Safran CORTEX CRT Quantum, User Manual

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COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
Ref. DTU 100042
Is.Rev. 5.17
Date: Dec.
03, 2021Sept. 30, 2021
© Safran Data Systems
This document is the property of
Safran Data Systems
.
It cannot be duplicated or distributed without expressed written consent.
Page 137
3.5.3.
CLCW Checking & IF Carrier Sweeping
The CORTEX CRT Quantum provides IF carrier sweeping to allow fast carrier acquisition by the on-board
receiver in case of high Doppler. Five sweeping modes are available:

OFF: The carrier frequency remains fixed.

ON: Step 1: add programmed offset to programmed IF frequency
Step 2: increase frequency to (F0 + sweep range)
Step 3: decrease frequency to (F0 + offset - sweep range)
Go to step 2

AUTO: Carrier sweeping automatically started when uplinking a telecommand.
Sweeping automatically stopped when the on-board RF receiver is locked.

AUTO+RZ: Idem AUTO mode, with the carrier automatically returned to the programmed
frequency when the on-board RF receiver is locked (see RZ mode).

RZ: Return to the programmed frequency (F0). The RZ protocol depends on the
RzMode flag in the Windows registry. On reception of the RZ command:
If flag RzMode = 0:
On reception of the RZ command, immediately sweep back to F0 using
the programmed sweep rate.
If flag RzMode = 1:
On reception of the RZ command, continue the sweep until the current
or the next positive sweep slope (increasing frequency) crosses the
programmed frequency (Fo), then stop sweeping. If the sweep slope
cannot cross the programmed frequency (e.g: the sweep offset is
positive and greater than the sweep range), immediately sweep back to
Fo using the programmed sweep rate (as per RzMode = 0).
If flag RzMode = 2:
On reception of the RZ command, continue the sweep until the current
or the next negative sweep slope (decreasing frequency) crosses the
programmed frequency (Fo), then stop sweeping. If the sweep slope
cannot cross the programmed frequency (e.g: the sweep offset is
negative and greater than the sweep range), immediately sweep back
to Fo using the programmed sweep rate (as per RzMode = 0).
Important:

The sweep rate can be changed dynamically while sweeping.

If the carrier frequency (F0) or the sweep range or the sweep offset is re-programmed while
sweeping, the sweep is stopped, the carrier is returned to the programmed frequency (F0) and the
sweep resumes.