As I understand it, the iTelescope instruments that were located in New Mexico were moved, around the start of 2023, to new site in western Utah. For the time being, I have made copies for myself of the info General telescope setups and modified the site coordinates. (I have been experimenting with scope T05 and T11.) This seems to allow accurate WCS results. But I was wondering whether (or when) it would be advisable for the Administrator to revise the General set ups.
I haven't yet done any transformations with the image data from the new site. And I was wondering whether it would be wise to do that. I assume that the coefficients now listed in the general set-ups were done with results from the prior, New Mexico site. I would surely prefer to continue to make use of the earlier work on the transformations for T11 by Arne Hendon. But is it still appropriate to do that?
Mark O [OMAA]
Thanks for the reminder. ;-)
Do you have a table of data you collected? Would save me some time if you could share it.
The transform coeffs should be the same for the same systems. Updating them requires help from iTelescope.
I will ask Brad if he wants to take some standard field images.
Ken (kenmenstar @gmail.com)
I have limited myself to changing the location info, so far. New site is:
37.778 N; -113.6875 W; Elevation 1570 meters.
Not sure which data table format would be of most use to you. I have only made some basic text exposures to estimate the appropriate exposure times.
FYI - here is a copy of the FITS header from a recent 'test' image - which may have other details that will help:
SIMPLE = T
BITPIX = 16 /8 unsigned int, 16 & 32 int, -32 & -64 real
NAXIS = 2 /number of axes
NAXIS1 = 4008 /fastest changing axis
NAXIS2 = 2672 /next to fastest changing axis
BSCALE = 1.0000000000000000 /physical = BZERO + BSCALE*array_value
BZERO = 32768.000000000000 /physical = BZERO + BSCALE*array_value
DATE-OBS= '2023-03-09T04:38:15.89' /YYYY-MM-DDThh:mm:ss observation, UT
EXPTIME = 180.00000000000000 /Exposure time in seconds
EXPOSURE= 180.00000000000000 /Exposure time in seconds
SET-TEMP= -25.000000000000000 /CCD temperature setpoint in C
CCD-TEMP= -25.187500000000000 /CCD temperature at start of exposure in C
XPIXSZ = 9.0000000000000000 /Pixel Width in microns (after binning)
YPIXSZ = 9.0000000000000000 /Pixel Height in microns (after binning)
XBINNING= 1 /Binning factor in width
YBINNING= 1 /Binning factor in height
XORGSUBF= 0 /Subframe X position in binned pixels
YORGSUBF= 0 /Subframe Y position in binned pixels
READOUTM= '12 MHz ' / Readout mode of image
FILTER = 'B ' / Filter used when taking image
IMAGETYP= 'Light Frame' / Type of image
FOCALLEN= 2280.0000000000000 /Focal length of telescope in mm
APTDIA = 508.00000000000000 /Aperture diameter of telescope in mm
APTAREA = 171854.91339300585 /Aperture area of telescope in mm^2
SBSTDVER= 'SBFITSEXT Version 1.0' /Version of SBFITSEXT standard in effect
SWCREATE= 'MaxIm DL Version 6.26 211016 1NURE' /Name of software
SWSERIAL= '1NURE-W5KP0-V31P2-TUEQ3-MM333-3P' /Software serial number
SITELAT = '37 44 16' / Latitude of the imaging location
SITELONG= '-113 41 51' / Longitude of the imaging location
JD = 2460012.6932394677 /Julian Date at time of exposure
JD-HELIO= 2460012.6886725677 /Heliocentric Julian Date at time of exposure
OBJECT = ' '
TELESCOP= ' ' / telescope used to acquire this image
INSTRUME= 'FLI ' / instrument or camera used
OBSERVER= ' '
NOTES = ' '
ROWORDER= 'TOP-DOWN' / Image write order, BOTTOM-UP or TOP-DOWN
FLIPSTAT= ' '
CSTRETCH= 'Medium ' / Initial display stretch mode
CBLACK = 2978 /Initial display black level in ADUs
CWHITE = 3903 /Initial display white level in ADUs
PEDESTAL= 0 /Correction to add for zero-based ADU
SWOWNER = 'Brad Moore' / Licensed owner of software
- Mark O (email@example.com)
In VPhot telescope settings, I just updated the Lat/Long/Elev of all the iTelescopes that were moved from New Mexico to Utah.
I asked Brad if he would like the transform coeffs updated as well. It was approved. I will collect M67 images for T5, T11 and T21 since they have multiple Johnson Cousins photometric filters (UBVRI).
PS: You do not need to create your own personal scopes with this system info. You can just select the specific common iTelescope for any images forwarded to your own VPhot Image List.
Thank you for the prompt start on this update work. It will help me get started with a reliable, efficient workflow.
It's particularly good news that there can be new standard-field data for these scopes. While I think it's best to leave the decisions about how to update transform coefficients to experienced observers like yourself, if I can help with some of the basic spadework on the M67 data, let me know.