[daip] New Ticket - [!IDT-632492]: Data weights in Aips

[Enno Middelberg]

New Ticket: Data weights in Aips

Hello,


I'm processing some VLBA data and noticed that SPLIT and UVSUB both modify the visibility weights. The data are from the DiFX 2.0 software correlator, and all have weights set to 1.0 after loading the IDI fits files. SPLIT then calculates weights of the order of 10^-5 when I average all 16 channels per IF. When I set DOCALIB=100 in SPLIT the weights are set to 16, which I can understand.

Further down my processing I am using UVSUB to divide the data by a model, and this again changes the weights.

What are the weights calculations of SPLIT and UVSUB based on? My gut feeling is that they're doing the right thing, ie, weighting down data with larger scatter, but how is this determined?


Thanks,

Enno Middelberg


Ticket Details
===================
Ticket ID: IDT-632492
Department: AIPS Data Processing
Priority: Default
Status: Open
Link:  https://help.nrao.edu/staff/index.php?_m=tickets&_a=viewticket&ticketid=513