Joint Astronomy Centre
Show document only
JAC Home
JCMT
UKIRT
Contact info
JAC Divisions
OMP
Outreach
Seminars
Staff-only Wiki
Weather
Web Cameras
____________________

JCMT home
Telescope
Pointing
20060823 report

CW inclinometry OK


A central bearing load adjustment was done in the afternoon. Tomas Chylek reports:

"The scheduled central bearing adjustment was successfully
performed by LLJ, JNK and TCH. The load distribution between
the central bearing and the rollers has been kept at 85%/15% of the
total antenna weight. The full results are available . . "
here

  • Current antenna mass: 103 655 kg (corresponds to hydraulic pressure 6520 psi)
  • load on central bearing: 864,327 N
  • total load on azimuth rollers: 152,538 N
  • Target adjustment achieved with 3.2% LVDT error
A CW inclinometry run followed, but not before the 'Filter' switch on the inclinometer in the cabin (the 'TMU'-inclinometer) was set to its correct position - OFF !

    Datasets  El Dirn     HST     mean leg temperatures   Humidity
                          start     start   middle   end       %
  ( 20060129  89  cw      19:40      5.1      5.1    5.0      22 
    20060821  89  cw      00:29      8.0      7.4    7.0      -- )
    20060822  89  cw      18:00       -        -      -       --

(The datafile was given a UT-related name !) The data stream recorded is from the 3 active inclinometers only: no strain gauge data, for instance.

The raw data from channels 1,4,7 (inclinometer X-axes), 2,5,8 (Y-axes) and 3,6,9 (temperature) are shown below:

Click on images for better view

The data are v.clean and show none of the problems seen a day or so ago. The (pure CW) track model derived from these data is:

and the new CW model was merged with the (CW-CCW) template from 2005 to create a hybrid track model, which was installed at HST 21:00 on 22 August 2006.

The difference between the new (CW) mode and that of