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Telemetry architecture, rates and on-board storage capacity

For both the GIS and the SIS, the telemetry will be organized in superframes of 64 frames of 128 8-bit words, although the words will be different for the two instruments.

Three bit rates will be used: high (32768 bps), medium (4096 bps) and low (1024 bps). The corresponding time resolution for these rates depends on the instrument (GIS or SIS) and on the observing mode. It ranges from 61 microseconds (GIS: PH mode, high bit rate) to 64 s (SIS: 4-CCD mode, low bit rate).

The data recorder on the satellite can store 36h 24m 32s (131,072 s) of data in low bit rate, 9h 6m 8s (32,768 s) in medium bit rate and 1h 8m 16s (4,096 s) in high bit rate.

Keith Arnaud