Improve Handling of VLA Sub-Arrays

NRAO Interactive Services Modification Request 3C2n308, June 2008

1. Introduction

The VLA can currently be divided into up to five sub-arrays to observe different fields or frequencies simultaneously. They are mostly independent, but there are some rules about how the correlator allocates resources to each subarray (see below).

2. Background

Currently, the PST does not incorporate sub-arrays in the Session page but we require that a user add the necessary resource information for each sub-array. Therefore, under the current PST the time estimate is overestimated for the total telescope time.

3. Requirements

On the Sessions page there are four column headings: Source Group, Resource, Time, and RMS Noise. Add a column called Subarray that will allow the user to specify to which subarray this Source Group/Resource belongs. The default is that all Source Group/Resources belong to Subarray 1. The tool will have to look for Group/Resources that have the same time request with different subarrays. The time estimate for a session should take the maximum value of the time for all sub-arrays plus the sum of any other Source Group/Resources that are listed. At some future time some validation could be done so that hardware/software rules are enforced (pertaining to correlator resources allocated to each sub-array; once the new WIDAR correlator comes along those rules will change from what they are now). For now, this change should allow total times to be calculated correctly.

For example,

Source Group     Resources     Time(Hrs)   RMS Noise(mJy)     Subarray
Group1           Res1          5           0.02               1
Group2           Res1          10          0.1                1
Group2           Res2          10          0.05               2
Group3           Res3          20          0.1                1
Group3           Res2           7          0.3                1
Group4           Res2           7          0.2                2
Group4           Res1           7          0.07               3

Here the total time would be: 5 + 10 + 20 + 7 = 42hrs.

4. Design

Technical lead should provide a brief description of how this will be implemented in the code.

5. Deployment Checklist

Documentation? Systems/hardware/networking things needed for deployment?

6. Test Plan

6.1 Internal Testing

6.2 Sponsor Testing

6.3 Integration/Regression Tests


APPROVED: I acknowledge that my request is fully contained in this MR, and if the Open Sky (or other NIS or PST developers) deliver exactly what I specified, I will be happy.

ACCEPTED: I acknowledge that I have validated the completed code according to the acceptance tests, and I am happy with the results.

Written - - - - -
Checked - - - - -
Approved by Scientific Sponsor - - - - -
Accepted/Delivered by Sponsor - - - - -

  • Use %X% if MR is not complete (will display ALERT!)
  • Use %Y% if MR iscomplete (will display DONE)

Discussion Area

-- DanaBalser - 19 Feb 2008
Topic revision: r5 - 2008-04-16, MarkClaussen
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