Notes, 2014 July 10
Attending: Bastian, Chen, Fleishman, Gary, Hales, Hudson, Remijan, Shimojo, Sugimoto, White
Today's discussion focused on implementation of the test plan as outlined in the memo by Bastian et al. Referring to the subsection numbers from that memo, we discussed 3.1 (test MD mode for all available antennas) and 3.2 (interferometry in MD mode). We deferred discussion of 3.3 (SD fast scanning) until Richard can participate.
- Bastian, Yagoubov, and Sugimoto-san had some e-mail exchanges over the past week establishing what is needed to perform the tests described in 3.1. Pending checks of the scripts (see below) we hope to proceed with these tests as soon as possible.
- Coordination is needed between Tony R's EOC group, engineering, & SSR. Tony is willing to serve as POC in this coordination process. It is imperative that we our requests go to him and the coordination group for their Wednesday meetings so that they can establish plans on a rolling 2 wk time frame.
- Tony has assigned Akihiko Hirota support the solar effort in SSR, a welcome development. He will be key to developing standard solar observing scripts. Daytime tests will need to be balanced against engineering test priorities; nighttime tests will need to be balanced against EOC priorities. August looks * promising for executing 3.2.1 (see below).
- Thanks to Shimojo-san for circulating a detailed test plan for the tests described in section 3.2. I realize that not everyone has had a chance to review them in detail. Please do so and send comments to the group. We'll want to converge on the plan for 3.2.1 fairly soon.
- 3.1 The objective of these tests is to characterize all available antennas in MD mode with regard to gain, stability, and linearity.
- evaluate as many 7m and 12m antennas as possible using the tuning parameters recommended by Pavel Yagoubov
- note that Pavel recommended Solar 1 (quiet Sun) and Solar 2 (active Sun) settings for band 3
- for band 6, the Solar 1 setting is nominal but detuning is required for Solar 2
- priority should be given to Solar 1 settings; Solar 2 settings should be tested time permitting
- While we did not discuss bands 7 and 9 explicitly, the recommended tuning parameters for these bands need to be established. Until they are, I base initial estimates below on the assumption that we'll be working with bands 3 and 6.
- Sugimoto-san estimates that 1 hr of test time is needed per band per antenna. Assuming we can test ~8 antennas at a time, it will take ~12 hrs of test time to characterize 48 antennas in MD mode for bands 3 and 6 for one set of tunings (Solar 1). Another 6 hrs will will be needed to test Solar 2 settings for band 3, for a total of 18 hrs. Depending on Pavel's recommendations, another 12-24 hrs will be needed to characterize the performance of bands 7 and 9 in MD mode.
- Before any such tests can be conducted, Antonio needs to review the relevant script(s) to determine whether the script can be run on multiple antennas in parallel. Antonio will look at this issue in the next few days.
- While we did not discuss this explicitly, I assume these tests can be performed under the JIRA ticket opened for originally testing the MD mode?
- 3.2.1 The objective of 3.2.1 is to perform interferometry on a strong calibrator at night time in MD mode in order to check amplitude and phase stability when switching between SM and MD modes; and to measure the differential complex gain between SM and MD mode.
- Shimojo-san's test plan outlines the protocol and observing sequence. He points out that a minimum of 4 x 12m and 1x7m antennas are needed (for amplitude and phase closure). The use of more antennas for this test, of course, is desirable.
- A night time observation is preferred. If feasible, we should try to do these tests in August because night time observing will become more difficult to schedule during the long baseline campaign in Sep-Nov.
- Before these tests can be done, we need to check whether the system responds benignly to switching between the SM and MD modes. Antonio is going to try to run a test in the coming week to determine whether this is the case.
- I assume a new JIRA ticket needs to be opened for section 3.2 testing.
- 3.2.2 These tests explore the optimum strategy for transferring calibration to source data
- We did not discuss these tests in detail pending further input from the group on Shimojo-san's draft plan.
- While the tests are more complex than 3.2.1, the amount of time required to execute them is estimated to be ~1 hr per band.
- These tests require daytime observing because solar scans are needed. They will occur after 3.2.1.
- We will discuss 3.2.2 and 3.3 in greater detail in our next meeting. Please correct anything above and add anything I've missed. Thanks.