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authordencheva <dencheva@stsci.edu>2010-09-30 15:07:47 -0400
committerdencheva <dencheva@stsci.edu>2010-09-30 15:07:47 -0400
commit02ba60cfb8db0288977724ebe73a13ee68544c31 (patch)
tree0bc705ff56e531f8acb15da60a11c95a86fc0e82 /updatewcs/corrections.py
parent9011189f4969aa74150abe493bf4b22886f7c372 (diff)
downloadstwcs_hcf-02ba60cfb8db0288977724ebe73a13ee68544c31.tar.gz
Added documentaion
git-svn-id: http://svn.stsci.edu/svn/ssb/stsci_python/stsci_python/trunk/stwcs@10441 fe389314-cf27-0410-b35b-8c050e845b92
Diffstat (limited to 'updatewcs/corrections.py')
-rw-r--r--updatewcs/corrections.py52
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):