mil.navy.nps.rra
Class Beam

java.lang.Object
  |
  +--mil.navy.nps.rra.Beam

public class Beam

extends java.lang.Object

A Beam is defined as the volume swept out by four Rays as they traverse the ocean environment.

This class forms a Beam from four Ray calculations, which are acoustically propagated according to the sound speed profile (SSP) & Surface & Bottom. Calculated values can be used to produce a VRML representation of the Beam.

Beams of energy can be considered to consist of bundles of sound rays. The energy in a bundle can be shown not to diverge from the bundle. Thus the energy in a bundle is constant, and subsequently the product of the intensity versus the area of the bundle perpendicular to direction of propagation is a constant as well. Therefore a beam is a fundamental building block for constructing a multiple-beam Lobe of a sonar pattern.

Version:

1.0

Author:

LT Timothy M. Holliday USN

Contact: Don Brutzman (web.nps.navy.mil/~brutzman) brutzman@nps.navy.mil

Source Code:

~/vrtp/mil/navy/nps/rra/Beam.java

http://devo.stl.nps.navy.mil/~brutzman/vrtp/mil/navy/nps/rra/Beam.java

History:

15 November 97	Timothy M. Holliday	New
17 March 98	Timothy M. Holliday	Added HTML comment convention
12 April 98	Timothy M. Holliday	Parameterless Constructors
14 April 98	Timothy M. Holliday	Simplified VRML Routines
21 April 98	Timothy M. Holliday	Fixed Problem with calculateSoundPressureLevel
16 October 98	Don Brutzman	Javadoc updates for jdk1.2b4
24 April 99	Don Brutzman	Javadoc updates for jdk1.2.1

Reference:

Holliday, Timothy, Real-Time 3D Sonar Modeling and Visualization, Master's Thesis, Naval Postgraduate School, Monterey California, June 1998. Available at vrtp/rra/HollidayRRAthesis.pdf. and devo.stl.nps.navy.mil/~brutzman/vrtp/rra/HollidayRRAthesis.pdf. Slideset available in Powerpoint and Acrobat .pdf formats.

See Also:

Ray, Lobe, Bottom, Surface, SSP, ExampleBeamStatic, ExampleBeamDynamic, Vec3d

Field Summary

static int	NONE Enumeration flag to avoid further attenuation of color intensity.
static int	T_L Enumeration flag to attenuate color intensity by transmission loss (T_L, pronounced "T sub L").
static int	TIME Enumeration flag to attenuate color intensity by timestep.

Constructor Summary

Beam()
Use accessor methods to set initial values of member variables.

Method Summary

void	calculateBeam(Targets targets) This method calculates the trajectory of the beam of energy enclosed by the defining rays of the beam tube.
void	calculateSoundPressureLevel(double[][][] field, double deltaRange, double deltaDepth, double frequency) This method calculates the trajectory of the beam of energy enclosed by the defining rays of the beam tube.
java.lang.String	dynamicVRML() This method creates a dynamic VRML string shape that is the three dimensional representation of the beam pulse that is propogated.
static boolean	getAppendLineFeed() This is a static method that returns the current line appendage.
double	getAzimuth() This method returns the azimuthal angle.
int	getBeamNumber() This returns BeamNumber.
Bottom	getBottom() This method returns the handle to the bottom object.
double	getDeltaTime() This method returns the simulation time step.
int	getDetectCount() This method returns the total number of detects by the beam
double	getDetectEchoLevel(int N) This method returns the echo level of the detected target
double	getDetectTime(int N) This method returns the detect time for a given detect in the beam
int	getDuration() This method sets the duration of the sonar pulse.
double	getElevation() This method returns the elevation angle.
double	getEndTime() This method returns the simulation end time.
double	getHalfBeamWidthX() This method returns the half beam width of the beam in the azimuthal direction.
double	getHalfBeamWidthY() This method returns the half beam width of the beam in the azimuthal direction.
Vec3d	getPosition() This method returns the position of the beam.
SSP	getSsp() This method returns the handle to the sound speed profile object.
Surface	getSurface() This method returns the handle to the surface object.
java.lang.String	pingTimerVRML() This method returns a VRML timer string that contains the appropriate timing information for the beam
void	reset() This method resets all of the beam parameters after instanciation has occurred, since reuse is more time efficient than garbage collection and reallocation.
static void	setAppendLineFeed(boolean pAppendLineFeed) This is a static method used to indicate whether a line feed is desired at the end of every line.
void	setAzimuth(double phi) This method sets the azimuthal angle, which is the angle from the x-axis to the z-axis rotating about the y-axis.
void	setBeamNumber(int number) This method sets BeamNumber.
void	setBottom(Bottom pBottom) This method sets the handle to the bottom object.
void	setDeltaTime(double pDeltaTime) This method sets the time step in the simulation.
void	setDuration(int duration) This method sets the duration of the sonar pulse.
void	setElevation(double beta) This method sets the elevation angle, which is the angle from the y-axis to the x-axis rotating about the z-axis .
void	setEndTime(double pEndTime) This method sets the simulation end time.
void	setHalfBeamWidthX(double pHalfBeamWidthX) This method sets the half beam width of the beam in the azimuthal direction.
void	setHalfBeamWidthY(double pHalfBeamWidthY) This method sets the half beam width of the beam in the elevation direction.
void	setPosition(double x, double y, double z) This method sets the position of the beam.
void	setSsp(SSP pSsp) This method sets the handle to the sound speed profile object.
void	setSurface(Surface pSurface) This method sets the handle to the surface object.
java.lang.String	staticVRML(int colorChoice, int intensityChoice) This method writes to the console a VRML shape that is the three dimensional representation of the beam that is propagated.

Methods inherited from class java.lang.Object

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

Field Detail

T_L

public static final int T_L

Enumeration flag to attenuate color intensity by transmission loss (T_L, pronounced "T sub L").

TIME

public static final int TIME

Enumeration flag to attenuate color intensity by timestep.

NONE

public static final int NONE

Enumeration flag to avoid further attenuation of color intensity.

Constructor Detail

Beam

public Beam()

Use accessor methods to set initial values of member variables.

Method Detail

reset

public void reset()

This method resets all of the beam parameters after instanciation has occurred, since reuse is more time efficient than garbage collection and reallocation.

setAzimuth

public void setAzimuth(double phi)

This method sets the azimuthal angle, which is the angle from the x-axis to the z-axis rotating about the y-axis.

getAzimuth

public double getAzimuth()

This method returns the azimuthal angle.

setHalfBeamWidthX

public void setHalfBeamWidthX(double pHalfBeamWidthX)

This method sets the half beam width of the beam in the azimuthal direction.

getHalfBeamWidthX

public double getHalfBeamWidthX()

This method returns the half beam width of the beam in the azimuthal direction.

setElevation

public void setElevation(double beta)

This method sets the elevation angle, which is the angle from the y-axis to the x-axis rotating about the z-axis .

getElevation

public double getElevation()

This method returns the elevation angle.

setHalfBeamWidthY

public void setHalfBeamWidthY(double pHalfBeamWidthY)

This method sets the half beam width of the beam in the elevation direction.

getHalfBeamWidthY

public double getHalfBeamWidthY()

This method returns the half beam width of the beam in the azimuthal direction.

setPosition

public void setPosition(double x,
                        double y,
                        double z)

This method sets the position of the beam.

getPosition

public Vec3d getPosition()

This method returns the position of the beam.

setDeltaTime

public void setDeltaTime(double pDeltaTime)

This method sets the time step in the simulation.

getDeltaTime

public double getDeltaTime()

This method returns the simulation time step.

setEndTime

public void setEndTime(double pEndTime)

This method sets the simulation end time. This value is reletive to the start time which is 0.0.

getEndTime

public double getEndTime()

This method returns the simulation end time.

setDuration

public void setDuration(int duration)

This method sets the duration of the sonar pulse. The integer refers to the number of deltaTime increments. currently only 1 or 2 are allowed.

getDuration

public int getDuration()

This method sets the duration of the sonar pulse. The integer refers to the number of deltaTime increments.

setBottom

public void setBottom(Bottom pBottom)

This method sets the handle to the bottom object.

getBottom

public Bottom getBottom()

This method returns the handle to the bottom object.

setSurface

public void setSurface(Surface pSurface)

This method sets the handle to the surface object.

getSurface

public Surface getSurface()

This method returns the handle to the surface object.

setSsp

public void setSsp(SSP pSsp)

This method sets the handle to the sound speed profile object.

getSsp

public SSP getSsp()

This method returns the handle to the sound speed profile object.

setBeamNumber

public void setBeamNumber(int number)

This method sets BeamNumber. It is used to uniquely identify each beam for ROUTEing in VRML.

getBeamNumber

public int getBeamNumber()

This returns BeamNumber. Which is used to uniquely identify each beam for ROUTEing in VRML.

staticVRML

public java.lang.String staticVRML(int colorChoice,
                                   int intensityChoice)

This method writes to the console a VRML shape that is the three dimensional representation of the beam that is propagated.

dynamicVRML

public java.lang.String dynamicVRML()

This method creates a dynamic VRML string shape that is the three dimensional representation of the beam pulse that is propogated.

calculateBeam

public void calculateBeam(Targets targets)

This method calculates the trajectory of the beam of energy enclosed by the defining rays of the beam tube. It also determines when there is a detection.

calculateSoundPressureLevel

public void calculateSoundPressureLevel(double[][][] field,
                                        double deltaRange,
                                        double deltaDepth,
                                        double frequency)

This method calculates the trajectory of the beam of energy enclosed by the defining rays of the beam tube.

getDetectCount

public int getDetectCount()

This method returns the total number of detects by the beam

getDetectTime

public double getDetectTime(int N)

This method returns the detect time for a given detect in the beam

getDetectEchoLevel

public double getDetectEchoLevel(int N)

This method returns the echo level of the detected target

pingTimerVRML

public java.lang.String pingTimerVRML()

This method returns a VRML timer string that contains the appropriate timing information for the beam

setAppendLineFeed

public static void setAppendLineFeed(boolean pAppendLineFeed)

This is a static method used to indicate whether a line feed is desired at the end of every line. 'true' indicates a linefeed is desired and 'false' indicates that a space is desired"

getAppendLineFeed

public static boolean getAppendLineFeed()

This is a static method that returns the current line appendage.