Daily Image
02-02-2007
Pavement Pizza
| Submitter: | Oleg Smirnov |
| Description: | The ionosphere remains one of the two main preoccupations of LOFAR calibration (the other is station beamshapes). This simulation by participants of the 2nd MeqTree workshop shows the effect of the ionosphere on the image of a grid of 3x3 test sources, as a function of time. In particular, it shows the differential motion of the sources relative to the central source, which is kept stationary by calibration. It is clear that separate calibration is needed for all sources in a LOFAR field. This will be expensive in processing. The good news is that, even though the movement and distortion of the sources looks rather intimidating, the simulated ionosphere is relatively simple and tractable. Since the simulated behaviour is very similar to that of real sources, as observed by the GMRT radio telescope in India, this bodes well for LOFAR calibration. Note how the 'wildness' of the ionosphere changes as a function of time. Also how the central source, which is imaged perfectly, is distorted by the distortion of the other sources. |
| Copyright: | The MeqTree Foundation |
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