Localiser.bearingLocaliser

Interface BearingLocaliser

All Known Implementing Classes:

MLGridBearingLocaliser, PairBearingLocaliser

public interface BearingLocaliser

Class to estimate bearings, with errors from a closely spaced hydrophone array

Author:

Doug Gillespie

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.
void	prepare(int[] arrayElements, long timeMillis, double timingError) Do any preparation necessary (e.g.

Method Detail

prepare

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

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

Parameters:

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

timeMillis, - current time for this localisation

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).

getArrayType

int getArrayType()

Returns:

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

getHydrophoneMap

int getHydrophoneMap()

Get a hydrophone map for this localiser

Returns:

bitmap of used hydrophones.

getArrayAxis

PamVector[] getArrayAxis()

Get the principle axis of the array

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.

localise

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

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.

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.