Structures and type definitions

typedef UCHAR COORType

To be changed to INT2 COORType if the number of pixels in the x-direction exceeds 255.

struct HOUGHBorder

This structure stores the border of a circle clipped on the projected plane. The fields are:

INT4 yUpper

Upper y pixel index affected by this border.

INT4 yLower

Lower y pixel index affected by this border. yUpper$<$yLower or yUpper$<0$ are possible.

INT4 yCenter

y pixel value of the center of the circle.

UINT2 ySide

Length of xPixel.

COORType *xPixel

x pixel index of the border to be marked.

struct HOUGHBin2Border

This structure stores the border indexes corresponding to one frequency bin plus the corrections to be added to the first column of the patch. The fields are:

INT2 leftB1

Border index to be used (start-border `$+1$').

INT2 rightB1

Border index to be used (stop-border `$-1$').

INT2 leftB2

Border index to be used (start-border `$+1$').

INT2 rightB2

Border index to be used (stop-border `$-1$').

INT2 piece1max

: Interval limits of the (first piece) correction to the first column.

INT2 piece1min

: If piece1min > piece1max no corrections should be added.

INT2 piece2max

: Interval limits of the (second piece) correction to the first column.

INT2 piece2min

: If piece2min > piece2max no corrections should be added.

struct HOUGHptfLUT

This structure stores the patch-time-frequency look up table. The fields are:

INT2 timeIndex

Time index of the LUT.

INT8 f0Bin

Frequency bin for which it has been constructed.

REAL8 deltaF

Frequency resolution df=1/TCOH, where 1/TCOH is the coherent integration time used in teh demodulation procedure.

INT4 nFreqValid

Number of frequencies where the LUT is valid.

INT4 iniBin

First bin affecting the patch with respect to f0.

INT4 nBin

Exact number of bins affecting the patch.

INT4 offset

Frequency bin corresponding to center of patch measured with respect to f0Bin (zero in modulated case)

UINT2 maxNBins

Maximum number of bins affecting the patch (for memory allocation purposes).

UINT2 maxNBorders

Maximum number of borders affecting the patch (for memory allocation purposes).

HOUGHBorder *border

The annulus borders.

HOUGHBin2Border *bin

Bin to border correspondence.

struct HOUGHPatchGrid

This structure stores patch-frequency grid information. The fields are:

REAL8 f0

Frequency to construct grid.

REAL8 deltaF

Frequency resolution: df=1/TCOH.

REAL8 patchSizeX

Patch size in radians along x-axis.

REAL8 patchSizeY

Patch size in radians along y-axis.

REAL8 minWidthRatio

Ratio between the minimum annulus width for this search, and the minimun annulus width for 1 year integration time. This value should be in the interval [1.0, 25.0].

REAL8 deltaX

Longitudinal space resolution, x-direction.

REAL8 xMin

Patch limit, as the coordinate of the center of the first pixel.

REAL8 xMax

Patch limit, as the coordinate of the center of the last pixel.

UINT2 xSide

Real number of pixels in the x direction (in the projected plane). It should be less than or equal to xSideMax.

UINT2 xSideMax

Maximun number of pixels in the x direction (for memory allocation), i.e. length of xCoor.

REAL8 *xCoor

Coordinates of the pixel centers.

REAL8 deltaY

Longitudinal space resolution, y-direction.

REAL8 yMin

Patch limit, as center of the first pixel.

REAL8 yMax

Patch limit, as center of the last pixel.

UINT2 ySide

Real number of pixels in the y-direction (in the projected plane). It should be less than or equal to ySideMax.

UINT2 ySideMax

Maximun number of pixels in the y direction (for memory allocation), i.e. length of yCoor.

REAL8 *yCoor

Coordinates of the pixel centers.

struct HOUGHResolutionPar

This structure holds the parameters needed for gridding the patch The fields are:

REAL8 f0

Frequency at which construct the grid.

REAL8 deltaF

Frequency resolution: df=1/TCOH.

REAL8 patchSizeX

Patch size in radians along x-axis.

REAL8 patchSizeY

Patch size in radians along y-axis.

REAL8 minWidthRatio

Ratio between the minimum annulus width for this search and the minimun annulus width for one year integration time. This value should be in the interval [1.0, 25.0].

struct REAL8Cart3Coor

Three dimensional Cartessian coordinates. The fields are:

REAL8 x

REAL8 y

REAL8 z

struct REAL8Cart2Coor

Two dimensional Cartessian coordinates. The fields are:

REAL8 x

REAL8 y

struct REAL8Polar2Coor

Two dimensional polar coordinates. The fields are:

REAL8 alpha

REAL8 radius

struct REAL8UnitPolarCoor

Polar coordinates of a unitary vector on the sphere. The fields are:

REAL8 alpha

Any value

REAL8 delta

In the interval [ $-\pi/2, \pi/2$]

struct HOUGHDemodPar

Demodulation parameters needed for the Hough transform. All coordinates are assumed to be with respect to the same reference system. The fields are:

REAL8 deltaF

: Frequency resolution: df=1/TCOH.

REAL8UnitPolarCoor skyPatch

: $N_{center}$ (alpha, delta): position of the center of the patch.

REAL8 patchSizeX

Patch size in radians along x-axis.

REAL8 patchSizeY

Patch size in radians along y-axis.

REAL8Cart3Coor veloC

: $v(t)/c$ (x,y,z): Relative detector velocity

REAL8Cart3Coor positC

: $(x(t)-x(t0))/c$ (x,y,z): Position of the detector.

REAL8 timeDiff

: $T_{\hat N} (t)-T_{\hat N} (\hat t_0)$: Time difference.

REAL8Vector spin

: Spin down information. It includes the fields: length: maximum order of spin-down parameter, and *data: pointer to spin-down parameter set $F_k$.

struct HOUGHParamPLUT

Parameters needed to construct the partial look up table. The fields are:

INT8 f0Bin

Frequency bin for which it has been constructed

REAL8 deltaF

Frequency resolution: df=1/TCOH.

REAL8UnitPolarCoor xi

Center of the circle on the celestial sphere, $\xi$(alpha,delta) in the rotated coordinates.

REAL8 cosDelta

$\Delta \cos(\phi)$ corresponding to one annulus.

INT4 offset

Frequency bin corresponding to center of patch; measured w.r.t. f0Bin.

INT4 nFreqValid

Number of frequency bins for which the LUT is valid.

REAL8 cosPhiMax0

$\max(\cos(\phi))$ of the f0Bin.

REAL8 cosPhiMin0

$\min(\cos(\phi))$ of the f0Bin.

REAL8 epsilon

maximum angle (distance in radians) from the pole to consider a circle as a line in the projected plane.

Author: Sintes, A.M.,  Papa, M.A.,  Krishnan, B.
$Id: LUT.h,v 1.3 2003/05/19 15:30:50 sintes Exp $