University of Rochester / Ultrasound Research Laboratory 2D Array Library

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Aperture Class Reference

The Aperture class provides the mechanism for managing both transmit and receive apertures. More...

Inherited by TRxAper and TTxAper.

List of all members.

Public Members

Aperture ( void)
~Aperture ( void)
void Init ( WPAIR size)
void SetupAper ( unsigned type, WPAIR size)
void SetupAper ( unsigned type, float, float, float, float, float)
void CalcDelays ( float range, float elevation, float azimuth)
void CalcDelaysAbs ( float range, float elevation, float azimuth)
WORD CalcApodization ( WORD apodtype)
void SetApodization ( float **user_data)
void SetDelay ( float **user_data)
void SetCenterEl ( WPAIR n)
void SetNumSubs (WPAIR n)
void SetWaveSize ( WPAIR wave_size)
void SetWavePoints ( unsigned npts)
WPAIR GetAperSize ( void)
WPAIR GetWaveSize ( void)
WPAIR GetMaxSubSize ( void)
unsigned GetAperType ( void) const
unsigned GetNumWavePts ( void) const
WPAIR GetNumSubs ( void)
WPAIR GetCorner0 ( unsigned i)
WPAIR GetCorner1 ( unsigned i)
WPAIR GetCenterEl ( void)
float GetApodPoint ( int i, int j)
float GetDelay ( int i, int j)
float GetAberDelay ( int i, int j)
float GetMaxDelay ( void)
BYTE GetChannel ( int col, int row)
BYTE GetChannel ( WPAIR )
int CalcAperSize ( float, float)
WORD FillAberrationDelays ( FILE *)
WORD FillAberrationDelays ( char *, int, int)
float GetSPEED (void)
void SetSPEED (float)
float range0
float range1
float elevation
float azimuth
float delay_center
float sos

Protected Members

WPAIR maxsubsize
INT16 max_xsubs
INT16 max_ysubs
WPAIR size
WPAIR center
unsigned type
unsigned points
WPAIR wave_size
WPAIR num_subapers
WPAIR* subcorner0
WPAIR* subcorner1
float f_number
float** apodization
float** delay
float** aber_delay

Detailed Description

The Aperture class provides the mechanism for managing both transmit and receive apertures.

All of the functions, common to transmit and receive aperture types are included in this class.

Aperture size is controlled by F/number and the range.

$Revision: 1.1 $

Member Function Documentation

inline Aperture::Aperture( void)

Constructor sets everything to 0 and centers the aperture

Aperture::~Aperture( void)

This destructor deletes arrays controlled by the Aper Class

inline void Aperture::Init( WPAIR p)

Used to size different Aperture Types. Hardware limits the TxAperture to 8x16 and the RxAperture to 4x4. This function sets the protected variables: maxsubsize, max_xsubs, and max_ysubs. This function in called by the constructor for TRxAper and TTxAper. The user should never have to call this one directly.

void Aperture::SetupAper( unsigned t, WPAIR s)

Member uses size to control construction, all delays set to 0.0

void Aperture::SetupAper( unsigned t, float r0, float r1, float e, float a, float fn)

Member used to set up aperture size based on:

r0 (near range in mm),
r1 (far range in mm),
e (elevation steering angle in radians),
a (azimuth steerig angle in radians), and
fn (numerical aperture (F/number)).

Examples:: pe3.cpp and Txaper.cpp.

void Aperture::CalcDelays( float r, float e, float a)

Delays are expressed in microseconds based on user input of:

r (range in mm),
e (elevation steering angle in radians), and
a (azimuth steering angle in radians). This version returns the relative delays for each point in the aperture: i.e., minimum delay is zero

Examples:: pe3.cpp.

void Aperture::CalcDelaysAbs( float r, float e, float a)

Delays are expressed in microseconds based on user input of:

r (range in mm),
e (elevation steering angle in radians), and
a (azimuth steering angle in radians). This version returns the absolute one-way delays for each point in the aperture to the point specified by r, e, and a.

WORD Aperture::CalcApodization( WORD apodtype)

Function used to fill the Aperture Apodization Array. The apodization array is assumed to be the same size as the aperture. Currently available apodtype are:

RECT (rectangular...all weights set to 1),
CIRCLE (all weights within the radius set to 1), and
COSINE (weights within the radius set to calculated using an offset cosine apodization).

Any non-sero return value indicates a problem.

Examples:: pe3.cpp.

void Aperture::SetApodization( float **a)

The 2D array a is loaded into the protected variable apodization. Function assumes that the size of **a can be determined from wave_size.

void Aperture::SetDelay( float **a)

The 2D array a is loaded into the protected variable delay. Function assumes that the size of **a can be determined from wave_size.

void Aperture::SetCenterEl( WPAIR n)

Function used to define the position of the aperture.

Examples:: pe3.cpp.

void Aperture::SetNumSubs( WPAIR n)

Function used to set protected variable num_subapers

void Aperture::SetWaveSize( WPAIR n)

Function used to set protected variable wave_size

Examples:: pe3.cpp and Txaper.cpp.

void Aperture::SetWavePoints( unsigned n)

Function used to set protected variable points

Examples:: Txaper.cpp.

inline WPAIR Aperture::GetAperSize( void)

Returns a WPAIR describing the aperture size

Examples:: pe3.cpp and Txaper.cpp.

inline WPAIR Aperture::GetWaveSize( void)

Returns the x,y size of 3D array used to store waveforms

Examples:: Txaper.cpp.

inline unsigned Aperture::GetNumWavePts( void) const

Returns the number of points in the 3D array used to store waveforms

Examples:: Txaper.cpp.

inline float Aperture::GetApodPoint( int i, int j)

Returns the (ith,jth) element of apodization

Examples:: Txaper.cpp.

inline float Aperture::GetDelay( int i, int j)

Returns the (ith,jth) element of delay

Examples:: Txaper.cpp.

inline float Aperture::GetAberDelay( int i, int j)

Returns the (ith,jth) element of aber_delay

float Aperture::GetMaxDelay( void)

Function returns the maximum value of delay that applies in the current aperture. Total delay is assumed to be the (geometric delay) - (aberration delay).

Examples:: Txaper.cpp.

inline BYTE Aperture::GetChannel( int x_col, int y_row)

Returns the channel number associated with a particular element.

inline BYTE Aperture::GetChannel( WPAIR ele)

Returns the channel number associated with a particular element.

Examples:: Txaper.cpp.

int Aperture::CalcAperSize( float range, float fn)

Returns aperture size (an odd number of elements) based on:

range (mm) and
fn (F/number)

Examples:: pe3.cpp.

WORD Aperture::FillAberrationDelays( FILE *fp)

Function used to read aberration delay values from a file written by aberration correction software. Assumes an open file pointed to by *fp. The file is assumed to contain a raw record header

typedef struct {
  int  nX;
  int  nY;
  int  npt;
  int nAscan;
  int nZone;
  int delay;
  int T;
  int txDepth;
  int txXcenter, txYcenter;
  int rxXcenter, rxYcenter;
  int txSize;
  int txCenterDelay;
//  int sr;               //sample rate MHz
//  int pitch;            //microns
  int dummy[18];
} RAW_RECORD_HEADER_TYPE;

followed by a 2D array of short integers. Before using any of the data it is ByteSwaped and then integer delay values are converted from int to float by dividing by 10000.

WORD Aperture::FillAberrationDelays( char *name, int ia, int iz)

Function used to read aberration delay values from a multi-line, multi-zone file written by the aberration correction software.

*name is the string pointer containing the name of the file,
ia is the ascan line of interest and
iz is the focal sone of interest. The file is assumed to contain a 2048 byte test header, followed by a record index, and then followed by a series 2D arrays containing the delays. Before using any of the data it is ByteSwaped and then integer delay values are converted from int to float by dividing by 10000.

Examples:: pe3.cpp.

inline float Aperture::GetSPEED( void)

Get the speed of sound variable

inline void Aperture::SetSPEED( float q)

Set the speed of sound variable used for subsequent time calculations

The documentation for this class was generated from the following files:

aper.h
Aper.cpp

Software written by
Larry Busse of LJB Development
and Bill Glenn, Al Murphy and John Losche of TETRAD Corporation
Documentation generated 3/11/1999