Some ASTERIX categories provide data positions that are relative to a location. As a result, the LuciadLightspeed ASTERIX decoders don’t decode the data of those ASTERIX categories as WGS84 longitude/latitude coordinates. Category 240 Radar data, for example, specifies positions relative to a radar location. To handle such cases, the ASTERIX decoders rely on an ALcdASTERIXReferenceProvider to define the radar location. You can set the ASTERIX reference provider through the method setReferenceProvider.

  • For a static radar, you use TLcdASTERIXReferenceProvider.

  • For a moving or rotating radar, you must implement ALcdASTERIXReferenceProvider. The decoders call its getModelReference for each decoded record. The following code shows an example implementation that translates and rotates the radar location for each method invocation.

Program: Implementing getModelReference for a moving or rotating radar.
ILcd2DEditablePoint position = = new TLcdLonLatPoint(0, 0);
TLcdASTERIXLiveDecoder liveDecoder = new TLcdASTERIXLiveDecoder();
liveDecoder.setReferenceProvider(new ALcdASTERIXReferenceProvider() {
  double rotation = 0;

  public ILcdModelReference getModelReference(int aSacSic, ALcdASTERIXModelDescriptor aDescriptor, Object aObject) {
    position.translate2D(1e-3, 1e-3);
    rotation += 0.1;
    return new TLcdGridReference(
        new TLcdGeodeticDatum(),
        new TLcdAzimuthalEquidistant(position.getX(), position.getY()),
        0, 0,
        1, 1,