| | 24 | Warwick gave a report on the status of CABB, which has advanced a lot now. |
| | 25 | The system has produced images (from simultaneous observations) that look very close to the old system. |
| | 26 | * polarisation images differ. It may be just the error response that differs, i.e. it could be that the differences are not significant. |
| | 27 | * relative amplitudes and phases (of the antennae?) appear to be wrong. |
| | 28 | * needs a change to Tsys output formatting (right data being written to wrong record) |
| | 29 | * need to investigate how the XY phase is being formed and how it is being recorded |
| | 30 | * continuum output available only (no zooms) |
| | 31 | * already writing autocorrelation data, though in a potentially wasteful way. |
| | 32 | * the data are being written as two fake 'timing bins'. ugh. |
| | 33 | * the way they are being written means there is a lot of redundant data.[[BR]] |
| | 34 | !MarkW suggested 'packing' the correlations in some way, after discussion this was judged not worth the effort. |
| | 35 | * Coping with hardware failures: if a module dies, lots of channels will disappear from the bandpass. However these will not be in a contiguous chunk. We'll need a way to deal with this. The discussion suggested the 'channel weight' flags can be used for the continuum case at least. |
| | 36 | * In the case of zoom nodes, each central frequency is a separate (FITS binary) table with all baselines in it (including the n-n "autocorrelation baselines"). The spectral weights feature is in the RPFITS library already, but it writes all baselines for every visibility; this leads to a 50% overhead in the raw data files. It's unclear how to deal with this. |
| | 37 | |
| | 38 | Warwick sees two main issues for the software side: |
| | 39 | 1. using information in the autocorrelations to calibrate on a per-channel basis |
| | 40 | 1. dealing with the spectral weights issue. |
| | 41 | |
| | 42 | |
| | 43 | Xmas absences: |
| | 44 | |
| | 45 | || Who ||Last Day ||Back In|| |
| | 46 | ||Dave ||19 Dec ||05 Jan|| |
| | 47 | ||Dave || ? Jan || ?+4 weeks|| |
| | 48 | ||Emil ||19 Dec ||12 Jan|| |
| | 49 | ||Jamie || N/A ||12 Jan|| |
| | 50 | ||!MarkC ||24 Dec ||12 Jan|| |
| | 51 | ||!MarkW || ? || ? || |
| | 52 | ||Naomi ||19 Dec ||late 2009|| |
| | 53 | ||Vince ||24 Dec ||05 Jan|| |
| | 54 | ||Warwick||24 Dec ||05 Jan|| |
| | 55 | |
| | 56 | |
| | 57 | |
| | 58 | === Actions === |
| | 59 | * Emil becomes PS as of today. |
| | 60 | * Jamie will be dealing with "CABB issues" from day 1. He will be doing calibrator observations and reductions, for example, which may well turn up problems. |
| | 61 | * Emil, in collaboration with Jim Caswell, to select some test fields - for repeated observations as the system implementation goes forward. |
| | 62 | * Vince to work with !MarkC on implementing a 'test version' of all the programs. |
| | 63 | * Next meeting 2009-01-09. |
| | 64 | |
