Localiser
Class MLGridBearingLocaliser

java.lang.Object
  Localiser.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.

Field Summary

private PamVector[]	arrayAxis
private int	arrayType
private int[][]	crawlPairs
private PamArray	currentArray
private double[][][]	delayErrorGrid
private double[][][]	delayGrid
private boolean	firstGrid
(package private) double[][]	likelihoodLUT
private int	nPairs
private int	nPhiBins
private int	nPhones
private int	nThetaBins
private int[]	pairBearingLocaliserPairs
private PairBearingLocaliser[]	pairBearingLocalisers
private double[]	phiRange
private double	phiStep
private int[]	phoneNumbers
private int[][]	phonePairs
(package private) int[][]	simplex
private double	speedOfSound
private double	speedOfSoundError
private double[]	thetaRange
private double	thetaStep
private double	timingError

Constructor Summary

MLGridBearingLocaliser(int[] hydrophoneList, double timingError)

MLGridBearingLocaliser(int hydrophoneBitMap, double timingError)

Method Summary

private int	findPairLocaliser(PamVector pamVector) Find a pair of phones which line up well with pamVector and return a pair localiser made from them .
private double[][]	fullGridSearch(double[] delays)
PamVector[]	getArrayAxis() Get the principle axis of the array
int	getArrayType()
private double	getCurvature(double v1, double v2, double v3)
private double[]	getErrors(int thetaBin, int phiBin, double[] delays) Calculate the errors on theta and phi based on the curvature of the likelihood surface around the central bins
private double	getLLValue(int[] bins, double[] delays)
private double	getLLValue(int thetaBin, int phiBin, double[] delays)
private void	initialiseLLLut()
double[][]	localise(double[] delays) Calculate angles theta and phi, based on a set of delays.
double[][]	localiseByBisection(double[] delays)
double[][]	localiseByCrawl(double[] delays)
private double[][]	localiseBySimplex(double[] delays)
private int	phiAngleToBin(double phi) Convert an angle into a bin, constrained to 0 <= bin < nBins
private double	phiBintoAngle(double bin) Convert a bin into an angle.
void	prepare(int[] arrayElements, double timingError) Do any preparation necessary (e.g.
private void	prepare(int[] arrayElements, double timingError, double thetaStep, double phiStep)
private int	thetaAngleToBin(double theta) Convert an angle into a bin, constrained to 0 <= bin < nBins
private double	thetaBinToAngle(double bin) Convert a bin into an angle.

Methods inherited from class java.lang.Object

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

Field Detail

nPhones

private int nPhones

nPairs

private int nPairs

phoneNumbers

private int[] phoneNumbers

arrayType

private int arrayType

arrayAxis

private PamVector[] arrayAxis

currentArray

private PamArray currentArray

speedOfSound

private double speedOfSound

speedOfSoundError

private double speedOfSoundError

delayGrid

private double[][][] delayGrid

delayErrorGrid

private double[][][] delayErrorGrid

phonePairs

private int[][] phonePairs

thetaRange

private double[] thetaRange

phiRange

private double[] phiRange

nThetaBins

private int nThetaBins

nPhiBins

private int nPhiBins

thetaStep

private double thetaStep

phiStep

private double phiStep

pairBearingLocalisers

private PairBearingLocaliser[] pairBearingLocalisers

pairBearingLocaliserPairs

private int[] pairBearingLocaliserPairs

timingError

private double timingError

simplex

int[][] simplex

likelihoodLUT

double[][] likelihoodLUT

crawlPairs

private int[][] crawlPairs

firstGrid

private boolean firstGrid

Constructor Detail

MLGridBearingLocaliser

public MLGridBearingLocaliser(int hydrophoneBitMap,
                              double timingError)

MLGridBearingLocaliser

public MLGridBearingLocaliser(int[] hydrophoneList,
                              double timingError)

Method Detail

prepare

public void prepare(int[] arrayElements,
                    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).

prepare

private void prepare(int[] arrayElements,
                     double timingError,
                     double thetaStep,
                     double phiStep)

findPairLocaliser

private int findPairLocaliser(PamVector pamVector)

Find a pair of phones which line up well with pamVector and return a pair localiser made from them .

Parameters:

pamVector -

Returns:

thetaBinToAngle

private double thetaBinToAngle(double bin)

Convert a bin into an angle.

Parameters:

bin - bin index

Returns:

angle

thetaAngleToBin

private int thetaAngleToBin(double theta)

Convert an angle into a bin, constrained to 0 <= bin < nBins

Parameters:

theta - angle

Returns:

bin

phiBintoAngle

private double phiBintoAngle(double bin)

Convert a bin into an angle.

Parameters:

bin - bin index

Returns:

angle

phiAngleToBin

private int phiAngleToBin(double phi)

Convert an angle into a bin, constrained to 0 <= bin < nBins

Parameters:

phi - angle

Returns:

bin

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)

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.

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.

localiseBySimplex

private double[][] localiseBySimplex(double[] delays)

initialiseLLLut

private void initialiseLLLut()

getLLValue

private double getLLValue(int[] bins,
                          double[] delays)

getLLValue

private double getLLValue(int thetaBin,
                          int phiBin,
                          double[] delays)

getErrors

private double[] getErrors(int thetaBin,
                           int phiBin,
                           double[] delays)

Calculate the errors on theta and phi based on the curvature of the likelihood surface around the central bins

Parameters:

thetaBin - central theta bin

phiBin - central phi bin

Returns:

errors on theta and phi.

getCurvature

private double getCurvature(double v1,
                            double v2,
                            double v3)

localiseByCrawl

public double[][] localiseByCrawl(double[] delays)

fullGridSearch

private double[][] fullGridSearch(double[] delays)

localiseByBisection

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