2005-09-15 ALMA Calibration Group Telecon Agenda and Minutes

---

ALMA Calibration Group Telecon Date: September 15, 2005 (Thursday) Time: 15:00 UT Duration: 1.0 hr USA Toll Free Number: 1-877-919-7148 International: +1-203-566-1039 Passcode: 5 1 0 4 6 8 Leader: JeffMangum

Table of Contents:

---

Complete List of Action Items

---

Action Items from Last Telecon

Assigned To	Due Date	Description	State	Notify
JeffMangum	2005-09-15	First-draft of calibration examples complete. See CalExamples wiki for details.	closed	JeffMangum	edit

---

Agenda and Minutes

NOTE: Discussion from the telecon is shown in italic.

Attendees

1. EdFomalont
2. Mark Gurwell
3. MarkHoldaway
4. RobertLucas
5. JeffMangum
6. JohnRicher
7. AlisonStirling
8. Shinnaga
9. BaltasarVilaVilaro
10. Jack Welch

---

Calibration Plan

Thanks to those who contributed to the recent significant revision to the Calibration Plan. More work needs to be done on this document before it can be considered "done". Recall that we have organized ourselves into small groups concentrate on specific sections of the plan. I list below these groups, with the "lead volunteer" denoted in bold:

1. Amplitude and Flux Calibration (Welch, Butler, Carter, Gibson, Holdaway, Mangum, Martin-Pintado, Kawabe, Wilson)
2. Phase Calibration (Hills, Holdaway, Mundy, Richer, Stirling, Wootten)
3. Bandpass Calibration (Guilloteau, Bacmann)
4. Polarization Calibration (Myers, Holdaway, Laing)
5. Pointing Calibration (Mangum, Lucas, Holdaway)
6. Antenna Location Calibration (Conway, Wright, Morita)
7. Antenna and Electronic Delay Calibration (Lucas)
8. Optics Calibration (Butler, Saito)
9. Total Power Calibration (Holdaway, Mangum, Mundy, Kawabe)
10. Primary Beam Calibration (Holdaway, Wilson)
11. Archiving and Accessing Calibration Quantities (Lucas, Mangum)

With regards the updates to the individual Calibration Plan chapters, with the exception of the changes identified through the Action Items, the Calibration Plan appears to be in pretty good shape.

From JeffMangum: All group members should read through the current version of the plan and suggest changes. Deadline is September 26, 2005.

Assigned to	Due date	Description	State	Notify
JeffMangum	2005-09-26	Final comments on Calibration Plan due.	closed	JeffMangum	edit

_From AlWootten: First execution of the calibration plan will occur during prototype system integration (PSI) at the ATF. The current schedule is available._

---

Calibration Examples

As noted by AlWootten, an action item for Science from the Systems Requirements Review (SRR) was to fill out the "calibration examples" which should accompany the Calibration Plan. The examples should be relevant to the DRSP and be generally applicable.

We need to have drafts of these example documents in-hand by 15 September. A Calibration Examples Wiki page has been set-up for this task. A final version of a document which describes the step-by-step process by which amplitude calibration is done, by RobertLucas and JeffMangum, has been posted to give an example of what I think we are looking for.

The following "volunteers" have been assigned to write these documents:

1. Amplitude and Flux Calibration (RobertLucas, JeffMangum)
2. Phase Calibration (MarkHoldaway)
3. Bandpass Calibration (RobertLucas)
4. Polarization Calibration (StevenMyers)
5. Pointing Calibration (JeffMangum)
6. Antenna Location Calibration (MarkHoldaway)
7. Antenna and Electronic Delay Calibration (RobertLucas)
8. Optics Calibration (BaltasarVilaVilaro)
9. Total Power Calibration (MarkHoldaway)
10. Primary Beam Calibration (MarkHoldaway)
11. ACA Calibration Issues (EdFomalont, MarkHoldaway)

First drafts of several of the "example" documents were posted to the CalExamples wiki by September 15, 2005 (Thanks!). All should read the drafts and comment to the author with cc to the group.

Assigned to	Due date	Description	State	Notify
RobertLucas	2005-10-01	Draft of Bandpass calibration examples document due.	closed	RobertLucas	edit
RobertLucas	2005-10-01	Draft of Delay calibration examples document due. see document at: https://safe.nrao.edu/wiki/pub/ALMA/CalExamples/DelayCalSteps.pdf	closed	RobertLucas	edit
EdFomalont, MarkHoldaway	2005-11-01	Draft of ACA calibration examples document due (following Ed's visit to Mitaka).	closed	EdFomalont, MarkHoldaway	edit

---

Amplitude Calibration Subsystem Development Reports

• Berkeley Absolute Flux Calibration System (JimGibson)
  • Have been making waveguide loss measurements.
  • Continue to work on data analysis of measurements made at BIMA last fall.

• Semi-Transparent Vane (STV) Calibration System (ThomasWilson)
  • See amplitude calibration device review discussion below.

• Multi/Dual-Load (M/DL) Calibration System (Matt Carter)
  • See amplitude calibration device review discussion below.

• Amplitude Calibration Device Review (JeffMangum)
  • The relative amplitude calibration device review was held in Grenoble on 2005/08/25. Committee report has been issued. Committee found that:
    1. STV and ML prototypes showed that these designs cannot meet amplitude calibration spec.
    2. Recommendation for two-load (hot and ambient) system. This design is an adaptation (simplification) of the IRAM ML design by Carter.
  • Jack Welch pointed out that a relatively-new compact refrigerator system (the details for which Jack will send around to the group) should be considered for the DL system design. This would replace the hot load. This cold load design could run at 50 K with +-0.1 K stability.

---

Weather (Ancilliary) Measurement Devices

Final version of the "ancilliary" measurement devices specifications and requirements document has been submitted. See the CalAncillary wiki for a link to the final version. JeffMangum has started working on actual hardware specification for weather instrument systems.

---

Calibration Specifications and Requirements

Please read the latest version of the Calibration Specifications and Requirements document (sent previously to the group). Please send comments to JeffMangum.

This should be ready for putting through the Change Request process, replacing the outdated current version, Chapter 3 of the defunct Project Book, by September 26, 2005.

Assigned to	Due date	Description	State	Notify
JeffMangum	2005-09-26	Final comments on Calibration Specifications and Requirements document due.	closed	JeffMangum	edit

---

Date of Next Phone Meeting

The next ALMA Calibration Group telecon will be 2005, October 13th 15:00 UT (back on our normal "15:00 UT on the second thursday of each month" schedule).

This will occur during the Cost Review; many will not be available. Should this be changed? Group thought no, as it affects only AlWootten and ThomasWilson.

-- JeffMangum - 15 Sep 2005