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List WCS Keywords The List WCS Keywords command finds all the
World Coordinate System ("WCS") related
keywords in an image header and lists them into
a
Text window. If the
Image window contains an
image set, the current image or the image set may be
listed according to the status of the
Process Image Set flag, or Note that specific combinations of WCS keywords are required for the image to have a valid WCS calibration, and even one missing keyword may prevent the image from having a WCS calibration. This command may also be used to determine if the image has a WCS calibration.
The example below lists WCS keywords from a fully calibrated image header. Note that the ".txt" extension is automatically appended to the window title after the contents were saved to a file.
WCS Projection TypesThe mathematical relationship between pixel location and World Coordinates is known as the world coordinate projection. The projection type is represented in the FITS header using the CTYPEn keyword, where n refers to the axis dimension. Equatorial calibration usually employs the "Tangent Plane (gnomonic)" projection with CTYPEn Code = TAN. In the FITS header, this equatorial projection for right ascension (axis 1) and declination (axis 2) appears as CTYPE1 = 'RA---TAN' and CTYPE2 = 'DEC--TAN'. Mira supports the types of WCS projection listed in the table below. The projection type may be obtained using the class method CImage:GetWcsType() in the Mira Pro x64 Script language. In the table below, nWcsProj is returned by CImage:GetWcsType().The CTYPEn Code is listed in FITS header as the string value of the CTYPEn keyword. The Description is reported in the output from the List WCS Keywords command.
Related TopicsWorld Coordinate System Keywords
Mira Pro x64 User's Guide, Copyright Ⓒ 2023 Mirametrics, Inc. All
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button. If no WCS or WCS keywords are found,
this result is listed in the window (see below).
