diff --git a/sw/airborne/pprz_algebra_float.h b/sw/airborne/pprz_algebra_float.h
new file mode 100644
index 0000000000..92c2361d16
--- /dev/null
+++ b/sw/airborne/pprz_algebra_float.h
@@ -0,0 +1,8 @@
+#ifndef PPRZ_ALGEBRA_FLOAT_H
+#define PPRZ_ALGEBRA_FLOAT_H
+
+
+
+
+
+#endif /* PPRZ_ALGEBRA_FLOAT_H */
diff --git a/sw/airborne/pprz_geodetic_float.c b/sw/airborne/pprz_geodetic_float.c
new file mode 100644
index 0000000000..a084c0ce42
--- /dev/null
+++ b/sw/airborne/pprz_geodetic_float.c
@@ -0,0 +1,35 @@
+#include "pprz_geodetic_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;
+  /* compute lon and lat */
+
+}
+
+void init_ltp_from_lla_f(struct LtpRef_f* ref_param, struct LlaCoor_f* ref_pos) {
+  ref_param->lla.lon = ref_pos->lon;
+  ref_param->lla.lat = ref_pos->lat;
+  /* compute ecef */
+
+}
+
+void enu_of_ecef_f(struct LtpRef_f* ref_param, struct EnuCoor_f* out, struct EcefCoor_f* in) {
+
+  const FLOAT_T sin_lat = sin(ref_param->lla.lat);
+  const FLOAT_T cos_lat = cos(ref_param->lla.lat);
+  const FLOAT_T sin_lon = sin(ref_param->lla.lon);
+  const FLOAT_T cos_lon = cos(ref_param->lla.lon);
+
+  const FLOAT_T dx = in->x - ref_param->ecef.x;
+  const FLOAT_T dy = in->y - ref_param->ecef.y;
+  const FLOAT_T dz = in->z - ref_param->ecef.z;
+  
+  out->x = -sin_lon         * dx + cos_lon         * dy;
+  out->y = -sin_lat*cos_lon * dx - sin_lat*sin_lon * dy + cos_lat * dz;
+  out->z =  cos_lat*cos_lon * dx + cos_lat*sin_lon * dy + sin_lat * dz;
+
+}