PBWProjectFT.h

Classes

PBWProjectFT -- An FTMachine for Gridded Fourier transforms including effects of primary beam and pointing offsets and the w-term (full description)

class PBWProjectFT : public FTMachine

Interface

Public Members

PBWProjectFT(const RecordInterface& stateRec)

PBWProjectFT(const PBWProjectFT &other)

PBWProjectFT &operator=(const PBWProjectFT &other)

~PBWProjectFT()

void setEPJones(EPJones* ep_j)

void setDOPBCorrection(Bool doit=True)

void initializeToVis(ImageInterface<Complex>& image, const Complex& vb)

void initializeToVis(ImageInterface<Complex>& image, const Complex& vb, VisBuffer<Complex>& griddedVis, Array<Double>& uvscale)

void finalizeToVis()

void initializeToSky(ImageInterface<Complex>& image, Complex<Float>& weight, const Matrix& vb)

void finalizeToSky()

void initVisBuffer(VisBuffer& vb, Type whichVBColumn)

void initVisBuffer(VisBuffer& vb, Type whichVBColumn, Int row)

void get(VisBuffer& vb, Int row=-1)

void get(VisBuffer& vb, Cube<Complex>& degrid, Array<Complex>& griddedVis, Array<Double>& scale, Int row=-1)

void get(VisBuffer& vb, Cube<Float>& pointingOffsets, Int row=-1, Type whichVBColumn=FTMachine::MODEL,Int Conj=0)

void get(VisBuffer& vb, VisBuffer& gradAzVB,VisBuffer& gradElVB, Cube<Float>& pointingOffsets,Int row=-1, Type whichVBColumn=FTMachine::MODEL, Type whichGradVBColumn=FTMachine::MODEL, Int Conj=0, Int doGrad=1)

void get(VisBuffer& vb, Cube<Complex>& degrid, Array<Complex>& griddedVis, Array<Double>& scale, Cube<Float>& pointingOffsets,Int row=-1)

void put(const VisBuffer&, TempImage<Complex>&, Vector<Double>&, int, Vector*, Bool)

void put(const VisBuffer& vb, Int row=-1, Bool dopsf=False, FTMachine::Type type=FTMachine::OBSERVED)

void makeImage(FTMachine::Type type, VisSet& vs, ImageInterface<Complex>& image, Complex<Float>& weight)

ImageInterface<Complex>& getImage(Complex<Float>&, Bool normalize=True)

void getWeightImage(ImageInterface<Float>&, Matrix<Float>&)

Bool toRecord(String& error, RecordInterface& outRec, Bool withImage=False)

Bool fromRecord(String& error, const RecordInterface& inRec)

Bool isFourier()

Bool changed(const VisBuffer& vb)

Int findPointingOffsets(const VisBuffer&, Array<Float>&, Array<Float>&, Bool Evaluate=True)

MDirection::Convert makeCoordinateMachine(const VisBuffer&, const MDirection::Types&, const MDirection::Types&, MEpoch& last)

void makeAveragePB(const VisBuffer& vb, const ImageInterface<Complex>& image, Int& polInUse, Complex<Float>& PB, Complex<Float>& avgPB)

*/ void makeAveragePB(const VisBuffer& vb, const ImageInterface<Complex>& image, Int& polInUse, Complex<Float>& avgPB)

Vector<Int> makeConjPolMap(const VisBuffer& vb)

void reset()

void setPAIncrement(const Quantity &paIncrement)

Protected Members

Int nint(Double val)

Int locateConvFunction(Int Nw, Int polInUse, const VisBuffer& vb, Float &pa)

void cacheConvFunction(Int which, Array<Complex>& cf, CoordinateSystem& coord)

void findConvFunction(const ImageInterface<Complex>& image, const Complex& vb)

void makeConvFunction(const ImageInterface<Complex>& image, const Complex& vb, Float pa)

Array<Complex>* getDataPointer(const IPosition&, Bool)

void ok()

void init()

Int getVisParams()

Bool recordOnGrid(const VisBuffer& vb, Int rownr) const

Int getIndex(const ROMSPointingColumns& mspc, const Double& time, const Double& interval)

Bool getXYPos(const VisBuffer& vb, Int row)

void normalizeAvgPB()

Description

Prerequisite

• FTMachine module
• SkyEquation module
• VisBuffer module
• EPJones module

Etymology

Synopsis

The SkyEquation needs to be able to perform Fourier transforms on visibility data. PBWProjectFT allows efficient handling of direction dependent effects due to the primary beam and antenna pointing offsets using a VisBuffer which encapsulates a chunk of visibility (typically all baselines for one time) together with all the information needed for processing (e.g. UVW coordinates).

Using this FTMachine, errors due antenna pointing offsets can be corrected during deconvolution. One form of antenna pointing error which is known a-priori is the VLA polarization squint (about 6% of the Primary beam width at any frequency). For Stokes imaging, using this FTMachine, the VLA polarization squint and beam polarization can also be corrected. Also since the effects of antenna pointing errors is strongest in the range of 1-2GHz band (where the sky is not quite empty while the beams are not too large either), this FTMachine can also be setup to correct for the w-term.

Switches are provided in the get() method to compute the derivatives with respect to the parameters of the primary beam (only pointing offsets for now). This is used in the pointing offset solver.

See the documentation of other FTMachines for details about the design of the FTMachines in general.

Example

Motivation

Encapsulate the correction of direction dependent effects via visibility plane convolutions with a potentially different convolution function for each baseline.

To Do

Include the antenna based complex gain term as well since that can interfere with the effects of pointing offsets.
Factor out the actual convolution functions as a separate class making FTMachines for various direction dependent effects generic.

Member Description

PBWProjectFT(const RecordInterface& stateRec)

Construct from a Record containing the PBWProjectFT state

PBWProjectFT(const PBWProjectFT &other)

Copy constructor

PBWProjectFT &operator=(const PBWProjectFT &other)

Assignment operator

~PBWProjectFT()

void setEPJones(EPJones* ep_j)

void setDOPBCorrection(Bool doit=True)

void initializeToVis(ImageInterface<Complex>& image, const Complex& vb)

Initialize transform to Visibility plane using the image as a template. The image is loaded and Fourier transformed.

void initializeToVis(ImageInterface<Complex>& image, const Complex& vb, VisBuffer<Complex>& griddedVis, Array<Double>& uvscale)

This version returns the gridded vis...should be used in conjunction with the version of 'get' that needs the gridded visdata

void finalizeToVis()

Finalize transform to Visibility plane: flushes the image cache and shows statistics if it is being used.

void initializeToSky(ImageInterface<Complex>& image, Complex<Float>& weight, const Matrix& vb)

Initialize transform to Sky plane: initializes the image

void finalizeToSky()

Finalize transform to Sky plane: flushes the image cache and shows statistics if it is being used. DOES NOT DO THE FINAL TRANSFORM!

void initVisBuffer(VisBuffer& vb, Type whichVBColumn)

void initVisBuffer(VisBuffer& vb, Type whichVBColumn, Int row)

void get(VisBuffer& vb, Int row=-1)

Get actual coherence from grid by degridding

void get(VisBuffer& vb, Cube<Complex>& degrid, Array<Complex>& griddedVis, Array<Double>& scale, Int row=-1)

Get the coherence from grid return it in the degrid is used especially when scratch columns are not present in ms.

void get(VisBuffer& vb, Cube<Float>& pointingOffsets, Int row=-1, Type whichVBColumn=FTMachine::MODEL,Int Conj=0)

void get(VisBuffer& vb, VisBuffer& gradAzVB,VisBuffer& gradElVB, Cube<Float>& pointingOffsets,Int row=-1, Type whichVBColumn=FTMachine::MODEL, Type whichGradVBColumn=FTMachine::MODEL, Int Conj=0, Int doGrad=1)

void get(VisBuffer& vb, Cube<Complex>& degrid, Array<Complex>& griddedVis, Array<Double>& scale, Cube<Float>& pointingOffsets,Int row=-1)

Get the coherence from grid return it in the degrid is used especially when scratch columns are not present in ms.

void put(const VisBuffer&, TempImage<Complex>&, Vector<Double>&, int, Vector*, Bool)

Put coherence to grid by gridding.

void put(const VisBuffer& vb, Int row=-1, Bool dopsf=False, FTMachine::Type type=FTMachine::OBSERVED)

void makeImage(FTMachine::Type type, VisSet& vs, ImageInterface<Complex>& image, Complex<Float>& weight)

Make the entire image

ImageInterface<Complex>& getImage(Complex<Float>&, Bool normalize=True)

Get the final image: do the Fourier transform and grid-correct, then optionally normalize by the summed weights

void getWeightImage(ImageInterface<Float>&, Matrix<Float>&)

Get the final weights image

Bool toRecord(String& error, RecordInterface& outRec, Bool withImage=False)

Save and restore the PBWProjectFT to and from a record

Bool fromRecord(String& error, const RecordInterface& inRec)

Bool isFourier()

Can this FTMachine be represented by Fourier convolutions?

Bool changed(const VisBuffer& vb)

Bool changed(const VisBuffer& vb) {return vpSJ->changed(vb,1);};

Int findPointingOffsets(const VisBuffer&, Array<Float>&, Array<Float>&, Bool Evaluate=True)

MDirection::Convert makeCoordinateMachine(const VisBuffer&, const MDirection::Types&, const MDirection::Types&, MEpoch& last)

void makeAveragePB(const VisBuffer& vb, const ImageInterface<Complex>& image, Int& polInUse, Complex<Float>& PB, Complex<Float>& avgPB)

*/ void makeAveragePB(const VisBuffer& vb, const ImageInterface<Complex>& image, Int& polInUse, Complex<Float>& avgPB)

Vector<Int> makeConjPolMap(const VisBuffer& vb)

void reset()

void reset() {vpSJ->reset();}

void setPAIncrement(const Quantity &paIncrement)

Int nint(Double val)

Int locateConvFunction(Int Nw, Int polInUse, const VisBuffer& vb, Float &pa)

Locate convolution functions on the disk

void cacheConvFunction(Int which, Array<Complex>& cf, CoordinateSystem& coord)

void findConvFunction(const ImageInterface<Complex>& image, const Complex& vb)

Find the convolution function

void makeConvFunction(const ImageInterface<Complex>& image, const Complex& vb, Float pa)

Array<Complex>* getDataPointer(const IPosition&, Bool)

Get the appropriate data pointer

void ok()

void init()

Int getVisParams()

Bool recordOnGrid(const VisBuffer& vb, Int rownr) const

Is this record on Grid? check both ends. This assumes that the ends bracket the middle

Int getIndex(const ROMSPointingColumns& mspc, const Double& time, const Double& interval)

Bool getXYPos(const VisBuffer& vb, Int row)

void normalizeAvgPB()

VLACalcIlluminationConvFunc vlaPB;

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