Localiser.bearingLocaliser

Class MLGridBearingLocaliser

java.lang.Object

Localiser.bearingLocaliser.MLGridBearingLocaliser

All Implemented Interfaces:

BearingLocaliser

public class MLGridBearingLocaliser
extends java.lang.Object
implements BearingLocaliser

Maximum likelihood bearing localiser to get bearings from a closely spaced hydrophone array.

Author:

Doug Gillespie.

Constructor Summary

Constructors

Constructor and Description
MLGridBearingLocaliser(int[] hydrophoneList, long timMillis, double timingError)
MLGridBearingLocaliser(int hydrophoneBitMap, long timMillis, double timingError)

Method Summary

Methods

Modifier and Type	Method and Description
PamVector[]	getArrayAxis() Get the principle axis of the array
int	getArrayType()
int	getHydrophoneMap() Get a hydrophone map for this localiser
double[][]	localise(double[] delays, long timeMillis) Calculate angles theta and phi, based on a set of delays.
double[][]	localiseByBisection(double[] delays)
double[][]	localiseByCrawl(double[] delays, long timeMillis)
void	prepare(int[] arrayElements, long timMillis, double timingError) Do any preparation necessary (e.g.

Methods inherited from class java.lang.Object

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

Constructor Detail

MLGridBearingLocaliser

public MLGridBearingLocaliser(int hydrophoneBitMap,
                      long timMillis,
                      double timingError)

MLGridBearingLocaliser

public MLGridBearingLocaliser(int[] hydrophoneList,
                      long timMillis,
                      double timingError)

Method Detail

prepare

public void prepare(int[] arrayElements,
           long timMillis,
           double timingError)

Description copied from interface: BearingLocaliser

Do any preparation necessary (e.g. creation of look up tables)

Specified by:

prepare in interface BearingLocaliser

Parameters:

arrayElements - list of hydrophone array elements in the sub array for this localiser.

timingError - expected timing error for each measurement (typically 1/12 of an ADC bin, or less if interpolation is being used in the cross correlation function).

getArrayAxis

public PamVector[] getArrayAxis()

Description copied from interface: BearingLocaliser

Get the principle axis of the array

Specified by:

getArrayAxis in interface BearingLocaliser

Returns:

for a linear array this will be a vector along the array;

for a planar array, this will be the vector on the plane between two hydrophones which is closest to the y axis.

getArrayType

public int getArrayType()

Specified by:

getArrayType in interface BearingLocaliser

Returns:

the type of array - linear, planar, volumetric, etc.

localise

public double[][] localise(double[] delays,
                  long timeMillis)

Description copied from interface: BearingLocaliser

Calculate angles theta and phi, based on a set of delays. The number of delays should be equal to n(n-1)/2 where n is the number of hydrophone elements in the sub array.

Specified by:

localise in interface BearingLocaliser

Parameters:

delays - array of delay times.

timeMillis - of this detection. This is relatively unused except in situation where hydrophone elements are moving relative to each other with time.

Returns:

theta, phi and their estimated errors all in radians.

Data are packed into a two row array, the first row of which contains one or two angles, the second (optional) row contains the errors on those angles.

localiseByCrawl

public double[][] localiseByCrawl(double[] delays,
                         long timeMillis)

localiseByBisection

public double[][] localiseByBisection(double[] delays)

getHydrophoneMap

public int getHydrophoneMap()

Description copied from interface: BearingLocaliser

Get a hydrophone map for this localiser

Specified by:

getHydrophoneMap in interface BearingLocaliser

Returns:

bitmap of used hydrophones.