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clutterGenerator

Add clutter generator for radar

    Description

    example

    genclutter = clutterGenerator(scenario,radar,Name=Value) adds a ClutterGenerator object genclutter for the radar to the radarScenario scenario.

    Examples

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    Generate clutter from a surface having two clutter regions. Start by creating a radarDataGenerator. Use a radar frequency of 1 GHz, a 100 meter range resolution, a 5 kHz pulse repetition frequency (PRF), and 128 pulses. The beam is symmetric with a 4 degree two-sided beamwidth in azimuth and elevation.

    fc = 1e9;
    rangeRes = 100;
    prf = 5e3;
    numPulses = 128;
    beamwidth = 4;

    Use the PRF and number of pulses to calculate the nominal Doppler and range-rate resolution. The radar will update once each coherent processing interval (CPI).

    dopRes = prf/numPulses;
    lambda = freq2wavelen(fc);
    rangeRateRes = dop2speed(dopRes,lambda)/2;
    cpiTime = numPulses/prf;
    
    rdr = radarDataGenerator(1,'No scanning','UpdateRate',1/cpiTime, ...
        'DetectionMode','Monostatic','TargetReportFormat','Detections', ...
        'DetectionCoordinates','Scenario', ...
        'HasINS',true,'HasElevation',true,'HasFalseAlarms',false, ...
        'HasNoise',false,'HasRangeRate',true, ...
        'HasRangeAmbiguities',true,'HasRangeRateAmbiguities',true, ...
        'CenterFrequency',fc,'FieldOfView',beamwidth, ...
        'AzimuthResolution',beamwidth,'ElevationResolution', ...
        beamwidth,'RangeResolution', ...
        rangeRes,'RangeRateResolution',rangeRateRes, ...
        'ReferenceRange',20e3,'ReferenceRCS',0, ...
        'DetectionProbability',0.9);

    Create a scenario using the radarScenario object, setting the update rate to zero so that the update interval is derived from sensors in the scene.

    scenario = radarScenario('UpdateRate',0,'IsEarthCentered',false);

    Now create the scenario surface. Choose a constant-gamma reflectivity model with a gamma value appropriate for flatland. This gamma value can be found using the surfacegamma function. Using this value, create a surfaceReflectivityLand object to add to a LandSurface using the RadarReflectivity property.

    gammaDB = surfacegamma('Flatland');
    refl = surfaceReflectivityLand('Model','ConstantGamma', ...
        'Gamma',gammaDB);
    landSurface(scenario,'RadarReflectivity',refl);

    Add two clutter regions to the scenario. Use the clutterGenerator object function to construct a clutter generator and enable clutter generation for the radar. The Resolution property defines the nominal spacing of clutter patches. Set this to be 1/5th of the range resolution to get multiple clutter patches per range gate. Set the range limit to 20 km. UseBeam indicates if clutter generation should be performed automatically for the mainlobe of the antenna pattern.

    cluttergen = clutterGenerator(scenario,rdr,'Resolution', ...
        rangeRes/5,'RangeLimit',20e3,'UseBeam',true);
    rgn1 = ringClutterRegion(cluttergen,1000,10000,30,45);
    rgn2 = ringClutterRegion(cluttergen,1000,10000,30,105);

    The getClutterGenerator function displays the two ring-shaped clutter regions belonging to the scenario.

    getClutterGenerator(scenario,rdr)
    ans = 
      ClutterGenerator with properties:
    
          Resolution: 20
          RangeLimit: 20000
             UseBeam: 1
        UseShadowing: 1
             Regions: [1x2 radar.scenario.RingClutterRegion]
               Radar: [1x1 radarDataGenerator]
    
    

    Input Arguments

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    Radar scenario, specified as a radarScenario object.

    Radar, specified as a radarDataGenerator or radarTransceiver object.

    Name-Value Arguments

    Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

    Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

    Example: Resolution = 34

    Nominal resolution of clutter patches, specified as a positive scalar. The nominal value is the expected resolution ground of the radar system. Units are in meters.

    Data Types: double

    Range limit of clutter generation, specified as a positive scalar. Clutter generation is limited to this range when the clutter region is unbounded. Units are in meters.

    Data Types: double

    Enable use of the beam footprint as the clutter region, specified as true or false. When true, the mainlobe clutter return is automatically included. Use the ringClutterRegion object function of the ClutterGenerator to create a custom region.

    Data Types: logical

    Enable use of surface self-occlusion when generating clutter, specified as true or false. Surface self-occlusion is referred to as shadowing.

    Data Types: logical

    Output Arguments

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    Clutter generator, returned as a ClutterGenerator object.

    Version History

    Introduced in R2022a