Changes between Version 23 and Version 24 of Changes/atlod

Timestamp:

03/06/07 12:00:53 (17 years ago)

Author:

mci156

Comment:

--

Changes/atlod

@@ -13 +13 @@
 
 == SYSCAL Record Changes ==
-  The SYSCAL records will change from their current form.
+ The SYSCAL records will change from their current form.
 
-    SamplerStatistics::
-      we no longer use these. So we need to avoid checking for them with CABB-type data.
+ SamplerStatistics::
+  we no longer use these. So we need to avoid checking for them with CABB-type data.
 
-    StorageOfSYSCALData::
+ 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.
+  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.
 
-     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.
+ 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.
 
-     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.
-
-      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.
+   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 ==