A tenative v271a schedule

[Leonid Petrov <Leonid.Petrov@xxxxxxxxxxx>]

Dear colleagues,

  I have prepared a tentative schedule for v271a experiment
on 2008.08.10_00:00:00.0. We have a 24 hour slot for 7 stations,
45, At, Cd, Mo, Ha, Ho, Pa. Station 45 available for 8 hours only.

Please find schedule files at 

http://vlbi.lpetrov.net/lcs/v271a/v271a.vex
http://vlbi.lpetrov.net/lcs/v271a/v271a.stat
http://vlbi.lpetrov.net/lcs/v271a/v271a.plan
http://vlbi.lpetrov.net/lcs/v271a/v271a.skd
http://vlbi.lpetrov.net/lcs/v271a/v271a.skf

  I used AT20G catalogue for selecting 200 candidate sources with 
a) flux density at 8.6 GHZ > 150 mJy
b) spectral index flatter than -0.5
c) not detected in prior experiments and not scheduled in v254b.

I also used a list of 277 tropospheric calibrators.

Scheduling was done similar to v254b:

1) each candidate source is targeted for observations in 3 scans 
   of 120 seconds each;

2) every 1 hour a burst of tropospheric calibrators is observed 4 sources 
   in the elevation range
   [ 12, 45] deg
   [ 30, 85] deg
   [ 12, 60] deg
   [ 30, 85] deg
  Each tropospheric calibrator is observed for 90 seconds.

The difference wrt v254b scheduling strategy:

a) station Hartrao is scheduled in the tag-alone mode. This means that 
   Hartrao is excluded for schedule optimization. It is added to the 
   schedules to those scans in which it can participate. The zone of
   mutual visibility of Hartrao + Australia is so narrow, that no schedule
   in the survey mode is feasible if Hartrao would require to observe every
   scan.

b) The minimum span between scans of the same targeted source is set 
   to 4 hours in v271a, compare with 1 hour in v254b. This will improve 
   accuracy of source position and improve uv-coverage.


Among 200 candidates, 131 sources was picked up for scheduling:

  2 sources in  1 scans
 23 sources in  2 scans
106 sources in  3 scans

Total on source time:  14.22 hours, efficiency: 0.593
On target source time: 12.20 hours, efficiency: 0.508

# scans:  447    # observations:  10192
   
If you have comments, suggestions, please let me know.

  Alessanrda, I had to prepare v271a schedule without any knowledge of
results of v254b. I know, you have not complete correlation. Anyway, any
comments about v254b results that you have seen would be very helpful.

Sincerely,
Leonid Petrov
24-JUL-2008 22:23:23