[evla-sw-discuss] Delay models to station boards

[Barry Clark]

OK, Kevin's remark about location seems compelling, and Rich has already
implemented it (thanks Rich), so I'm ready to comment about content.

I am still dubious about the use of ISO 8601, because it looks like 
encoding it is a significant impact on the Executor.

float is inadequate for t0, it must be double.  On the other hand, for
all of the coefficients except index=0, float is fine.  But it probably
isn't worth the effort to take advantage of that.

The coefficient index and subband ID should be type xs:int - jaxb does 
very annoying things with xs:integer.

The units of the coefficients should be stated in the documentation.
I'm not sure what units you are expecting but something like microseconds,
microseconds per day, microseconds per day per day make nice readable 
numbers.  Clocks instead of microseconds is still pretty reasonable, 
but clocks per clock is annoyingly small.

Similarly a documentatin matter - are the sbDelayModel coefficients
ab initio or as an offset from the bbDelayModel?  (if the latter,
floats are adequate.)

I think for testing purposes, we need a few fields to make it easy to
check if we think something might be going to the wrong place.  These 
would be antenna ID (xs:string) and a sequence number (xs:int) as 
attributes of vciStbDelayModel and an IF ID (xs:string) as an attribute 
of the bbDelayModel.  

Do we want to retain the 'vci' epithet in vciStbDelayModel?  It seems to 
me that we've gotten rather far from the rest of the VCI.

It is likely that all records for some years will use three coefficients.
The nasty OTF case requires three, and three is adequate for everything
we currently are thinking about.  The only very obvious cases where more 
are needed are VLBI and tracking LEOS.  Currently not a lot of constituency
for either.

Similarly, all initial testing will be without sbDelayModels.  I've done
no infrastructure, expecting to eventually import code from the OPT when
it learns how to deal with them.

Not sure when I can support 3bit samplers, either.  I don't really want
to do anything about it until I at least have a design for supporting
the baseband slope correctors, and I haven't a clue.