diff --git a/sw/ground_segment/cockpit/map2d.ml b/sw/ground_segment/cockpit/map2d.ml
index 83b4d3ed56..59aebea84e 100644
--- a/sw/ground_segment/cockpit/map2d.ml
+++ b/sw/ground_segment/cockpit/map2d.ml
@@ -352,7 +352,7 @@ let _ =
     load_map geomap xml_map_file
   end;
 
-  ignore (Glib.Timeout.add 1000 (fun () -> Ground_Pprz.message_req "map2d" "AIRCRAFTS" [] (fun _sender vs -> live_aircrafts_msg geomap vs); false));
+  ignore (Glib.Timeout.add 5000 (fun () -> Ground_Pprz.message_req "map2d" "AIRCRAFTS" [] (fun _sender vs -> live_aircrafts_msg geomap vs); false));
 
   ignore (Ground_Pprz.message_bind "NEW_AIRCRAFT" (fun _sender vs -> one_new_ac geomap (Pprz.string_assoc "ac_id" vs)));
 
diff --git a/sw/ground_segment/multimon/pprzlib.c b/sw/ground_segment/multimon/pprzlib.c
index 32079947f6..297fce1e8b 100644
--- a/sw/ground_segment/multimon/pprzlib.c
+++ b/sw/ground_segment/multimon/pprzlib.c
@@ -81,7 +81,8 @@ static float corr_space_q[CORRLEN];
 
 /* ---------------------------------------------------------------------- */
 
-#define INPUT_BUF_LEN 1000
+#define TEMP_BUF_LEN 10
+#define OUTPUT_BUF_LEN 512
 
 
 static int verbose_level = 0;
@@ -103,12 +104,9 @@ static void
 pprz_tmtc_send(unsigned char *data, unsigned int len, char* data_received)
 {
   unsigned char i;
-  /***/printf("%d:", len);
-  for (i=0; i < len && glob_data_received_len < INPUT_BUF_LEN; i++) {
+  for (i=0; i < len && glob_data_received_len < OUTPUT_BUF_LEN; i++) {
     data_received[glob_data_received_len++] = data[i];
-    /***/printf("%02x", data[i]);
   }
-  /***/printf("\ngdrl=%d\n", glob_data_received_len);
 }
 
 	
@@ -131,7 +129,7 @@ my_pprz_baudot_rxbit(struct demod_state *s, int bit, char* data)
     }
   }
 
-  if ((s->l2.hdlc.rxptr - s->l2.hdlc.rxbuf) >= INPUT_BUF_LEN) {
+  if ((s->l2.hdlc.rxptr - s->l2.hdlc.rxbuf) >= TEMP_BUF_LEN) {
     pprz_tmtc_send(s->l2.hdlc.rxbuf, s->l2.hdlc.rxptr - s->l2.hdlc.rxbuf, data);
     /* reset data buffer */
     s->l2.hdlc.rxptr = s->l2.hdlc.rxbuf;
@@ -236,74 +234,70 @@ union {
 int stereo = 1;
 unsigned int sample_rate = FREQ_SAMP;
 
-int fdebug;
-
 static int
 input_init(const char *ifname) {
   int sndparam;
 
-  fdebug=open("dump.dsp", O_WRONLY|O_CREAT);
-
   if ((fd = open(ifname, O_RDONLY)) < 0) {
     perror("open");
     exit (10);
   }
-#if 0
-  sndparam = AFMT_S16_LE; /* we want 16 bits/sample signed */
-  /* little endian; works only on little endian systems! */
-  if (ioctl(fd, SNDCTL_DSP_SETFMT, &sndparam) == -1) {
-    perror("ioctl: SNDCTL_DSP_SETFMT");
-    exit (10);
-  }
-  if (sndparam != AFMT_S16_LE) {
-    fmt = 1;
-    sndparam = AFMT_U8;
+  if (!strncmp("/dev", ifname, 4)) {
+    sndparam = AFMT_S16_LE; /* we want 16 bits/sample signed */
+    /* little endian; works only on little endian systems! */
     if (ioctl(fd, SNDCTL_DSP_SETFMT, &sndparam) == -1) {
       perror("ioctl: SNDCTL_DSP_SETFMT");
       exit (10);
     }
-    if (sndparam != AFMT_U8) {
-      perror("ioctl: SNDCTL_DSP_SETFMT");
+    if (sndparam != AFMT_S16_LE) {
+      fmt = 1;
+      sndparam = AFMT_U8;
+      if (ioctl(fd, SNDCTL_DSP_SETFMT, &sndparam) == -1) {
+	perror("ioctl: SNDCTL_DSP_SETFMT");
+	exit (10);
+      }
+      if (sndparam != AFMT_U8) {
+	perror("ioctl: SNDCTL_DSP_SETFMT");
+	exit (10);
+      }
+    }
+    stereo = TRUE;
+    sndparam = 1;   /* we want 2 channels */
+    if (ioctl(fd, SNDCTL_DSP_STEREO, &sndparam) == -1) {
+      perror("ioctl: SNDCTL_DSP_STEREO");
       exit (10);
     }
+    if (sndparam == 0) {
+      fprintf(stderr, "soundif: Error, cannot set the channel "
+	      "number to 2: using mono\n");
+      stereo=FALSE;
+    } else if (sndparam != 1) {
+      fprintf(stderr, "soundif: Error, cannot set the channel "
+	      "number to 2\n");
+      exit (10);
+    }
+    sndparam = sample_rate; 
+    if (ioctl(fd, SNDCTL_DSP_SPEED, &sndparam) == -1) {
+      perror("ioctl: SNDCTL_DSP_SPEED");
+      exit (10);
+    }
+    if ((10*abs(sndparam-sample_rate)) > sample_rate) {
+      perror("ioctl: SNDCTL_DSP_SPEED");
+      exit (10);
+    }
+    if (sndparam != sample_rate) {
+      fprintf(stderr, "Warning: Sampling rate is %u, "
+	      "requested %u\n", sndparam, sample_rate);
+    }
   }
-  stereo = TRUE;
-  sndparam = 1;   /* we want 2 channels */
-  if (ioctl(fd, SNDCTL_DSP_STEREO, &sndparam) == -1) {
-    perror("ioctl: SNDCTL_DSP_STEREO");
-    exit (10);
-  }
-  if (sndparam == 0) {
-    fprintf(stderr, "soundif: Error, cannot set the channel "
-	    "number to 2: using mono\n");
-    stereo=FALSE;
-  } else if (sndparam != 1) {
-    fprintf(stderr, "soundif: Error, cannot set the channel "
-	    "number to 2\n");
-    exit (10);
-  }
-  sndparam = sample_rate; 
-  if (ioctl(fd, SNDCTL_DSP_SPEED, &sndparam) == -1) {
-    perror("ioctl: SNDCTL_DSP_SPEED");
-    exit (10);
-  }
-  if ((10*abs(sndparam-sample_rate)) > sample_rate) {
-    perror("ioctl: SNDCTL_DSP_SPEED");
-    exit (10);
-  }
-  if (sndparam != sample_rate) {
-    fprintf(stderr, "Warning: Sampling rate is %u, "
-	    "requested %u\n", sndparam, sample_rate);
-  }
-#endif
   return fd;
 }
 
 
 static struct demod_state dem_st[2];
 
-char data_left[INPUT_BUF_LEN+1];
-char data_right[INPUT_BUF_LEN+1];
+char data_left[OUTPUT_BUF_LEN+1];
+char data_right[OUTPUT_BUF_LEN+1];
 struct data data_received = {data_left, 0, data_right, 0};
 unsigned int fbuf_cnt = 0;
 
@@ -340,8 +334,6 @@ pprz_demod_read_data(void) {
     }
   } else {
     i = read(fd, sp = b.s, sizeof(b.s));
-    // *** int j; for(j=0; j < 10; j++) printf("%04x", *(sp+j)); printf("\n");
-    write(fdebug, sp, i);
     if (i < 0 && errno != EAGAIN) {
       perror("read");
       exit(4);
@@ -361,17 +353,13 @@ pprz_demod_read_data(void) {
       if (fbuf_cnt > overlap) {
 
 	glob_data_received_len = 0;
-	/***/printf("XXX\n");
 	afsk48p_demod(&dem_st[LEFT], fbuf[LEFT], fbuf_cnt-overlap, data_received.data_left);
 
-	/***/printf("gl=%d\n", glob_data_received_len);
 	data_received.len_left = glob_data_received_len;
 	memmove(fbuf[LEFT], fbuf[LEFT]+fbuf_cnt-overlap, overlap*sizeof(fbuf[LEFT][0]));
 	if (stereo) {
 	  glob_data_received_len = 0;
-	/***/printf("YYY\n");
 	  afsk48p_demod(&dem_st[RIGHT], fbuf[RIGHT], fbuf_cnt-overlap, data_received.data_right);
-	/***/printf("gl=%d\n", glob_data_received_len);
 	  data_received.len_right = glob_data_received_len;
 	  memmove(fbuf[RIGHT], fbuf[RIGHT]+fbuf_cnt-overlap, overlap*sizeof(fbuf[RIGHT][0]));
 	}
diff --git a/sw/ground_segment/tmtc/Makefile b/sw/ground_segment/tmtc/Makefile
index 4fd21ede2a..aaeefaab6c 100644
--- a/sw/ground_segment/tmtc/Makefile
+++ b/sw/ground_segment/tmtc/Makefile
@@ -24,7 +24,7 @@ include ../../../conf/Makefile.local
 CONF = ../../../conf
 VAR = ../../../var
 
-all: hw_modem_listen receive messages $(VAR)/boa.conf
+all: hw_modem_listen receive messages $(VAR)/boa.conf stereo_demod
 
 clean:
 	rm -f hw_modem_listen wavecard_connect receive messages *.bak *~ core *.o .depend *.opt *.out *.cm*
@@ -57,10 +57,10 @@ hw_modem_listen : modem.cmo hw_modem_listen.ml ../../lib/ocaml/lib-pprz.cma
 	@echo 'exec lablgtk2 -I $$PAPARAZZI_SRC/sw/lib/ocaml glibivy-ocaml.cma lib-pprz.cma -I $$PAPARAZZI_SRC/sw/ground_segment/tmtc $$PAPARAZZI_SRC/sw/ground_segment/tmtc/modem.cmo $$PAPARAZZI_SRC/sw/ground_segment/tmtc/hw_modem_listen.ml $$*' >> $@
 	@chmod a+x $@
 
-demod_listen : ../multimon/multimon.cma demod_listen.ml ../../lib/ocaml/lib-pprz.cma
+stereo_demod : ../multimon/multimon.cma stereo_demod.ml ../../lib/ocaml/lib-pprz.cma
 	$(OCAMLC) $(INCLUDES) -I ../multimon -o $@ lablgtk.cma glibivy-ocaml.cma lib-pprz.cma multimon.cma $^
 	@cat ../../../pprz_src_test.sh > $@
-	@echo 'exec lablgtk2 -I $$PAPARAZZI_SRC/sw/lib/ocaml -I $$PAPARAZZI_SRC/sw/ground_segment/multimon glibivy-ocaml.cma lib-pprz.cma -I $$PAPARAZZI_SRC/sw/ground_segment/tmtc $$PAPARAZZI_SRC/sw/ground_segment/multimon/multimon.cma $$PAPARAZZI_SRC/sw/ground_segment/tmtc/demod_listen.ml $$*' >> $@
+	@echo 'exec lablgtk2 -I $$PAPARAZZI_SRC/sw/lib/ocaml -I $$PAPARAZZI_SRC/sw/ground_segment/multimon glibivy-ocaml.cma lib-pprz.cma -I $$PAPARAZZI_SRC/sw/ground_segment/tmtc $$PAPARAZZI_SRC/sw/ground_segment/multimon/multimon.cma $$PAPARAZZI_SRC/sw/ground_segment/tmtc/stereo_demod.ml $$*' >> $@
 	@chmod a+x $@
 
 receive : receive.ml ../../lib/ocaml/lib-pprz.cma
diff --git a/sw/ground_segment/tmtc/demod_listen.ml b/sw/ground_segment/tmtc/demod_listen.ml
deleted file mode 100644
index c80a1cac30..0000000000
--- a/sw/ground_segment/tmtc/demod_listen.ml
+++ /dev/null
@@ -1,133 +0,0 @@
-(*
- * $Id$
- *
- * Hardware modem receiver
- *  
- * Copyright (C) 2004 CENA/ENAC, Pascal Brisset, Antoine Drouin
- *
- * This file is part of paparazzi.
- *
- * paparazzi is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * paparazzi is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with paparazzi; see the file COPYING.  If not, write to
- * the Free Software Foundation, 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA. 
- *
- *)
-
-open Printf
-
-(** Ivy messages are initially tagged "modem" and with the A/C
-id as soon as it is identified (IDENT message) *)
-let ac_id = ref "modem"
-
-let modem_msg_period = 1000 (** ms *)
-
-module Tele_Class = struct let name = "telemetry_ap" end
-module Tele_Pprz = Pprz.Protocol(Tele_Class)
-module PprzTransport = Serial.Transport(Tele_Pprz)
-
-(** Monitoring of the message reception *)
-type status = {
-    mutable rx_byte : int;
-    mutable rx_msg : int;
-    mutable rx_err : int
-  }
-let status = { rx_byte = 0; rx_msg = 0; rx_err = 0 }
-
-(** Callback for each decoded message *)
-let use_pprz_message = fun (msg_id, values) ->
-  status.rx_msg <- status.rx_msg + 1; (** Monitoring update *)
-  let msg = Tele_Pprz.message_of_id msg_id in
-  if msg.Pprz.name = "IDENT" then
-    ac_id := Pprz.string_assoc "id" values;
-  (***)prerr_endline msg.Pprz.name;
-  Tele_Pprz.message_send !ac_id msg.Pprz.name values
-
-(** Listen on a dsp device *)
-let listen_pprz_modem = fun pprz_message_cb devdsp ->
-  let fd = Demod.init devdsp in
-
-  (** Callback for a checksumed pprz message *)
-  let use_pprz_buf = fun buf ->
-    status.rx_byte <- status.rx_byte + String.length buf;
-    Debug.call 'P' (fun f -> fprintf f "use_pprz: %s\n" (Debug.xprint buf));
-    pprz_message_cb (Tele_Pprz.values_of_bin buf) in
-
-  (** Callback for available chars *)
-  let cb =
-    let buffer = ref "" in
-    fun _ ->
-      printf("get_date\n%!");
-      let (data_left, data_right) = Demod.get_data () in
-      (***)printf "left=%s\n%!" (Debug.xprint  data_left);
-      (***)printf "right=%s\n%!" (Debug.xprint  data_right);
-      (** Accumulate in a buffer *)
-      let b = !buffer ^ data_left in
-      Debug.call 'M' (fun f -> fprintf f "Pprz buffer: %s\n" (Debug.xprint b));
-      (** Parse as pprz message and ... *)
-      let x = PprzTransport.parse use_pprz_buf b in
-      status.rx_err <- !PprzTransport.nb_err;
-      (** ... remove from the buffer the chars which have been used *)
-      buffer := String.sub b x (String.length b - x);
-      true
-  in
-
-  (** Attach the callback to the channel *)
-  ignore (Glib.Io.add_watch [`IN] cb (Glib.Io.channel_of_descr fd))
-
-(** Modem monitoring messages *)
-let send_modem_msg =
-  let rx_msg = ref 0 
-  and rx_byte = ref 0 
-  and start = Unix.gettimeofday () in
-  fun () ->
-    let dt = float modem_msg_period /. 1000. in
-    let t = int_of_float (Unix.gettimeofday () -. start) in
-    let byte_rate = float (status.rx_byte - !rx_byte) /. dt
-    and msg_rate = float (status.rx_msg - !rx_msg) /. dt in
-    rx_msg := status.rx_msg;
-    rx_byte := status.rx_byte;
-    let vs = ["run_time", Pprz.Int t;
-	      "rx_bytes_rate", Pprz.Float byte_rate; 
-	      "rx_msgs_rate", Pprz.Float msg_rate;
-	      "rx_err", Pprz.Int status.rx_err;
-	      "rx_bytes", Pprz.Int status.rx_byte;
-	      "rx_msgs", Pprz.Int status.rx_msg
-	    ] in
-    Tele_Pprz.message_send !ac_id "DOWNLINK_STATUS" vs
-
-(* main loop *)
-let _ =
-  let ivy_bus = ref "127.255.255.255:2010" in
-  let port = ref "/dev/dsp" in
-  let options =
-    [ "-b", Arg.Set_string ivy_bus, (sprintf "Ivy bus (%s)" !ivy_bus);
-      "-d", Arg.Set_string port, (sprintf "Port (%s)" !port)] in
-  Arg.parse
-    options
-    (fun x -> fprintf stderr "Warning:ignoring %s\n" x)
-    "Usage: ";
-  
-  Ivy.init "Paparazzi hw_modem_listen" "READY" (fun _ _ -> ());
-  Ivy.start !ivy_bus;
-
-  (** Listening on the given port (serial device or multimon fifo)*)
-  listen_pprz_modem use_pprz_message !port;
-
-  (** Sending periodically modem and downlink status messages *)
-  ignore (Glib.Timeout.add modem_msg_period (fun () -> send_modem_msg (); true));
-  
-  let loop = Glib.Main.create true in
-  while Glib.Main.is_running loop do
-    ignore (Glib.Main.iteration true)
-  done
diff --git a/sw/simulator/sim_gps.c b/sw/simulator/sim_gps.c
index 67cef7a5d2..013f72fdb6 100644
--- a/sw/simulator/sim_gps.c
+++ b/sw/simulator/sim_gps.c
@@ -42,7 +42,7 @@ value sim_use_gps_pos(value x, value y, value z, value c, value a, value s, valu
   for(i = 0; i < gps_nb_channels; i++) {
     gps_svinfos[i].svid = 7 + i;
     gps_svinfos[i].elev = (cos(((100*i)+time)/100.) + 1) * 45;
-    gps_svinfos[i].azim = (time/gps_nb_channels + 20 * i) % 360;
+    gps_svinfos[i].azim = (time/gps_nb_channels + 50 * i) % 360;
     gps_svinfos[i].cno = 40 + sin(time/100.) * 10.;
     gps_svinfos[i].flags = 0x01;
     gps_svinfos[i].qi = (int)((time / 1000.) + i) % 8;