Index: contrib/spatial/src/java/org/apache/lucene/spatial/tier/projections/IProjector.java
===================================================================
--- contrib/spatial/src/java/org/apache/lucene/spatial/tier/projections/IProjector.java	(révision 819480)
+++ contrib/spatial/src/java/org/apache/lucene/spatial/tier/projections/IProjector.java	(copie de travail)
@@ -25,4 +25,5 @@
 public interface IProjector {
   public String coordsAsString(double latitude, double longitude);
   public double[] coords(double latitude, double longitude);
+  public double[] range();
 }
\ No newline at end of file
Index: contrib/spatial/src/java/org/apache/lucene/spatial/tier/projections/SinusoidalProjector.java
===================================================================
--- contrib/spatial/src/java/org/apache/lucene/spatial/tier/projections/SinusoidalProjector.java	(révision 819480)
+++ contrib/spatial/src/java/org/apache/lucene/spatial/tier/projections/SinusoidalProjector.java	(copie de travail)
@@ -14,9 +14,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package org.apache.lucene.spatial.tier.projections;
 
+import java.lang.Math;
+
 /**
  * Based on Sinusoidal Projections
  * Project a latitude / longitude on a 2D cartesian map
@@ -26,7 +27,8 @@
  * release.</font>
  */
 public class SinusoidalProjector implements IProjector {
-
+  public static final double LATITUDE_RANGE= java.lang.Math.PI;
+  public static final double LONGITUDE_RANGE = 2* java.lang.Math.PI;
   
   public String coordsAsString(double latitude, double longitude) {
     return null;
@@ -41,4 +43,9 @@
     
   }
   
+  public double[] range() {
+	  double ranges[]= { LATITUDE_RANGE, LONGITUDE_RANGE};
+	  return ranges;
+  } 
+  
 }
Index: contrib/spatial/src/java/org/apache/lucene/spatial/tier/projections/CartesianTierPlotter.java
===================================================================
--- contrib/spatial/src/java/org/apache/lucene/spatial/tier/projections/CartesianTierPlotter.java	(révision 819480)
+++ contrib/spatial/src/java/org/apache/lucene/spatial/tier/projections/CartesianTierPlotter.java	(copie de travail)
@@ -24,6 +24,7 @@
  */
 public class CartesianTierPlotter {
   public static final String DEFALT_FIELD_PREFIX = "_tier_";
+  public static final double EARTH_CIRC_MILES= 28892.0d;
   
   final int tierLevel;
   int tierLength;
@@ -31,7 +32,6 @@
   int tierVerticalPosDivider;
   final IProjector projector;
   final String fieldPrefix;
-  Double idd = new Double(180);
   
   public CartesianTierPlotter (int tierLevel, IProjector projector, String fieldPrefix) {
   
@@ -88,22 +88,19 @@
   public double getTierBoxId (double latitude, double longitude) {
     
     double[] coords = projector.coords(latitude, longitude);
+    double[] ranges= projector.range();
     
-    double id = getBoxId(coords[0]) + (getBoxId(coords[1]) / tierVerticalPosDivider);
+    double id = getBoxCoord(coords[0], ranges[0]) + (getBoxCoord(coords[1], ranges[1]) / tierVerticalPosDivider);
     return id ;
   }
   
   
-  private double getBoxId (double coord){
+  private double getBoxCoord (double coord, double range){
     
     
-    return Math.floor(coord / (idd / this.tierLength));
+    return Math.floor(coord * (this.tierLength / range));
   }
   
-  @SuppressWarnings("unused")
-  private double getBoxId (double coord, int tierLen){
-    return Math.floor(coord / (idd / tierLen) );
-  }
   /**
    * get the string name representing current tier
    * _localTier&lt;tiedId&gt;
@@ -133,23 +130,17 @@
    *  Distances less than a mile return 15, finer granularity is
    *  in accurate
    */
-  public int bestFit(double miles){
-    
-    //28,892 a rough circumference of the earth
-    int circ = 28892;
-    
-    double r = miles / 2.0;
-    
-    double corner = r - Math.sqrt(Math.pow(r, 2) / 2.0d);
-    double times = circ / corner;
-    int bestFit =  (int)Math.ceil(log2(times)) + 1;
-    
-    if (bestFit > 15) {
-      // 15 is the granularity of about 1 mile
-      // finer granularity isn't accurate with standard java math
-      return 15;
-    }
-    return bestFit;
+  public int bestFit(double range){
+	    double times= EARTH_CIRC_MILES / (2.0d * range);
+	    
+	    int bestFit =  (int)Math.ceil(log2(times));
+	    
+	    if (bestFit > 15) {
+	      // 15 is the granularity of about 1 mile
+	      // finer granularity isn't accurate with standard java math
+	      return 15;
+	    }
+	    return bestFit;
   }
   
   /**