ALMA Phase Correction Workshop
Allegro, Leiden, May 30 – June 3, 2016
A workshop focused on how to improve the ALMA phase corrections is jointly organized by the ALMA observatory and Allegro. It will be held at Leiden Observatory from May 30 – Jun 3. Participation is by invitation only. Find more details below:
ALMA imaging observations – particularly on long baselines – are often limited more by phase fluctuations than atmospheric transmission or PWV. To enable more long-baseline or high-frequency observations, or improve existing data, we need to look at ways to improve the phase correction.
The aims of this workshop are:
- Review the methods that could improve ALMA phase correction and image fidelity. Including (but not limited to) baseline accuracy, WVR corrections, pressure and other environmental fluctuations, cycle times, online/offline WVR correction.
- Summarise the results from the related test observations during the 2014 and 2015 long-baseline campaigns, and identify and quantify the methods that do produce noticeable improvements.
- Make recommendations for changes in ALMA software, hardware and/or observing methods which will improve phase correction
A pdf detailed version of the program can be found in this link: Phasemeeting_final_agenda
| Mon 30/05 | (Afternoon Session) | Room HL 204 |
|---|---|---|
| 13:30-13:45 | Welcome & Logistics | Remo |
| 13:45-14:15 | Outline of the meeting & Topic Organisation | Ed – Bill |
| Single Source Statistics | ||
| 14:30-15:00 | ALMA Long Baseline Campaign 2014/2015 – Basic Phase Characteristics & Pseudo cycling | Satoki |
| 15:00-15:20 | COFFEE BREAK | |
| 15:20-15:50 | ALMA Long Baseline Campaign 2014 – Weather Correlations & Use of the Two-Point-Deviation | Luke |
| 16:00-16:30 | Examination of the GonoGo criterion – Results from 2014/2015 – | Bill |
| 16:40-18:00 | Open Discussion Time | |
| Tue 31/05 | (Morning Session) | Room HL 204 |
|---|---|---|
| WVR Discussions | ||
| 09:00-09:45 | Introduction to Radiometer-based Phase Correction – Principles, Instrumentation and Application | Richard |
| 10:00-10:20 | The O2 Oxygen sounder – Applicability in better atmosphere models | George |
| 10:20-10:30 | COFFEE BREAK | |
| 10:30-10:50 | WVR application timescale, 1 sec vs. 6 sec | Ed |
| 11:00-11:30 | Optimising WVR solutions (scaling) – improved phases and images | Luke |
| 11:40-12:00 | Cloud Continuum removal – Effectiveness, applicability | Bill |
| 12:10-12:30 | TelCal WVR online, monitoring and phase RMS calculations | Dominique |
| 12:40-13:00 | Correlation of changes with measured pressure over the array | Satoki |
| Tue 31/05 | (Afternoon Session) | Room HL 204 |
|---|---|---|
| 14:00-15:00 | Open Discussion Time | |
| 15:00-15:20 | COFFEE BREAK | |
| Antenna Position Measurements | ||
| 15:20-15:40 | ‘Inside’ Tc Antpos – phase correction, analysis, SPW combination and plots | Dominique |
| 15:50-16:20 | Long baseline antenna measurements | Todd |
| 16:20-16:40 | COFFEE BREAK | |
| 16:40-17:10 | Are antenna position changes related to tropospheric changes? | Ed |
| 17:20-17:40 | Suggested observing strategies for the next long baselines to reduce the effect of ‘changes’ | Ed |
| 17:40-18:30 | Open Discussion Time | |
| Wed 01/06 | (Morning Session) | Room HL 106 |
|---|---|---|
| Phase referencing statistics | ||
| 09:00-09:20 | Is the GonoGo criteria good for estimating the phase referencing scheme | Bill |
| 09:30-10:00 | Phase referencing statistics and correlations – Fast switching experiments 2014/2015. Details of source separation, cycle time and image quality. When does and doesn’t fast switching work | Yoshi |
| 10:10-10:20 | What about the calibrators? Searches and contributions | Anita |
| 10:30-10:40 | Multi frequency AGN survey with the KVN | Taehyun |
| 10:40-10:50 | COFFEE BREAK | |
| 10:50-11:10 | Pushing bands 9 and 10 beyond 5 km configurations – ‘normal’ observing techniques | Ed |
| 11:20-11:40 | Testing phase referencing in marginal conditions – does very-fast referencing really help | Yoshi – Ed |
| 11:50-12:10 | Diurnal properties of the long baseline phase statistics | Bill – Ed |
| 12:00-13:00 | Open Discussion Time | |
| Wed 01/06 | (Afternoon Session) | Room HL 106 |
|---|---|---|
| Astrometry | ||
| 14:00-14:20 | Astrometry results from the long baseline campaign – multi source observations for accurate astrometry | Antonio |
| 14:30-15:00 | Is this single test sufficient, further examination, astrometry runs, multi calibrators in science data | Ed – Antonio – Open discussion |
| 15:00-15:20 | Long term astrometry: Parallax studies, proper motions, planet/stellar wobbles – tests, feasibility, offered observation modes for LB? | Ed |
| 15:20-15:30 | COFFEE BREAK | |
| 15:30-15:50 | Check sources for Astrometry | Ed |
| 16:00-17:00 | Open Discussion Time | |
| Group Meal Evening — Belgisch Bier Cafe Olivier – 7 pm (Directions) | ||
| Thu 02/06 | (Morning Session) | Room HL 106 |
|---|---|---|
| ALMA Long Baseline experience | ||
| 10:00-10:20 | Lessons Learned at LB (1) | Crystal (LINK) |
| 10:30-10:50 | Lessons Learned at LB (2) | Anita |
| 11:00-10:20 | The use of Check sources during the observations – What the QA2 current script does with check sources and plans for improvements | Todd (LINK) |
| 11:20-11:40 | COFFEE BREAK | |
| 11:40-12:40 | Open Discussion Time | |
| Thu 02/06 | (Afternoon Session) | Room HL 106 |
|---|---|---|
| Higher Frequencies | ||
| 14:00-14:20 | ALMA Band-to-Band (B2B) tests attempts | Ed |
| 14:30-14:50 | Band 3 to Band 7 fast switching results | Yoshi |
| 15:00-15:20 | Dual frequency simulation using sub-arrays – Band 3 to 6 tests | Luke |
| 15:20-15:40 | COFFEE BREAK | |
| 15:40-16:00 | ALMA High Frequency calibrator cone searches | Yanett – Carmen |
| 16:10-17:30 | Open Discussion Time | |
| Fri 03/06 | (Morning Session) | Room HL 106 |
|---|---|---|
| Summary and Future | ||
| 09:30-10:00 | Conference Summary | Remo |
| 10:15-… | Open Session | |
Please, find the workshop presentations and summary in the password protected area (password notified by email, no username required):
Link to online presentations and presentations review.
The workshop is jointly organized by the ALMA observatory and Allegro, the Netherlands ARC node. It will be held at Leiden Observatory from May 30 – Jun 3. Participation is by invitation only.
Hotel occupancy in Leiden is expected to be high for this period and you are urged to book early. A block reservation has been arranged at the IBIS hotel, opposite Leiden Centraal railway station: Link to Ibis hotel
This booking is held until 18/04/2016. After this date rooms that have not been reserved will be canceled. Workshop attendees receive a discounted price. Reservations need to be made via email to H8087-RE@accor.com mentioning the booking code STER280516:
o Single room incl. breakfast: €81.50 (€ 79 room plus € 2.50 tax per person/per day)
o Double room incl. breakfast: €97.00 (€92 room plus €2.50 tax per person/per day)
For those of you staying at the IBIS hotel situated adjacent from Leiden Centraal Station there will be taxis arranged to take you to the university and back each day. There will be enough space for ~15 people in total.
| Leave Ibis | Leave University | Monday | 13:00 | 18:00 | Tuesday | 08:30 | 18:30 | Wednesday | 08:30 | 17:30 | Thursday | 09:30 | 17:30 | Friday | 09:00 | 12:30 |
|---|
As an alternative there are regular buses from the station, buses 43 (direction Den Haag) or bus 57 (direction Nieuw Vennep). These take around 7 minutes. Please see the link below for more specific details if you will be coming by bus.
Instructions on how to get to Leiden Observatory, including transportation from Schiphol Airport, can be found here:
https://www.lorentzcenter.nl/howto.php
And a site map can be found here:
https://www.lorentzcenter.nl/map_LC_hotels_stat_web.php
Note these specify the route to the Lorentz Center, which is in the forward leaning building in the photo. Leiden Observatory and Allegro are located on the 4th and 5th floor of that same building. Note that this is not the old Observatory in the center of Leiden. The workshop will be held on the First and Second floors of the joining building – The Huygens Building (HL) – in either rooms 204 or 106 (see directions below).
WEBEX link for remote participation (only Mac and Windows OS):
This is be open every day of the meeting, you simply click and follow the instructions below (see also Webex_Getting_Started ).
Instructions:
– Use a Windows or Mac OsX computer (NOT Linux) and point the browser to the provided link.
Firefox works, but there are sporadic reports of Safari not working. To be safe, also quit
Skype before you start since under some conditions it can latch on the mic/speaker.
– After signing in (your name and an email address) click the large button on the left “Connect to Audio” –> “Call Using this Computer –>
(select correct audio devices –> be sure to hit “OK” (audio won’t work in meeting until you hit the “OK”). (See page 1 & 3 of the attached guide).
– If possible, use earphones with a microphone.
– Note there are tabs (upper left) for different pages, so check those first if you can not find your way.
– On the right there are buttons to open “Participants”, “Chat” etc. panels. If you make your window large enough it
is possible to have both panels open at the same time. Chat will work even when audio/video is not working
(assuming the person on the other end keeps an eye on it).
– The gear box above the video panel allows you to set the video source (it default for a mac to the camera
on the notebook display which may be closed and you’ll have to then set it to the camera on the external display.)
– The “audio” button below the participants list opens the audio selection/test panel.
The evening meal will be on Wed 7 pm at the Belgisch Bier Cafe Olivier – Hooigracht 23, 2312 KM Leiden.
Find directions from Leiden Centraal station to the restaurant here:
And the menu here: Menu_Olivier_Eng
| Name |
|---|
| Anita Richards |
| Richard Hills |
| Satoki Matsushita |
| Yoshiharu Asaki |
| Bill Dent |
| Ed Fomalont |
| Ray Blundell |
| Juan R. Pardo |
| George Bendo |
| Scott Paine |
| Dominique Broguiere |
| Taehyun Jung |
| Neil Phillips |
| Michael Bremer |
| Bojan Nikolic |
| Antonio Hales |
| Allegro |
Requested remote participation (see instructions here):
| Name |
|---|
| Crystal Bogan |
| Todd Hunter |
| Liz Humphreys |
| Alan Roy |
