Getting started

First, let us start with a simple example which will also test the code of PEARL. Execute the following commands to read a data set delivered with $\cal OYST\!ER\,$and the model of a double star fit to these data. Compute the complex model visibilities (calcmodel) to have a “perfect” data set for which one should be able to get a good image.

cd oyster/lab/data/2001
binary_model.period=200 		; Binary will move during obs. otherwise
scans.vissqcerr=abs(scans.vissqcerr)			; Use all data
scans.triplephasecerr=abs(scans.triplephasecerr)	; Use all data
calcmodel				; Compute model visibilities

After starting PEARL, you will be presented with GUI as shown in Fig. 29.1.

Figure 29.1: Main PEARL GUI

Drag the slider under the large display of the synthesized point spread function (aka “dirty beam”) to the right to run an interactive version of the CLEAN algorithm (the counter above the slider shows the number of CLEAN components added to the model and subtracted from the “dirty image” shown in then lower-right display (green dots show the locations of the CLEAN components). You can also drag the slider to the left to remove the CLEAN components from the model. The convolution of the model with the CLEAN beam (central peak of the dirty beam) is shown in the small upper-right display.

When you click the Update button, the current model is used to compute the complex model visibilites, run a phase self-calibration, and display the residual image in the lower right panel, and the final image (CLEAN components convolved with the CLEAN beam added to the residual image) in the upper right panel.

Figure 29.2: Main PEARL GUI