Index: trunk/psModules/src/astrom/pmAstrometryModel.c
===================================================================
--- trunk/psModules/src/astrom/pmAstrometryModel.c	(revision 19506)
+++ trunk/psModules/src/astrom/pmAstrometryModel.c	(revision 19595)
@@ -9,6 +9,6 @@
  *
  *  @author EAM, IfA
- *  @version $Revision: 1.5 $ $Name: not supported by cvs2svn $
- *  @date $Date: 2008-09-12 01:04:49 $
+ *  @version $Revision: 1.6 $ $Name: not supported by cvs2svn $
+ *  @date $Date: 2008-09-17 23:07:02 $
  *
  *  Copyright 2007 Institute for Astronomy, University of Hawaii
@@ -710,7 +710,8 @@
     char *refChip  = psMetadataLookupStr(&status, file->fpa->concepts, "REF_CHIP"); REQUIRE (status, "missing REF_CHIP");
 
+    // XXX we've swapped the sign and parity of POS (add to model)
     // apply true posangle = -(POS - POS_ZERO)
     psLogMsg ("psModules.astrom", 4, "Position Angle: %f, Model Position Angle Zero Point: %f\n", POS, PosZero);
-    psPlaneTransform *fromTPA = psPlaneTransformRotate (NULL, file->fpa->fromTPA, (POS - PosZero));
+    psPlaneTransform *fromTPA = psPlaneTransformRotate (NULL, file->fpa->fromTPA, (PosZero - POS));
     psFree (file->fpa->fromTPA);
     file->fpa->fromTPA = fromTPA;