Index: trunk/ppStack/src/ppStackMatch.c
===================================================================
--- trunk/ppStack/src/ppStackMatch.c	(revision 20654)
+++ trunk/ppStack/src/ppStackMatch.c	(revision 20710)
@@ -384,4 +384,7 @@
         (void)psBinaryOp(readout->image, readout->image, "+",
                          psScalarAlloc(- psStatsGetValue(bg, PS_STAT_ROBUST_MEDIAN), PS_TYPE_F32));
+        psMetadataAddF32(readout->analysis, PS_LIST_TAIL, "PPSTACK.WEIGHTING", 0,
+                         "Weighting by 1/noise^2 for stack",
+                         1.0 / PS_SQR(psStatsGetValue(bg, PS_STAT_ROBUST_STDEV)));
     }
     psFree(bg);