minor

src/main/java/org/orekit/rugged/atmosphericrefraction/AtmosphericRefraction.java

@@ -18,6 +18,7 @@ package org.orekit.rugged.atmosphericrefraction;
 
 
 import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
+import org.orekit.rugged.errors.RuggedException;
 import org.orekit.rugged.raster.Tile;
 import org.orekit.rugged.utils.NormalizedGeodeticPoint;
 
@@ -27,6 +28,6 @@ import org.orekit.rugged.utils.NormalizedGeodeticPoint;
  */
 public interface AtmosphericRefraction {
 
-    NormalizedGeodeticPoint getPointOnGround(Vector3D pos, Vector3D los, Vector3D zenith, double altitude, Tile tile);
+    NormalizedGeodeticPoint getPointOnGround(Vector3D pos, Vector3D los, Vector3D zenith, double altitude, Tile tile) throws RuggedException;
 
 }

src/main/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModel.java

@@ -16,7 +16,6 @@
  */
 package org.orekit.rugged.atmosphericrefraction;
 
-import com.sun.org.apache.xpath.internal.operations.Mult;
 import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
 import org.apache.commons.math3.util.FastMath;
 import org.orekit.bodies.OneAxisEllipsoid;
@@ -29,7 +28,10 @@ import org.orekit.rugged.utils.NormalizedGeodeticPoint;
 import org.orekit.utils.Constants;
 import org.orekit.utils.IERSConventions;
 
-import java.util.*;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.TreeMap;
 
 /**
  * Multi layer model for atmospheric refraction.