shall be position in response to manual control signals, external slave link or program control signals, or autotrack error signals. The command antenna shall be positioned by manual control or by external slave link signals.
    1. Tracking Rates. All antenna's shall be capable of angular velocities and angular accellerations compatible with the satellite's expected motion.
    2. Slaving. All antennas shall be capable of being positioned using using digital aquisition data received from the STC. During steady state operation of the tracking antenna in this mode, the difference between the antenna encoder outputs and the commanded antenna position shall be less than 6.1 mrad. The TT&C and 200-MHz autotrack antennas shall furnish syncro analog position data to the station synchro slave bus for the purpose of slaving other antennas or other position indicators.
    3. Autotracking. The TT&C and 200 MHz Autotracker antennas shall be capable of autotracking a satellite in a 100 nmi circular orbit at an angular velocity of up to 15 deg/sec in both axes (Az and El) through any path within a minimum of 75 deg. of the horizon. Autotracking shall not be required of the Command antenna.
  1. Track Data Generation. The TT&C and 200 MHz Autotracker antennas shall each generate the following data:
    1. Antenna Position. Azimuth and elevation data shall indicate each antennas position. This data shall be available for display and processing.
    2. Data Quality. Data quality bits shall be generated for each type tracking data. In addition, track data shall be generated by the TT&C antenna as follows:
    In addition, track data shall be generated by the TT&C antenna as follows:
    1. SGLS Range Rate. Digital range rate tracking data shall be provided in a 24-bit parallel binary words derived from a 1.8/2.25 MHz phase-coherent tracking link (256:205 ratio). The doppler frequency of compatable satellites shall be measured with an error equivalent to a range rate error of 0.2ft/sec rms or less. 2
      1. SGLS Range Data. Digital range tracking data shall be provided in 30 bit words binary derived from a two-way transmission pseudorandom noise (PRN) code on the 1.8/2.25 GHz phase-coherent tracking link. The least significant bit of the range word shall have resolution of 7.8 ft.3

    2.2.3 Commanding The basic command functions to be performed as shown in Figure 2-7 are as follows:

    1. Command Initiation. Digital command data from the STC will be stored on prepass disk. Commands will be initiated manually by the Systems Operations Controller as directed by the STC.
    2. Command transmission.
      1. Frequency Bands. The capability shall exist for command transmission in either the 370 to 470 MHz (low power) or 1.75 to 1.85 GHz frequency bands.

    2Range rate is related to doppler count, Ro as follows:

    26240N1 + 2048 Ro
     one-way radial velocity
     velocity of light
     N1 bias frequency +/- two-way doppler frequency
     Ro </=  37777778  (>/= 4000000 for negative one's complement)
    Note: Resolution of the least significant bit in the readout is equivalent to 0.036 ft/sec at R = 0.

    3Based on a least significant increment of one doppler count, which is equivalent to approximatley 0.0013 nmi.

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