Route-b

In the task CALIB we increase the value of the AIPS adverb UVRAN to a moderate value of $4K\lambda$ and solve for the Central square antennas in addition to the nearest arm-antennas only (i.e., W01, W02, E02 and S01). The data calibrated using the derived complex gains is shown in panel 2 of Fig. 3. At this stage, one may question the wisdom of choosing only W01, W02, E02 and S01 and increasing the value of UVRAN only to 4 not 3 or 6. Following are the justifications for this approach:

• One should definitely increase the uv-range by an amount which allows one to include some more antennas for solving since that is the aim of whole bootstrapping exercise. We noted that UVRAN=3 does no good in this regard but UVRAN=4 is good enough to have sufficient baselines for all the above mentioned antennas.

• Image model from the previous step with UVRAN=2 should be a better model for this stage with UVRAN=4 rather than, say for a value of 6 or 8 $K\lambda$.

• Breaking the bootstrapping into these small steps allows one to check intermediate results, i.e. it gives a better control on the whole process. This was important as we did not know apriori if the method would definitely work!