TABLE 2-2
SGLS DOWNLINK BASEBAND STRUCTURE

Carrier Data Type Data Bandwidth or Bit Rate Subcarrier Frequency Subcarrier Modulation Subcarrier Deviation
1 IRIG Telemetry Channels 1-21 and A-H to 20 KHz 1.7 MHz FM 75 kHz p-p
  PAM 0.125 to 256 kb/s 1.7 MHz FM 75 kHz p-p
  PCM 0.125 to 256 kb/s 1.7 MHz PSK (biphase) +/- 90 deg
  PCM 0.0078 to 128 kb/s 1.024 MHz PSK (biphase) +/- 90 deg
  PRN Ranging Code 1 Mb/s N/A N/A N/A
  Range Clock 0.5 MHz N/A N/A N/A
2 PCM 128 to 1024 kb/s Carrier (5 MHz below Carrier 1) Carrier (direct biphase) N/A
3 Wideband Data 30 Hz to 200 kHz
30 Hz to 1 MHz
30 Hz to 10 MHz
2200 to 2300 MHz (satellite peculiar) FM N/A

Tracking data processing. After acquisition, digital tracking data from the RDT link and syncro data from the synchro generation equipment at the TT&C and 200 MHz Autotracker antennas shall be continuously accepted and processed to provide status and history data. In addition, the TT&C antenna will provide continuous updating data to the slave bus.

Tracking status and digital data from any two of six possible remote tracking data link input signals shall be inputted under control of the computer program. Tracking receiver signal strength data shall be multiplexed with other analog data, digitized, and then provided to the computer program.

Telemetry Data Processing. Telemetry data processing shall be provided as follows:

    IRIG FM/FM data (up to 64 analog signals, plus parallel data from up to seven sources) processed through the TDPII.
  1. 24 bit word transfers from each of two remote PCM decommutators to the computer program with the capability of providing data and instructions to the same decommutators from the computer program.
Command Data Processing. The data processing configuration shall be capable of supporting command functions as follows:
  1. Providing simultaneously buffered digital command and echo check interfaces with the computer program.

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