[daip] uvcon

[Leonia Kogan]

Dear Stuart,

First of all I'like to recomend you starting hadlinng UVCON with the 
model given at SMODEl:

Say

SMODEL = 10, 0
It means that UVCON will create the UV data for the point source with 
flux=10 located at the center.
IN2name can be left blank at this case.

Such an aproach will aloow you to feel the input file and simulated 
uvdata (outname, ...).
Having created succesfully output uvdata you can run UVPRT and see all 
visibilities equaled 10 because
the model source is the point source with the flux 10.

Do you understand parameters INVERS, BCOMP, NCOMP, CMETHOD, CMODEL?
They describe the model details when it is determined as an IMAGE or CC 
component file

Now step by step about your problems:

1.If  you type 'aips > getn 4' to revoke in2name,.. for the model you 
are doing wrong.
You have to type 'get2n 4'
Anyway you should see the expected in2name, in2class, in2seq, in2disk at 
the list of iUVCON inputs.
You can reach it typing directely: in2name='...", in2class=..., 
in2seq=.., in2disk=...
This is a technical problem not related with UVCON.

2. About your input file.
I do not like the stars at the second lines (positions at the equatorial 
coordinate system) of the UVCON print out. Check your X, Y, Z
 What are they (X,Y,Z)?  You use the first column at you input file as 
'1' . That means axis Z is directed to local zenith.
Your XYZ are supposed (I think so)  to have origin at the Earth center. 
Do you understand what is the "local"zenith at this case?
If  XYZ are positions at the equatorial coordinate (I guess so) system 
then the first column shoud be '0'!!
(read the explain file to UVCON.
The first line (for each antenna) and the second line at the UVCON print 
out should be identical  at this case.
You can use the standard VLBA file (just for practicing). You should 
type INFILE='AIPSTARS:VLBA_UVCON'

3. You used default for APARM, BPARM...
    It is not a good idea. For example BPARM(1)=0   => the noise is 
added to the data with factor 1
  (read help!) I do not thoink you you want to start simulation with 
noise. Pay attention on APARM(1-7)

Any other questions about UVCON send to me and to daip at nrao.edu

Leonid Kogan