[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Paparazzi-devel] GPS/UTM conversion issues in Utah

From: pascal . brisset
Subject: Re: [Paparazzi-devel] GPS/UTM conversion issues in Utah
Date: Thu, 5 Feb 2009 09:49:42 +0100 (CET)


I've fixed a bug in the MOVE_WP message (sent when you move a waypoint on the 
GCS). This bug was related to the recent format change (from decimal degrees to 
integer degrees*1e7) and to the fact that native OCaml integers use only 31 
bits, which is not enough for such a large longitude:

address@hidden:~/pprz/savannah/paparazzi3$ ocaml
        Objective Caml version 3.10.2

# -1110000000;;
Integer literal exceeds the range of representable integers of type int

Int32 have to be used (

So, "cvs update sw/ground_segment/tmtc/; make" should fix your problem


PS: Yes, unit tests are missing :-(

----- Original Message -----
From: "Austin Jensen" <address@hidden>
To: address@hidden
Sent: Wednesday, 4 February, 2009 02:33:46 GMT +01:00 Amsterdam / Berlin / Bern 
/ Rome / Stockholm / Vienna
Subject: [Paparazzi-devel] GPS/UTM conversion issues in Utah

Hey we just noticed a problem with what we though was a problem with commiting 
waypoints but we think it actually might be an issue with converting from GPS 
to UTM. Here's what happens... 

If we make a flight plan over here in Utah (lat0="41.81554" lon0="-111.98160") 
and try to change the location of a waypoint, the waypoint is actually changed 
on the aircraft to some crazy value (x=226 y=28285 from the origin). And it 
doesn't matter which waypoint, they all change to this value. This not only 
happens on the aircraft, but also in the simulator. 

To try and make sure it is not a problem with some of the code we are working 
on, we downloaded fresh code from the paparazzi server and tried it with the 
TJ1 A/C. The problem did not occur if we used the origin which is originally in 
the versatile flight plan (lat0="43.4622" lon0="1.2729"). However, when we 
changed the origin in the versatile flight plan to our origin (lat0="41.81554" 
lon0="-111.98160") the problem occurs again. 

Since the problem occurs in one area and not in the other, it seems like maybe 
the current code works for converting from GPS to UTM in one area but doesn't 
work for the other. Does anybody else have this problem? 


Austin Jensen, Research Engineer 
Utah Water Research Laboratory (UWRL) 
Utah State University, 8200 Old Main Hill 
Logan, UT, 84322-8200, USA 
E: address@hidden 
T: (435)797-3315 

Paparazzi-devel mailing list

reply via email to

[Prev in Thread] Current Thread [Next in Thread]