20190711 Offset Data Analysis
Last Updated: July 21, 2019


  1. Initial Observing Notes
  2. Collection, review, and measurement of images
  3. Plate scales are measured and plotted.



Initial Observing Notes

On 20190711, during engineering work after a FPA takedown, we made observations designed for deriving the gc1,gc2 plate scale. We took sets of acm,gc1,gc2 images with guiding done on acm. We moved acm fiducial to move the scope in approximately 8" and 4" dithers. The RA duties were being perfomed by JP, but MS and SCO were present, with CC as TO. The acm field is extremely rich with stars.

 

Original notes made by SCO: 
==================================================================================
Start taking images at 04:01:02
First offset  - 04:08:35
Second offset - 04:13:40
I transferred the [acm,gc1,gc2] images to /media/sco/DataDisk1/sco/AD/HET_work/acm_nights/20190711.
==================================================================================




Collection, review, and measurement of images

The image sets were collected and measured.

 

==================================================================================
Collection, review, and measurement of images  

  Position     Time of stable images 
    P1         04:01:02.0  04:08:35.0 
    P2         04:08:35.0  04:13:40.0 
    P3          04:13:40.0  04:23:40.0     ???       

**********************   Process the acm images  ******************************
   pas_imlistgen l acm N                      # 853 acm images 
   mv list.IMAGES list.acm 

   There are only 31 acm images in total and my notes are not so
   detailed, so I make a full bigds9 review of all images. 
    % bigds9 list.acm 1 40 
      **** The last 5 images are empty, so I eliminate them fro list.acm , 
           so I start with 26 images. 
    % bigds9 list.acm 1 30 

     New time table:   
      P1      04:01:01.6    04:01:19.9 
      P2      04:08:15.4    04:09:55.0 
      P3      04:13:13.5    04:14:44.2  

  The P1 images are just a few, and then the jump to P2 is very small. Hence, we
  really have only one good offset comprised of two positions (A,B): 

    Pos         Start         End 
      A      04:08:15.4    04:09:55.0 
      B      04:13:13.5    04:14:44.2  

   To collect and measure A position:
   select_pas_images_by_time list.acm EX0 04:08:15.4 04:09:55.0  acmA N          # 11 images 
   Move into ./acmA

    cp ../acmA.* . 
    cp acmA.images list.acmA
    bigds9 list.acmA 1 30                                                  
    ds9_imstats_fitslist list.acmA FixedRegions N  
 
# all 11 images look good 
    **** I measure 5 stars 
 
   To collect and measure B position:
   select_pas_images_by_time list.acm EX0 04:13:13.5 04:14:44.2  acmB N          # 10 images  
   Move into ./acmB

    cp ../acmB.* . 
    cp acmB.images list.acmB
    bigds9 list.acmB 1 17  
                       
# all 15 images look pretty good 

    ds9_imstats_fitslist list.acmB FixedRegions N 

   To compute the possible sets of offsets: 

    cd /home/sco/GC_Plate_Scales/20190711
    table_XY_offsets.sh ./acmA/XYmean ./acmB/XYmean xmean ymean xme yme N
    pas_XY_offsets.sh ./acmA/list.acmA ./acmB/list.acmB  1.0  N

    Collect the offsets:
           SCO centroid                                     PAS centroids 
     --------------------------------------        --------------------------------------
     44.827       44.833        0.157     5        44.545       44.253        0.446    10       acmAB


**********************   Process the gc1 images  ******************************
   pas_imlistgen l gc1 N                      # 35 gc1 images 
   mv list.IMAGES list.gc1 

     Pos         Start         End 
      A      04:08:15.4    04:09:55.0 
      B      04:13:13.5    04:14:44.2  

   To collect and measure A position:
   select_pas_images_by_time list.gc1 EX0  04:08:15.4 04:09:55   gc1A N         # 16 images 
   Move into ./gc1A

    cp ../gc1A.* . 
    cp gc1A.images list.gc1A
    bigds9 list.gc1A 1 40                               # all 16 images look good 
    ds9_imstats_fitslist list.gc1A FixedRegions N  

   To collect and measure B position:
   select_pas_images_by_time list.gc1 EX0  04:13:13.5  04:14:44.2  gc1B N       # 15 images 
   Move into ./gc1B
   
    cp ../acmB.* . 
    cp gc1B.images list.gc1B
    bigds9 list.gc1B 1 40                               # all 15  images look good 
    ds9_imstats_fitslist list.gc1B FixedRegions N  
     
   To compute the possible sets of offsets: 
     
     cd /home/sco/GC_Plate_Scales/20190711
     table_XY_offsets.sh ./gc1A/XYmean ./gc1B/XYmean xmean ymean xme yme N
     pas_XY_offsets.sh ./gc1A/list.gc1A ./gc1B/list.gc1B  1.0  N
      
    Collect the offsets:
           SCO centroid                                     PAS centroids 
     --------------------------------------        --------------------------------------
     61.539       61.539        0.455     1        -999.0      -999.0        -999.0     0       gc1AB 


**********************   Process the gc2 images  ******************************
   pas_imlistgen l gc2 N                      # 35 gc2 images 
   mv list.IMAGES list.gc2 

     Pos         Start         End 
      A      04:08:15.4    04:09:55.0 
      B      04:13:13.5    04:14:44.2  

   To collect and measure A position:

   select_pas_images_by_time list.gc2 EX0  04:08:15.4 04:09:55.0  gc2A N          # 17 images 
   Move into ./gc2A

    cp ../gc2A.* . 
    cp gc2A.images list.gc2A
    bigds9 list.gc2A 1 40                               # all 17 okay (star near edge) 

    ds9_imstats_fitslist list.gc2A FixedRegions N  

   To collect and measure B position:

   select_pas_images_by_time list.gc2 EX0  04:13:13.5 04:14:44.2  gc2B N          # 15 images 
   Move into ./gc2B

    cp ../acmB.* . 
    cp gc2B.images list.gc2B
    bigds9 list.gc2B 1 40                               # all 15 imags are good

    ds9_imstats_fitslist list.gc2B FixedRegions N
 
     
   To compute the possible sets of offsets: 

    cd /home/sco/GC_Plate_Scales/20190720 
    table_XY_offsets.sh ./gc2A/XYmean ./gc2B/XYmean xmean ymean xme yme N
    pas_XY_offsets.sh ./gc2A/list.gc2A ./gc2B/list.gc2B  1.0  N
 

    Collect the offsets:
           SCO centroid                                     PAS centroids 
     --------------------------------------        --------------------------------------
     62.353       62.353        0.521     1        18.287       17.706        0.577    16      gc2AB 
 
 



Plate scales are measured and plotted.

The plate scale values for the one offset (AB) are computed.

 

I collect offsets in  

% pwd
/home/sco/GC_Plate_Scales/20190720/PS_extimates
Build a file names 20190711.dat: 
% cat 20190711.dat 
AB
     44.827       44.833        0.157     5        44.545       44.253        0.446    10       acmAB
     61.539       61.539        0.455     1        -999.0      -999.0        -999.0     0       gc1AB 
     62.353       62.353        0.521     1        -999.0      -999.0        -999.0     0       gc2AB 

Next we compute the plate scale
% gcps.sh 20190711.dat N  
To make a plot of the estimates (for example):
 % Generic_Points 
 % xyplotter_auto gc1_plate_scales q q 1 N 
   (edit Axws.1 List.1)
 % xyplotter List.1 Axes.1 N 
 



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