diff options
Diffstat (limited to 'updatewcs/makewcs.py')
| -rw-r--r-- | updatewcs/makewcs.py | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/updatewcs/makewcs.py b/updatewcs/makewcs.py index 6e9b7a5..4210fd3 100644 --- a/updatewcs/makewcs.py +++ b/updatewcs/makewcs.py @@ -8,20 +8,18 @@ from pytools import fileutil class MakeWCS(object): """ - Purpose - ======= Recompute basic WCS keywords based on PA_V3 and distortion model. - Algorithm - ========= - - update reference chip wcs - - -- CRVAL: reference chip model zero point (XREF/YREF) on the sky + Notes + ----- + - Compute the reference chip WCS: + + -- CRVAL: transform the model XREF/YREF to the sky -- PA_V3 is calculated at the target position and adjusted for each chip orientation -- CD: PA_V3 and the model scale are used to cnstruct a CD matrix - - update extension wcs + - Compute the second chip WCS: -- CRVAL: - the distance between the zero points of the two chip models on the sky @@ -30,6 +28,8 @@ class MakeWCS(object): between CRVAL and these vectors is the new CD matrix for each chip. -- CRPIX: chip's model zero point in pixel space (XREF/YREF) + - Time dependent distortion correction is applied to both chips' V2/V3 values. + """ tdd_xyref = {1: [2048, 3072], 2:[2048, 1024]} def updateWCS(cls, ext_wcs, ref_wcs): @@ -213,11 +213,11 @@ class MakeWCS(object): def troll(roll, dec, v2, v3): """ Computes the roll angle at the target position based on: - the roll angle at the V1 axis(roll), - the dec of the target(dec), and - the V2/V3 position of the aperture (v2,v3) in arcseconds. + the roll angle at the V1 axis(roll), + the dec of the target(dec), and + the V2/V3 position of the aperture (v2,v3) in arcseconds. - Based on the algorithm provided by Colin Cox that is used in + Based on algorithm provided by Colin Cox and used in Generic Conversion at STScI. """ # Convert all angles to radians |