2.1 Global Fringe Fitting

1 FTE-w was spent on planning this activity and in travel to and participation in the June ALBiUS meeting in Garching. The default plan is that the work will proceed in three phases:

1. Evaluate global fringe fitting algorithms (TBD), target date 1 January 2010. 2. Implement version of fringe fitting task within CASA sufficient for EVLA/ALMA commissioning and related activities (NRAO), target date 1 July 2010. 3. Implement VLBI/eMerlin CASA fringe fitting task by augmenting the task developed in Phase 2 (JBO/JIVE), target date 1 January 2011. 4. Testing/tuning of fringe fitting task (All), 31 December 2011.

If no partner is able to investigate global fringe fitting algorithms in Phase 1, then the delivery will be a task with classical fitting techniques. This will still be a considerable advance as CASA will then be interoperable with VLBI and eMerlin instruments, which require the fringe fitting capability which is otherwise not available within CASA.

2.2.2 Primary Beam/Mosaicing

The following work occurred in this task in from 1 January 2009 through 30 June 2009 at NRAO, totaling 6 FTE-w.

1. Generalization of PB handling in existing mosaicing tasks, improvements in PB flux scale handling. 2. Non-symmetric PB correction for mosaicking - about 6-8 weeks (not yet complete). Use a model for the antenna aperture illumination and its rotation with Parallactic angle. Add the pointing offsets (for each pointing in a mosaic) to correct for the effects of PB as a function of time during the deconvolution major-minor cycles. 3. Pointing correction (primarily because pointing correction is the basic algorithm used to PB correction in mosaicking). A solver for pointing offsets using the same aperture illumination model. This however has been tested for a single pointing observation only.

Note: The above efforts might have to be considered in-kind contributions until ALBiUS charge codes are established at NRAO, TBD.