Changeset 3389 for trunk/Ohana/src/libohana/doc/coordtrans.txt

Timestamp:

Mar 7, 2005, 6:15:46 PM (21 years ago)

Author:

eugene

Message:

adding mosaic astrometry concepts

File:

• trunk/Ohana/src/libohana/doc/coordtrans.txt (modified) (1 diff)

trunk/Ohana/src/libohana/doc/coordtrans.txt

@@ +1 @@
+
+I have changed the meaning of coord type PLY from the historical
+meaning.  The only previous use that is in a DVO-style database is in
+the loneos data (all cfht data needed to go to linear terms).  these
+can be easily converted by changing from PLY to DIS.
+
+There are now three types of higher-order transformation which may be
+used depending on the circumstance.  The new naming scheme is:
+
+PLY : a cartesian transformation (ie, no projection implied)
+DIS : equivalent to TAN projection with up-to-3rd order polynomial
+WRP : a second-level cartesian transformation, implying the presence
+      of a DIS coord frame (must be registered with libohana function)
 
 {