Changes between Version 25 and Version 26 of Changes/atlod

Timestamp:

03/06/07 12:03:27 (17 years ago)

Author:

mci156

Comment:

--

Changes/atlod

@@ -16 +16 @@
 
  SamplerStatistics::
-  we no longer use these. So we need to avoid checking for them with CABB-type data.
+ we no longer use these. So we need to avoid checking for them with CABB-type data.
 
  StorageOfSYSCALData::
-  Now that there are no sampler statistics, we need a different way of carrying along [wiki:Glossary/Tsys Tsys] and  
-  [wiki:Glossary/XYPhase XYPhase] data than we have at present. 
-  At present there are 24 scalar values of Tsys (6 antennae * 2 polarizations * 2 IFs) written into every integration, and
-  12 (6 ant. * 2 IFs) of XYPhase.[BR]
-  [BR]
-  In the new system there will likely be a spectrum of each, in the form of autocorrelations.
-  Tsys is formed from the XX and YY polarisations of the autocorrelations, with the noise diode on and off;
-  XYPhase from the XY (or its conjugate, YX) with the diode on and off.
+ Now that there are no sampler statistics, we need a different way of carrying along [wiki:Glossary/Tsys Tsys] and  
+ [wiki:Glossary/XYPhase XYPhase] data than we have at present. 
+ At present there are 24 scalar values of Tsys (6 antennae * 2 polarizations * 2 IFs) written into every integration, and
+ 12 (6 ant. * 2 IFs) of XYPhase.[BR]
+ [BR]
+ In the new system there will likely be a spectrum of each, in the form of autocorrelations.
+ Tsys is formed from the XX and YY polarisations of the autocorrelations, with the noise diode on and off;
+ XYPhase from the XY (or its conjugate, YX) with the diode on and off.
 
-  Deciding what to do here in terms of data representation requires discussions with WarwickWilson.
-  Making changes here has flow on effects to other tasks that use Tsys or XYPhase.
+ Deciding what to do here in terms of data representation requires discussions with WarwickWilson.
+ Making changes here has flow on effects to other tasks that use Tsys or XYPhase.
 
  ApplyingXYPhaseCorrections::
-  At present atlod applies the XYPhase during filling. Nothing else (except maybe atxy) uses them.
-  So we can compute the corrections, apply them and drop the XYPhase information, during ATLOD?
-  May need to order the RPFITS data stream so that autocorrelations come before cross-correlations
-  (and after SYSCAL records), so that the corrections for the cross-correlation can be computed
-  before reaching the cross-correlations.
-  We will need to carry Tsys info along but may be able to do it more compactly than storing the autocorrelations themselves.
-  [BR]
-  Research required: The phase values computed on a per channel basis will be noisy, and applying them will just introduce noise.
-  We need to understand how much smoothing across frequency will be needed.
-  Need to do some experiments to understand the sequence of events in reading in a file.
+ At present atlod applies the XYPhase during filling. Nothing else (except maybe atxy) uses them.
+ So we can compute the corrections, apply them and drop the XYPhase information, during ATLOD?
+ May need to order the RPFITS data stream so that autocorrelations come before cross-correlations
+ (and after SYSCAL records), so that the corrections for the cross-correlation can be computed
+ before reaching the cross-correlations.
+ We will need to carry Tsys info along but may be able to do it more compactly than storing the autocorrelations themselves.[BR]
+[BR]
+ Research required: The phase values computed on a per channel basis will be noisy, and applying them will just introduce noise.
+ We need to understand how much smoothing across frequency will be needed.
+ Need to do some experiments to understand the sequence of events in reading in a file.
 
  == DataSizeLimits ==