Tianlai Analysis Teleconference

US/Central
Peter Timbie (UW-Madison), Peter Timbie

Minutes

  1. Next discussion of the TNCCS paper will be at this meeting time on Nov 19
  2. Xuelei mentioned:  the NAOC director, Prof. Jifeng Liu, asked me to send out this invitation for the meeting AI-Empowered Astronomy for Open Science, which is to take place Jan 5-7 2025 in Hangzhou. If you or anyone in the Tianlai international collaboration are interested, please let me know, and please feel free to send this to anyone you think might be interested.  Invitation letter is attached below.
  3. Shifan presented an update on his cylinder cross-coupling paper.   It now includes both polarizations.
  4. Jixia discussed drone measurements of the cylinder.  See his PowerPoint slides attached below.   There was a question in the chat from Reza that Jixia answered afterward by email:   Why not use the dish to map the drone beam in 2D? 

Jixia:  Actually, at first I also wanted to use the dish antenna. But unfortunately, when I just arrived  here, I found that the technicians from the dish antenna manufactory already disconnected all the cables of the dish antennas. They are here to add RFI-shielding boxes in order to eliminate the RFIs from the dish antennas (and also install two new dish antennas). The work was not done until the day before yesterday, although the RFI is still not totally eliminated. We think the socket  for the cables to pass through the box is not ideal. 

But even if the dish antennas can be used, there still exists, I think, more difficulties than using dipole antenna. The beam of the dish is narrow: 4 degress, so we have to move the dish antenna to point exactly at the drone. Pointing error may be a problem. And pointing near the zenith is even more difficult when measuring the drone beam near zenith angle 0 degree, because the dish antenna must change its azimuth from e.g. 0 to 180 as soon as possible - note that the drone is still in the sky waiting for the dish antennas to rotate and the endurance of the drone is very limited. I'm not sure if it's possible or not. Maybe, I can have a try.

Also, the RFI from dish antenna is still not eliminated. We have to power off and on which brings at least 15 seconds more for each zenith angle. 

So I think using a dipole antenna seems to be easier. The dipole antenna is fixed on the ground. Itsbeam shape is smooth and wide. The only er

ror comes from the simulation for the dipole beam. 

There are minutes attached to this event. Show them.
    • 07:45 07:46
      Minutes for last meeting (Nov 5) are posted 1m
    • 07:50 08:10
      Update of crosstalk analysis in Tianlai Cylinder data 20m
      Speaker: Dr Shifan Zuo (NAOC)
    • 08:10 08:30
      Drone Measurements 20m
      Speaker: Dr Jixia Li (NAOC)
    • 08:35 08:55
      AI-Empowered Astronomy for Open Science - meeting in January in Hangzhou 20m
      Speaker: Xuelei Chen (NAOC)