TRxAper Class Reference

Constructor...

Cleanup TRxAper

Function uses the protected variables t_start & t_stop to determine the number of points required and allocates the required memory by calling SetUpWaveforms(npts)

Function used to allocate memory required for 3D waveforms. The number of rows and columns is controlled by previous calls to SetWaveSize( WPAIR rxSize). This function also allocates memory for the protected array cache in case signal averaging is enabled at a later time.

The number of points is controlled primarily by the argument npts. However, extra points are added so that there is enough raw data collected to focus the data at range1.

Function to set protected variables t_start & t_stop. Also determines the number of points required and allocates the required memory by calling SetUpWaveforms(npts)

Examples:

pe3.cpp.

Function used to unload the UAS. count is the current data acquisition cycle. The arguments pC0 and pC1 refer to the physical corners of the currently active RxSubaperture (in element coordinate system). The arguments aC0 and aC1 refer to the logical corners of the currently active RxSubaperture (in aperture coordinate system).

Examples:

pe3.cpp.

Function to set the 3 time control variables directly

Function to set the 3 time control variables based on aperture requirements. t_start will be based on the minimum distance from an element in the aperture to range0. t_stop will be based on the maximum distance from an element in the aperture to range1. t_delay will be zero for now.

Returns a data point from the 3D waveform array

Returns a pointer to the waveform at row i and column j.

Function used to control signal averaging. Sets the avg_count and also set AvgFlag to TRUE

Examples:

pe3.cpp.

Returns the number of signals to be averaged

Examples:

pe3.cpp.

Member function performs write raw RxAper waveforms to disk. Each write consists of a 128 bytes header (RAW_RECORD_HEADER_TYPE)

  typedef struct {
    int  nX;                      //Number of X measurements
    int  nY;                      //Number of Y measurements
    int  npt;                     //Number of data points
    int nAscan;                   //This A-scan number
    int nZone;                    //This focal zone number
    int delay;                    //sample at which data recording begins
    int T;                        //Temperature (.01C)
    int txDepth;                  //Transmit depth (microns)
    int txXcenter, txYcenter;     //(X,Y) coordinate of TxAperture
    int rxXcenter, rxYcenter;     //(X,Y) coordinate of RxAperture
    int txSize;                   //TxAperture Size (always square)
    int txCenterDelay;            //Time at which center element fires (nanoseconds)
    int dummy[18];                //Pad to 128 bytes
  } RAW_RECORD_HEADER_TYPE;

followed by the waveform data (16 bit signed integers) written in the following order:

  for each column
    for each row
      write the waveform
    next row
  next column

Function performs write raw RxAper waveforms to disk. Each write consists of a small header

  struct { 
    WORD nx,       // Number of rows
         ny,       // Number of cols
         nz,       // Number of points
         xcenter,  // Physical X of Aperture Center
         ycenter,  // Physical Y of Aperture Center
         bytes; }  // Number of bytes/data point

followed by the waveform data (16 bit signed integers) written in the following order:

  for each column
    for each row
      write the waveform
    next row
  next column

Examples:

pe3.cpp.

Function performs read raw RxAper waveforms to disk. Each write consists of a small header. The header is not yet complete.

  struct { 
    WORD nx,       // Number of rows
         ny,       // Number of cols
         nz,       // Number of points
         xcenter,  // Physical X of Aperture Center
         ycenter,  // Physical Y of Aperture Center
         bytes; }  // Number of bytes/data point

followed by the waveform data written in the following order:

  for each column
    for each row
      read the waveform
    next row
  next column

Member function performs Read raw RxAper waveforms from disk. Each read consists of a 128 bytes header (RAW_RECORD_HEADER_TYPE)

  typedef struct {
    int  nX;                      //Number of X measurements
    int  nY;                      //Number of Y measurements
    int  npt;                     //Number of data points
    int nAscan;                   //This A-scan number
    int nZone;                    //This focal zone number
    int delay;                    //sample at which data recording begins
    int T;                        //Temperature (.01C)
    int txDepth;                  //Transmit depth (microns)
    int txXcenter, txYcenter;     //(X,Y) coordinate of TxAperture
    int rxXcenter, rxYcenter;     //(X,Y) coordinate of RxAperture
    int txSize;                   //TxAperture Size (always square)
    int txCenterDelay;            //Time at which center element fires (nanoseconds)
    int dummy[18];                //Pad to 128 bytes
  } RAW_RECORD_HEADER_TYPE;

followed by the waveform data (16 bit signed integers) read in the following order:

  for each column
    for each row
      read the waveform
    next row
  next column

Function used to zero the 3D waveforms array

Examples:

pe3.cpp.

Function used to remove the DC component of each waveform

Examples:

pe3.cpp.

Function loads the RxAperture data into the MuxTwoDType structure

Examples:

pe3.cpp.

Focus the data in the receive aperture.

• freq is the array frequency in MHz and
• tx_area is the total number of elements in the TxAperture. Currently, spline interpolation is being used to interpolate sampled RxWaveforms while beam-forming. The focused data (or partial A-scan) for the currently active zone is stored in a private variable.

Examples:

pe3.cpp.

This version of Compensation figures out where the aperture is placed, then compensates...

This version of RxCompensation figures out where the aperture is placed, then compensates...

Function used to compensate raw waveforms. User specifies aperture placement.

Examples:

pe3.cpp.

Function used to compensate raw waveforms. User specifies aperture placement. This function gets called only if there is a separate RxCompensation file available. In this case, it is assumed that the data are available at 20 MHz sampling rate....No resampling needed.

Examples:

pe3.cpp.

Returns the number of points in the focused Ascan

Examples:

pe3.cpp.

Member used to retrieve the data from a partial A-scan. Pointer *data must reference a block of data allocated by the user.

Examples:

pe3.cpp.

Returns the private variable t_start

Returns the private variable t_stop

Member used to time-shift the raw waveforms based on data in the aber_delay array. Spline interpolation used to implement shifts. Section added to shift raw data LJB 06/04/98.