[alma-config] pointing error in UVCON

[Leonia Kogan]

Dear Koh-Ichiro,

I have added the pointing error simmulation to my AIPS simulation task UVCON.

The simulation of the pointing error can work if the model is represented by 
CC components.

The simulation of the pointing error does not work if the model 
is represented by an image.

If the model is represented by image (there is no CC table), then it simple 
to get the cc table corresponed to the image using UVCON => IMAGR.

UVCON with simulation of the pointing error requires 50% more time 
in comparison with no simulation of the pointong error.

On my ULTRA-1 SUN, simulation of snapshot observation with 64 antennas 
with simulation of the pointing error spends < 2minutes.

The three type of the primary beam are considered in UVCON:

1. the circular dish with flat ilumination.
2. Ilumination goes down 10db at the dish edge. 
3. Ilumination goes down 15db at the dish edge.

The last two may correspond to the future ALMA's antenna (peter Napier).

I used the new option of UVCON for one of the doughnut configuration using 
model of M51 given to me by John Conway.

In this test I could not reproduce the result given at your memo (internet).
I mean the decreasing of DR and FI in > 6times (for spiral) 
when pointing error is becoming 2.4% of the FWHM_PB.

In my test the effect of the pointing error is not so dramatic.

Many reasons can explain the contradiction:

different configuration;
different model;
different parameters of the error;
different software;
.....; 

I'll put the modified version of UVCON into the AIPS system at the end of 
the week. So it will be available then for all people using AIPS with 
mid night job.

I can send you (and any person) the UVCON version if you do not have 
mid night job.

I am AIPS designator this week. So I can not be active now.
But next week I can try using UVCON for simmulation of your ring (for example) 
with your model, if you send me the model and configuration.

Thank you

Leonia