Safran CORTEX CRT Quantum - Page 235

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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Page 155
The following Quality Factor values should be observed in various noise conditions, in the case of ESA mode,
with a 1 Hz loop bandwidth and an Integration time of 1 s:
S/N
0
(dB.Hz)
Quality Factor
No extra noise
100
45
100
35
98
25
95
20
93
20
97
(Integration time = 5s)
One should note that the probability of having an erroneous ambiguity solving is very high when Q ≤ 92.
In fact, if Q < 95, it is recommended to increase the Integration Time on minor tones and, if possible, to reduce
the PLL bandwidth. Indeed, as indicated in the previous table, at a signal-to-noise ratio S/No = 20 dB.Hz, by
setting the Integration Time at 5 s instead of 1 s, the Quality Factor increases from 93 to 97.
The Quality Factor can be < 95 in the case of bad programming too. It is advised to check the programming of:
 Minor tones frequencies
 Ground Correction
 Board Correction
 Sequence Timing & Ambiguity Resolution
 Maximum Distance.