Index: /trunk/ppStack/src/ppStackConvolve.c
===================================================================
--- /trunk/ppStack/src/ppStackConvolve.c	(revision 32169)
+++ /trunk/ppStack/src/ppStackConvolve.c	(revision 32170)
@@ -377,5 +377,6 @@
             0.5 * (values->data.F32[numGood / 2 - 1] + values->data.F32[numGood / 2]);
 
-        float rms = 0.74 * (values->data.F32[numGood * 3 / 4] -
+	// EAM/MEH ensure RMS is positive
+        float rms = 0.74 * fabsf(values->data.F32[numGood * 3 / 4] -
                             values->data.F32[numGood / 4]); // Estimated RMS from interquartile range
         psFree(values);
Index: /trunk/ppStack/src/ppStackMatch.c
===================================================================
--- /trunk/ppStack/src/ppStackMatch.c	(revision 32169)
+++ /trunk/ppStack/src/ppStackMatch.c	(revision 32170)
@@ -441,5 +441,6 @@
                 assert(item->type == PS_DATA_UNKNOWN);
                 pmSubtractionKernels *kernels = item->data.V; // Convolution kernels
-                sum += kernels->mean;
+		// EAM/MEH sum the RMS instead of the mean now  
+		sum += kernels->rms;
                 num++;
             }