UVModelfit Improvements

CASA Modification Request 29C108, November 2007



1. Introduction

Fitting Gaussian component models directly to the visibility data is useful. It can be used in order to determine radio source parameters and error estimates more robustly than from the image. The fitting may be used in the future for partial deconvolution of bright isolated components in order to avoid the errors in deconvolution when a bright sources is not precisely located on a pixel.

2. Background

3. Requirements

The present task, uvmodelfit, works well, but needs to be enlarged to handle more components. This should be a relatively simple extension of the task; however, with several interacting components, some of the available parameters (six parameters for each Gaussian component), must be held fixed in order to obtain convergence. See the fitting in difmap for a good template.

4. Design

5. Deployment Checklist

6. Test Plan

6.1 Internal Testing

6.2 Sponsor Testing

6.3 Integration/Regression Tests

6.4 Testing for Scientific Validity


Signatures

APPROVED: I acknowledge that my request is fully contained in this MR, and if the CASA development group delivers exactly what I specified, I will be happy.

ACCEPTED: I acknowledge that I have validated the completed code according to the acceptance tests, and I am happy with the results.

Written - - - - -
Checked - - - - -
Approved by Scientific Sponsor - - - - -
Accepted/Delivered by Sponsor - - - - -

Symbols:
  • Use %X% if MR is not complete (will display ALERT!)
  • Use %Y% if MR iscomplete (will display DONE)


Discussion Area

-- NicoleRadziwill - 30 Oct 2007

-- EdFomalont - 06 Nov 2007

-- EdFomalont - 07 Nov 2007
Topic revision: r3 - 2007-11-08, EdFomalont
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