Quick check of the pointing of the Telescope

In order to have a quick check of the telescope pointing one can use the following procedure:

from a terminal login on glslogin2 :

ssh glslogin2

create a directory and copy some files :

mkdir testpointing
cd testpointing
cp ~chazelas/alignmentutils/astrometrie-image.py .
cp ~chazelas/Etoiles_brillantes.rdb .

 One can use the catalogue Etoile_brillantes.rdb (in the EDP you have to point to the RDB file that you just copied in the testpointing directory) to take a picture of a bright star. Once the image taken and saved, one can use the script astrometrie-image.py  to measure the pointing precision.

~weber/anaconda3/bin/python astrometrie-image.py one [PATH to the image]

for example :

~weber/anaconda3/bin/python astrometrie-image.py one /gls/data/raw/2022-01-30/ECAM.2022-01-31T08:04:44.000.fits

Starting ASTROMETRY SESSION
Namespace(action='one', ignore_offsets=False, keyword=None, keyword_value=None, lazy=False, output=False, output_monitor=False, path='/gls/data/raw/2022-01-30/ECAM.2022-01-31T08:04:44.000.fits', unique=False)
Start Analysis of : /gls/data/raw/2022-01-30/ECAM.2022-01-31T08:04:44.000.fits
2022-01-31 08:05:39.514
2022-01-31 08:05:39.518
Reading input file 1 of 1: "ECAM.2022-01-31T08:04:44.000.fits"...
Extracting sources...
Downsampling by 4...
simplexy: found 2233 sources.
Solving...
Reading file "./ECAM.2022-01-31T08:04:44.000.axy"...
Only searching for solutions within 5 degrees of RA,Dec (178.262,-46.0717)
Field 1 did not solve (index index-2mass-06-10.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-06-09.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-06-06.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-05-10.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-05-09.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-05-06.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-04-41.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-04-38.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-04-24.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-03-41.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-03-38.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-03-24.fits, field objects 1-10).
Field 1 did not solve (index index-2mass-06-10.fits, field objects 11-20).
Field 1 did not solve (index index-2mass-06-09.fits, field objects 11-20).
Field 1 did not solve (index index-2mass-06-06.fits, field objects 11-20).
Field 1 did not solve (index index-2mass-05-10.fits, field objects 11-20).
  log-odds ratio 112.085 (4.76536e+48), 15 match, 0 conflict, 21 distractors, 20 index.
  RA,Dec = (178.267,-46.0719), pixel scale 0.215407 arcsec/pix.
  Hit/miss:   Hit/miss: ++++++-++---+-+++-+-----+----------+(best)----------------------------------------------------------------
Field 1: solved with index index-2mass-05-09.fits.
Field 1 solved: writing to file ./ECAM.2022-01-31T08:04:44.000.solved to indicate this.
Field: ECAM.2022-01-31T08:04:44.000.fits
Field center: (RA,Dec) = (178.266917, -46.071864) deg.
Field center: (RA H:M:S, Dec D:M:S) = (11:53:04.060, -46:04:18.709).
Field size: 15.0404 x 15.1062 arcminutes
Field rotation angle: up is 0.0545668 degrees E of N
Creating new FITS file "./ECAM.2022-01-31T08:04:44.000.new"...

WARNING: FITSFixedWarning: RADECSYS= 'ICRS ' / radecsys / Coordinate reference frame 
the RADECSYS keyword is deprecated, use RADESYSa. [astropy.wcs.wcs]
UL
Image in UL mode
<SkyCoord (ICRS): (ra, dec) in deg
    (178.262085, -46.0716667)>
<SkyCoord (ICRS): (ra, dec) in deg
    (178.26678847, -46.07147491)>
Results for /gls/data/raw/2022-01-30/ECAM.2022-01-31T08:04:44.000.fits
Asked : 72.94004917349316 deg, 186.305286161042 deg, Measured 72.94069015330678 deg, 186.29436124015447 deg
-0.0006409798136104428 deg, 0.010924920887532608 deg
 Delta El : -2.307527328997594 arcsec, Delta Az : 26.28783217307144 arcsec
Position angle of WCS is 0.03827 degrees.
Image orientation is North Up, East Left.
Finished the analysis of : /gls/data/raw/2022-01-30/ECAM.2022-01-31T08:04:44.000.fits

 

Look at the Delta El, Delta Az values

if the star is within 30 arcsec from the center this is fine (I mean not worse that the last pointing situation this needs to be improved)