diff -u -r1.2 -r1.3
--- StereoPair.java	27 Jul 2013 01:52:49 -0000	1.2
+++ StereoPair.java	30 Jul 2013 00:53:07 -0000	1.3
@@ -3,9 +3,11 @@

 import org.lcsim.detector.tracker.silicon.SiSensor;
 
 /**

+ * A class describing an SVT stereo pair.

  * 
  * @author Per Hansson <[log in to unmask]>

- * @version $Id: StereoPair.java,v 1.2 2013/07/27 01:52:49 omoreno Exp $ 

+ * @author Omar Moreno <[log in to unmask]>
+ * @version $Id: StereoPair.java,v 1.3 2013/07/30 00:53:07 omoreno Exp $ 

  */
 public class StereoPair {
 

@@ -16,7 +18,11 @@

 	// The axial and stereo sensors
 	private SiSensor axialSensor = null; 
 	private SiSensor stereoSensor = null;

-

+	
+	// The detector volume in which the stereo pair resides 
+	public enum detectorVolume{ Top, Bottom }; 
+	private detectorVolume volume = detectorVolume.Top; 
+	

 	/**
 	 * Default Ctor
 	 * 

@@ -29,12 +35,15 @@

 	/**
 	 * Ctor
 	 * 

-	 * @param layerNumber : Layer number to shich the stereo pair belongs to

+	 * @param layerNumber : Layer number to which the stereo pair belongs to
+	 * @param volume : detector volume (detectorVolume.Top or detector Volume.Bottom) in 
+	 * 					which the stereo pair resides 

 	 * @param axialSensor 
 	 * @param stereoSensor
 	 */

-	public StereoPair(int layerNumber, SiSensor axialSensor, SiSensor stereoSensor){

+	public StereoPair(int layerNumber, detectorVolume volume, SiSensor axialSensor, SiSensor stereoSensor){

 		this.layerNumber = layerNumber; 

+		this.volume = volume; 

 		this.axialSensor = axialSensor; 
 		this.stereoSensor = stereoSensor; 
 	}

@@ -58,6 +67,15 @@

 	}
 	
 	/**

+	 * Set the SVT volume in which the stereo pair resides
+	 * 
+	 * @param volume : detectorVolume.Top or detectorVolume.Bottom
+	 */
+	public void setDetectorVolume(detectorVolume volume){
+		this.volume = volume; 
+	}
+	
+	/**

 	 * Get the axial sensor of the stereo pair
 	 * 
 	 * @return Axial sensor. Returns null if it hasn't been set yet.

@@ -85,6 +103,15 @@

 	}
 	
 	/**

+	 * Get the SVT volume in which the stereo pair resides
+	 * 
+	 * @return volume : detectorVolume.Top or detectorVolume.Bottom
+	 */
+	public detectorVolume getDetectorVolume(){
+		return volume; 
+	}
+	
+	/**

 	 * Return a string describing the stereo pair
 	 * 
 	 * @return stereo pair description

diff -u -r1.14 -r1.15
--- SvtUtils.java	27 Jul 2013 01:52:49 -0000	1.14
+++ SvtUtils.java	30 Jul 2013 00:53:07 -0000	1.15
@@ -21,12 +21,13 @@

 
 import org.lcsim.hps.util.Pair;
 import org.lcsim.hps.recon.tracking.StereoPair;

+import org.lcsim.hps.recon.tracking.StereoPair.detectorVolume;

 
 /**
  * A class providing various utilities related to the HPS SVT. 
  *
  * @author Omar Moreno <[log in to unmask]>

- * @version $Id: SvtUtils.java,v 1.14 2013/07/27 01:52:49 omoreno Exp $

+ * @version $Id: SvtUtils.java,v 1.15 2013/07/30 00:53:07 omoreno Exp $

  */
 public class SvtUtils {
 

@@ -473,9 +474,9 @@

     			
     			trackerLayer = (layerNumber + 1)/2; 
     			if(this.isAxial(firstSensor)){

-    				stereoPairs.add(new StereoPair(trackerLayer, firstSensor, secondSensor));

+    				stereoPairs.add(new StereoPair(trackerLayer, detectorVolume.Top,  firstSensor, secondSensor));

     			} else {

-    				stereoPairs.add(new StereoPair(trackerLayer, secondSensor, firstSensor));

+    				stereoPairs.add(new StereoPair(trackerLayer, detectorVolume.Top, secondSensor, firstSensor));

     			}
     			
     			firstSensor = this.getBottomSensor(layerNumber, sensorNumber);

@@ -484,9 +485,9 @@

     			if(firstSensor == null || secondSensor == null) continue;
     			
     			if(this.isAxial(firstSensor)){

-    				stereoPairs.add(new StereoPair(trackerLayer, firstSensor, secondSensor));

+    				stereoPairs.add(new StereoPair(trackerLayer, detectorVolume.Bottom, firstSensor, secondSensor));

     			} else {

-    				stereoPairs.add(new StereoPair(trackerLayer, secondSensor, firstSensor));

+    				stereoPairs.add(new StereoPair(trackerLayer, detectorVolume.Bottom, secondSensor, firstSensor));

     			}
     		}
     	}