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Version 1.9 Build 1556

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What vpmanager does:

Set a Given Telescope's VP/PB model

The vpmanager recognizes the names of several telescopes: ATCA, GBT, GMRT, HATCREEK, NMA, NRAO12M, NRAO140FT, OVRO, VLA, WSRT. New telescopes and their default VP/PB models will need to be added to the system.

Common VP/PB Models

Many common voltage pattern (vp) and primary beam (pb) models have been coded into AIPS++. Currently, the recognized models include DEFAULT, ATCA_L1, ATCA_L2, ATCA_L3, ATCA_S, ATCA_C, ATCA_X, GBT, GMRT, HATCREEK, NRAO12M, NRAO140FT, OVRO, VLA, VLA_INVERSE, VLA_NVSS, VLA_2NULL, VLA_4, VLA_P, VLA_L, VLA_C, VLA_X, VLA_U, VLA_K, VLA_Q, WSRT, and WSRT_LOW. In all cases, the VP/PB model and the beam squint (if present) scale linearly with wavelength. If DEFAULT is selected, the approrpiate VP/PB model is selected for the telescope and observing frequency.

1-D Beam Models

Most beam models are rotationally symmetric (excepting beam squint). From the beam parameterization in terms of the various coefficients and other terms, an internal lookup table with 10000 elements is created for application of the VP/PB to an image.

Beam Squint

The VP/PB models include beam squint. The VLA_L, VLA_C, VLA_X, VLA_U, VLA_K, and VLA_Q models (which are the defaults for those VLA bands), have the appropriate squint magnitude and orientation, though the orientation has not been verified through processing actual data.

Multiple VP/PB Models for one MS

The VPManager can have VP information for multiple telescopes. However, the internals of imager cannot yet deal with VP/PB's for multiple telescopes. In the case of a MS with multiple telescopes present, the primary beam of the first telescope present in the MS will be used, even if it is not the first telescope specified in the VP description table produced by vpmanager.

Antenna-dependent Voltage Patterns

are not yet supported.

Two-dimensional Voltage Pattern Images

are supported via setpbimage.

Example
The following example shows a simple way to make a new voltage pattern table.

Note that this can be more easily done from the toolmanager.

include 'vpmanager.g'
# 
# make the vpmanager
#
algore := vpmanager();
#
# Lets say we want an Airy Disk voltage pattern for our
# HATCREEK data, but we want to use the system default
# for the OVRO data:
#
algore.setpbairy(telescope='HATCREEK', dopb=T, dishdiam='6.0m', blockagediam='0.6m',
  maxrad='2arcmin', reffreq='100GHz', dosquint=F);
#
algore.setcannedpb(telescope='OVRO', dopb=T, commonpb='DEFAULT', dpsquint=F);
#
algore.summarizevps();
#
algore.saveastable(tablename='California.Beaming');
#

Constructors

vpmanager	Construct a vpmanager tool

Functions

done	Terminate the vpmanager
saveastable	Save the vp or pb descriptions as a table
setcannedpb	Select a vp/pb from our library of common pb models
setpbairy	Make an airy disk vp
setpbcospoly	Make a vp/pb from a polynomial of scaled cosines
setpbgauss	Make a Gaussian vp/pb
setpbimage	Make a vp/pb from a user-supplied image
setpbinvpoly	Make a vp/pb as an inverse polynomial
setpbnumeric	Make a vp/pb from a user-supplied vector
setpbpoly	Make a vp/pb from a polynomial
summarizevps	Summarize the currently accumulated VP descriptions