Index: trunk/psastro/src/psastroUtils.c
===================================================================
--- trunk/psastro/src/psastroUtils.c	(revision 10830)
+++ trunk/psastro/src/psastroUtils.c	(revision 10855)
@@ -37,4 +37,5 @@
 	for (int i = 0; i < fpa->chips->n; i++) {
 	    pmChip *chip = fpa->chips->data[i];
+	    if (!chip->process || !chip->file_exists) { continue; }
 	    
 	    pixelScale1 = hypot (chip->toFPA->x->coeff[1][0], chip->toFPA->x->coeff[0][1]);
@@ -50,4 +51,5 @@
     for (int i = 0; i < fpa->chips->n; i++) {
 	pmChip *chip = fpa->chips->data[i];
+	if (!chip->process || !chip->file_exists) { continue; }
 
 	psPlaneTransform *toFPA = chip->toFPA;