diff --git a/sw/configurator/flightplan.ml b/sw/configurator/flightplan.ml
index bc8d6e1039..d53909c46b 100644
--- a/sw/configurator/flightplan.ml
+++ b/sw/configurator/flightplan.ml
@@ -32,7 +32,7 @@ let calibrate_xy = fun x0 y0 ->
   let print x y =
     let xl = x0 + truncate (float x *. scale)
     and yl = y0 + truncate (float y *. scale) in
-    let wgs84 = Latlong.wgs84_of_lambertIIe xl yl in
+    let wgs84 = Latlong.of_lambertIIe {lbt_x=xl;lbt_y= yl} in
     Console.write (Printf.sprintf "%d %d %f %f\n" x y ((Rad>>Deg)wgs84.Latlong.posn_lat)  ((Rad>>Deg)wgs84.Latlong.posn_long)) in
   
   Console.write (Printf.sprintf "Calibration for x0=%d y0=%d:\n--8<----------------------\n" x0 y0);
diff --git a/sw/lib/ocaml/latlong.ml b/sw/lib/ocaml/latlong.ml
index b672f71ed4..f2c854e7c3 100644
--- a/sw/lib/ocaml/latlong.ml
+++ b/sw/lib/ocaml/latlong.ml
@@ -344,7 +344,15 @@ let utm_sub = fun u1 u2 ->
   (u1.utm_x -. u2.utm_x, u1.utm_y -. u2.utm_y)
 
   
-let wgs84_of_lambertIIe = fun x y -> (WGS84<<NTF)(of_lambert lambertIIe {lbt_x = x; lbt_y = y})
+let of_lambertIIe = fun lbt ->
+  (WGS84<<NTF)(of_lambert lambertIIe lbt)
+let lambertIIe_of = fun wgs84 ->
+  lambert_of lambertIIe ((NTF<<WGS84)wgs84)
+
+let lbt_add = fun {lbt_x=x; lbt_y=y} (dx, dy) ->
+  {lbt_x = x + truncate dx; lbt_y = y + truncate dy }
+let lbt_sub = fun {lbt_x=x1; lbt_y=y1} {lbt_x=x2; lbt_y=y2} ->
+  (float (x2-x1), float (y2-y1))
 
 let space = Str.regexp "[ \t]+"
 let fos = float_of_string
@@ -357,7 +365,7 @@ let of_string = fun s ->
   | ["UTM";x;y;zone] ->
       of_utm WGS84 { utm_x = fos x; utm_y = fos y; utm_zone = ios zone}
   | ["LBT2e";x;y] ->
-      wgs84_of_lambertIIe (ios x) (ios y)
+      of_lambertIIe {lbt_x=ios x; lbt_y=ios y }
   | _ -> invalid_arg (Printf.sprintf "Latlong.of_string: %s" s)
 
 
diff --git a/sw/lib/ocaml/latlong.mli b/sw/lib/ocaml/latlong.mli
index 7d4565682e..c8b7a9dbe2 100644
--- a/sw/lib/ocaml/latlong.mli
+++ b/sw/lib/ocaml/latlong.mli
@@ -114,7 +114,14 @@ val utm_sub : utm -> utm -> (fmeter * fmeter)
 (** [utm_sub u1 u2] Raises Invalid_arg if [u1] and [u2] are not in the same
 UTM zone *)
 
-val wgs84_of_lambertIIe : meter -> meter -> geographic
+val of_lambertIIe : lambert -> geographic
+val lambertIIe_of : geographic -> lambert
+val lbt_add : lambert -> (fmeter * fmeter) -> lambert
+(** [add_lbt utm (east,north)] *)
+
+val lbt_sub : lambert -> lambert -> (fmeter * fmeter)
+(** Returns (east,north) *)
+
 
 val of_string : string -> geographic
 (** [of_string pos] Parses [pos] as "WGS84 45.678 1.2345", "UTM 500123 4500300 31" or "LBT2e 544945 1755355" *) 
diff --git a/sw/lib/ocaml/mapCanvas.ml b/sw/lib/ocaml/mapCanvas.ml
index 77ca9abd11..b377e75eb5 100644
--- a/sw/lib/ocaml/mapCanvas.ml
+++ b/sw/lib/ocaml/mapCanvas.ml
@@ -15,7 +15,7 @@ type utm_zone = int
 type projection = 
     Mercator (* 1e-6 = 1 world unit, y axis reversed *)
   | UTM (* 1m = 1 world unit, y axis reversed *)
-  | Lambert2 (* 1m = 1 world unit, y axis reversed *)
+  | LambertIIe (* 1m = 1 world unit, y axis reversed *)
 
 let default_georef = { LL.posn_lat = 0.; LL.posn_long = 0. }
 
@@ -141,7 +141,11 @@ class basic_widget = fun ?(height=800) ?width ?(projection = Mercator) ?georef (
 	      let xw = (wgs84.LL.posn_long -. georef.LL.posn_long) *. mercator_coeff
 	      and yw = -. (ml -. mlref) *. mercator_coeff in
 	      (xw, yw)
-	  | _ -> failwith "#world_of : unknown projection"
+	  | LambertIIe ->
+	      let lbtref = LL.lambertIIe_of georef
+	      and lbt = LL.lambertIIe_of wgs84 in
+	      let (wx, y) = LL.lbt_sub lbt lbtref in
+	      (wx, -.y)
 	end
       | None -> failwith "#world_of : no georef"
 
@@ -152,13 +156,15 @@ class basic_widget = fun ?(height=800) ?width ?(projection = Mercator) ?georef (
 	    UTM ->
 	      let utmref = LL.utm_of LL.WGS84 georef in
 	      LL.of_utm LL.WGS84 (LL.utm_add utmref (wx, -.wy))
+	  | LambertIIe ->
+	      let utmref = LL.lambertIIe_of georef in
+	      LL.of_lambertIIe (LL.lbt_add utmref (wx, -.wy))
 	  | Mercator ->
 	      let mlref = LL.mercator_lat georef.LL.posn_lat in
 	      let ml = mlref -. wy /. mercator_coeff in
 	      let lat = LL.inv_mercator_lat ml
 	      and long = wx /. mercator_coeff +. georef.LL.posn_long in
 	      { LL.posn_lat = lat; posn_long = long }
-	  | _ -> failwith "#of_world : unknown projection"
 	end
       | None -> failwith "#of_world : no georef"