diff options
Diffstat (limited to 'updatewcs/corrections.py')
| -rw-r--r-- | updatewcs/corrections.py | 52 |
1 files changed, 34 insertions, 18 deletions
diff --git a/updatewcs/corrections.py b/updatewcs/corrections.py index 686277c..ee73d61 100644 --- a/updatewcs/corrections.py +++ b/updatewcs/corrections.py @@ -12,19 +12,31 @@ DGEOCorr = dgeo.DGEOCorr class TDDCorr(object): """ - Purpose - ======= - Apply time dependent distortion correction to SIP coefficients and basic - WCS keywords. It is applicable only to ACS/WFC data. + Apply time dependent distortion correction to distortion coefficients and basic + WCS keywords. This applies only to ACS/WFC data. + + Parameters + ---------- + ext_wcs: HSTWCS object + An HSTWCS object to be modified + ref_wcs: HSTWCS object + A reference HSTWCS object + + Notes + ----- + Compute the ACS/WFC time dependent distortion terms + as described in [1]_. - Ref: Jay Anderson, ACS ISR 2007-08, Variation of the Distortion - Solution of the WFC + The zero-point terms account for the skew accumulated between + 2002.0 and 2004.5, when the latest IDCTAB was delivered. + alpha = 0.095 + 0.090*(rday-dday)/2.5 + beta = -0.029 - 0.030*(rday-dday)/2.5 + + + References + ---------- + .. [1] Jay Anderson, "Variation of the Distortion Solution of the WFC", ACS ISR 2007-08. - :Parameters: - `ext_wcs`: HSTWCS object - An extension HSTWCS object to be modified - `ref_wcs`: HSTWCS object - A reference HSTWCS object """ def updateWCS(cls, ext_wcs, ref_wcs): @@ -119,11 +131,13 @@ class TDDCorr(object): class VACorr(object): """ - Purpose - ======= Apply velocity aberation correction to WCS keywords. - Modifies the CD matrix and CRVAL1/2 - + + Notes + ----- + Velocity Aberration is stored in the extension header keyword 'VAFACTOR'. + The correction is applied to the CD matrix and CRVALs. + """ def updateWCS(cls, ext_wcs, ref_wcs): @@ -148,9 +162,11 @@ class VACorr(object): class CompSIP(object): """ - Purpose - ======= - Compute SIP coefficients from idc table coefficients. + Compute SIP coefficients from IDC table coefficients. + + Notes + ----- + """ def updateWCS(cls, ext_wcs, ref_wcs): |