wrong altitude
  • I use navigator free for 2 or 3 years.
    It is only today that I report the following anomaly !
    The altitude is constantly wrong about 50 meters.
    At home, navigator displays 510 instead of 460 which is the reality (confirmed multiple soures, google earth etc.
    How to rectify?
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  • Apologies.
    I realize that the problem comes from my device !
  • Excuse me.
    After thorough investigation, it is the application that is the cause of this error.
    Does anyone see the same problem?
    Am I the only one ... it would be byzarre ...
    How to rectify?
  • Are you sure? Try multiple apps.
    Android 5.x has a well-known bug which results in wrong altitudes. Only few phone manufacturers corrected this bug. Even Samsung did not correct it (I had a Samsung S5).
    So are you on 5.x?
  • Also:
    Some navi/tracker applications have available automatic correction of WGS84 geoid altitude on the true sea level, either in the app, in the maps or as a correction file. GPS uses this to correct on the measured altitude.

    Without this WGS84 correction, the uncorrected GPS altitude in central Europe is about 40m to 60m higher than the true altitude.

    Question at @lubos and @tomas: Does Mapfactor do automatic WGS84 correction?
    This could also explain the deviation. (510 instead of 460)
  • no, it does not, we think this should be done by Android
  • No, it does not. We would have to stop using the location API and make Navigator using NMEA.
  • Hello hvdwolf, Tomas, Lubos.
    I am French. I am not a specialist in gps and I understand English differently (I use Google translation for this dialogue!).
    I understand that the correction "WGS84" is not made. It is neither made by android nor by Mapfactor / Navigator.
    It is true that the mistake I see is 50 meters too high (and I live in France, Auvergne).
    I understand from Tomas that this correction should be made by android?
    I think I understand from Lubos that this correction can not be made by android? and that API leasing should be abandoned in favor of NMEA?
    But I'm using Tomtom cards. So how do you go from API to NMEA with Navigator.
  • @georem - Android is doing the correction on the most of the devices. Adding the correction on already correct altitude would generate even bigger error, also only one solution is to stop using Android's API for location and implement own solution. I think this won't happen.

    It is not a bug of the app but of some Android versions.
  • Lubos.
    thank you very much.
    I understand problem is android and it is necessary to stop using Android's API for location and implement own solution.
    But How may I do "implement own solution". Where is ? What is ?
  • You cannot, it would mean to reimplement it by us
  • Lubos.
    Thank you very much.
    I understand that you are a member of the development team of the application.
    I think you make the right diagnosis.
    For my part, I am sure of the altitude difference, about 50 meters too much.
    I do not know how you can implement a new version with NMEA settings? download from your site?
    Tomorrow morning I am absent for a few days. It is not the right way to undertake the big maneuvers.
    I get back on my return.
    Best regards.
    Georges ROBIN.
  • Hi guys,

    even though Android seems to be the dirty part on some devices or versions, how about implementing the altitude addition as a correction on/off feature in MFN's configuration settings? Just to make MFN damn near to perfect.

    OK, a motorbike preset with an appropriate icon is still missing, but who cares....

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