casa::refim::SkyJones Class Reference

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

#include <SkyJones.h>

Inheritance diagram for casa::refim::SkyJones:

Public Member Functions
	SkyJones ()
	Allowed types of VisJones matrices we should use the namespace casa ones enum Type{E,T,F,D};.
virtual	~SkyJones ()
	Destructor.
virtual ImageInterface< Complex > &	apply (const ImageInterface< Complex > &in, ImageInterface< Complex > &out, const vi::VisBuffer2 &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 vi::VisBuffer2 &vb, Int row)=0
virtual ImageInterface< Float > &	applySquare (const ImageInterface< Float > &in, ImageInterface< Float > &out, const vi::VisBuffer2 &vb, Int row)=0
virtual SkyComponent &	apply (SkyComponent &in, SkyComponent &out, const vi::VisBuffer2 &vb, Int row, Bool forward=True)=0
	Apply Jones matrix to a sky component (and adjoint).
virtual SkyComponent &	applySquare (SkyComponent &in, SkyComponent &out, const vi::VisBuffer2 &vb, Int row)=0
virtual Bool	changed (const vi::VisBuffer2 &vb, Int row)=0
	Has this operator changed since the last application?
virtual Bool	changedBuffer (const vi::VisBuffer2 &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 vi::VisBuffer2 &vb, Int row)=0
	Assure.
virtual Bool	change (const vi::VisBuffer2 &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 ::casa::SkyJones::Type	type ()=0
	Return the type of this Jones matrix (actual type of derived class).
virtual ImageInterface< Complex > &	applyGradient (ImageInterface< Complex > &result, const vi::VisBuffer2 &vb, Int row)=0
	Apply gradient.
virtual SkyComponent &	applyGradient (SkyComponent &result, const vi::VisBuffer2 &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 vi::VisBuffer2 &vb, Int row, const Float sumwt, const Float chisq, const Matrix< Complex > &c, const Matrix< Float > &f)=0
	Add to Gradient Chisq.
virtual ImageRegion *	extent (const ImageInterface< Complex > &im, const vi::VisBuffer2 &vb, const Int irow=-1, const Float fPad=1.2, const Int iChan=0, const casa::SkyJones::SizeType sizeType=casa::SkyJones::COMPOSITE)=0
	Solve virtual Bool solve (SkyEquation& se) = 0;.
virtual ImageRegion *	extent (const ImageInterface< Float > &im, const vi::VisBuffer2 &vb, const Int irow=-1, const Float fPad=1.2, const Int iChan=0, const casa::SkyJones::SizeType sizeType=casa::SkyJones::COMPOSITE)=0
virtual String	telescope ()=0
virtual Int	support (const vi::VisBuffer2 &vb, const CoordinateSystem &cs)=0
virtual void	setThreshold (const Float t)
virtual 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 170 of file SkyJones.h.

Constructor & Destructor Documentation

casa::refim::SkyJones::SkyJones ( )

Allowed types of VisJones matrices we should use the namespace casa ones enum Type{E,T,F,D};.

enum SizeType{COMPOSITE, POWEROF2, ANY};

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

Destructor.

Member Function Documentation

virtual void casa::refim::SkyJones::addGradients	(	const vi::VisBuffer2 &	vb,
		Int	row,
		const Float	sumwt,
		const Float	chisq,
		const Matrix< Complex > &	c,
		const Matrix< Float > &	f
	)			`[pure virtual]`

Add to Gradient Chisq.

Implemented in casa::refim::BeamSkyJones.

virtual SkyComponent& casa::refim::SkyJones::apply	(	SkyComponent &	in,
		SkyComponent &	out,
		const vi::VisBuffer2 &	vb,
		Int	row,
		Bool	forward = `True`
	)			`[pure virtual]`

Apply Jones matrix to a sky component (and adjoint).

Implemented in casa::refim::BeamSkyJones.

virtual ImageInterface<Float>& casa::refim::SkyJones::apply	(	const ImageInterface< Float > &	in,
		ImageInterface< Float > &	out,
		const vi::VisBuffer2 &	vb,
		Int	row
	)			`[pure virtual]`

Implemented in casa::refim::BeamSkyJones.

virtual ImageInterface<Complex>& casa::refim::SkyJones::apply	(	const ImageInterface< Complex > &	in,
		ImageInterface< Complex > &	out,
		const vi::VisBuffer2 &	vb,
		Int	row,
		Bool	forward = `True`
	)			`[pure virtual]`

Apply Jones matrix to an image (and adjoint).

Implemented in casa::refim::BeamSkyJones.

virtual SkyComponent& casa::refim::SkyJones::applyGradient	(	SkyComponent &	result,
		const vi::VisBuffer2 &	vb,
		Int	row
	)			`[pure virtual]`

Implemented in casa::refim::BeamSkyJones.

virtual ImageInterface<Complex>& casa::refim::SkyJones::applyGradient	(	ImageInterface< Complex > &	result,
		const vi::VisBuffer2 &	vb,
		Int	row
	)			`[pure virtual]`

Apply gradient.

Implemented in casa::refim::BeamSkyJones.

virtual SkyComponent& casa::refim::SkyJones::applySquare	(	SkyComponent &	in,
		SkyComponent &	out,
		const vi::VisBuffer2 &	vb,
		Int	row
	)			`[pure virtual]`

Implemented in casa::refim::BeamSkyJones.

virtual ImageInterface<Float>& casa::refim::SkyJones::applySquare	(	const ImageInterface< Float > &	in,
		ImageInterface< Float > &	out,
		const vi::VisBuffer2 &	vb,
		Int	row
	)			`[pure virtual]`

Implemented in casa::refim::BeamSkyJones.

virtual void casa::refim::SkyJones::assure	(	const vi::VisBuffer2 &	vb,
		Int	row
	)			`[pure virtual]`

Assure.

Implemented in casa::refim::BeamSkyJones.

virtual Bool casa::refim::SkyJones::change ( const vi::VisBuffer2 & vb ) [pure virtual]

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.

Dec 30 1999

Implemented in casa::refim::BeamSkyJones.

virtual Bool casa::refim::SkyJones::changed	(	const vi::VisBuffer2 &	vb,
		Int	row
	)			`[pure virtual]`

Has this operator changed since the last application?

Implemented in casa::refim::BeamSkyJones.

virtual Bool casa::refim::SkyJones::changedBuffer	(	const vi::VisBuffer2 &	vb,
		Int	row1,
		Int &	row2
	)			`[pure virtual]`

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.

Implemented in casa::refim::BeamSkyJones.

virtual ImageRegion* casa::refim::SkyJones::extent	(	const ImageInterface< Float > &	im,
		const vi::VisBuffer2 &	vb,
		const Int	irow = `-1`,
		const Float	fPad = `1.2`,
		const Int	iChan = `0`,
		const casa::SkyJones::SizeType	sizeType = `casa::SkyJones::COMPOSITE`
	)			`[pure virtual]`

Implemented in casa::refim::BeamSkyJones.

virtual ImageRegion* casa::refim::SkyJones::extent	(	const ImageInterface< Complex > &	im,
		const vi::VisBuffer2 &	vb,
		const Int	irow = `-1`,
		const Float	fPad = `1.2`,
		const Int	iChan = `0`,
		const casa::SkyJones::SizeType	sizeType = `casa::SkyJones::COMPOSITE`
	)			`[pure virtual]`

Solve virtual Bool solve (SkyEquation& se) = 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). fPad: extra fractional padding beyond the primary beam support (note: we do not properly treat squint yet, this will cover it for now) iChan: frequency channel to take: lowest frequency channel is safe for all SizeType: COMPOSITE = next larger composite number, POWEROF2 = next larger power of 2, ANY = just take what we get!

Potential problem: this ImageRegion includes all Stokes and Frequency Channels present in the input image. COMMENTING out for now as this depend on PBMathInterface and which depends back on SkyJones::sizeType

Implemented in casa::refim::BeamSkyJones.

virtual void casa::refim::SkyJones::finalizeGradients ( ) [pure virtual]

Finalize for gradient search.

Implemented in casa::refim::BeamSkyJones.

virtual void casa::refim::SkyJones::initializeGradients ( ) [pure virtual]

Initialize for gradient search.

Implemented in casa::refim::BeamSkyJones.

virtual Bool casa::refim::SkyJones::isSolveable ( ) [pure virtual]

Is this solveable?

Implemented in casa::refim::BeamSkyJones, and casa::refim::VPSkyJones.

virtual void casa::refim::SkyJones::reset ( ) [pure virtual]

Reset.