diff --git a/Modules/IGT/Testing/mitkNavigationDataTest.cpp b/Modules/IGT/Testing/mitkNavigationDataTest.cpp
index 603d88cb6c..5ee59e216e 100644
--- a/Modules/IGT/Testing/mitkNavigationDataTest.cpp
+++ b/Modules/IGT/Testing/mitkNavigationDataTest.cpp
@@ -1,518 +1,579 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #include "mitkTestingMacros.h"
 #include "mitkNavigationData.h"
 #include "mitkVector.h"
 #include <vnl/vnl_math.h>
 #include <itkIndent.h>
 
 
 using namespace mitk;
 
 /**
  * helper function which checks if the non position / orientation / covariance related members are all set to certain values
  */
 static bool AreBasicNavigationMembersEqual(const NavigationData::Pointer nd, const bool dataValid,
     const NavigationData::TimeStampType timeStamp, const std::string name)
 {
   bool result = true;
   result = result && (nd->IsDataValid() == dataValid);
   result = result && (mitk::Equal(nd->GetIGTTimeStamp(), timeStamp));
   result = result && (0 == name.compare(nd->GetName()));
 
   return result;
 }
 
 /**
  * helper function which checks if the basic members, meaning the members not related to position / orientation / covariance
  * are the same for two NavigationData objects.
  */
 static bool AreBasicNavigationMembersEqual(const NavigationData::Pointer nd1, const NavigationData::Pointer nd2)
 {
   return AreBasicNavigationMembersEqual(nd1, nd2->IsDataValid(),
       nd2->GetIGTTimeStamp(),
       nd2->GetName());
 }
 
+/**
+ * Test if the NavigationData object nd has the correct settings for covariance matrix specific members.
+ *
+ * @param nd
+ * @param hasPosition the desired value for the hasPosition member
+ * @param hasOrientation  the desired value for the hasOrientation member
+ * @param covMatrix the covariance matrix nd should have
+ * @return
+ */
 static bool AreCovarianceNavigationMembersEqual(const NavigationData::Pointer nd, bool hasPosition,
     bool hasOrientation, NavigationData::CovarianceMatrixType covMatrix)
 {
   bool result = true;
   result = result && (nd->GetHasPosition() == hasPosition);
   result = result && (nd->GetHasOrientation() == hasOrientation);
   result = result && (mitk::MatrixEqualElementWise(nd->GetCovErrorMatrix(), covMatrix));
 
   return result;
 }
 
-
+/**
+ * Checks if the covariance related members of the two NavigationData objects are the same
+ *
+ * @see AreCovarianceNavigationMembersEqual
+ *
+ * @param nd1
+ * @param nd2
+ * @return
+ */
 static bool AreCovarianceNavigationMembersEqual(const NavigationData::Pointer nd1, const NavigationData::Pointer nd2)
 {
   return AreCovarianceNavigationMembersEqual(nd1,
       nd2->GetHasPosition(), nd2->GetHasOrientation(), nd2->GetCovErrorMatrix());
 }
 
 
+/**
+ * Creates a fully set NavigationData object for testing purposes.
+ *
+ * @return a smartpointer to the object
+ */
 static mitk::NavigationData::Pointer GetTestData()
 {
   mitk::NavigationData::Pointer nd = mitk::NavigationData::New();
   mitk::NavigationData::PositionType p;
   mitk::FillVector3D(p, 44.4, 55.5, 66.66);
   nd->SetPosition(p);
   mitk::NavigationData::OrientationType o(1.0, 2.0, 3.0, 4.0);
   nd->SetOrientation(o);
   nd->SetDataValid(true);
   nd->SetIGTTimeStamp(100.111);
   nd->SetHasPosition(false);
   nd->SetHasOrientation(false);
   mitk::NavigationData::CovarianceMatrixType m;
   m.Fill(17.17);
   m(2, 2) = 1000.01;
   nd->SetCovErrorMatrix(m);
   nd->SetName("my NavigationData");
   nd->SetPositionAccuracy(100.0);
   nd->SetOrientationAccuracy(10.0);
   return nd;
 }
 
 
 static void TestInstatiation()
 {
   // Test instantiation of NavigationData
   mitk::NavigationData::Pointer nd = mitk::NavigationData::New();
   MITK_TEST_CONDITION(nd.IsNotNull(),"Test instatiation");
 }
 
 
 static void TestGetterSetter()
 {
   mitk::NavigationData::Pointer nd = mitk::NavigationData::New();
 
   mitk::NavigationData::PositionType p;
   mitk::FillVector3D(p, 44.4, 55.5, 66.66);
   nd->SetPosition(p);
   MITK_TEST_CONDITION(nd->GetPosition() == p, "Set-/GetPosition()");
 
   mitk::NavigationData::OrientationType o(1.0, 2.0, 3.0, 4.0);
   nd->SetOrientation(o);
   MITK_TEST_CONDITION(nd->GetOrientation() == o, "Set-/GetOrientation()");
 
   nd->SetDataValid(true);
   MITK_TEST_CONDITION(nd->IsDataValid() == true, "Set-/IsDataValid()");
 
   nd->SetIGTTimeStamp(100.111);
   MITK_TEST_CONDITION(mitk::Equal(nd->GetIGTTimeStamp(), 100.111), "Set-/GetIGTTimeStamp()");
 
   nd->SetHasPosition(false);
   MITK_TEST_CONDITION(nd->GetHasPosition() == false, "Set-/GetHasPosition()");
 
   nd->SetHasOrientation(false);
   MITK_TEST_CONDITION(nd->GetHasOrientation() == false, "Set-/GetHasOrientation()");
 
   mitk::NavigationData::CovarianceMatrixType m;
   m.Fill(17.17);
   m(2, 2) = 1000.01;
   nd->SetCovErrorMatrix(m);
   MITK_TEST_CONDITION(nd->GetCovErrorMatrix() == m, "Set-/GetCovErrorMatrix()");
 
   nd->SetName("my NavigationData");
   MITK_TEST_CONDITION(std::string(nd->GetName()) == "my NavigationData", "Set-/GetName()");
 
   nd->SetPositionAccuracy(100.0);
   mitk::NavigationData::CovarianceMatrixType result = nd->GetCovErrorMatrix();
   MITK_TEST_CONDITION(mitk::Equal(result(0, 0), 10000.0)
     && mitk::Equal(result(1, 1), 10000.0)
     && mitk::Equal(result(2, 2), 10000.0), "SetPositionAccuracy()");
 
   nd->SetOrientationAccuracy(10.0);
   mitk::NavigationData::CovarianceMatrixType result2 = nd->GetCovErrorMatrix();
   MITK_TEST_CONDITION(mitk::Equal(result2(3, 3), 100.0)
     && mitk::Equal(result2(4, 4), 100.0)
     && mitk::Equal(result2(5, 5), 100.0), "SetOrientationAccuracy()");
 }
 
 static void TestGraft()
 {
   //create test data
   mitk::NavigationData::Pointer nd = GetTestData();
 
   mitk::NavigationData::Pointer graftedCopy = mitk::NavigationData::New();
   graftedCopy->Graft(nd);
 
   bool graftIsEqual = (nd->GetPosition() == graftedCopy->GetPosition())
     && (nd->GetOrientation() == graftedCopy->GetOrientation())
     && AreCovarianceNavigationMembersEqual(nd, graftedCopy)
     && AreBasicNavigationMembersEqual(nd, graftedCopy);
 
   MITK_TEST_CONDITION(graftIsEqual, "Graft() produces equal NavigationData object");
 }
 
 static void TestPrintSelf()
 {
   mitk::NavigationData::Pointer nd = GetTestData();
   itk::Indent myIndent = itk::Indent();
 
   MITK_TEST_OUTPUT(<<"Testing method PrintSelf(), method output will follow:");
   bool success = true;
   try
   {
     nd->PrintSelf(std::cout,myIndent);
   }
   catch(...)
   {
     success = false;
   }
   MITK_TEST_CONDITION(success, "Testing method PrintSelf().");
 }
 
 
 static void TestWrongInputs()
 {
   mitk::NavigationData::Pointer nd = GetTestData();
 
   // Test CopyInformation
   bool success = false;
   try
   {
     nd->CopyInformation(NULL);
   }
   catch(itk::ExceptionObject e)
   {
     success = true;
   }
   MITK_TEST_CONDITION(success, "Testing wrong input for method CopyInformation.");
 
 
   // Test Graft
   success = false;
   try
   {
     nd->Graft(NULL);
   }
   catch(itk::ExceptionObject e)
   {
     success = true;
   }
   MITK_TEST_CONDITION(success, "Testing wrong input for method Graft.");
 }
 
 
 static mitk::Quaternion quaternion;
 static mitk::Vector3D   offsetVector;
 static mitk::Point3D    offsetPoint;
 static mitk::Matrix3D   rotation;
 
 static mitk::Quaternion quaternion2;
 static mitk::Vector3D   offsetVector2;
 static mitk::Point3D    offsetPoint2;
 static mitk::Matrix3D   rotation2;
 
 static mitk::Point3D  point;
 
+/**
+ * Helper method setting up data required for tests (like points which shall be transformed by the NavigationData).
+ */
 static void SetupNaviDataTests()
 {
   // set rotation matrix to
   /*
   * 0 -1  0
   * 1  0  0
   * 0  0  1
   */
   rotation.Fill(0);
   rotation[0][1] = -1;
   rotation[1][0] =  1;
   rotation[2][2] =  1;
 
   // set quaternion to quaternion equivalent
   // values calculated with javascript at
   // http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/
   quaternion = mitk::Quaternion(0, 0, 0.7071067811865475, 0.7071067811865476);
 
   // set offset to some value. Some tests need vectors, offers points.
   double offsetArray[3] = {1.0,2.0,3.123456};
   offsetVector          = offsetArray;
   offsetPoint           = offsetArray;
 
   /***** Second set of data for compose tests ****/
 
   // set rotation2 matrix to
   /*
   * 1  0  0
   * 0  0 -1
   * 0  1  0
   */
   rotation2.Fill(0);
   rotation2[0][0] =  1;
   rotation2[1][2] = -1;
   rotation2[2][1] =  1;
 
   quaternion2                = mitk::Quaternion(0.7071067811865475, 0, 0, 0.7071067811865476);
   mitk::ScalarType offsetArray2[3] = {1, 0, 0};
   offsetVector2              = offsetArray2;
   offsetPoint2               = offsetArray2;
 
   /***** Create a point to be transformed *****/
   mitk::ScalarType pointArray[] = {1.0, 3.0, 5.0};
   point        = pointArray;
 }
 
 /**
 * Helper method, which creates a NavigationData object using the data created in SetupNaviDataTests()
 */
 static mitk::NavigationData::Pointer CreateNavidata(mitk::Quaternion quaternion, mitk::Point3D offset)
 {
   mitk::NavigationData::Pointer navigationData = mitk::NavigationData::New();
   navigationData->SetOrientation(quaternion);
   navigationData->SetPosition(offset);
 
   return navigationData;
 }
 
+/**
+ * Helper method which creates an affine transformation only composed by a rotation and a translation (no scalings and the likes).
+ *
+ * @param rotationMatrix
+ * @param offset
+ * @return
+ */
 static mitk::AffineTransform3D::Pointer CreateAffineTransform(mitk::Matrix3D rotationMatrix, mitk::Vector3D offset)
 {
   mitk::AffineTransform3D::Pointer affineTransform3D = mitk::AffineTransform3D::New();
   affineTransform3D->SetOffset(offset);
   affineTransform3D->SetMatrix(rotationMatrix);
 
   return affineTransform3D;
 }
 
+/**
+ * Test if NavigationData::GetInverse returns the correct inverse
+ */
 static void TestInverse()
 {
   SetupNaviDataTests();
   mitk::NavigationData::Pointer nd = CreateNavidata(quaternion, offsetPoint);
 
   mitk::NavigationData::Pointer ndInverse = nd->GetInverse();
 
   // calculate expected inverted position vector: b2 = -A2b1
 
   // for -A2b1 we need vnl_vectors.
   vnl_vector_fixed<mitk::ScalarType, 3> b1;
   for (int i = 0; i < 3; ++i) {
     b1[i] = nd->GetPosition()[i];
   }
   vnl_vector_fixed<mitk::ScalarType, 3> b2;
   b2 = -(ndInverse->GetOrientation().rotate(b1));
 
   // now copy result back into our mitk::Point3D
   mitk::Point3D invertedPosition;
   for (int i = 0; i < 3; ++i) {
     invertedPosition[i] = b2[i];
   }
 
   MITK_TEST_CONDITION(mitk::Equal(nd->GetOrientation().inverse(), ndInverse->GetOrientation()),"Testing GetInverse: orientation inverted");
   MITK_TEST_CONDITION(mitk::Equal(invertedPosition, ndInverse->GetPosition()), "Testing GetInverse: position inverted");
 
   bool otherFlagsOk = AreBasicNavigationMembersEqual(nd, ndInverse)
       && AreCovarianceNavigationMembersEqual(ndInverse, false, false, nd->GetCovErrorMatrix());
   // covariance update mechanism not yet implemented, thus validities are set to false.
 
 
   MITK_TEST_CONDITION(otherFlagsOk, "Testing GetInverse: other flags are same");
 }
 
+/**
+ * Test if the original orientation and position are retained after inverting two times.
+ */
 static void TestDoubleInverse()
 {
   SetupNaviDataTests();
   mitk::NavigationData::Pointer nd = CreateNavidata(quaternion, offsetPoint);
 
   mitk::NavigationData::Pointer ndDoubleInverse = nd->GetInverse()->GetInverse();
 
   MITK_TEST_CONDITION(mitk::Equal(nd->GetOrientation(), ndDoubleInverse->GetOrientation()),"Testing GetInverse double application: orientation preserved");
   MITK_TEST_CONDITION(mitk::Equal(nd->GetPosition(), ndDoubleInverse->GetPosition()), "Testing GetInverse double application: position preserved");
 }
 
+/**
+ * Tests if NavigationData::GetInverse throws an error if the NavigationData has no inverse
+ * (e.g. after it is initialized, no rotation is stored -> the transformation cannot be inverted).
+ */
 static void TestInverseError()
 {
   // initialize empty NavigationData (quaternion is zeroed)
   mitk::NavigationData::Pointer nd = mitk::NavigationData::New();
   mitk::Quaternion quaternion;
   quaternion.fill(0);
   nd->SetOrientation(quaternion);
 
   MITK_TEST_FOR_EXCEPTION(mitk::Exception&, nd->GetInverse());
 }
 
+/**
+ * Tests if NavigationData::TransformPoint works.
+ */
 static void TestTransform()
 {
   SetupNaviDataTests();
   mitk::NavigationData::Pointer navigationData = CreateNavidata(quaternion, offsetPoint);
 
   point = navigationData->TransformPoint(point);
 
   mitk::ScalarType resultingPointArray[] = {-2, 3, 8.123456};
   mitk::Point3D    resultingPoint        = resultingPointArray;
   MITK_TEST_CONDITION(mitk::Equal(resultingPoint, point), "Testing point transformation");
 }
 
+/**
+ * Tests if the construction of a NavigationData object from an
+ * affine transformation which is only composed of a rotation and translation works.
+ */
 static void TestAffineConstructor()
 {
   SetupNaviDataTests();
   mitk::AffineTransform3D::Pointer affineTransform3D = CreateAffineTransform(rotation, offsetVector);
 
   mitk::NavigationData::Pointer navigationData = mitk::NavigationData::New(affineTransform3D);
 
 
   MITK_TEST_CONDITION(AreBasicNavigationMembersEqual(navigationData, true, 0.0, ""),
       "Testing affine constructor: dataValid, timeStamp and name have been initialized to default values");
 
   NavigationData::CovarianceMatrixType covMatrix; // empty covariance matrix
   MITK_TEST_CONDITION(AreCovarianceNavigationMembersEqual(navigationData, true, true, covMatrix),
       "Testing affine constructor: covariance matrix values have been correctly initialized"); // TODO: discuss with Alfred
   // why this is the desired initialization of the covariance information.
 
   MITK_TEST_CONDITION(mitk::Equal(navigationData->GetPosition(), offsetPoint), "Testing affine constructor: offset");
   MITK_TEST_CONDITION(mitk::Equal(navigationData->GetOrientation(), quaternion), "Testing affine constructor: quaternion");
 }
 
-
+/**
+ * Tests if the construction of a NavigationData object throws an error when constructing from an
+ * affine transformation which is orthogonal.
+ */
 static void TestAffineConstructorErrorTransposedNotInverse()
 {
   SetupNaviDataTests();
   rotation.SetIdentity();
   rotation[1][0] = 2; // this matrix has determinant = 1 (triangular matrix with ones in diagonal) but transposed != inverse
   mitk::AffineTransform3D::Pointer affineTransform3D = CreateAffineTransform(rotation, offsetVector);
 
   MITK_TEST_FOR_EXCEPTION(mitk::Exception&, mitk::NavigationData::New(affineTransform3D));
 }
 
-
+/**
+ * Tests if the construction of a NavigationData object throws an error when constructing from an
+ * affine transformation which is not normal.
+ */
 static void TestAffineConstructorErrorDeterminantNonEqualOne()
 {
   SetupNaviDataTests();
   rotation.SetIdentity();
   rotation[0][0] = 2; // determinant for diagonal matrices is product of diagonal elements => det = 2
   mitk::AffineTransform3D::Pointer affineTransform3D = CreateAffineTransform(rotation, offsetVector);
 
   MITK_TEST_FOR_EXCEPTION(mitk::Exception&, mitk::NavigationData::New(affineTransform3D));
 }
 
 
+/**
+ * Tests if the error suppression mechanism works if a NavigationData object is created from a
+ * invalid affine transformation (one that is not only rotation and translation).
+ */
 static void TestAffineConstructorErrorCheckingFalse()
 {
   SetupNaviDataTests();
   rotation.SetIdentity();
   rotation[0][0] = 2; // determinant for diagonal matrices is product of diagonal elements => det = 2
   mitk::AffineTransform3D::Pointer affineTransform3D = CreateAffineTransform(rotation, offsetVector);
 
   bool exceptionSuppressed = true;
   try
   {
     mitk::NavigationData::New(affineTransform3D, false);
   }
   catch (mitk::Exception&)
   {
     exceptionSuppressed = false;
   }
 
   MITK_TEST_CONDITION(exceptionSuppressed, "Test affine constructor: exception can be suppressed.")
 }
 
-
+/**
+ * Test if NavigationData::GetAffineTransform3D() returns the correct affine transformation.
+ */
 static void TestAffineGetter()
 {
   SetupNaviDataTests();
   mitk::NavigationData::Pointer navigationData = CreateNavidata(quaternion, offsetPoint);
 
   mitk::AffineTransform3D::Pointer affineTransform = navigationData->GetAffineTransform3D();
 
   MITK_TEST_CONDITION(mitk::Equal(affineTransform->GetOffset(), offsetVector), "Testing AffineTransform3D getter: offset");
   MITK_TEST_CONDITION(mitk::MatrixEqualElementWise(affineTransform->GetMatrix(), rotation), "Testing AffineTransform3D getter: rotation");
 }
 
 /**
 * This test tests the complete chain from affineTransform -> NavigationData -> affineTransform
 */
 static void TestAffineToNaviDataToAffine()
 {
   SetupNaviDataTests();
   mitk::AffineTransform3D::Pointer affineTransform3D = CreateAffineTransform(rotation, offsetVector);
 
   // there and back again: affineTransform -> NavigationData -> affineTransform
   mitk::NavigationData::Pointer navigationData = mitk::NavigationData::New(affineTransform3D);
   mitk::AffineTransform3D::Pointer affineTransform3D_2;
   affineTransform3D_2 = navigationData->GetAffineTransform3D();
 
   MITK_TEST_CONDITION(mitk::Equal(affineTransform3D->GetOffset(), affineTransform3D_2->GetOffset()), "Testing affine -> navidata -> affine chain: offset");
   MITK_TEST_CONDITION(mitk::MatrixEqualElementWise(affineTransform3D->GetMatrix(), affineTransform3D_2->GetMatrix()), "Testing affine -> navidata -> affine chain: rotation");
 }
 
 
 static void TestCompose(bool pre = false)
 {
   SetupNaviDataTests();
   mitk::NavigationData::Pointer    nd = CreateNavidata(quaternion, offsetPoint);
   mitk::AffineTransform3D::Pointer at = CreateAffineTransform(rotation, offsetVector);
   // second transform for composition
   mitk::NavigationData::Pointer    nd2 = CreateNavidata(quaternion2, offsetPoint2);
   mitk::AffineTransform3D::Pointer at2 = CreateAffineTransform(rotation2, offsetVector2);
   // save point for affinetransform
   mitk::Point3D point2 = point;
 
 
   nd->Compose(nd2, pre);
   point  = nd->TransformPoint(point);
 
   at->Compose(at2, pre);
   point2 = at->TransformPoint(point2);
 
   MITK_TEST_CONDITION(mitk::Equal(point, point2), "Compose pre = " << pre << ": composition works ");
 
   bool covarianceValidityReset = !nd->GetHasOrientation() && !nd->GetHasPosition();
 
   MITK_TEST_CONDITION(covarianceValidityReset, "Compose pre = " << pre << ": covariance validities reset because not implemented yet.");
 }
 
 static void TestReverseCompose()
 {
   TestCompose(true);
 }
 
 
 /**
 * This function is testing the Class mitk::NavigationData. For most tests we would need the MicronTracker hardware, so only a few
 * simple tests, which can run without the hardware are implemented yet (2009, January, 23rd). As soon as there is a working
 * concept to test the tracking classes which are very close to the hardware on all systems more tests are needed here.
 */
 int mitkNavigationDataTest(int /* argc */, char* /*argv*/[])
 {
   MITK_TEST_BEGIN("NavigationData");
 
   TestInstatiation();
   TestGetterSetter();
   TestGraft();
   TestPrintSelf();
   TestWrongInputs();
 
   TestAffineConstructor();
   TestAffineConstructorErrorDeterminantNonEqualOne();
   TestAffineConstructorErrorTransposedNotInverse();
   TestAffineConstructorErrorCheckingFalse();
 
   TestAffineGetter();
   TestAffineToNaviDataToAffine();
 
   TestTransform();
 
   TestInverse();
   TestDoubleInverse();
   TestInverseError();
 
   TestCompose();
   TestReverseCompose();
 
   MITK_TEST_END();
 }