+static gboolean terraserver_topo_coord_to_mapcoord ( const VikCoord *src, gdouble xmpp, gdouble ympp, MapCoord *dest );
+static int terraserver_topo_download ( MapCoord *src, const gchar *dest_fn );
+
+static gboolean terraserver_aerial_coord_to_mapcoord ( const VikCoord *src, gdouble xmpp, gdouble ympp, MapCoord *dest );
+static int terraserver_aerial_download ( MapCoord *src, const gchar *dest_fn );
+
+static gboolean terraserver_urban_coord_to_mapcoord ( const VikCoord *src, gdouble xmpp, gdouble ympp, MapCoord *dest );
+static int terraserver_urban_download ( MapCoord *src, const gchar *dest_fn );
+
+static void terraserver_mapcoord_to_center_coord ( MapCoord *src, VikCoord *dest );
+
+static DownloadOptions terraserver_options = { NULL, 0, a_check_map_file };
+