diff --git a/src/Terrain/TerrainQuery.cc b/src/Terrain/TerrainQuery.cc
index 829718ae61bce213d34029d6fecffe7a7ec2d351..3c63063cd20351c012d7bc9c8c9db868878b3c42 100644
--- a/src/Terrain/TerrainQuery.cc
+++ b/src/Terrain/TerrainQuery.cc
@@ -229,12 +229,10 @@ TerrainOfflineAirMapQuery::TerrainOfflineAirMapQuery(QObject* parent)
 void TerrainOfflineAirMapQuery::requestCoordinateHeights(const QList<QGeoCoordinate>& coordinates)
 {
     if (coordinates.length() == 0) {
-        return false;
+        return;
     }
 
-    _tileBatchManager->addQuery(this, coordinates);
-
-    return false;
+    _terrainTileManager->addCoordinateQuery(this, coordinates);
 }
 
 void TerrainOfflineAirMapQuery::requestPathHeights(const QGeoCoordinate& fromCoord, const QGeoCoordinate& toCoord)
@@ -249,7 +247,7 @@ void TerrainOfflineAirMapQuery::requestCarpetHeights(const QGeoCoordinate& swCoo
 
 void TerrainOfflineAirMapQuery::_signalCoordinateHeights(bool success, QList<double> heights)
 {
-    emit coordinateHeights(success, heights)
+    emit coordinateHeights(success, heights);
 }
 
 void TerrainOfflineAirMapQuery::_signalPathHeights(bool success, double latStep, double lonStep, const QList<double>& heights)
@@ -267,10 +265,10 @@ TerrainTileManager::TerrainTileManager(void)
 
 }
 
-void TerrainTileManager::addQuery(TerrainOfflineAirMapQuery* terrainQueryInterface, const QList<QGeoCoordinate>& coordinates)
+void TerrainTileManager::addCoordinateQuery(TerrainOfflineAirMapQuery* terrainQueryInterface, const QList<QGeoCoordinate>& coordinates)
 {
     if (coordinates.length() > 0) {
-        QList<float> altitudes;
+        QList<double> altitudes;
 
         if (!_getAltitudesForCoordinates(coordinates, altitudes)) {
             QueuedRequestInfo_t queuedRequestInfo = { terrainQueryInterface, coordinates, QueryMode::QueryModeCoordinates };
@@ -279,11 +277,11 @@ void TerrainTileManager::addQuery(TerrainOfflineAirMapQuery* terrainQueryInterfa
         }
 
         qCDebug(TerrainQueryLog) << "All altitudes taken from cached data";
-        terrainQueryInterface->_signalTerrainData(coordinates.count() == altitudes.count(), altitudes);
+        terrainQueryInterface->_signalCoordinateHeights(coordinates.count() == altitudes.count(), altitudes);
     }
 }
 
-bool TerrainTileManager::_getAltitudesForCoordinates(const QList<QGeoCoordinate>& coordinates, QList<float>& altitudes)
+bool TerrainTileManager::_getAltitudesForCoordinates(const QList<QGeoCoordinate>& coordinates, QList<double>& altitudes)
 {
     foreach (const QGeoCoordinate& coordinate, coordinates) {
         QString tileHash = _getTileHash(coordinate);
@@ -322,7 +320,7 @@ bool TerrainTileManager::_getAltitudesForCoordinates(const QList<QGeoCoordinate>
 
 void TerrainTileManager::_tileFailed(void)
 {
-    QList<float>    noAltitudes;
+    QList<double>    noAltitudes;
 
     foreach (const QueuedRequestInfo_t& requestInfo, _requestQueue) {
         if (requestInfo.queryMode == QueryMode::QueryModeCoordinates) {
@@ -393,7 +391,7 @@ void TerrainTileManager::_fetchedTile()
 
     // now try to query the data again
     for (int i = _requestQueue.count() - 1; i >= 0; i--) {
-        QList<float> altitudes;
+        QList<double> altitudes;
         if (_getAltitudesForCoordinates(_requestQueue[i].coordinates, altitudes)) {
             if (_requestQueue[i].queryMode == QueryMode::QueryModeCoordinates) {
                 _requestQueue[i].terrainQueryInterface->_signalCoordinateHeights(_requestQueue[i].coordinates.count() == altitudes.count(), altitudes);
diff --git a/src/Terrain/TerrainQuery.h b/src/Terrain/TerrainQuery.h
index 31cc01de30353c5d37ec59fc2c4a65ddcec5a147..d79910dac117d5c0beef3051394cfa9b0bb13c0b 100644
--- a/src/Terrain/TerrainQuery.h
+++ b/src/Terrain/TerrainQuery.h
@@ -114,18 +114,12 @@ class TerrainTileManager : public QObject {
 public:
     TerrainTileManager(void);
 
-    void addQuery(TerrainOfflineAirMapQuery* terrainQueryInterface, const QList<QGeoCoordinate>& coordinates);
+    void addCoordinateQuery(TerrainOfflineAirMapQuery* terrainQueryInterface, const QList<QGeoCoordinate>& coordinates);
 
 private slots:
     void _fetchedTile       (void);                             /// slot to handle fetched elevation tiles
 
 private:
-    typedef struct {
-        TerrainOfflineAirMapQuery*  terrainQueryInterface;
-        QList<QGeoCoordinate>       coordinates;
-        QueryMode                   queryMode;
-    } QueuedRequestInfo_t;
-
     enum class State {
         Idle,
         Downloading,
@@ -137,8 +131,14 @@ private:
         QueryModeCarpet
     };
 
+    typedef struct {
+        TerrainOfflineAirMapQuery*  terrainQueryInterface;
+        QList<QGeoCoordinate>       coordinates;
+        QueryMode                   queryMode;
+    } QueuedRequestInfo_t;
+
     void _tileFailed(void);
-    bool _getAltitudesForCoordinates(const QList<QGeoCoordinate>& coordinates, QList<float>& altitudes);
+    bool _getAltitudesForCoordinates(const QList<QGeoCoordinate>& coordinates, QList<double>& altitudes);
     QString _getTileHash(const QGeoCoordinate& coordinate);     /// Method to create a unique string for each tile
 
     QList<QueuedRequestInfo_t>  _requestQueue;
diff --git a/src/TerrainTile.cc b/src/TerrainTile.cc
index c68e42ad79ae3121f02e43416addfc76140b81b5..a22fdb52431b8b601b1c0ff4a3da7de540d04e2b 100644
--- a/src/TerrainTile.cc
+++ b/src/TerrainTile.cc
@@ -125,10 +125,10 @@ TerrainTile::TerrainTile(QJsonDocument document)
             _gridSizeLon = row.count();
             qCDebug(TerrainTileLog) << "Received tile has size in longitued direction: " << row.count();
             if (_gridSizeLon > 0) {
-                _data = new float*[_gridSizeLat];
+                _data = new double*[_gridSizeLat];
             }
             for (int k = 0; k < _gridSizeLat; k++) {
-                _data[k] = new float[_gridSizeLon];
+                _data[k] = new double[_gridSizeLon];
             }
         }
         if (row.count() < _gridSizeLon) {
@@ -154,7 +154,7 @@ bool TerrainTile::isIn(const QGeoCoordinate& coordinate) const
     return ret;
 }
 
-float TerrainTile::elevation(const QGeoCoordinate& coordinate) const
+double TerrainTile::elevation(const QGeoCoordinate& coordinate) const
 {
     if (_isValid) {
         qCDebug(TerrainTileLog) << "elevation: " << coordinate << " , in sw " << _southWest << " , ne " << _northEast;
diff --git a/src/TerrainTile.h b/src/TerrainTile.h
index 6f6254fc2c0cc02f8c746e5c83c9288ebd54584d..200a24d9284366f805e1994230590de8b0b52705 100644
--- a/src/TerrainTile.h
+++ b/src/TerrainTile.h
@@ -47,28 +47,28 @@ public:
     * @param coordinate
     * @return elevation
     */
-    float elevation(const QGeoCoordinate& coordinate) const;
+    double elevation(const QGeoCoordinate& coordinate) const;
 
     /**
     * Accessor for the minimum elevation of the tile
     *
     * @return minimum elevation
     */
-    float minElevation(void) const { return _minElevation; }
+    double minElevation(void) const { return _minElevation; }
 
     /**
     * Accessor for the maximum elevation of the tile
     *
     * @return maximum elevation
     */
-    float maxElevation(void) const { return _maxElevation; }
+    double maxElevation(void) const { return _maxElevation; }
 
     /**
     * Accessor for the average elevation of the tile
     *
     * @return average elevation
     */
-    float avgElevation(void) const { return _avgElevation; }
+    double avgElevation(void) const { return _avgElevation; }
 
     /**
     * Accessor for the center coordinate
@@ -84,11 +84,11 @@ private:
     QGeoCoordinate      _southWest;                                     /// South west corner of the tile
     QGeoCoordinate      _northEast;                                     /// North east corner of the tile
 
-    float               _minElevation;                                  /// Minimum elevation in tile
-    float               _maxElevation;                                  /// Maximum elevation in tile
-    float               _avgElevation;                                  /// Average elevation of the tile
+    double              _minElevation;                                  /// Minimum elevation in tile
+    double              _maxElevation;                                  /// Maximum elevation in tile
+    double              _avgElevation;                                  /// Average elevation of the tile
 
-    float**             _data;                                          /// 2D elevation data array
+    double**            _data;                                          /// 2D elevation data array
     int                 _gridSizeLat;                                   /// data grid size in latitude direction
     int                 _gridSizeLon;                                   /// data grid size in longitude direction
     bool                _isValid;                                       /// data loaded is valid