Telemetry Data Processing.

 

The 4 Seismic field stations beam in their FM telemetry in real-time. These stations being Woodbank (WBK), Neenton (NTN),Spaceguard (SPG) and Bryn Du (SBD) as previousley stated the telemetry is a 676Hz audio tone which deviates by as much as + /- 40% depending upon movement of the seismic sensor. The telemetry is received at the local station Neenton (NTN) via UHF radio of which the audio output is sent to the FM Demodulator whos purpose is to decode the tone into a voltage, zero volts represent 676Hz and this varies by + /- 5 volts depending on the input tone. This voltage is then processed by a 16 bit digitiser and the serial output fed to a PC whos clock is governed by GPS. The Earthworm software is made up of configurable modules as depicted in the diagram.