difar

Class DIFARTargetMotionInformation

java.lang.Object

difar.DIFARTargetMotionInformation

All Implemented Interfaces:

TargetMotionInformation

public class DIFARTargetMotionInformation
extends java.lang.Object
implements TargetMotionInformation

Constructor Summary

Constructors

Constructor and Description
DIFARTargetMotionInformation(DifarProcess difarProcess, java.util.ArrayList<PamDetection> difarDataUnits)

Method Summary

Methods

Modifier and Type	Method and Description
GpsData	getBeamLatLong(LatLong localised) Calculate the beam latitude and longitude.
long	getBeamTime(GpsData beamPos) Calculate the beam time.
java.util.ArrayList<PamDetection>	getCurrentDetections() Returns the pamDetections which will be used for this target motion localisation.
PamQuaternion[]	getEulerAngles() Get the Euler angles for each detection.
LatLong	getGPSReference() The GPS point which corresponds to (0,0,0).
java.util.ArrayList<java.util.ArrayList<javax.vecmath.Point3f>>	getHydrophonePos() Returns the positions of the hydrophones, relative to (0,0,0) for every pamDetection
double[]	getMeanPosition()
int	getNDetections() The number of detections to be used in this target motion.
PamVector[]	getOrigins() Returns the origin of the hydrophone array for each detection point- this is in meters relative to 0,0,0;
int	getReferenceHydrophones()
java.util.ArrayList<java.util.ArrayList<java.lang.Double>>	getTimeDelayErrors() Returns the time delay errors for each detection.
java.util.ArrayList<java.util.ArrayList<java.lang.Double>>	getTimeDelays() Returns the time delays for each detection.
java.lang.Long	getTimeMillis() Get a time for the detection (usually an average of all the individual detectiopns)
PamVector[][]	getWorldVectors() The real world vectors for each detection.
PamVector	latLongToMetres(LatLong ll)
LatLong	metresToLatLong(PamVector pt) Convert a point in your cartesian co-ordinate frame

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DIFARTargetMotionInformation

public DIFARTargetMotionInformation(DifarProcess difarProcess,
                            java.util.ArrayList<PamDetection> difarDataUnits)

Method Detail

getMeanPosition

public double[] getMeanPosition()

Returns:

the mean position of all buoys in x,y coordinates.

getCurrentDetections

public java.util.ArrayList<PamDetection> getCurrentDetections()

Description copied from interface: TargetMotionInformation

Returns the pamDetections which will be used for this target motion localisation.

Specified by:

getCurrentDetections in interface TargetMotionInformation

Returns:

a list fo the current detections to be localised with target motion algorithms

getNDetections

public int getNDetections()

Description copied from interface: TargetMotionInformation

The number of detections to be used in this target motion.

Specified by:

getNDetections in interface TargetMotionInformation

Returns:

the number of detections we have in total getCurrentDetection().size();

getTimeDelays

public java.util.ArrayList<java.util.ArrayList<java.lang.Double>> getTimeDelays()

Description copied from interface: TargetMotionInformation

Returns the time delays for each detection. The number of time delays per detection is going to be based on the number of hydrophones in the array.

Specified by:

getTimeDelays in interface TargetMotionInformation

Returns:

a list of time delays. Each ArrayList corresponds to the time delays calculated from a PamDtection,. Time delays are related to channel numbers by the indexM1 and indexM2 functions in AbstractLocalisation.

getTimeDelayErrors

public java.util.ArrayList<java.util.ArrayList<java.lang.Double>> getTimeDelayErrors()

Description copied from interface: TargetMotionInformation

Returns the time delay errors for each detection. This should be based on the uncertainty in spacing between hydrophones for target motion analysis.

Specified by:

getTimeDelayErrors in interface TargetMotionInformation

Returns:

a list of time delay errors. Each ArrayList corresponds to the time delays calculated from a PamDtection,. Time delays are related to channel numbers by the indexM1 and indexM2 functions in AbstractLocalisation.

getOrigins

public PamVector[] getOrigins()

Description copied from interface: TargetMotionInformation

Returns the origin of the hydrophone array for each detection point- this is in meters relative to 0,0,0;

Specified by:

getOrigins in interface TargetMotionInformation

Returns:

the vector of a PamDetections origin were (0,0,0) is the origin.

getWorldVectors

public PamVector[][] getWorldVectors()

Description copied from interface: TargetMotionInformation

The real world vectors for each detection. There may be an ambiguity in the vectors in which case we would have two world vectors per detections e.g. for a stereo array there are two bearings whilst for a 3D towed array there would usually be only one three dimensional bearing.

Specified by:

getWorldVectors in interface TargetMotionInformation

Returns:

a 2D array of world vectors corresponding to each pamDetection in the currentDetectionsGroup.

getEulerAngles

public PamQuaternion[] getEulerAngles()

Description copied from interface: TargetMotionInformation

Get the Euler angles for each detection. We are assumming that any pamDetection used for the target motion localiser will be from a group which is within a rigid array. Hence the hydrophones within that array will all have the same euler angles.

Note on Euler Angles:

We need to know the position and depth of the array but we also must know the rotation of the array. It would be nice to store the rotation as vector, however a unit vector cannot describe fully the rotation of the array. e.g say we have the unit vector (-0.71 0.0 0.71), this would describe a heading of 270 and pitch of 45 degrees. However this unit vector tells us nothing about the roll (tilt) of the array. This is because we had to start off with a unit vector (0,1,0) to rotate to begin with. We can transform co-ordinate systems all we want but a unit vector will only ever tell us two Euler angles. Hence we have to store euler angles as a PamQuaternion not a PamVector.

Specified by:

getEulerAngles in interface TargetMotionInformation

Returns:

PamQuaternion angles for each PamDetection.

See Also:

PamQuaternion

getHydrophonePos

public java.util.ArrayList<java.util.ArrayList<javax.vecmath.Point3f>> getHydrophonePos()

Description copied from interface: TargetMotionInformation

Returns the positions of the hydrophones, relative to (0,0,0) for every pamDetection

Specified by:

getHydrophonePos in interface TargetMotionInformation

Returns:

a list of hydrophone positions. Each corresponds to the hydrophone positions for one PamDetection.

getGPSReference

public LatLong getGPSReference()

Description copied from interface: TargetMotionInformation

The GPS point which corresponds to (0,0,0).

Specified by:

getGPSReference in interface TargetMotionInformation

Returns:

the lat long which has been used for the (0,0,0) reference.

latLongToMetres

public PamVector latLongToMetres(LatLong ll)

Specified by:

latLongToMetres in interface TargetMotionInformation

Returns:

metresToLatLong

public LatLong metresToLatLong(PamVector pt)

Description copied from interface: TargetMotionInformation

Convert a point in your cartesian co-ordinate frame

Specified by:

metresToLatLong in interface TargetMotionInformation

Returns:

getReferenceHydrophones

public int getReferenceHydrophones()

Specified by:

getReferenceHydrophones in interface TargetMotionInformation

Returns:

getTimeMillis

public java.lang.Long getTimeMillis()

Description copied from interface: TargetMotionInformation

Get a time for the detection (usually an average of all the individual detectiopns)

Specified by:

getTimeMillis in interface TargetMotionInformation

Returns:

getBeamLatLong

public GpsData getBeamLatLong(LatLong localised)

Description copied from interface: TargetMotionInformation

Calculate the beam latitude and longitude. The beam lat long is basically the point on the GPS path which is closest to the localised position of the animal

Specified by:

getBeamLatLong in interface TargetMotionInformation

Returns:

lat long

getBeamTime

public long getBeamTime(GpsData beamPos)

Description copied from interface: TargetMotionInformation

Calculate the beam time. This is not the time that the vessel was at the beam lat long but the time the streamer passed that point. Note that if there are multiple streamers passing the point the streamer lengths are averaged and used as our beam lat long. We use the model for each streamer to to work out when it passed the beam lat long point.

Specified by:

getBeamTime in interface TargetMotionInformation

Returns:

the time at which the hydrophone array passed the beam lat long point.