diff --git a/sw/airborne/pprz_algebra_float.h b/sw/airborne/pprz_algebra_float.h
index 92c2361d16..719917b555 100644
--- a/sw/airborne/pprz_algebra_float.h
+++ b/sw/airborne/pprz_algebra_float.h
@@ -3,6 +3,13 @@
 
 
 
+#define PPRZ_FLOAT_VECT_COPY(_o, _i) {		\
+    _o.x = _i.x;				\
+    _o.y = _i.y;				\
+    _o.z = _i.z;				\
+  }
+
+
 
 
 #endif /* PPRZ_ALGEBRA_FLOAT_H */
diff --git a/sw/airborne/pprz_geodetic_float.c b/sw/airborne/pprz_geodetic_float.c
index a084c0ce42..63bd42bb3d 100644
--- a/sw/airborne/pprz_geodetic_float.c
+++ b/sw/airborne/pprz_geodetic_float.c
@@ -1,11 +1,10 @@
 #include "pprz_geodetic_float.h"
 
+#include "pprz_algebra_float.h"
 #include <math.h>
 
 void init_ltp_from_ecef_f(struct LtpRef_f* ref_param, struct EcefCoor_f* ref_pos) {
-  ref_param->ecef.x = ref_pos->x;
-  ref_param->ecef.y = ref_pos->y;
-  ref_param->ecef.z = ref_pos->z;
+  PPRZ_FLOAT_VECT_COPY(ref_param->ecef, (*ref_pos));
   /* compute lon and lat */
 
 }
diff --git a/sw/airborne/pprz_geodetic_float.h b/sw/airborne/pprz_geodetic_float.h
new file mode 100644
index 0000000000..5fbb37e61c
--- /dev/null
+++ b/sw/airborne/pprz_geodetic_float.h
@@ -0,0 +1,43 @@
+#ifndef PPRZ_GEODETIC_FLOAT_H
+#define PPRZ_GEODETIC_FLOAT_H
+
+/* Earth Centered Earth Fixed in meters */
+struct EcefCoor_f {
+  FLOAT_T x;
+  FLOAT_T y;
+  FLOAT_T z;
+};
+
+/* lon, lat in radians */
+/* alt in meters       */
+struct LlaCoor_f {
+  FLOAT_T lon;
+  FLOAT_T lat;
+  FLOAT_T alt;
+};
+
+/* North East Down local tangeant plane */
+struct NedCoor_f {
+  FLOAT_T x;
+  FLOAT_T y;
+  FLOAT_T z;
+};
+
+/* East North Down local tangeant plane */
+struct EnuCoor_f {
+  FLOAT_T x;
+  FLOAT_T y;
+  FLOAT_T z;
+};
+
+/* Local tangeant plane reference */
+struct LtpRef_f {
+  struct EcefCoor_f ecef;
+  struct LlaCoor_f  lla;
+};
+
+extern void init_ltp_from_ecef_f(struct LtpRef_f* ref_param, struct EcefCoor_f* ref_pos);
+extern void init_ltp_from_lla_f(struct LtpRef_f* ref_param, struct LlaCoor_f* ref_pos);
+extern void enu_of_ecef_f(struct LtpRef_f* ref_param, struct EnuCoor_f* out, struct EcefCoor_f* in);
+
+#endif /* PPRZ_GEODETIC_FLOAT_H */
diff --git a/sw/airborne/test/Makefile b/sw/airborne/test/Makefile
new file mode 100644
index 0000000000..8bdc02c6f0
--- /dev/null
+++ b/sw/airborne/test/Makefile
@@ -0,0 +1,13 @@
+
+
+CC = gcc
+CFLAGS = -I.. -DFLOAT_T=double -Wall
+LDFLAGS = -lm
+
+test_geodetic: test_geodetic.c ../pprz_geodetic_float.c
+	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
+
+
+
+clean:
+	rm -f *~ test_geodetic
diff --git a/sw/airborne/test/test_geodetic.c b/sw/airborne/test/test_geodetic.c
new file mode 100644
index 0000000000..7e27485334
--- /dev/null
+++ b/sw/airborne/test/test_geodetic.c
@@ -0,0 +1,43 @@
+/*
+  http://en.wikipedia.org/wiki/Geodetic_system
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+#define DEG_OF_RAD(_r) (_r * 180. / M_PI)
+#define RAD_OF_DEG(_d) (_d / 180. * M_PI)
+
+#include "pprz_geodetic_float.h"
+
+
+/* 
+ * toulouse 43.605278,1.442778,180.0 -> 4624497.0 116475.0 4376563.0
+ */
+
+int main(int argc, char** argv) {
+
+  struct LlaCoor_f ref_coor;
+  ref_coor.lat = RAD_OF_DEG(43.605278);
+  ref_coor.lon = RAD_OF_DEG(1.442778);
+  ref_coor.alt = 180.0;
+  
+  struct LtpRef_f lpt_param;
+  init_ltp_from_lla_f(&lpt_param, &ref_coor);
+
+  /*  FIXME: init_ltp_from_lla_f not implemented */
+  lpt_param.ecef.x = 4624497.0;
+  lpt_param.ecef.y =  116475.0;
+  lpt_param.ecef.z = 4376563.0;
+
+  struct EcefCoor_f my_ecef_point = { 4624491.0, 116475.0, 4376563.0};
+  struct EnuCoor_f my_enu_point;
+  enu_of_ecef_f(&lpt_param, &my_enu_point, &my_ecef_point);
+
+  printf("ecef to enu : (%f,%f,%f) -> (%f,%f,%f)\n", 
+	 my_ecef_point.x, my_ecef_point.y, my_ecef_point.z, 
+	 my_enu_point.x, my_enu_point.y, my_enu_point.z );
+  
+  return 0;
+}