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Table 7-4. KuSA Forward Service Real-Time Configuration Changes
Real-Time Configuration Changes GCMR OPM
Forward Service
Signal Interruption
Customer Receiver Center Frequency 98/04 OPM 03 Yes
Doppler Compensation Inhibit 98/08 OPM 11 No
Doppler Compensation Reinitiation 98/04 OPM 03 No
Forward Service Reacquisition (note 1) 98/03 OPM 02 Yes
Forward Service Sweep Request (refer to
Table 7-1)
98/05 OPM 04 Yes
Data Rate 98/04 OPM 03 No
Polarization 98/04 OPM 03 Yes
Initiation or termination of the command
channel PN code (note 2)
Forward Service Normal/High Power Mode
EIRP Change
98/04 OPM 03 No
98/06 OPM 06 No
Notes:
1. Forward service reacquisition is a TDRSS reinitiation of forward link service by applying a 1
MHz frequency offset for 3 seconds to the predicted customer receive frequency specified in
the customer’s service specification code (refer to Section 10, paragraph 10.2.2).
2. Initiation or termination of the command channel PN code enables or disables all forward link
PN modulation (including the command and range channel, if applicable), respectively.
7.3 KuSA Return Services
7.3.1 General
The RF signals provided by the customer platform to the TDRS and the characteristics
of data provided at the SN ground terminal interface are defined in paragraphs 7.3.2
through 7.3.6. This discussion assumes that an appropriate return service has been
scheduled and a data signal is present at the TDRS interface. The KuSA return service
supports data services using the SN ground terminal receivers and an IF service, where
automation of this service is currently being considered for implementation. Contact
Code 450 for availability.
7.3.2 Signal Parameters
The TDRSS KuSA return service signal parameters are listed in Table 7-5. Refer to
paragraph 7.3.6 for KuSA return IF service signal parameter characteristics and
recommendations. The services are divided into 2 major groups, Data Group 1 (DG1)
and Data Group 2 (DG2). DG1 services utilize spread spectrum modulation while DG2
services are non-spread. A description of the features inherent in the DG1 and DG2
services is discussed in paragraphs 7.3.2.2 and 7.3.2.3, respectively. Within each data
group, there are several types of modulation. Additionally, both data groups support
coherent and noncoherent modes. A description of these general characteristics is
provided in paragraph 7.3.2.1.
Revision 10 7-13 450-SNUG