[evla-sw-discuss] Metadata related to WIDAR: getting this to the SDM

[Martin Pokorny]

Michael Rupen wrote:
> correlationMode -- default to CROSS_AND_AUTO .
>   The options are CROSS_AND_AUTO, CROSS_ONLY, AUTO_ONLY. 
>   The Configuration Mapper sets up the BlBs to produce as many
>   auto-correlations as possible, so for OSRO and most RSRO we will
>   be in the CROSS_AND_AUTO case.  Note that this implies only that _some_
>   auto-correlations are produced -- in general, and certainly for the first
>   observations, we will have only half of the possible auto-correlations.
>   It is the CBE's responsibility to store zeroes and binary flags for the
>   unmeasured auto-correlations.  We have used CROSS_ONLY in the past
>   for manual BlB setups and to avoid bugs in the filler.

The CBE determines the value of correlationMode recorded in the BDFs 
based on its configuration. If the CM always produces some 
auto-correlations, then fixing this value in the SDM should be OK; 
otherwise, we could end up with an inconsistency.

> axesOrderArray -- default to 1 6 BAL BAB SPW BIN SPP POL
>   The number and order of the axes must match that of the visibility
>   data in the BDF file.  The ordering of those axes is implicit, as given
>   by the ordering of the AxisName enumeration in Table 1 of the BDF
>   definition document.

Actually, this should be BAL BAB SPW BIN SPP STO.

> numAntenna -- default to the value for the first scan I guess

This is determined by the CBE from the list of station ids in its 
configuration document, and is recorded in the BDF. Must the values of 
numAntenna be the same in the BDF and the ExecBlock table?

> numChan -- from the VCI fragment <widar:pp spectralChannels="XX">
>   Note that the number of channels must be identical for all pol'n products
>   at the moment (all OSRO and RSRO data).

When we do the Fourier transform in the CBE, the number of channels is 
reduced by half; otherwise, not. In the BDF, the equivalent of "numChan" 
is set by the CBE configuration document, and its value should account 
for the final number of channels; the CM must account for that in 
creating the CBE configuration message. Does MCAF need to do the same?

-- 
Martin