Safran CORTEX CRT Quantum - Page 53

COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
Ref. DTU 100042
Is.Rev. 5.17
Date: Dec. 03, 2021Sept.
30, 2021
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It cannot be duplicated or distributed without expressed written consent.
Page 28
1.6.3. Satellite Ranging
 Ranging standards ESA tone and ESA code standards
ESA-like and USB tone standards (programmable frequencies and tone
sequence)
INMARSAT and LMCO tone standards
PN Codes (CRT eXplorer only)
Hybrid Ranging (SQPN uplink / PM downlink)
 Ranging tones Tone frequency : 2 Hz to 1.5 MHz
Number of tones : 1 major tone, 1 to 6 minor tones (8 for USB)
 Code length 0 to 24 (ESA code standard), 2 or 4 (PN Codes)
 Integration time 0.25 to 500 seconds
 Downlink tone tracking 2nd-order digital PLL
 PLL bandwidth (2 Bn) 0.1 to 8 Hz (CRT XL Quantum)
0.001 to 8 Hz (CRT eXplorer)
 Measurement standard deviation ≤ 1dB vs theory in the presence of noise
 Phase measurement resolution 0.0055° (360°/216)
 PN Ranging Measurement degradation
< 0.5 dB from theory (vs noise). See section 3.6.12
 Ambiguity solving (after Doppler compensation on minor tones and programmable phase corrections)
 Distance measurement resolution 1 ns
 Local ranging capability
 Doppler Rate Aid capability and Doppler Aid capability
 Hybrid Ranging:
o Uplink:
 MTC2: PCM/SRRC-UQPSK / ETSI EN301 926 compliant +:
 Chiprate up to 3.9 Mchips/s
 Code Length: I rail 2
L
-1, 9 ≤ L ≤ 13
 Code Length: Q rail (2
L
-1)2
X
5 ≤ X ≤ 9
 RRC rolloff from 0.2 to 0.9
o Downlink:
 Carrier is PM modulated by ranging tones.
 Up to 8 tones defined by ratio tone frequency / long code epoch rate (code on Q rail)
 Integration time in multiples of long code Epoch period.