Ranging Sequence (All Modes Except Inmarsat And Lmco) - Safran CORTEX CRT Quantum User Manual

3.6.1.5. Ranging Sequence (All modes except INMARSAT and LMCO)

The ranging sequence is as follows:

1. Reception of a ranging request from the Ranging Client on port RNG. The request indicates the
type of measurement to perform: calibration (ranging loop at IF or RF) or range measurement.

2. The RAU checks the validity of the ranging request and returns, on port RNG, a primary
transaction response message to the Ranging Client showing whether the request was correct or
not (bad syntax), or indicating that the CORTEX CRT Quantum was in alarm or not properly
configured to accept the ranging request. In case of request rejection, the sequence is then aborted.

3. If the ranging request is accepted, the RAU computes the tone definition tables. Should this
computation fail, a « programming » alarm is triggered and stored in the RAU monitoring table; the
ranging sequence is aborted and the RAU returns, on port RNG, a negative secondary transaction
response message with a code indicating « wrong programming ».

4. If the computation is successful, the RAU starts the measurement sequence. Should the ranging
sequence fail (open loop, loss of lock, etc...), a negative secondary transaction response message is
returned to the Ranging Client with a code indicating the type of failure (open loop or loss of lock or
hardware alarm). If the measurement is successful, phase measurements are processed and stored in
a ranging transaction response message which is returned to the Ranging Client on port MEAS.

5. Step 4 is automatically repeated (N-1) times if the programmed number of sequences (N) is
greater than 1.
If the selected ranging standard is ESA tone, ESA-like, ESA-Code, PN Ranging or USB and if the
programmed number of sequences is 0, then the CORTEX enter the Continuous mode: permanent
transmission of the major tone, phase offset measurement, distance update and transmission of
ranging transaction response messages until a Stop ranging request is received on the RNG
ranging port.
Next figure illustrates the above process.
© Safran Data Systems
COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
This document is the property of
It cannot be duplicated or distributed without expressed written consent.
Safran Data Systems
.
Ref. DTU 100042
Is.Rev. 5.17
Date: Dec.
03, 2021Sept. 30, 2021
Page 150