Index: trunk/doc/modules/CameraImages.tex
===================================================================
--- trunk/doc/modules/CameraImages.tex	(revision 9744)
+++ trunk/doc/modules/CameraImages.tex	(revision 11596)
@@ -1005,4 +1005,13 @@
 \tbd{EAM needs to update this section.}
 
+\code{pmAstromWCS} is a structure which represents the FITS WCS
+keywords in a single header.  In a traditional astronomy image, this
+includes the conversion from pixel coordinates via rotations, scaling,
+and offset, to a coordinate system corresponding to linear degree
+offsets relative to the reference pixel.  This linear (2D) coordinate
+frame is then converted to a spherical (3D) coordinate frame via a
+defined projection.
+
+
 Astrometry is a basic functionality required for the IPP that will be
 used repeatedly, both for low-precision (roughly where is my favorite