Task 6.2.2.3: Image plane effects - polarization
Lead institute: Cambridge
Local Leader: Paul Alexander - interim leader (see below)
Objective: The objective of this task is to characterise image-plane effects associated with full polarization imaging. It is well known that the polarization response varies across a field of view and while this can be ignored to first order (especially for small fields of view) for high dynamic range imaging and high spectral purity imaging this must be properly taken into account. In addition to the basic theoretical variation, telescope imperfections and errors will introduce (calibratable) effects which will also in general vary across the field of view. The specific aim of this task is then to develop a general description of such effects which can be used within the context of the measurement equation - forms for an appropriate basis set of functions describing the image plane variations will also be developed. Finally, these concepts will be implemented in MeqTrees/CASA and tested against data from interferometers covering the parameter space of: mount (alt/az vs equatorial), feed and with or without focal plane arrays. Close interaction between this task and 6.2.2 (image plane primary beam) will be required.
Major milestones + End Q4 2009 Development of a (mathematical) framework for characterising image-plane effects for full polarization imaging. (4 man months) + End Q2 2010 Development of a generic parameterised telescope description for full stokes imaging for the measurement equation. (3 man months) + End Q3 2010 Implementation a system in MeqTrees or/and CASA. (5 man months)
Note this brings the delivery date in-line with that for the other image-plane development tasks.
Platform: Proposed implementation will be in MeqTrees and/or CASA
Manpower: The EC post will have to be advertised, but expect at least the following contributions from existing people: Alexander (1 month - development of framework), Grainge (1 month - telescope description), Scaife (2 months algorithm design), Ford/Grigorescu (2 months software development), EC post (6 months)
Issues There is an ongoing issue in the UK with funding from our research council - STFC. The matching effort for this task is included in grant applications which have been approved, and under normal curcumstances the grant would have been awarded. Wowever at present the STFC has put a freeze on all grant announcements. We are unable to commit to this work until we can guarantee that the matching effort can be supplied. Once this situation is resolved we will review the local leader of this task.
Task 6.3.1.3 Data excision
Lead institute: Oxford
Local Leader: Paul Alexander - interim leader (see below)
Objectives The overall objective of this and the related tasks in 6.3.1 is to improve the implementation of methods for the identification and excision of RFI and other corrupted data. This sub-task will take the work done in 6.3.1.1 and 6.3.1.2 and implement excision tools in CASA and/or MeqTrees.
Major milestones + End Q4 2010 Assessment of approaches to implement algorithms identified in 6.3.1.1 and 6.3.1.2 (2 man months), re-use of existing tasks, scripting approach, new tasks. (2 man months) + End Q1 2011 Prototype system. (3 man months) + Start Q3 2011 Testing of approaches and modification of algorithms (3 man months) + End Q3 20100 Final system implemented
Manpower: The EC post will have to be advertised, but expect at least the following contributions from existing people: Hobson (1 month), Ford/Grigorescu (3 months software development), EC post (6 months)
Issues There is an ongoing issue in the UK with funding from our research council - STFC. The matching effort for this task is included in grant applications which have been approved, and under normal curcumstances the grant would have been awarded. Wowever at present the STFC has put a freeze on all grant announcements. We are unable to commit to this work until we can guarantee that the matching effort can be supplied. Once this situation is resolved we will review the local leader of this task.
