PBMath1DAiry is a 1-D Airy Disk voltage pattern & Primary Beam. More...

#include <PBMath1DAiry.h>

Inheritance diagram for casa::PBMath1DAiry:

Public Member Functions
	PBMath1DAiry ()
	PBMath1DAiry (Quantity dishDiam, Quantity blockedDiam, Quantity maxRad, Quantity refFreq, BeamSquint squint=BeamSquint(MDirection(Quantity(0.0,"deg"), Quantity(0.0,"deg"), MDirection::Ref(MDirection::AZEL)), Quantity(1.0,"GHz")), Bool useSymmetricBeam=False)
	Instantiation from arguments; referenceFreq is used to scale maximumradius.
PBMath1DAiry &	operator= (const PBMath1DAiry &other)
	Instantiation from a row in the Beam subTable PBMath1DAiry(const Table& BeamSubTable, Int row, Bool useSymmetricBeam=False);.
	~PBMath1DAiry ()
	Clone the object CountedPtr<PBMathInterface> clone();.
PBMathInterface::PBClass	whichPBClass ()
	Get the type of PB this is.
void	summary (Int nValues=0)
	Flush the construction parameters to disk Bool flushToTable(Table& beamSubTable, Int iRow);.
Protected Member Functions
void	fillPBArray ()
	Fill in vp_p array from construction parameters.
Private Attributes
Quantity	dishDiam_p
Quantity	blockedDiam_p

Detailed Description

PBMath1DAiry is a 1-D Airy Disk voltage pattern & Primary Beam.

Intended use:

Public interface

Prerequisite

PBMathInterface class
PBMath1D class

Etymology

PBMath1DAiry: derived from PBMath1D, implements an Airy pattern PB and VP

Synopsis

See PBMath1D for a general synopsis of the 1D PB types.

For an unblocked dish: VP(x) = 2 * j1(x)/x

For blockage: areaRatio = (dish/block)^2; lengthRat = (dish/block); VP(x) = ( areaRatio* 2 * j1(x)/x - 2 j1(x*lengthRat)/(x*lengthRat) ) / (areaRatio - 1);

Example

       PBMath1DAiry airyPB( Quantity(24.5,"m"), Quantity(2.5,"m"),
                            Quantity(2*0.8564,"deg"), Quantity(1.0,"GHz") );
       airyPB.applyPB( inImage, outImage, pointingDir);

Motivation

All of the 1-D PB types have everything in common except for the details of their parameterization. This lightweight class deals with those differences: construction, filling the PBArray from construction parameters, and flushing to disk.

To Do

constructor from a MS beam subtable
flush to MS beam subtable

Definition at line 91 of file PBMath1DAiry.h.

Constructor & Destructor Documentation

casa::PBMath1DAiry::PBMath1DAiry ( )

casa::PBMath1DAiry::PBMath1DAiry	(	Quantity	dishDiam,
		Quantity	blockedDiam,
		Quantity	maxRad,
		Quantity	refFreq,
		BeamSquint	squint = `BeamSquint(MDirection(Quantity(0.0,"deg"), Quantity(0.0,"deg"), MDirection::Ref(MDirection::AZEL)), Quantity(1.0,"GHz"))`,
		Bool	useSymmetricBeam = `False`
	)