Index: branches/eam_branches/ipp-dev-20210817/psastro/src/psastroMosaicOneChip.c
===================================================================
--- branches/eam_branches/ipp-dev-20210817/psastro/src/psastroMosaicOneChip.c	(revision 41799)
+++ branches/eam_branches/ipp-dev-20210817/psastro/src/psastroMosaicOneChip.c	(revision 41814)
@@ -134,4 +134,8 @@
     int astNstar = results->yStats->clippedNvalues;
 
+    // astStdev is the average 1D stdev of median residuals in arcsec ('results' are in FPA units = microns)
+    // the median residuals are calculated in a grid of N x N bins 
+    float astStdev = 0.5*(results->xStdev + results->yStdev) * plateScale;
+
     // if we clip away too many stars, the order may be invalid
     if (order == 3) { minNstar = PS_MAX (15, minNstar); }
@@ -142,5 +146,6 @@
 
     // XXX should these result in errors or be handled another way?
-    psLogMsg ("psastro", PS_LOG_INFO, "astrometry solution: error: %f arcsec, Nstars: %d", astError, astNstar);
+    // psLogMsg ("psastro", PS_LOG_INFO, "astrometry solution: error: %f arcsec, Nstars: %d", astError, astNstar);
+    psLogMsg ("psastro", PS_LOG_INFO, "astrometry solution: error: %f arcsec, Nstars: %d, stdev: %f arcsec", astError, astNstar, astStdev);
     if ((maxError > 0) && (astError > maxError)) {
         psLogMsg("psastro", PS_LOG_INFO, "residual error is too large, failed to find a solution: %f > %f", astError, maxError);
@@ -155,4 +160,5 @@
     psMetadataAddF32 (updates, PS_LIST_TAIL, "PERROR",   PS_META_REPLACE, "astrometry error (pixels)", pixError);
     psMetadataAddF32 (updates, PS_LIST_TAIL, "CERROR",   PS_META_REPLACE, "astrometry error (arcsec)", astError);
+    psMetadataAddF32 (updates, PS_LIST_TAIL, "CERSTD",   PS_META_REPLACE, "astrometry stdev (arcsec)", astStdev);
     if (validSolution) {
         psMetadataAddF32 (updates, PS_LIST_TAIL, "CPRECISE", PS_META_REPLACE, "astrometry precision (arcsec)", astError/sqrt(astNstar));
Index: branches/eam_branches/ipp-dev-20210817/psastro/src/psastroOneChipFit.c
===================================================================
--- branches/eam_branches/ipp-dev-20210817/psastro/src/psastroOneChipFit.c	(revision 41799)
+++ branches/eam_branches/ipp-dev-20210817/psastro/src/psastroOneChipFit.c	(revision 41814)
@@ -192,4 +192,8 @@
     float astError = 0.5*(rawXstdev + rawYstdev) * plateScale;
 
+    // astStdev is the average 1D stdev of median residuals in arcsec ('results' are in FPA units = microns)
+    // the median residuals are calculated in a grid of N x N bins 
+    float astStdev = 0.5*(results->xStdev + results->yStdev) * plateScale;
+
     // x and y are forced to use the same subset of values:
     int astNstar = results->yStats->clippedNvalues;
@@ -198,5 +202,5 @@
 
     // XXX should these result in errors or be handled another way?
-    psLogMsg ("psastro", PS_LOG_INFO, "astrometry solution: error: %f arcsec, Nstars: %d", astError, astNstar);
+    psLogMsg ("psastro", PS_LOG_INFO, "astrometry solution: error: %f arcsec, Nstars: %d, stdev: %f arcsec", astError, astNstar, astStdev);
     if (astError > maxError) {
         psLogMsg("psastro", PS_LOG_INFO, "residual error is too large, failed to find a solution: %f > %f", astError, maxError);
@@ -211,4 +215,5 @@
     psMetadataAddF32 (updates, PS_LIST_TAIL, "PERROR",   PS_META_REPLACE, "astrometry error (pixels)", pixError);
     psMetadataAddF32 (updates, PS_LIST_TAIL, "CERROR",   PS_META_REPLACE, "astrometry error (arcsec)", astError);
+    psMetadataAddF32 (updates, PS_LIST_TAIL, "CERSTD",   PS_META_REPLACE, "astrometry stdev (arcsec)", astStdev);
     if (validSolution) {
         psMetadataAddF32 (updates, PS_LIST_TAIL, "CPRECISE", PS_META_REPLACE, "astrometry precision (arcsec)", astError/sqrt(astNstar));