Decoding the STRaND-1 amateur radio telemetry beacon

STRaND-1 PSLV-C20 Launch - Image credit ISRO

STRaND-1 PSLV-C20 Launch – Image credit ISRO

STRaND-1 carries an amateur radio AX.25 packet radio downlink on 437.568 MHz using 9600 bps FSK modulated data with HDLC frame, NRZI encoding.

Dr Chris Bridges would be delighted to receive all available telemetry files by email to

Excel Spreadsheet of STRaND-1 Telemetry Format_20130327

On the AMSAT Bulletin Board Mark Hammond N8MH has provided these tips to decode STRaND-1:

(1) Sprint-2 TNC set at 9600 baud in KISS mode (or any 9600 in KISS mode probably)

(2) Using this software to capture:

(3) And using this software to decode the captured KISS files:

Thanks to Mike Rupprecht DK3WN for the excellent software.

Jan PE0SAT describes how he used the free TNC emulator software AGWPE and SDR# to decode the telemetry. This approach means you don’t have to buy a dedicated hardware TNC it simply uses your existing PC and radio that supports 9600 bps data:

(1) Record a pass using SDR# and a FUNcube Dongle Pro+ and save the IQ wav file so you can work with it after the pass.
(2) Configure AGW Packet Engine (AGWPE) as a 9600 baud modem using your audio mixer as input. If you don’t have an audio mixer, use audio VAC to route the received audio to the AGW audio input.
(3) When the AGW packet engine is running use AGW-Online-KISS from DK3WN to connect to the packet engine and decode the telemetry.
(4) Open the IQ wav file within SDR# and playback the recorded file and tune to the correct receive frequency, now you can see decoded data within Online-Kiss.
(5) Feed the files captured to KISS-Dump

STRaND-1 Ground Station Antennas

STRaND-1 Ground Station Antennas

Descriptions of ONLINE KISS +, AGW ONLINE KISS and KISS Dump + are at

The free AGWPE soundcard packet software is available at

Guide on how to use AGWPE

Tracking Information

Free satellite tracking software:
• SimpleSat Look Down
• Gpredict
• Orbitron

Keplerian Two Line Elements (TLE’s) ‘Keps’