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3.6.3.3. Phase-shift Measurement
Phase measurements transmitted to the Ranging Client are raw phase measurements (∆Φ������), whatever the
selected ranging standard:
∆Φ������ = (���������������������� �������� �������������������������� ��ℎ������) − (���������������� �������� �������������������������� ��ℎ������)
In the ESA, ESA-like and USB standards, raw phase measurements are then corrected to obtain net phase
measurements for ambiguity solving and distance computation. Phase correction depends on the ranging
request contents:
If the ranging request is a « range measurement request », the following correction applies:
If the ranging request is a « calibration request », the following correction applies:
where:
∆Φ����������������
∆Φ������������_��������
equipment that are inserted in the station calibration loop but not used
during satellite range measurement (example: Test Loop Translator).
∆Φ����������_��������
The above correction parameters are programmable by commands received on the Control port.
3.6.3.4. Phase-shift Correction for Ambiguity Solving
IMPORTANT:
PHASE-SHIFT CORRECTION ONLY APPLY TO TONE STANDARDS WITH AMBIGUITY SOLVING
(ESA AND ESA-LIKE).
3.6.3.4.1. "Spectrum Correction"
Parameter Spectrum Correction (∆������������������) allows to compensate for phase offset due to frequency
mixing and FM/PM ranging loops. Any of the following scenario can be selected:
© Safran Data Systems
COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
∆Φ������ = ∆Φ������ − ∆Φ���������������� − ∆Φ����������_��������
∆Φ������ = ∆Φ������ − ∆Φ���������������� − ∆Φ������������_��������
Compensation for contribution to phase measurement of ground
Compensation for satellite contribution to range measurement.
No spectrum correction.
Spectrum inversion due to the presence of an IF or RF frequency mixer in the ranging loop.
Phase measurements are corrected by 180°.
FM (uplink) and PM (downlink) modulation schemes. Phase measurements are corrected
by + 90°.
Spectrum inversion and FM/PM loop: phase measurements are corrected by - 90°.
This document is the property of
It cannot be duplicated or distributed without expressed written consent.
-offset.
Safran Data Systems
.
Ref.
DTU 100042
Is.Rev.
5.17
Date:
Dec.
03, 2021Sept. 30, 2021
Page 157
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