Solving the TLE lottery

TLEsWhen amateur radio satellites are initially deployed Two Line Elements (TLE) Keplerian orbital data sets for tracking the satellites are released by NORAD. Unfortunately they are only given object identifiers of A, B, C, D etc not satellite names. Some of the debris from the launch and deployment may also be given alphabetic identifiers. The problem is working out which of the 10 or more objects is the satellite you want to listen to.

Mike DK3WN has developed a simple solution to this perennial problem by using an SDR-IQ receiver and a bit of software.

In the case of Masat-1 he chose a high elevation pass (89 deg) where the doppler shift should be significant and recorded the complete pass with his SDR-IQ without doppler correction. With some software he simulated the entire pass with different TLE’s.

He then chose the TLE that best matched the doppler shift of the audio signal.

Read Mike’s full article with pictures on his website at

Student Satellite Launch To Be Broadcast Live

Artists impression of Vega launch

Artists impression of Vega launch

The launch of eight student amateur radio satellites from the space center at Kourou in the Caribbean will be broadcast live on the Internet.

The launch should take place between 1000-1300 UT on Monday, February 13 and you’ll be able to watch it at

The student teams have requested reception reports. During the Launch and Early Operations Phase (LEOP) Monday, listeners are encouraged to gather at the IRC “cubesat” channel to exchange all the latest available information. Simply point your browser to and join the #cubesat channel. In the Nickname: field enter “name_callsign” and in the Channels: field enter #cubesat

Preliminary Vega TLE’s for launch at 1000, 1100 or 1200 UT here

Assuming a 1000 UT launch the satellites should deploy their antennas and start transmitting at about 1140 UT. It looks like the first to get reception will be Central America followed quickly by a pass up the East coast of North America. The first pass for the United Kingdom should be a horizon skimmer across the NW at around 1207 UT.

Student amateur radio satellite downlink frequencies:
+ AlmaSat-1   437.465 MHz 1200 bps FSK, 2407.850 MHz
+ E-St@r        437.445 MHz 1200 bps AFSK
+ Goliat          437.485 MHz 1200 bpx AFSK
+ Masat-1      437.345 MHz 625/1250 bps GFSK, CW
+ PW-Sat       145.900 MHz 1200 bps BPSK AX25, CW
+ Robusta      437.325 MHz 1200 bps FM telemetry – one data burst of 20 secs every 1 min
+ UniCubeSat 437.305 MHz 9600 bps FSK
+ XaTcobeo     437.365 MHz FFSK with AX.25

Masat-1 telemetry decode software

URLs for the student satellite websites are at

Vega Elliptical Orbit Video

Satscape Free Satellite Tracking Software 

N2YO Real Time Satellite Tracking