ObitSkyModelVMSquint.h File Reference

ObitSkyModelVMIon class represents VLA beam squint corrected sky models and their Fourier transforms. More...

#include "Obit.h"
#include "ObitErr.h"
#include "ObitFArray.h"
#include "ObitCArray.h"
#include "ObitCInterpolate.h"
#include "ObitImageMosaic.h"
#include "ObitUV.h"
#include "ObitSkyModelVM.h"

Go to the source code of this file.

Classes
struct	ObitSkyModelVMSquint
	ObitSkyModelVMSquint Class structure. More...
struct	ObitSkyModelVMSquintClassInfo
	ClassInfo Structure. More...
Defines
#define	ObitSkyModelVMSquintUnref(in)   ObitUnref (in)
	Macro to unreference (and possibly destroy) an ObitSkyModelVMSquint returns a ObitSkyModelVMSquint*.
#define	ObitSkyModelVMSquintRef(in)   ObitRef (in)
	Macro to reference (update reference count) an ObitSkyModelVMSquint.
#define	ObitSkyModelVMSquintIsA(in)   ObitIsA (in, ObitSkyModelVMSquintGetClass())
	Macro to determine if an object is the member of this or a derived class.
Functions
void	ObitSkyModelVMSquintClassInit (void)
	Public: Class initializer.
ObitSkyModelVMSquint *	newObitSkyModelVMSquint (gchar *name)
	Public: Default Constructor.
ObitSkyModelVMSquint *	ObitSkyModelVMSquintCreate (gchar *name, ObitImageMosaic *mosaic)
	Public: Create/initialize ObitSkyModelVMSquint structures.
void	ObitSkyModelVMSquintInitMod (ObitSkyModel *in, ObitUV *uvdata, ObitErr *err)
	Public: initialize ObitSkyModelVMSquint structures.
void	ObitSkyModelVMSquintShutDownMod (ObitSkyModel *in, ObitUV *uvdata, ObitErr *err)
	Public: shutdown ObitSkyModel processes.
void	ObitSkyModelVMInitModel (ObitSkyModel *in, ObitErr *err)
	Public: initialize model for pass through data.
gconstpointer	ObitSkyModelVMSquintGetClass (void)
	Public: ClassInfo pointer.
ObitSkyModelVMSquint *	ObitSkyModelVMSquintCopy (ObitSkyModelVMSquint *in, ObitSkyModelVMSquint *out, ObitErr *err)
	Public: Copy (deep) constructor.
void	ObitSkyModelVMSquintClone (ObitSkyModelVMSquint *in, ObitSkyModelVMSquint *out, ObitErr *err)
	Public: Copy structure.
void	ObitSkyModelVMSquintUpdateModel (ObitSkyModelVM *in, gfloat time, gint suba, ObitUV *uvdata, ObitErr *err)
	Public: Routine to update model.
void	ObitSkyModelVMSquintChose (ObitSkyModel *in, ObitUV *uvdata)
	Private: Chose model type.

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Detailed Description

ObitSkyModelVMIon class represents VLA beam squint corrected sky models and their Fourier transforms.

This class represents sky models incorporating beam squint corrections for NRAO-like antennas with offset feeds.

This class is derived from the ObitSkyModelVM class.

The accurate model calculation used a Direct Fourier Transform (DFT) to calculate the effects of the offset in the beam in RR and LL. As such, this class can only operate on data sets containing RR and LL correlations. Requested Stokes should always be " ". Since this is a limitation on dynamic range the correction can be applied only to the brighter parts of a given CLEAN model and faster methods may be applied to the less bright parts of the model. Control over when the accurate, slow and less accurate but faster methods are used is controlled by InfoList members Threshold and maxResid (see below). Threshold sets the level for the accurate model. There are several cases:

• CLEANing For use in CLEANing, maxResid should be either unspecified or set to a negative number. In this case, the value used will be derived from the residual images. Whenever the maximum residual level at the start of a CLEAN major cycle exceeds Threshold, all component subtraction will use the high accuracy model. Otherwise, the modeling type is controlled by the info item Mode.
• Calculation of complete model. If a complete model calculation such as for a self calibration or model subtraction is needed then explicitly set maxResid to 0.0. In this case, the component lists will be compressed (all components in a given cell combined) and the decision to use the accurate or fast model calculation is made based on whether the component has an absolute value of flux density above or below Threshold.

Creators and Destructors

An ObitSkyModelVMSquint will usually be created using ObitSkyModelVMSquintCreate which allows specifying a name for the object as well as the ImageMosaic containing the model.

A copy of a pointer to an ObitSkyModelVMSquint should always be made using the ObitSkyModelVMSquintRef function which updates the reference count in the object. Then whenever freeing an ObitSkyModelVMSquint or changing a pointer, the function ObitSkyModelVMSquintUnref will decrement the reference count and destroy the object when the reference count hits 0. There is no explicit destructor.

Data selection

The selection of data to be modified is through values added to the info (ObitInfoList) member and include the following:

• "Stokes" OBIT_string (4,1,1) Selected output Stokes parameters: " "=> no translation, [default " "]
• "ionVer"OBIT_int (1,1,1) NI table version number, 0-> use highest, def=1
• "BChan" OBIT_int (1,1,1) First spectral channel selected. [def all]
• "EChan" OBIT_int (1,1,1) Highest spectral channel selected. [def all]
• "BIF" OBIT_int (1,1,1) First "IF" selected. [def all]
• "EIF" OBIT_int (1,1,1) Highest "IF" selected. [def all]
• "do3D" OBIT_bool (1,1,1) If 3D imaging wanted. [def false]
• "DIVIDE" OBIT_bool (1,1,1) If division rather than subtraction wanted. [def false]
• "REPLACE" OBIT_bool (1,1,1) If TRUE replace data with model. [def false]
• "PBCor" OBIT_bool (1,1,1) If TRUE make relative primary beam corrections [def true]
• "noNeg" OBIT_bool (1,1,1) If TRUE only positive flux comps are to be used [def false]
• "antSize" OBIT_float (1,1,1) Diameter of antennas for rel. r,.[def 25.0]
• "Factor" OBIT_float (1,1,1) model multiplications factor (-1=>add) [def 1]
• "minFlux" OBIT_float (1,1,1) Minimum flux density model or pixel [def -1.0e20]
• "ModelType" OBIT_int (1,1,1) Model type (ObitSkyModelVMSquintType) [def OBIT_SkyModel_Comps]
• "Mode" OBIT_int (1,1,1) Model mode (ObitSkyModelVMSquintMode) [def OBIT_SkyModel_Fastest]
• "MODPTFLX" OBIT_float (1,1,1) Point model flux in Jy, [def 0.0]
• "MODPTXOF" OBIT_float (1,1,1) Point model "x" offset in deg [def 0.0]
• "MODPTYOF" OBIT_float (1,1,1) Point model "y" offset in deg [def 0.0]
• "MODPTYPM" OBIT_float (4,1,1) Point other parameters [def all 0.0]
• "CCVer" OBIT_int (?,1,1) CC table versions to use [def all 0 => highest]
• "BComp" OBIT_int (?,1,1) Start CC to use per table, 1-rel [def 1 ]
• "EComp" OBIT_int (?,1,1) Highest CC to use per table, 1-rel [def to end ]
• "UpdateInt" OBIT_float (1,1,1) Model update interval (d) [def 1 min]
• "Threshold" OBIT_float (1,1,1) Threshold for high accuracy model [1.0e20]
• "maxResid" OBIT_float (1,1,1) Current maximum abs residual flux density if maxResid==0.0 then use accurate model for merged CC abs flux > Threshold and the gridded method for weaker summed components. [default or < 0 then determine from ImageMosaic]

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Define Documentation

#define ObitSkyModelVMSquintIsA (  in   )     ObitIsA (in, ObitSkyModelVMSquintGetClass())

Macro to determine if an object is the member of this or a derived class. Returns TRUE if a member, else FALSE in = object to reference

#define ObitSkyModelVMSquintRef (  in   )     ObitRef (in)

Macro to reference (update reference count) an ObitSkyModelVMSquint. returns a ObitSkyModelVMSquint*. in = object to reference

#define ObitSkyModelVMSquintUnref (  in   )     ObitUnref (in)

Macro to unreference (and possibly destroy) an ObitSkyModelVMSquint returns a ObitSkyModelVMSquint*. in = object to unreference

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Function Documentation

ObitSkyModelVMSquint* newObitSkyModelVMSquint (  gchar *  name  )

Public: Default Constructor. Initializes class if needed on first call. Parameters: name  An optional name for the object. Returns: the new object.

void ObitSkyModelVMInitModel (  ObitSkyModel *  inn, ObitErr *  err )

Public: initialize model for pass through data. Parameters: inn  SkyModel to initialize err  Obit error stack object.

void ObitSkyModelVMSquintChose (  ObitSkyModel *  inn, ObitUV *  uvdata )

Private: Chose model type. Parameters: in  Pointer to the ObitSkyModel . uvdata  UV data set

void ObitSkyModelVMSquintClassInit (  void   )

Public: Class initializer.

void ObitSkyModelVMSquintClone (  ObitSkyModelVMSquint *  in, ObitSkyModelVMSquint *  out, ObitErr *  err )

Public: Copy structure.

ObitSkyModelVMSquint* ObitSkyModelVMSquintCopy (  ObitSkyModelVMSquint *  in, ObitSkyModelVMSquint *  out, ObitErr *  err )

Public: Copy (deep) constructor. Parameters: in  The object to copy out  An existing object pointer for output or NULL if none exists. err  Obit error stack object. Returns: pointer to the new object.

ObitSkyModelVMSquint* ObitSkyModelVMSquintCreate (  gchar *  name, ObitImageMosaic *  mosaic )

Public: Create/initialize ObitSkyModelVMSquint structures. Parameters: name  An optional name for the object. mosaic  ObitImageMosaic giving one or more images/CC tables Returns: the new object.

gconstpointer ObitSkyModelVMSquintGetClass (  void   )

Public: ClassInfo pointer. Returns: pointer to the class structure.

void ObitSkyModelVMSquintInitMod (  ObitSkyModel *  inn, ObitUV *  uvdata, ObitErr *  err )

Public: initialize ObitSkyModelVMSquint structures. Parameters: in  SkyModel to initialize uvdata  uv data being modeled. err  Obit error stack object.

void ObitSkyModelVMSquintShutDownMod (  ObitSkyModel *  inn, ObitUV *  uvdata, ObitErr *  err )

Public: shutdown ObitSkyModel processes. Parameters: in  SkyModel to shutdown uvdata  uv data being modeled. err  Obit error stack object.

void ObitSkyModelVMSquintUpdateModel (  ObitSkyModelVM *  inn, gfloat  time, gint  suba, ObitUV *  uvdata, ObitErr *  err )

Public: Routine to update model. Parameters: in  SkyModelVM time  current time (d) suba  0-rel subarray number uvdata  uv data being modeled. err  Obit error stack object.

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