Receiver Position Not Updated in Radar Example?

I am working through this example on passively sensing radar:

https://www.mathworks.com/help/phased/ug/signal-parameter-estimations-in-a-radar-warning-receiver.html

But I'm confused about how the txPulseTrain is received by the collector. It appears that they are injested by the collector at a single angle, rather than at changing angles over time:

[~, tgtAng] = rangeangle(radarPos,rwrPos);
yr = collector(txPulseTrain,tgtAng);

This may be an okay approximation, but it seems like a more accurate approach is to model the receiver at each timestep, in the loop within helperRWR.simulateTransmission.

Also, in the above code, the rwrPos variable above is equal to its original value when the pulses were emitted, not when they were collected, which seems like an oversight?

Please let me know if I'm missing something with both of these issues. Thank you for putting together the example!

Answer 1

[Leepakshi]

Hey,

I have got few resources that might help you to sort this.

This MATLAB Answer talks about https://www.mathworks.com/matlabcentral/answers/1989263-how-to-define-local-refaxes-in-rangeangle-function-when-the-local-refaxes-is-moving-with-antenna?s_tid=answers_rc1-2_p2_MLT

For more information, you can also refer to the following MATLAB Documentation:

1. Refer to the “Input Arguments” section to understand the input arguments and their properties- https://in.mathworks.com/help/phased/ref/rangeangle.html
2. Function to model translational motion of platforms in space - https://in.mathworks.com/help/phased/ref/phased.platform-system-object.html
3. Refer to “Input Arguments” section - https://in.mathworks.com/help/phased/ref/phased.collector-system-object.html

Hope this helps!

[black cat]

Thank you for the resources. But it looks like rangeangle is calculated at a single separation, not a different separation for each pulse:

[~, tgtAng] = rangeangle(radarPos,rwrPos);

Here, radarPos and rwrPos are positions at a single time instant. But txPulseTrain is collected over multiple pulses, and therefore multiple times and multiple angles. So it seems like a mismatch that the example passes a single azimuth/elevation angle to collector.

yr = collector(txPulseTrain,tgtAng);