Created a utils package.

src/main/java/org/orekit/rugged/api/Rugged.java

@@ -40,11 +40,11 @@ import org.orekit.orbits.CartesianOrbit;
 import org.orekit.orbits.Orbit;
 import org.orekit.propagation.Propagator;
 import org.orekit.rugged.core.BasicScanAlgorithm;
-import org.orekit.rugged.core.ExtendedEllipsoid;
 import org.orekit.rugged.core.IgnoreDEMAlgorithm;
-import org.orekit.rugged.core.SpacecraftToObservedBody;
 import org.orekit.rugged.core.duvenhage.DuvenhageAlgorithm;
 import org.orekit.rugged.raster.IntersectionAlgorithm;
+import org.orekit.rugged.utils.ExtendedEllipsoid;
+import org.orekit.rugged.utils.SpacecraftToObservedBody;
 import org.orekit.time.AbsoluteDate;
 import org.orekit.utils.Constants;
 import org.orekit.utils.IERSConventions;

src/main/java/org/orekit/rugged/api/SensorMeanPlaneCrossing.java

@@ -25,7 +25,7 @@ import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
 import org.apache.commons.math3.util.FastMath;
 import org.orekit.errors.OrekitException;
 import org.orekit.frames.Transform;
-import org.orekit.rugged.core.SpacecraftToObservedBody;
+import org.orekit.rugged.utils.SpacecraftToObservedBody;
 import org.orekit.time.AbsoluteDate;
 import org.orekit.utils.Constants;
 import org.orekit.utils.PVCoordinates;

src/main/java/org/orekit/rugged/core/BasicScanAlgorithm.java

@@ -30,6 +30,7 @@ import org.orekit.rugged.raster.SimpleTile;
 import org.orekit.rugged.raster.SimpleTileFactory;
 import org.orekit.rugged.raster.Tile;
 import org.orekit.rugged.raster.TilesCache;
+import org.orekit.rugged.utils.ExtendedEllipsoid;
 
 /** Intersection computation using a basic algorithm based on exhaustive scan.
  * <p>

src/main/java/org/orekit/rugged/core/IgnoreDEMAlgorithm.java

@@ -21,6 +21,7 @@ import org.orekit.bodies.GeodeticPoint;
 import org.orekit.errors.OrekitException;
 import org.orekit.rugged.api.RuggedException;
 import org.orekit.rugged.raster.IntersectionAlgorithm;
+import org.orekit.rugged.utils.ExtendedEllipsoid;
 
 /** Intersection ignoring Digital Elevation Model.
  * <p>

src/main/java/org/orekit/rugged/core/duvenhage/DuvenhageAlgorithm.java

@@ -23,10 +23,10 @@ import org.orekit.errors.OrekitException;
 import org.orekit.rugged.api.RuggedException;
 import org.orekit.rugged.api.RuggedMessages;
 import org.orekit.rugged.api.TileUpdater;
-import org.orekit.rugged.core.ExtendedEllipsoid;
 import org.orekit.rugged.raster.IntersectionAlgorithm;
 import org.orekit.rugged.raster.Tile;
 import org.orekit.rugged.raster.TilesCache;
+import org.orekit.rugged.utils.ExtendedEllipsoid;
 
 /** Digital Elevation Model intersection using Bernardt Duvenhage's algorithm.
  * <p>

src/main/java/org/orekit/rugged/raster/IntersectionAlgorithm.java

@@ -19,7 +19,7 @@ package org.orekit.rugged.raster;
 import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
 import org.orekit.bodies.GeodeticPoint;
 import org.orekit.rugged.api.RuggedException;
-import org.orekit.rugged.core.ExtendedEllipsoid;
+import org.orekit.rugged.utils.ExtendedEllipsoid;
 
 /** Interface for Digital Elevation Model intersection algorithm.
  * @author Luc Maisonobe

src/main/java/org/orekit/rugged/core/ExtendedEllipsoid.java → src/main/java/org/orekit/rugged/utils/ExtendedEllipsoid.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.orekit.rugged.core;
+package org.orekit.rugged.utils;
 
 import org.apache.commons.math3.geometry.euclidean.threed.Line;
 import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;

src/main/java/org/orekit/rugged/core/SpacecraftToObservedBody.java → src/main/java/org/orekit/rugged/utils/SpacecraftToObservedBody.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.orekit.rugged.core;
+package org.orekit.rugged.utils;
 
 import org.orekit.attitudes.Attitude;
 import org.orekit.attitudes.AttitudeProvider;

src/test/java/org/orekit/rugged/core/AbstractAlgorithmTest.java

@@ -44,6 +44,7 @@ import org.orekit.rugged.core.duvenhage.MinMaxTreeTileFactory;
 import org.orekit.rugged.raster.CliffsElevationUpdater;
 import org.orekit.rugged.raster.VolcanicConeElevationUpdater;
 import org.orekit.rugged.raster.IntersectionAlgorithm;
+import org.orekit.rugged.utils.ExtendedEllipsoid;
 import org.orekit.time.AbsoluteDate;
 import org.orekit.time.TimeScalesFactory;
 import org.orekit.utils.Constants;

src/test/java/org/orekit/rugged/core/ExtendedEllipsoidTest.java → src/test/java/org/orekit/rugged/utils/ExtendedEllipsoidTest.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.orekit.rugged.core;
+package org.orekit.rugged.utils;
 
 import java.io.File;
 import java.net.URISyntaxException;
@@ -34,7 +34,7 @@ import org.orekit.frames.Frame;
 import org.orekit.frames.FramesFactory;
 import org.orekit.rugged.api.RuggedException;
 import org.orekit.rugged.api.RuggedMessages;
-import org.orekit.rugged.core.ExtendedEllipsoid;
+import org.orekit.rugged.utils.ExtendedEllipsoid;
 import org.orekit.utils.Constants;
 import org.orekit.utils.IERSConventions;