Revised pointing accuracy of the DR21M/IRAS20126 data taken 
in the 2006 July run 
-- Revised results with new pointcorr version released on  
  2006 Oct 11
_____________________________________________________________

  Using the new version of "pointcorr" software 
(corrected for the parity flip of the SHARCII 
array), pointing accuracy has been re-examined 
for the data taken during the run in July this year, 
using the same method (with daily pointing correction, 
see the text uploaded on 27 Sep 2006 on the analysis 
logbook web page).  

  The same plots (cazo vs za, czao vs za for both sources)
are attached here.  Comparing with the previous plots,  
some of big scatter data points (appeared close to za ~ 
44-45deg for i20126) have diminished.  

  Revised pointing accuracy of the same data sets 
for each science observations (after daily pointing 
correction) are as follows;  

 i20126 (26 data points in total)
   cazo rms = 1.36 (arcsec)
   czao rms = 1.75 (arcsec)

 dr21m (22 data points in total)
   cazo rms = 2.70 (arcsec)
   czao rms = 2.51 (arcsec)

  The reason why I20126 data show less scatter might be 
because the source is more compact compared to DR21M.  
Note that latest pointcorr software (as of 26 Oct 2006) 
doesn't always fit the flux peak position.  For some cases, 
fitting is affected more by the envelope structure of a source
rather than the peak position (as we discussed in the telecon 
on 5th Oct 2006).   So, there may be an ambiguity of about 
from half a pixel upto one pixel (~2.5 -- 5 arcsec) on the 
fitting results for some cases. 



 - Attached figures 
  DR21M... 
  dr21mcnt_new_cazoza.gif 
    cazo vs za plot after daily pointing offset correction
  dr21mcnt_new_czaoza.gif 
    czao vs za plot after daily pointing offset correction

  I20126... 
  i20126cnt_new_cazoza.gif 
    cazo vs za plot after daily pointing offset correction
  i20126cnt_new_czaoza.gif
    czao vs za plot after daily pointing offset correction

 - Attached data files
  DR21M... 
  dr21m_newpointcorr_output_cnt_27Oct2006.txt 
    table of pointing offsets of the data taken towards the center 
    (no daily pointing correction made)
  dr21m_newpointcorr_output_all_27Oct2006.txt 
    table of pointing offsets of all data 
    (no daily pointing correction made)

  I20126... 
  i20126_cnt_pointcorr_output_20061012.txt
    table of pointing offsets of the data taken towards the center
    (no daily pointing correction made)
  i20126_all_pointcorr_output_20061012.txt
    table of pointing offsets of all data
    (no daily pointing correction made)