public class TLcdLOSRadarPropagationFunction extends java.lang.Object implements ILcdLOSRadarPropagationFunction
The visibility of a point is limited by the terrain, represented by the terrain elevation provider
and by the cone of silence, represented by the minimum and maximum angle in the vertical direction.
The area between these angles holds the visual field for the given azimuth. Both angles start from
0
at the ground to 180
at zenith.
The propagation function supports both radar and visual lineofsight computations. The Kfactor
in the constructor is an indication of the reflection of the waves on the atmosphere. For radar
lineofsight computations, values should be greater than 1
, usually 4/3
.
For visual lineofsight computations the value should be equal to 1
.
The matrix resulting from this propagation function can contain the following special values:
ILcdLOSRadarPropagationFunction.INVISIBLE
: for points where the object is invisible.ILcdLOSRadarPropagationFunction.UNKNOWN
: for points where the visibility is unknown. For example when
no elevation data or invalid data was found at that point.The following image gives a visual explanation of this propagation function. The green line denotes the result given this terrain profile and the visibility properties of the helicopter pilot.
INVISIBLE, UNKNOWN
Constructor and Description 

TLcdLOSRadarPropagationFunction(TLcdEarthRepresentationMode aEarthRepresentationMode,
ALcdTerrainElevationProvider aTerrainElevationProvider,
TLcdCoverageAltitudeMode aAltitudeMode,
double aMinVerticalAngle,
double aMaxVerticalAngle,
double aKFactor)
Creates a propagation function which computes the minimal height from which one is visible from
the center point of a circular area.

TLcdLOSRadarPropagationFunction(TLcdEarthRepresentationMode aEarthRepresentationMode,
ALcdTerrainElevationProvider aTerrainElevationProvider,
TLcdCoverageAltitudeMode aAltitudeMode,
double aMinVerticalAngle,
double aMaxVerticalAngle,
double aMaxRadarTiltAngle,
double aMaxRadarTiltAzimuth,
double aKFactor)
Creates a propagation function which computes the minimal height from which one is visible from
the center point of a circular area.

TLcdLOSRadarPropagationFunction(TLcdEarthRepresentationMode aEarthRepresentationMode,
ALcdTerrainElevationProvider aTerrainElevationProvider,
TLcdCoverageAltitudeMode aAltitudeMode,
double aMinVerticalAngle,
double aMaxVerticalAngle,
double aMaxRadarTiltAngle,
double aMaxRadarTiltAzimuth,
double aKFactor,
TLcdLOSOptions aLOSOption)
Creates a propagation function which computes the minimal height from which one is visible from
the center point of a circular area.

Modifier and Type  Method and Description 

void 
applyForAzimuthSFCT(double aAzimuth,
ILcdLOSCoverageMatrix aLOSCoverageMatrixSFCT)
Computes the minimal heights from which one is visible around the center point of a lineofsight
coverage for a given azimuth and stores the resulting heights in the lineofsight coverage matrix.

ILcdLOSCoverageMatrix 
createLOSCoverageMatrix(ILcdLOSCoverage aLOSCoverage,
ILcdGeoReference aMatrixReference)
Creates a coverage matrix using the lineofsight coverage
aLOSCoverage and the matrix
reference aMatrixReference . 
TLcdCoverageAltitudeMode 
getAltitudeMode()
Returns the altitude mode indicating the definition of the resulting lineofsight values.

TLcdEarthRepresentationMode 
getEarthRepresentationMode()
Returns the earth representation mode used by this instance.

double 
getKFactor()
Returns the Kfactor indicating the reflection of radar waves on the atmosphere.

double 
getMaxRadarTiltAngle()
Returns the maximum radar tilt angle in degrees, starting from 0 at the horizontal
plane to 90 at zenith.

double 
getMaxRadarTiltAzimuth()
Returns the azimuth in degrees where the maximum radar tilt angle occurs.

double 
getMaxVerticalAngle()
Returns the maximum angle of the vertical extent in degrees, starting from 0 at
the ground to 180 at zenith.

double 
getMinVerticalAngle()
Returns the minimum angle of the vertical extent in degrees, starting from 0 at
the ground to 180 at zenith.

ALcdTerrainElevationProvider 
getTerrainElevationProvider()
Returns the elevation provider used to retrieve the terrain elevation data.

void 
initialize(ILcdLOSCoverage aLOSCoverage,
ILcdGeoReference aMatrixReference)
Initialize the propagation function with the given coverage
aLOSCoverage and the given
matrix reference aMatrixReference . 
public TLcdLOSRadarPropagationFunction(TLcdEarthRepresentationMode aEarthRepresentationMode, ALcdTerrainElevationProvider aTerrainElevationProvider, TLcdCoverageAltitudeMode aAltitudeMode, double aMinVerticalAngle, double aMaxVerticalAngle, double aKFactor)
null
, otherwise a NullPointerException
will be thrown.
Currently, two earth representation modes are supported. If another representation mode is used,
an IllegalArgumentException
will be thrown.
TLcdEarthRepresentationMode.SPHERICAL_FIXED_RADIUS
TLcdEarthRepresentationMode.SPHERICAL_EULER_RADIUS
The radar tilt angle is set to zero, meaning that the radar scans in a horizontal plane, the minimum and maximum viewing angles are constant independent of the viewing direction.
aEarthRepresentationMode
 The mode indicating which earth representation to use.aTerrainElevationProvider
 The terrain elevation provider.aAltitudeMode
 The altitude mode indicating the definition of the resulting values.aMinVerticalAngle
 The minimum angle of the vertical extent in degrees, starting from 0
at the ground to 180 at zenith. It is the minimum vertical angle when
the radar tilt angle is set to zero.aMaxVerticalAngle
 The maximum angle of the vertical extent in degrees, starting from 0
at the ground to 180 at zenith. It is the maximum vertical angle when
the radar tilt angle is set to zero.aKFactor
 A factor indicating the reflection of radar waves on the atmosphere.
For radar computations, values should be greater than 1, usually 4/3.
Setting the value equal to 1 will yield the same results as visual
lineofsight computations.java.lang.NullPointerException
 when the argument aTerrainElevationProvider
is
null
.java.lang.IllegalArgumentException
 aEarthRepresentationMode
is not one of the following
expected values (TLcdEarthRepresentationMode.SPHERICAL_FIXED_RADIUS
or
TLcdEarthRepresentationMode.SPHERICAL_EULER_RADIUS
,aAltitudeMode
is TLcdCoverageAltitudeMode.ABOVE_OBJECT
,aMinVerticalAngle
or aMaxVerticalAngle
lies outside the interval [0, 180] andaKFactor
is smaller than or equal to zero.public TLcdLOSRadarPropagationFunction(TLcdEarthRepresentationMode aEarthRepresentationMode, ALcdTerrainElevationProvider aTerrainElevationProvider, TLcdCoverageAltitudeMode aAltitudeMode, double aMinVerticalAngle, double aMaxVerticalAngle, double aMaxRadarTiltAngle, double aMaxRadarTiltAzimuth, double aKFactor)
null
, otherwise a NullPointerException
will be thrown.
Currently, two earth representation modes are supported. If another representation mode is used,
an IllegalArgumentException
will be thrown.
TLcdEarthRepresentationMode.SPHERICAL_FIXED_RADIUS
TLcdEarthRepresentationMode.SPHERICAL_EULER_RADIUS
The specified radar tilt angle is used to recomputed the minimum and maximum viewing angles in
the method applyForAzimuthSFCT(double, ILcdLOSCoverageMatrix)
. If the computed viewing
angle falls outside the viewing interval [0, 180], the angle outside the interval is clipped to
either 0
or 180
.
aEarthRepresentationMode
 The mode indicating which earth representation to use.aTerrainElevationProvider
 The terrain elevation provider.aAltitudeMode
 The altitude mode indicating the definition of the resulting values.aMinVerticalAngle
 The minimum angle of the vertical extent in degrees, starting from 0
at the ground to 180 at zenith. It is the minimum vertical angle when
the radar tilt angle is set to zero.aMaxVerticalAngle
 The maximum angle of the vertical extent in degrees, starting from 0
at the ground to 180 at zenith. It is the maximum vertical angle when
the radar tilt angle is set to zero.aMaxRadarTiltAngle
 The maximum radar tilt angle in degrees, starting from 0 at the horizontal
plane to 90 at zenith.aMaxRadarTiltAzimuth
 The azimuth in degrees where the maximum radar tilt angle occurs.aKFactor
 A factor indicating the reflection of radar waves on the atmosphere.
For radar computations, values should be greater than 1, usually 4/3. If equal to 1 this will produce
the same result as direct lineofsight computations.java.lang.NullPointerException
 when the argument aTerrainElevationProvider
is
null
.java.lang.IllegalArgumentException
 aEarthRepresentationMode
is not one of the following
expected values (TLcdEarthRepresentationMode.SPHERICAL_FIXED_RADIUS
or
TLcdEarthRepresentationMode.SPHERICAL_EULER_RADIUS
,aAltitudeMode
is TLcdCoverageAltitudeMode.ABOVE_OBJECT
,aMinVerticalAngle
or aMaxVerticalAngle
lies outside the interval [0, 180],aMaxRadarTiltAngle
lies outside the interval [0, 90] andaKFactor
is smaller than or equal to zero.public TLcdLOSRadarPropagationFunction(TLcdEarthRepresentationMode aEarthRepresentationMode, ALcdTerrainElevationProvider aTerrainElevationProvider, TLcdCoverageAltitudeMode aAltitudeMode, double aMinVerticalAngle, double aMaxVerticalAngle, double aMaxRadarTiltAngle, double aMaxRadarTiltAzimuth, double aKFactor, TLcdLOSOptions aLOSOption)
null
, otherwise a NullPointerException
will be thrown.
Currently, two earth representation modes are supported. If another representation mode is used,
an IllegalArgumentException
will be thrown.
TLcdEarthRepresentationMode.SPHERICAL_FIXED_RADIUS
TLcdEarthRepresentationMode.SPHERICAL_EULER_RADIUS
The specified radar tilt angle is used to recomputed the minimum and maximum viewing angles in
the method applyForAzimuthSFCT(double, ILcdLOSCoverageMatrix)
. If the computed viewing
angle falls outside the viewing interval [0, 180], the angle outside the interval is clipped to
either 0
or 180
.
aEarthRepresentationMode
 The mode indicating which earth representation to use.aTerrainElevationProvider
 The terrain elevation provider.aAltitudeMode
 The altitude mode indicating the definition of the resulting values.aMinVerticalAngle
 The minimum angle of the vertical extent in degrees, starting from 0
at the ground to 180 at zenith. It is the minimum vertical angle when
the radar tilt angle is set to zero.aMaxVerticalAngle
 The maximum angle of the vertical extent in degrees, starting from 0
at the ground to 180 at zenith. It is the maximum vertical angle when
the radar tilt angle is set to zero.aMaxRadarTiltAngle
 The maximum radar tilt angle in degrees, starting from 0 at the horizontal
plane to 90 at zenith.aMaxRadarTiltAzimuth
 The azimuth in degrees where the maximum radar tilt angle occurs.aKFactor
 A factor indicating the reflection of radar waves on the atmosphere.
For radar computations, values should be greater than 1, usually 4/3. If equal to 1 this will produce
the same result as direct lineofsight computations.aLOSOption
 A LOS option object containing parameters for the internals of this
propagation function and its resulting coveragesjava.lang.NullPointerException
 when the argument aTerrainElevationProvider
is
null
.java.lang.IllegalArgumentException
 aEarthRepresentationMode
is not one of the following
expected values (TLcdEarthRepresentationMode.SPHERICAL_FIXED_RADIUS
or
TLcdEarthRepresentationMode.SPHERICAL_EULER_RADIUS
,aAltitudeMode
is TLcdCoverageAltitudeMode.ABOVE_OBJECT
,aMinVerticalAngle
or aMaxVerticalAngle
lies outside the interval [0, 180],aMaxRadarTiltAngle
lies outside the interval [0, 90] andaKFactor
is smaller than or equal to zero.public ILcdLOSCoverageMatrix createLOSCoverageMatrix(ILcdLOSCoverage aLOSCoverage, ILcdGeoReference aMatrixReference)
ILcdLOSPropagationFunction
aLOSCoverage
and the matrix
reference aMatrixReference
. The result of this method is used as input parameter for the
method applyForAzimuthSFCT
, which will store the actual matrix values. The matrix should
be consistent with the given coverage. This means that all matrix rows and columns represent evenly
spaced radii and azimuths as defined by the radial and angular step sizes of the lineofsight coverage.
The method ILcdLOSPropagationFunction.initialize(com.luciad.tea.ILcdLOSCoverage, com.luciad.reference.ILcdGeoReference)
is called with the same arguments as supplied with this method.
The ILcdLOSCoverageMatrix
created by this method is guaranteed to be capable of determining
its own associatedPointX and associatedPointY properties. These values are not calculated by this ILcdPropagationFunction
. An ILcdLOSPropagationFunction
does not modify the values of the associatedPointX and
associatedPointY for its created ILcdLOSCoverageMatrix
.
createLOSCoverageMatrix
in interface ILcdLOSPropagationFunction
aLOSCoverage
 The covered area and the intermediate step sizes.aMatrixReference
 The reference in which this matrix is defined.public void initialize(ILcdLOSCoverage aLOSCoverage, ILcdGeoReference aMatrixReference)
ILcdLOSPropagationFunction
aLOSCoverage
and the given
matrix reference aMatrixReference
. For performance reasons, it is recommended that this
method initializes all fields that are common to all computations or which do not depend on a specific
azimuth.initialize
in interface ILcdLOSPropagationFunction
aLOSCoverage
 The covered area to use.aMatrixReference
 The matrix reference in which to compute the matrix values.public void applyForAzimuthSFCT(double aAzimuth, ILcdLOSCoverageMatrix aLOSCoverageMatrixSFCT)
Note that this implementation assumes that the default value of a matrix entry corresponds to the
value for invisible points (which is ILcdLOSRadarPropagationFunction.INVISIBLE
). Refer to the class documentation for more
information about the different special values.
applyForAzimuthSFCT
in interface ILcdLOSPropagationFunction
aAzimuth
 The azimuth in degrees.aLOSCoverageMatrixSFCT
 The coverage matrix to update.java.lang.NullPointerException
 if the aLOSCoverageMatrixSFCT is null
.public TLcdEarthRepresentationMode getEarthRepresentationMode()
ILcdLOSRadarPropagationFunction
getEarthRepresentationMode
in interface ILcdLOSRadarPropagationFunction
public TLcdCoverageAltitudeMode getAltitudeMode()
ILcdLOSRadarPropagationFunction
getAltitudeMode
in interface ILcdLOSRadarPropagationFunction
public double getKFactor()
ILcdLOSRadarPropagationFunction
getKFactor
in interface ILcdLOSRadarPropagationFunction
public double getMaxVerticalAngle()
ILcdLOSRadarPropagationFunction
getMaxVerticalAngle
in interface ILcdLOSRadarPropagationFunction
public double getMinVerticalAngle()
ILcdLOSRadarPropagationFunction
getMinVerticalAngle
in interface ILcdLOSRadarPropagationFunction
public double getMaxRadarTiltAngle()
ILcdLOSRadarPropagationFunction
getMaxRadarTiltAngle
in interface ILcdLOSRadarPropagationFunction
public double getMaxRadarTiltAzimuth()
ILcdLOSRadarPropagationFunction
getMaxRadarTiltAzimuth
in interface ILcdLOSRadarPropagationFunction
public ALcdTerrainElevationProvider getTerrainElevationProvider()
ILcdLOSRadarPropagationFunction
getTerrainElevationProvider
in interface ILcdLOSRadarPropagationFunction