bugGPSD - Bugs: bug #49175, AIS AIVDM data not correctly...


bug #49175: AIS AIVDM data not correctly decoded

Submitted by:  Andreas Bals <abad>
Submitted on:  Sat 24 Sep 2016 03:38:02 PM UTC  
Votes:  2  
Category:  None Severity:  3 - Normal
Item Group:  None Status:  None
Privacy:  Public Assigned to:  None
Open/Closed:  Open

Add a New Comment(Rich Markup)

You are not logged in

Please log in, so followups can be emailed to you.


Wed 06 Sep 2017 01:44:00 AM UTC, comment #1:

Andreas, please review the three divisors at gps.h line 898, and the code at gpsd_json.c around line 1628. It appears to be doing the exact division you specify.

Are you lookig at some output other than JSON?

Eric S. Raymond <esr>
Project Administrator
Sat 24 Sep 2016 03:38:02 PM UTC, original submission:

Input string:


GPSD tranlates it nearly correctly into:
211673150, -, 30416097, 4305075, 3600, 511, 0, -128, , 1
(MMSI, imo, lat, lon, couse, heading, speed, turn, callsign, type)

Unfortunately one processing step on lon/lat is missing.
AIVD-lon/lat is given in minutes * 10'000.

In order to get location in degrees you have to divide by (10'000 * 60):
30416097/(600'000) = 50.693495 deg lat
4305075/(600'000) = 7.175125 deg lon

Andreas Bals <abad>


(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach Files:

No files currently attached


Depends on the following items: None found

Items that depend on this one: None found


Carbon-Copy List
  • -email is unavailable- added by esr (Posted a comment)
  • -email is unavailable- added by abad (Voted in favor of this item)
  • -email is unavailable- added by abad (Submitted the item)

    Do you think this task is very important?
    If so, you can add your encouragement to it.
    This task has 2 encouragements so far.

    Only logged-in users can vote.




    Follows 1 latest change.

    Date Changed by Updated Field Previous Value => Replaced by
    2016-09-26 abad Carbon-Copy- => Added abad

    Back to the top

    Powered by Savane 3.3