Index: /trunk/archive/pslib/include/psAstrom.h
===================================================================
--- /trunk/archive/pslib/include/psAstrom.h	(revision 218)
+++ /trunk/archive/pslib/include/psAstrom.h	(revision 219)
@@ -14,4 +14,25 @@
 /* Include polynomial definitions */
 #include "psFunctions.h"
+
+/***********************************************************************************************************/
+
+/**
+ * Astrometry coefficients.
+ * These are composed of:
+ * (1) Coefficients in x and y --- a general spatial fit.
+ * (2) Coefficients in x and y for each polynomial order in magnitude, e.g. one set of coefficients in x and
+ * y for mag^1, another set of coefficients in x and y for mag^2.
+ * (3) Coefficients in x and y for each polynomial order in colour.
+ */
+typedef struct {
+    psDPolynomial2D *restrict ra, dec;	//!< Spatial coefficients, i.e. x and y
+    int magOrder;			//!< Order of polynomial in magnitude
+    psDPolynomial2D *restrict raMag, decMag; //!< An ARRAY of polynomials for each polynomial order in
+					     //!< magnitude
+    int colorOrder;			//!< Order of polynomial in colour
+    psDPolynomial2D *restrict raCol, decCol; //!< An ARRAY of polynomials for each polynomial order in colour
+    enum psColorRef colorRef;		//!< Colour reference
+} psAstromCoeffs;
+
 
 /***********************************************************************************************************/
@@ -148,7 +169,6 @@
 typedef struct {
     /* Focal plane to and from tangent plane */
-    psDPolynomial2D *restrict tpToFP;	//!< General astrometric solution for tangent plane to focal plane
-    psDPolynomial2D *restrict fpToTP;	//!< General astrometric solution for focal plane to tangent plane
-    enum psColorRef colorRef;		//!< Colour reference
+    psAstromCoeffs *restrict tpToFP;	//!< General astrometric solution for tangent plane to focal plane
+    psAstromCoeffs *restrict fpToTP;	//!< General astrometric solution for focal plane to tangent plane
     psMatrix *pattern;		        //!< Fixed pattern distortions for focal plane to tangent plane (simply
 					//!< * -1 for the reverse); MAY NEED TO BE REVISED UPON IMPLEMENTATION