Phil Karn KA9Q to give ISEE-3 presentation at Guildford

Phil Karn KA9Q

Phil Karn KA9Q

AMSAT-UK is pleased to announce that Phil Karn KA9Q will be traveling from California to attend this year’s International Space Colloquium which takes place at the Holiday Inn, Guildford on July 24-26.

He is well known in the amateur radio community for his work on the KA9Q Network Operating System (NOS), named after his amateur callsign, early 9600 bit/s FSK radio modems, and more recently, the introduction of forward error correction (FEC) into the Amateur Satellite Service, with FEC applied to the 400 bit/s PSK telemetry from the now-defunct AO-40 satellite.

Phil has been an active contributor in the IETF, especially in security, but is also a strong contributor to the Internet architecture. His name is on at least 6 RFCs. He is the inventor of Karn’s Algorithm, a method for calculating the round trip time for IP packet retransmission.

Phil will be giving a presentation to the Colloquium at 1:30 pm BST (1230 GMT) Sunday, July 26 titled “Data Recovery as part of the ISEE-3 Reboot Project”.

ISEE-3 - ICE Spacecraft - Image credit NASA

ISEE-3 – ICE Spacecraft – Image credit NASA

Phil has provided this summary of his presentation:

Last year I participated in the ISEE-3 Reboot Project led by Dennis Wingo KD4ETA of Skycorp by writing software to decode the spacecraft telemetry.

This included what I believes to be the largest Viterbi decoder ever used operationally, a k=24 monster that ran at the blazing speed of 225 bits per second. It was used successfully on the received signals at Arecibo (although the rock-crushing SNR wasn’t much of a challenge) and at the 20-meter AMSAT-DL dish in Bochum, Germany, where it actually got a workout.

Although the project was ultimately unsuccessful in recapturing ISEE-3 into earth orbit, I thoroughly enjoyed my participation in the project. I’d gladly do it again.

The International Space Colloquium is open to all. Admittance is £10 each day and car parking is free. Further details and the programme schedule are at