Index: trunk/psphot/src/find_defects_new.c
===================================================================
--- trunk/psphot/src/find_defects_new.c	(revision 4251)
+++ trunk/psphot/src/find_defects_new.c	(revision 4376)
@@ -9,4 +9,18 @@
   // measure 
 
+  // 3pt second moment (assume sky?)
+
+  // S0 = x[-1] + x[0] + x[1]
+  // S0 = sum (f - sky)
+  // S1 = sum (f - sky)*(x - x[0])
+  // S2 = sum (f - sky)*(x - x[0])^2
+  
+  // S1 = df[1] - df[-1]
+  // S2 = df[1]^2 + df[-1]^2
+  // S0 = df[0] + df[1] + df[-1]
+
+  // x1 = S1/S0
+  // sx = sqrt (S2/S0 - x1^2)
+
   return (true);
 }