Radio communications

GOLIAT uses two independently controlled  transceivers for data communications with the ground stations in the 70 cm radio amateur band anOBC, S-band transceiver and radio beacond in the 2.4 GHz ISM band.

  1. The Beacon is an UHF transceiver continuously transmitting telemetry data. It was built around a commercial low power radio amateur portable transceiver. The modulation is performed by an FX614 modem for transmitting 1200 bps AFSK packets. An AX.25 protocol was implemented on the microprocessor that controls this subsystem. The telemetry data is sent as morse code at a speed of approximately 20 wpm by keying on and off the modulation tones. This two transmission modes can be received with typical radio amateur equipment.
  2. The S-band transceiver is a commercial off the shelf product with previous flight experience on board CubeSat class satellites. It has a speed of up to 115.2 kbps and it was designed to operate just when in direct line of sight of Romanian ground stations. The high speed data link is meant to be used mainly for transmitting the images and data from the on board experiments and for uploading commands to the satellite.


Time since launch: