ObitUVCalPolarization.h File Reference

ObitUVCal utilities for applying polarization calibration to uv data. More...

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <glib.h>
#include "Obit.h"
#include "ObitErr.h"
#include "ObitUVDesc.h"
#include "ObitUVSel.h"
#include "ObitUVCal.h"

Go to the source code of this file.

Functions
void	ObitUVCalPolarizationInit (ObitUVCal *in, ObitUVSel *sel, ObitUVDesc *desc, ObitErr *err)
	Public: Init baseline dependent calibration.
void	ObitUVCalPolarization (ObitUVCal *in, float time, glong ant1, glong ant2, gfloat *RP, gfloat *visIn, ObitErr *err)
	Public: Apply polarization calibration.
void	ObitUVCalPolarizationShutdown (ObitUVCal *in, ObitErr *err)
	Public: Shutdown polarization calibration.
ObitUVCalPolarizationS *	ObitUVCalPolarizationSUnref (ObitUVCalPolarizationS *in)
	Public: Destroy polarization calibration structure .

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Detailed Description

ObitUVCal utilities for applying polarization calibration to uv data.

This is implemented as utility routines and a separate Structure definition to avoid circular definitions. The ObitUVCal must be visible here but the structure needed for this calibration is a member of the ObitUVCal. If it were implemented as an Obit class this would lead to a circular definition which c cannot deal with.

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Function Documentation

void ObitUVCalPolarization (  ObitUVCal *  in, float  time, glong  ant1, glong  ant2, gfloat *  RP, gfloat *  visIn, ObitErr *  err )

Public: Apply polarization calibration. For OBIT_UVPoln_VLBI and OBIT_UVPoln_ELORI, the parallactic angle correction is assumed to have already been applied. Polarization calibration structure, values in order: By IF (EIF-BIF+1) A 4x4 complex matrix to be multiplied by the observed polarization vector (RR,LL,RL,LR or XX,YY,XY,YX) to produce the corrected data. Adapted from the AIPSish DATPOL.FOR Notes on parallactic angle: For VLA style calibration (OBIT_UVPoln_Approx), no correction is made to the data early on to remove the parallactic angle. In this case, the instrumental polarization is constant, i.e.correction terms are not a function of parallactic angle whereas the corrected data must have RL,LR rotated by the parallactic angle. The VLBI stype calibration (OBIT_UVPoln_ELORI, OBIT_UVPoln_VLBI) require that the data be corrected for the effects of parallactic angle prior to any self calibration. In this case, the polarization corrections rotate with parallactic angle but the corrected data need no further rotation. Parameters: in  Polarization Calibration Object. time  Time of datum ant1  first antenna number of baseline ant2  second antanna of baseline. RP  Random parameters array. visIn  1 visibility as an array of floats err  ObitError stack.

void ObitUVCalPolarizationInit (  ObitUVCal *  in, ObitUVSel *  sel, ObitUVDesc *  desc, ObitErr *  err )

Public: Init baseline dependent calibration. Parameters: in  Polarization Object. sel  Data selector. desc  Data descriptor. err  ObitError stack.

void ObitUVCalPolarizationShutdown (  ObitUVCal *  in, ObitErr *  err )

Public: Shutdown polarization calibration. Parameters: in  Polarization Object. err  ObitError stack.

ObitUVCalPolarizationS* ObitUVCalPolarizationSUnref (  ObitUVCalPolarizationS *  in  )

Public: Destroy polarization calibration structure . Parameters: in  Polarization Object. Returns: NULL

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