parameters for backscatterRadarTarget and its target

in the example "Simulating a Polarimetric Radar Return for Weather Observation"

"

azpatangs = [-180 180];

elpatangs = [-90 90];

target = phased.BackscatterRadarTarget('EnablePolarization',true,...

'Model','Nonfluctuating','AzimuthAngles',azpatangs,...

'ElevationAngles',elpatangs,'ShhPattern',shhpat,'ShvPattern',shvpat,...

'SvvPattern',svvpat,'OperatingFrequency',fc);

"

Questions:

1. angle parameter in the following code "ang_az" should be in the range of the previous defined "azpatangs" ?

" tgtsig = target(txsig,[ang_az;zeros(size(ang_az))],axes);"

2. "ShhPattern" should be the pattern defined with azpatanges and elpatangs?

Answer 1

[Honglei Chen]

For question 1, the answer is no. However, the RCS pattern is only defined within the range specified by azpatangs and elpatangs. Therefore, for any angle beyond that region, the return is 0.

For question 2, the answer is yes. More precisely, the pattern region is defined by the parameters AzimuthAngles and ElevationAngles in BackscatterRadarTarget. In this case, they happen to be azpatangs and elpatangs.

HTH

[MatlabQuestion]

thank you very much for the answer. Could you plese help me to understand this example more ?

1. azpatangs = [-180 180]; elpatangs = [-90 90]; and scatter matrix are used to define backscatterRadarTarget, actually the pattern is defined only by one anlge, repeated for 2x2 angle region
2. then target is called with azimuth angle (ang_az) between -180 to 180, how is the target extracted with only one angle pattern to all other angle regions? Does this mean the pattern is uniform ?

Thank you for your help!

[Honglei Chen]

In this case, the RCS is defined for the two ends and I believe they are the same, so in this case you can think that the pattern is constant. In general if you define the two bounds, then the target would interpolate in between.

HTH

[MatlabQuestion]

I see. Thank you very much for the detail explaination.