Unformatted text preview: m the transmitting station to the proper spacecraft
4.3.1 CARRIER MODULATION MODES Carrier Modulation Modes (CMMs) consist of different states of data modulation upon the
RF carrier which creates the physical telecommand channel. The physical methods of
modulating the carrier, which may be either spread spectrum (e.g., TDRSS) or subcarrier
(e.g., conventional ground station) techniques, are described in Reference . The Carrier
Modulation Modes are shown in Table 4-1.
Table 4-1: Carrier Modulation Modes
CMM-1 Unmodulated CARRIER only CMM-2 CARRIER modulated with
ACQUISITION SEQUENCE CMM-3 CARRIER modulated with
TC data (e.g., CLTU) CMM-4 4.3.2 State CARRIER modulated with
IDLE SEQUENCE TELECOMMAND SESSION During a Telecommand Session, a series of CLTUs is transmitted to a remote spacecraft.
The session begins with the initial application of the RF carrier (CMM-1) and ends with the
removal of the carrier. The path is further controlled (activated or deactivated) by the
selection of appropria...
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This document was uploaded on 03/06/2014.
- Spring '14