diff --git a/sw/ground_segment/cockpit/intruders.ml b/sw/ground_segment/cockpit/intruders.ml
index 3b94a9e6b4..fe8ccd8ac7 100644
--- a/sw/ground_segment/cockpit/intruders.ml
+++ b/sw/ground_segment/cockpit/intruders.ml
@@ -30,15 +30,14 @@ type intruder = {
 let intruders = Hashtbl.create 1
 
 let new_intruder = fun id name time geomap ->
-  let track = new MapTrack.track ~size:10 ~icon:"intruder" ~name id geomap in
+  let track = new MapTrack.track ~size:20 ~icon:"intruder" ~name ~show_carrot:false id geomap in
   let intruder = { intruder_track = track; last_update = time } in
   Hashtbl.add intruders id intruder
 
 let remove_intruder = fun id ->
   try
     let intruder = Hashtbl.find intruders id in
-    intruder.intruder_track#clear ();
-    (* TODO delete something more ? mapTrack object ? *)
+    intruder.intruder_track#destroy ();
     Hashtbl.remove intruders id
   with _ -> () (* no intruder *)
 
diff --git a/sw/lib/ocaml/acIcon.ml b/sw/lib/ocaml/acIcon.ml
index c6efd0fd63..d959924ac3 100644
--- a/sw/lib/ocaml/acIcon.ml
+++ b/sw/lib/ocaml/acIcon.ml
@@ -168,9 +168,12 @@ let icon_home_template = {
 }
 
 let icon_intruder_template = {
-  lines = [];
+  lines = [
+    [| 0.; 0.; 0.; -24. |];
+    [| 6.; -15.; 0.; -24.;  -6.; -15.|];   (** Front Marker **)
+  ];
   ellipse = [
-    [| -10.; -10.; 10.; 10.|];
+    [| -8.; -8.; 8.; 8.|];
   ];
   width = 1
 }
diff --git a/sw/lib/ocaml/mapTrack.ml b/sw/lib/ocaml/mapTrack.ml
index 8e2a8173c2..4eacf9c52d 100644
--- a/sw/lib/ocaml/mapTrack.ml
+++ b/sw/lib/ocaml/mapTrack.ml
@@ -53,7 +53,7 @@ type desired =
   | DesiredCircle of LL.geographic*float*GnoCanvas.ellipse
   | DesiredSegment of LL.geographic*LL.geographic*GnoCanvas.line
 
-class track = fun ?(name="Noname") ?(icon="fixedwing") ?(size = 500) ?(color="red") (ac_id:string) (geomap:MapCanvas.widget) ->
+class track = fun ?(name="Noname") ?(icon="fixedwing") ?(size = 500) ?(color="red") ?(show_carrot=true) (ac_id:string) (geomap:MapCanvas.widget) ->
   let group = GnoCanvas.group geomap#canvas#root in
   let empty = ({LL.posn_lat=0.; LL.posn_long=0.},  GnoCanvas.line group) in
   let v_empty = ({LL.posn_lat=0.; LL.posn_long=0.},  0.0) in
@@ -78,7 +78,10 @@ class track = fun ?(name="Noname") ?(icon="fixedwing") ?(size = 500) ?(color="re
 
   let carrot = GnoCanvas.group group in
   let _ac_carrot =
-    ignore (GnoCanvas.polygon ~points:[|0.;0.;-5.;-10.;5.;-10.|] ~props:[`WIDTH_UNITS 1.;`FILL_COLOR "orange"; `OUTLINE_COLOR "orange"; `FILL_STIPPLE (Gdk.Bitmap.create_from_data ~width:2 ~height:2 "\002\001")] carrot) in
+    if show_carrot then
+      ignore (GnoCanvas.polygon ~points:[|0.;0.;-5.;-10.;5.;-10.|] ~props:[`WIDTH_UNITS 1.;`FILL_COLOR "orange"; `OUTLINE_COLOR "orange"; `FILL_STIPPLE (Gdk.Bitmap.create_from_data ~width:2 ~height:2 "\002\001")] carrot)
+    else ()
+  in
 
   let cam = GnoCanvas.group group in
 
@@ -126,6 +129,7 @@ object (self)
   val zone = GnoCanvas.rect group
   val mutable ac_cam_cover = GnoCanvas.rect ~fill_color:"grey" ~props:[`WIDTH_PIXELS 1 ; `FILL_STIPPLE (Gdk.Bitmap.create_from_data ~width:2 ~height:2 "\002\001")] cam
   val mutable event_cb = None
+  val mutable destroyed = false
   method color = color
   method set_color c = color <- c
   method track = track
@@ -361,9 +365,13 @@ object (self)
   method set_event_cb = fun (cb: string -> unit) -> event_cb <- Some cb
 
   initializer
-    ignore(geomap#zoom_adj#connect#value_changed
-             (fun () -> self#zoom geomap#zoom_adj#value))
+    (* could not properly disconnect adjustment signal, so only calling zoom method if group is still displayed *)
+    ignore(geomap#zoom_adj#connect#value_changed (fun () -> if not destroyed then self#zoom geomap#zoom_adj#value));
+    ignore(group#connect#destroy (fun () -> destroyed <- true))
+
+  (* destroy method *)
+  method destroy = fun () -> group#destroy ()
 
   initializer
-    Gc.finalise (fun self -> group#destroy ()) self
+    Gc.finalise (fun self -> self#destroy ()) self
 end
diff --git a/sw/lib/ocaml/mapTrack.mli b/sw/lib/ocaml/mapTrack.mli
index d9fd4394bf..aed95ad31e 100644
--- a/sw/lib/ocaml/mapTrack.mli
+++ b/sw/lib/ocaml/mapTrack.mli
@@ -27,6 +27,7 @@ class track :
   ?icon:string ->
   ?size:int ->
   ?color:string ->
+  ?show_carrot:bool ->
   string ->
   MapCanvas.widget ->
   object
@@ -69,4 +70,5 @@ class track :
     method zoom : float -> unit
     method event : GnoCanvas.item_event -> bool
     method set_event_cb : (string -> unit) -> unit
+    method destroy : unit -> unit
   end