Dear Josh,

My understanding is that Andrey did not apply any probe correction to this data. The whole point was to keep it as simple as possible.

Attached is a summary of the results that I have. You will see that the numbers that Andrey gets using his software are very similar to the ones that I get by processing the far field data he sent me (which are I suppose the same as he sent you). The values I get by processing the FF data you sent me - in K-space - are significantly different. This is especially true of the phase centre. It seems most likely that this is a result of the interpolation which is done on the NSI data.

Note that the effect of the probe corrections is small, which is as it should be because this data was taken with the low-gain "Andrey" horn. Where we get into trouble is with the higher-gain horn. There the correction is quite large and the results are quite a long way out, e.g. the spill-over efficiencies of the set of scans 94 to 99, which were taken just before this scan 103 but with the larger horn, are only ~91.5% when corrected with what we think are the right N's for that horn and ~94% if no correction is applied. (But of course a correction should be applied with that horn.)

Best Richard

-- ToddHunter - 26 Aug 2008

This topic: ALMA > WebHome > FrontEndIntegrationCenter > FEICBeamScanningResults > Aug25comparison
Topic revision: 2008-08-26, ToddHunter
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