Safran CORTEX CRT Quantum, User Manual

Page: 279 / 346

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 199
3.6.13.6.2.Ranging Calibration Operation
Calibration consists in measuring the delay of the path between the IFM output and the IFR input.
The Cortex CRT provides the ability to do calibration:

In very short loop (small cable between IFR and IFM) to measure its internal delay for
instance.

In short loop from the Cortex CRT IFM up to antenna and from the antenna down to the
Cortex IFR owing the TLT switch.
For this purpose, a calibration ranging request must be sent to the RAU (cf. STI 100013).
This can be done also with the MCS by clicking on the calibration icon:
Calibration request icon
The operation consists then in the following:

IFM output is switched off for a few seconds

IFM outputs a pure IF carrier without modulation for a few seconds.

The IFR is restarted to lock onto the IF tone.

When the IFR is locked, IFM outputs the carrier modulated in PM by the ranging hybrid tones.

The standard processing of measurement is then started.
The ranging measurements with the satellite equipment in the loop path, can be compared to the calibration
ranging value only if both definitions of the Epoch position in the SQPN signal are identical.