Index: /issm/trunk-jpl/src/c/Container/Observations.cpp
===================================================================
--- /issm/trunk-jpl/src/c/Container/Observations.cpp	(revision 14239)
+++ /issm/trunk-jpl/src/c/Container/Observations.cpp	(revision 14240)
@@ -125,5 +125,5 @@
 	/*Output and Intermediaries*/
 	int          nobs,i,index;
-	IssmPDouble  h2,hmin2,radius2;
+	IssmPDouble  hmin,h2,hmin2,radius2;
 	int         *indices      = NULL;
 	Observation *observation  = NULL;
@@ -133,13 +133,11 @@
 	_assert_(index>=0);
 	observation=dynamic_cast<Observation*>(this->GetObjectByOffset(index));
-	hmin2 = (observation->x-x_interp)*(observation->x-x_interp) + (observation->y-y_interp)*(observation->y-y_interp);
+	hmin = sqrt((observation->x-x_interp)*(observation->x-x_interp) + (observation->y-y_interp)*(observation->y-y_interp));
 
 	/*Compute radius square*/
-	if(radius==0) radius=this->quadtree->root->length;
+	if(radius==0 || hmin<radius){
+		radius=hmin;
+	}
 	radius2 = radius*radius;
-	if(hmin2<radius2){
-		radius =sqrt(hmin2);
-		radius2=hmin2;
-	}
 
 	/*Find all observations that are in radius*/