diff -u -r1.5 -r1.6
--- HPSStripMaker.java	29 Aug 2012 21:02:46 -0000	1.5
+++ HPSStripMaker.java	29 Sep 2012 00:19:41 -0000	1.6
@@ -32,8 +32,10 @@

     int _max_noaverage_nstrips = 4;
     // Absolute maximum cluster size
     int _max_cluster_nstrips = 10;

+    // Sensor simulation needed to correct for Lorentz drift
+    SiSensorSim _simulation;

     // Identifier helper (reset once per sensor)

-    SiTrackerIdentifierHelper _sid_helper;

+    SiTrackerIdentifierHelper _sid_helper;    

     // Temporary map connecting hits to strip numbers for sake of speed (reset once per sensor)
     Map<HPSFittedRawTrackerHit, Integer> _strip_map = new HashMap<HPSFittedRawTrackerHit, Integer>();
     double _oneClusterErr = 1 / Math.sqrt(12);

@@ -41,11 +43,16 @@

     double _threeClusterErr = 1 / 3;
     double _fourClusterErr = 1 / 2;
     double _fiveClusterErr = 1;

-

+    

     public HPSStripMaker(HPSClusteringAlgorithm algo) {
         _clustering = algo;
     }
 

+    public HPSStripMaker(SiSensorSim simulation, HPSClusteringAlgorithm algo) {
+        _clustering = algo;
+        _simulation = simulation;
+    }
+

     public String getName() {
         return _NAME;
     }

@@ -181,6 +188,7 @@

     }
 
     private Hep3Vector getPosition(List<HPSFittedRawTrackerHit> cluster, SiSensorElectrodes electrodes) {

+        boolean debug = false;

         List<Double> signals = new ArrayList<Double>();
         List<Hep3Vector> positions = new ArrayList<Hep3Vector>();
 

@@ -216,13 +224,21 @@

             position = VecOp.add(position, VecOp.mult(signal, positions.get(istrip)));
         }
         position = VecOp.mult(1 / total_charge, position);

+        if(debug) System.out.println(this.getClass().getSimpleName() + " charge weighted position "+position.toString() + " (before trans)");

         electrodes.getParentToLocal().inverse().transform(position);

-
-//        System.out.println("Position \n"+position);
-
-//        System.out.println("Lorentz corrected position \n"+position);
-

+        if(debug) System.out.println(this.getClass().getSimpleName() + " charge weighted position "+position.toString() + " (after trans)");
+        
+        // Swim position back through lorentz drift direction to midpoint between bias surfaces
+        if(_simulation!=null) {
+            _simulation.setSensor((SiSensor) electrodes.getDetectorElement());
+            _simulation.lorentzCorrect(position, electrodes.getChargeCarrier());
+            if(debug) System.out.println(this.getClass().getSimpleName() + ": Position " + position.toString() + " ( after Lorentz)");
+        }
+        

         // return position in global coordinates

+        Hep3Vector newpos = ((SiSensor) electrodes.getDetectorElement()).getGeometry().getLocalToGlobal().transformed(position);
+        if(debug) System.out.println(this.getClass().getSimpleName() + " newpos "+newpos.toString());
+        

         return ((SiSensor) electrodes.getDetectorElement()).getGeometry().getLocalToGlobal().transformed(position);
 //        return electrodes.getLocalToGlobal().transformed(position);
     }

diff -u -r1.14 -r1.15
--- HPSHelicalTrackHitDriver.java	28 Sep 2012 22:09:49 -0000	1.14
+++ HPSHelicalTrackHitDriver.java	29 Sep 2012 00:19:41 -0000	1.15
@@ -59,7 +59,7 @@

     private Map<String, String> _stereomap = new HashMap<String, String>();
     private Hep3Vector _orgloc = new BasicHep3Vector(0., 0., 0.);
     private boolean _doTranformToTracking = true;

-    private boolean addAllStripsToEventForDebug = false;

+    private boolean addAllStripsToEventForDebug = true;

     private HPSTransformations _detToTrk;
     String subdetectorName = "Tracker";