diff -u -r1.2 -r1.3
--- FieldMap3DTest.java	9 Sep 2013 19:43:33 -0000	1.2
+++ FieldMap3DTest.java	10 Sep 2013 19:19:13 -0000	1.3
@@ -29,7 +29,7 @@

         Detector det = reader.read(in);
         FieldMap map = det.getFieldMap();
 

-        double[] off = {1., 2., 3.};

+        double[] off = {2.117, 0.0, 45.72};

         double[] fp = {-250.0, -89.0, -1500.};
         double[] B = new double[3];
 

@@ -64,8 +64,8 @@

         assertEquals(fields.size(), 1);
         FieldMap3D cmap = (FieldMap3D) fields.get("FieldMap3DTest");
         double[] offsets = cmap.globalOffset();

-        assertEquals(offsets[0], 1.);
-        assertEquals(offsets[1], 2.);
-        assertEquals(offsets[2], 3.);             

+        assertEquals(offsets[0], off[0]);
+        assertEquals(offsets[1], off[1]);
+        assertEquals(offsets[2], off[2]);             

     }
 }

\ No newline at end of file

diff -u -r1.4 -r1.5
--- FieldMap3DTest.xml	5 Sep 2013 17:54:55 -0000	1.4
+++ FieldMap3DTest.xml	10 Sep 2013 19:19:13 -0000	1.5
@@ -11,24 +11,104 @@

     <constant name="world_y" value="world_side" />
     <constant name="world_z" value="world_side" />
 

-    <constant name="tracking_region_radius" value="1100.0*cm"/>
-    <constant name="tracking_region_zmax" value="150.0*cm"/>

+    <!-- tracking region -->
+        <constant name="tracking_region_radius" value="200.0*cm"/>
+        <constant name="tracking_region_min" value="5.0*cm"/>
+        <constant name="tracking_region_zmax" value="131.8*cm"/>
+    
+       <!-- SVT module dimensions -->
+        <constant name="moduleLength" value="100.0"/>
+        <constant name="moduleWidth" value="100.0"/>
+        
+        <!-- SVT sensor dimensions -->
+        <constant name="sensorLength" value="100.0"/>
+        
+        
+        <!-- Sensor width slightly less than 38.34 mm so sisim works. -->
+        <constant name="sensorWidth" value="100.0"/> 
+        
+        <!-- Positions of sensor centers along beam relative to nominal target position -->
+        <constant name="z01" value="92.5-3.685" />
+        <constant name="z02" value="92.5+3.685" />
+        <constant name="z03" value="192.5-3.685" />
+        <constant name="z04" value="192.5+3.685" />
+        <constant name="z05" value="292.5-3.685" />
+        <constant name="z06" value="292.5+3.685" />
+        <constant name="z07" value="492.5-3.685" />
+        <constant name="z08" value="492.5+3.685" />
+        <constant name="z09" value="692.5-3.685" />
+        <constant name="z10" value="692.5+3.685" />
+        <constant name="z11" value="892.5-3.685" />
+        <constant name="z12" value="892.5+3.685" />           

   </define>
 
   <materials>

+<!-- Set tracking material to vacuum. -->
+        <material name="TrackingMaterial">
+            <D type="density" unit="g/cm3" value="0.0000000000000001"/>
+            <fraction n="1.0" ref="Air" />
+        </material>      

   </materials>
 
   <detectors>

+        <detector id="1" name="SimpleTracker" type="HPSTracker2" readout="TrackerHits" combineHits="true">
+            <comment>The Silicon Vertex Tracker</comment>
+            <module name="TestPlane">
+                <box x="moduleLength" y="moduleWidth" />
+                <module_component thickness="0.032*cm" material = "TrackingMaterial" sensitive="true">
+                    <dimensions x="sensorLength" y="sensorWidth" /> 
+                </module_component>
+            </module>            
+            <layer id="1">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z01" rx="0.0" ry="0.0" rz="0.0"/>
+                  </layer>
+            <layer id="2">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z02" rx="0.0" ry="0.0" rz="0.0"/>
+                   </layer>
+            <layer id="3">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z03" rx="0.0" ry="0.0" rz="0.0"/>
+            </layer>
+            <layer id="4">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z04" rx="0.0" ry="0.0" rz="0.0"/>
+            </layer>
+            <layer id="5">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z05" rx="0.0" ry="0.0" rz="0.0"/>
+           </layer>
+            <layer id="6">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z06" rx="0.0" ry="0.0" rz="0.0"/>
+            </layer>
+            <layer id="7">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z07" rx="0.0" ry="0.0" rz="0.0"/>
+           </layer>
+            <layer id="8">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z08" rx="0.0" ry="0.0" rz="0.0"/>
+          </layer>
+            <layer id="9">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z09" rx="0.0" ry="0.0" rz="0.0"/>
+          </layer>
+            <layer id="10">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z10" rx="0.0" ry="0.0" rz="0.0"/>
+          </layer>
+            <layer id="11">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z11" rx="0.0" ry="0.0" rz="0.0"/>
+           </layer>
+            <layer id="12">
+                <module_placement name="TestPlane" id="0" x="0.0" y="0.0" z="z12" rx="0.0" ry="0.0" rz="0.0"/>
+            </layer>
+        </detector>      

   </detectors>
 
   <readouts>

+        <readout name="TrackerHits">
+            <id>system:6,barrel:3,layer:4,module:12,sensor:1,side:32:-2,strip:12</id> 
+        </readout>      

   </readouts>
   
   <fields>
    <field type="FieldMap3D" name="FieldMap3DTest" 
            filename="./testResources/org/lcsim/geometry/field/HPS_b18d36_unfolded.dat" 

-           xoffset="1.0"
-           yoffset="2.0"
-           zoffset="3.0" />   

+           xoffset="2.117"
+           yoffset="0.0"
+           zoffset="45.72" />   

   </fields>
 </lccdd>