NRAO Home > CASA > CASA Cookbook and User Reference Manual

[next] [prev] [prev-tail] [tail] [up]

Appendix E
The Measurement Equation and Calibration

The visibilities measured by an interferometer must be calibrated before formation of an image. This is because the wavefronts received and processed by the observational hardware have been corrupted by a variety of effects. These include (but are not exclusive to): the effects of transmission through the atmosphere, the imperfect details amplified electronic (digital) signal and transmission through the signal processing system, and the effects of formation of the cross-power spectra by a correlator. Calibration is the process of reversing these effects to arrive at corrected visibilities which resemble as closely as possible the visibilities that would have been measured in vacuum by a perfect system. The subject of this chapter is the determination of these effects by using the visibility data itself.

 E.1 The HBS Measurement Equation
 E.2 General Calibrater Mechanics

[next] [prev] [prev-tail] [front] [up]


More information about CASA may be found at the CASA web page

Copyright © 2010 Associated Universities Inc., Washington, D.C.

This code is available under the terms of the GNU General Public Lincense

Home | Contact Us | Directories | Site Map | Help | Privacy Policy | Search