Non-coherent spread spectrum for distance measurement

[senmeis]

Hi,I’ve heard of a technology that enables to measure the distance of a satellite to the ground station by using non-coherent spread spectrum. Can anybody tell me what’s the name of this technology?Senmeis

 

[Baluncore]

Non-coherent Ranging Systems.

Travel time ranging. Time delay ranging.

Telemetry Aided Doppler Tracking. (TADT).

Regenerative ranging. Pseudo-noise ranging systems.
Regenerative Pseudo-Noise-Like (PNL) ranging sequences
https://public.ccsds.org/Pubs/414x0g2.pdf

 

[senmeis]

Thank you. It seems similar to range measurements in GPS. Where can I find some products providing this mechanism?Senmeis

 

[Baluncore]

Exactly what are you trying to do ?

 

[senmeis]

I want to understand this technology, but with the implementation I will get a better understanding. I know this is a relative small application field so it’s not easy to find such info in internet.Senmeis

 

[Baluncore]

I know this is a relative small application field so it’s not easy to find such info in internet.

The problem is with the huge size and complexity of the fascinating field.
Google ' introduction to spread spectrum .pdf '

https://en.wikipedia.org/wiki/Pseudorandom_binary_sequence
You can conduct experiments with PRBS ranging codes on the bench or in coaxial cables without needing to transmit. If you make PRBS generators and clock them at slightly different rates, they will regularly move through synchronisation which you can detect with a simple phase detector such as an EXOR gate and low pass filter. In effect the PRBS code is a uniquely coded tape measure that is fed to a transponder and back again. By measuring the transit time you measure the distance.

 

[senmeis]

Thank you. I think I can understand this technique. What about the case if the flying object has its own onboard GPS equipment? The distance can be calculated if the flying object’s coordinate is broadcasted. Is it a better way?Senmeis

 

[Baluncore]

Is it a better way?

It will depend on what you are trying to do and why you are doing it.