Sky Jones: Model sky-plane instrumental effects for the SkyEquation. More...

#include <SkyJones.h>

Inheritance diagram for casa::SkyJones:

Public Types
enum	Type { E, T, F, D }
	Allowed types of VisJones matrices. More...
enum	SizeType { COMPOSITE, POWEROF2, ANY }
Public Member Functions
	SkyJones ()
virtual	~SkyJones ()
	Destructor.
virtual ImageInterface< Complex > &	apply (const ImageInterface< Complex > &in, ImageInterface< Complex > &out, const VisBuffer &vb, Int row, Bool forward=True)=0
	Apply Jones matrix to an image (and adjoint)
virtual ImageInterface< Float > &	apply (const ImageInterface< Float > &in, ImageInterface< Float > &out, const VisBuffer &vb, Int row)=0
virtual ImageInterface< Float > &	applySquare (const ImageInterface< Float > &in, ImageInterface< Float > &out, const VisBuffer &vb, Int row)=0
virtual SkyComponent &	apply (SkyComponent &in, SkyComponent &out, const VisBuffer &vb, Int row, Bool forward=True)=0
	Apply Jones matrix to a sky component (and adjoint)
virtual SkyComponent &	applySquare (SkyComponent &in, SkyComponent &out, const VisBuffer &vb, Int row)=0
virtual Bool	changed (const VisBuffer &vb, Int row)=0
	Has this operator changed since the last application?
virtual Bool	changedBuffer (const VisBuffer &vb, Int row1, Int &row2)=0
	Does this operator changed in this VisBuffer, starting with row1? If yes, we return in row2, the last row that has the same SkyJones as row1.
virtual void	reset ()=0
	Reset.
virtual void	assure (const VisBuffer &vb, Int row)=0
	Assure.
virtual Bool	change (const VisBuffer &vb)=0
	Does the operator change in this visbuffer or since the last call? I'm not sure this is useful -- come back to it m.a.h.
virtual Type	type ()=0
	Return the type of this Jones matrix (actual type of derived class).
virtual ImageInterface< Complex > &	applyGradient (ImageInterface< Complex > &result, const VisBuffer &vb, Int row)=0
	Apply gradient.
virtual SkyComponent &	applyGradient (SkyComponent &result, const VisBuffer &vb, Int row)=0
virtual Bool	isSolveable ()=0
	Is this solveable?
virtual void	initializeGradients ()=0
	Initialize for gradient search.
virtual void	finalizeGradients ()=0
	Finalize for gradient search.
virtual void	addGradients (const VisBuffer &vb, Int row, const Float sumwt, const Float chisq, const Matrix< Complex > &c, const Matrix< Float > &f)=0
	Add to Gradient Chisq.
virtual Bool	solve (SkyEquation &se)=0
	Solve.
virtual ImageRegion *	extent (const ImageInterface< Complex > &im, const VisBuffer &vb, const Int irow=-1, const Float fPad=1.2, const Int iChan=0, const SkyJones::SizeType sizeType=COMPOSITE)=0
	Get the ImageRegion of the primary beam on an Image for a given pointing Note: ImageRegion is not necesarily constrained to lie within the image region (for example, if the pointing center is near the edge of the image).
virtual ImageRegion *	extent (const ImageInterface< Float > &im, const VisBuffer &vb, const Int irow=-1, const Float fPad=1.2, const Int iChan=0, const SkyJones::SizeType sizeType=COMPOSITE)=0
virtual String	telescope ()=0
virtual Int	support (const VisBuffer &vb, const CoordinateSystem &cs)=0
virtual void	setThreshold (const Float t)
virtual const Float	threshold ()
Protected Member Functions
virtual String	typeName ()
	Could be over-ridden if necessary.
Protected Attributes
Float	threshold_p

Detailed Description

Sky Jones: Model sky-plane instrumental effects for the SkyEquation.

Intended use:

Public interface

Prerequisite

SkyEquation class

Etymology

SkyJones describes an interface for Components to be used in the SkyEquation . It is an Abstract Base Class: most methods must be defined in derived classes.

Synopsis

A SkyJones implements the instrumental effect of some sky-plane based calibration effect. It conceptually applies an image of Jones matrices to an image. For example, it takes an image of the sky brightness and applies the complex primary beam for a given interferometer. Only the interface is defined here in the Abstract Base Class. Actual concrete classes must be derived from SkyJones. Some (most) SkyJones are solvable: the SkyEquation can be used by the SkyJones to return gradients with respect to itself (via the image interface). Thus for a SkyJones to solve for itself, it calls the SkyEquation methods to get gradients of chi-squared with respect to the image pixel values. The SkyJones then uses these gradients as appropriate to update itself.

The following examples illustrate how a SkyJones can be used:

Mosaicing: one SkyJones for the primary beam. For efficiency the image must be cached and the VisSet iteration order set to minimize the number of recalculations.

Example

     // Low level code example:
   
       MeasurementSet ms("imagertest/3C273XC1.ms", Table::Update);
       VPSkyJones  unsquintedVPSJ(ms);
       VPSkyJones  squintedVPSJ(ms, True, Quantity(5.0, "deg"), BeamSquint::GOFIGURE);
       unsquintedVPSJ.reset();
       squintedVPSJ.reset();
   
       PagedImage<Complex> imageIn;
       PagedImage<Complex> imageOut;  // in reality, this ouwld need more construction with coords and shapes
   
       VisSet vs(ms,bi,chanSelection,interval);
   
       Int row = 0;
       VisIter &vi = vs.iter();
       VisBuffer vb(vi);
       for (vi.originChunks();vi.moreChunks();vi.nextChunk()) {
         cout << "This is integration: " << nChunks++ << endl;
         for (vi.origin();vi.more();vi++) {
           if (myVPSJ.change(vb)) { 
             cout << "State has changed: " << endl;
             squintedVPSJ.showState(os);
             squintedVPSJ.apply(imageIn, imageOut, vb, row);
           }
         }
       }
   
   
         // High Level Code Example:
   
   
         // Create an ImageSkyJones from an image on disk
         ImageSkyModel ism(PagedImage<Float>("3C273XC1.modelImage"));
   
         // Make an FTMachine: here we use a simple Grid and FT.
         GridFT ft;
   
         SkyEquation se(ism, vs, ft);
   
         // Make a Primary Beam Sky Model
         VPSkyJones pbsj(ms);
   
         // Add it to the SkyEquation
         se.setSkyJones(pbsj);
   
         // Predict the visibility set
         se.predict();
   
         // Read some other data
         VisSet othervs("3c84.MS.Otherdata");
   
         // Make a Clean Image and write it out
         HogbomCleanImageSkyJones csm(ism);
         if (csm.solve(othervs)) {
           PagedImage<Float> cleanImage=csm.image(0);
           cleanImage.setName("3c84.cleanImage");
         }

Motivation

The properties of sky-plane based calibration effects must be described for the SkyEquation

To Do

There are no Concrete Classes derived from SkyJones!
Solvable part needs implementation: we need to derive an image of gradients of the elements of the Jones matrix. See VisJones for how to do this.

Definition at line 168 of file SkyJones.h.

Member Enumeration Documentation

enum casa::SkyJones::SizeType

Enumerator:

COMPOSITE
POWEROF2
ANY

Definition at line 174 of file SkyJones.h.

enum casa::SkyJones::Type

Allowed types of VisJones matrices.

Enumerator:

E
T
F
D

Definition at line 172 of file SkyJones.h.

Constructor & Destructor Documentation

casa::SkyJones::SkyJones ( )

virtual casa::SkyJones::~SkyJones ( ) [virtual]

Destructor.

Member Function Documentation

virtual void casa::SkyJones::addGradients	(	const VisBuffer &	vb,
		Int	row,
		const Float	sumwt,
		const Float	chisq,
		const Matrix< Complex > &	c,
		const Matrix< Float > &	f
	)		`[pure virtual]`

Add to Gradient Chisq.

virtual ImageInterface<Complex>& casa::SkyJones::apply	(	const ImageInterface< Complex > &	in,
		ImageInterface< Complex > &	out,
		const VisBuffer &	vb,
		Int	row,
		Bool	forward = `True`
	)		`[pure virtual]`

virtual ImageInterface<Float>& casa::SkyJones::apply	(	const ImageInterface< Float > &	in,
		ImageInterface< Float > &	out,
		const VisBuffer &	vb,
		Int	row
	)		`[pure virtual]`

virtual SkyComponent& casa::SkyJones::apply	(	SkyComponent &	in,
		SkyComponent &	out,
		const VisBuffer &	vb,
		Int	row,
		Bool	forward = `True`
	)		`[pure virtual]`

virtual ImageInterface<Complex>& casa::SkyJones::applyGradient	(	ImageInterface< Complex > &	result,
		const VisBuffer &	vb,
		Int	row
	)		`[pure virtual]`

virtual void casa::SkyJones::assure	(	const VisBuffer &	vb,
		Int	row
	)		`[pure virtual]`

virtual Bool casa::SkyJones::changed	(	const VisBuffer &	vb,
		Int	row
	)		`[pure virtual]`

virtual Bool casa::SkyJones::changedBuffer	(	const VisBuffer &	vb,
		Int	row1,
		Int &	row2
	)		`[pure virtual]`

virtual ImageRegion* casa::SkyJones::extent	(	const ImageInterface< Complex > &	im,
		const VisBuffer &	vb,
		const Int	irow = `-1`,
		const Float	fPad = `1.2`,
		const Int	iChan = `0`,
		const SkyJones::SizeType	sizeType = `COMPOSITE`
	)		`[pure virtual]`

virtual Int casa::SkyJones::support	(	const VisBuffer &	vb,
		const CoordinateSystem &	cs
	)		`[pure virtual]`

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes