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3.6.12. PN Codes Standard (Regenerative PN Ranging)
Available under licence on Cortex CRT eXplorer
3.6.12.1.General
The ranging sequence consists in a continuous transmission of a pseudo noise sequence, which is a logical
combination of six binary periodic PN components used for ambiguity solving. One of these PN components,
called the range clock, represents the major tone.
By means of a digital PLL, the RAU produces a phase-locked replica of the major tone. The PN components are
correlated with the demodulated code to determine the number of major tone cycles in the range.
The PLL is a second-order whose bandwidth (2Bn) is programmable from 0.001 to 32 Hz.
3.6.12.2.Frequency Programming
The tone frequency is programmable through major tone parameters according to the following rule (in kHz):
in Hz and ��
Or (��
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with the restrictions described in § 3.6.2.
The tone frequency is half of the Chip Rate. According to CCSDS 414.1-B-2, two chip rates are selected:
M
ODE
P/Q
P+Q
500,000
© Safran Data Systems
COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
��
��������
in µHz)
����������_��������
��
= ��
��������
Q
P
29
30
29
60
517,147
0
1,034,295
Table 28: Available chip rates on Cortex
This document is the property of
It cannot be duplicated or distributed without expressed written consent.
��
����������_��������
= 500 ×
��
����������_��������
��
����������_��������
+
����������_��������
1 000 000
C
ORTEX
C
R
HIP
ATES
1,034,483 chips/s
2,068,966 chips/s
1,034,295 chips/s
2,068,590 chips/s
Safran Data Systems
.
Ref.
DTU 100042
Is.Rev.
5.17
Date:
Dec.
03, 2021Sept. 30, 2021
CCSDS
C
R
HIP
ATES
1,034,295 chips/s
2,068,590 chips/s
1,034,295 chips/s
2,068,590 chips/s
Page 185
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