the 145 MHz downlink. This mode is designed to work with low power transmitters and omni antenna.
145.919 MHz/145.939 MHz CW Beacon:
The CW transmissions will be callsign ID RS01S, select telemetry, and callsigns of people actively involved with the ARISS program.
145.920 MHz SSB BPSK-1000 Telemetry:
The BPSK transmissions will feature a new 1kBPSK protocol developed by Phil Karn, KA9Q to be readable in low signal level conditions. The BPSK data will transmit satellite telemetry.
The ARISSat-1 BPSK-1000 downlink is transmitted in SSB mode on 145.920 MHz. When the CW2 beacon on 145.919 MHz is active this indicates that the BPSK-1000 format is being transmitted. If the CW1 beacon on 145.939 MHz is active this indicates the backup of BPSK-400 format is being transmitted.
Transmitting at 100 mW, both BPSK rates include Forward Error Correction (FEC) and it is expected that modest quarter-wave antennas with low-loss coaxial cable will provide sufficient signal strength for decoding and display by the ARISSatTLM software.
An audio feed from an SSB receiver to the computer’s soundcard input is needed. An initial “Receive Only” configuration is easily done consisting of an audio patch cable between your radio and the soundcard. Take the speaker or headphone output from the radio and run it into the line (or mic) input on your PC sound card.
BPSK-1000 sounds like a “shusssch” with a higher pitch than the 400 bps growl. It is difficult to tune by ear. The CW2 beacon is used as a tuning signal for BPSK-1000. The PC and Mac ARISSatTLM software display contains a dotted line that you use to tune your receiver until the CW signal bumps lines up with the dotted line on your PC screen. This will allow you to decode the BPSK-1000 signal and you will also be able to copy the CW2 beacon.
Download the Windows ARISSatTLM free ground station soundcard demodulator and display software:
http://www.arissattlm.org/download/
ARISSatTLM_050_Setup.exe
Download the Mac ARISSatTLM software:
http://www.arissattlm.org/download/ARISSATTLM.zip
The ARISSatTLM software user guide is available:
http://tinyurl.com/42uhtyf (amsat.org)
Get your color ARISSat-1 Frequency Guide:
http://tinyurl.com/4t497t2 (amsat.org)
ARISSat-1 Presentation Slides (~1MB)
http://tinyurl.com/4n4pzkm (amsat.org)
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