problem with final number of kilometers

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    Thierry CHARLÈS

    Hello,

    Your are a Hiker, with a very slow speed less than 5 km/h. During your ride your GPS is in a BOX or in the pocket of your jacket.

    I'am in the wrong?

    Your GPS must see the sky alltime to track correctly the satellites near the horizon line.

    Here on this forum, we have already study this kind of issue: Place your GPS, to the sky out of a box or a jacket poket and your GPS can recrord a good track

    It is not a spécific issue to the GPS CROSS, but a généric issue of all GPS. The différence between the GPS is done by their position to see the sky

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    Thierry CHARLÈS

    Hello,

    To have a good altitudes, you must select this :

    • Altitude = Barometric + GPS,
    • Before the hiking, make a manula altitude calibration.

    It is the same recommandation for Garmin or TwoNav (Have a look to Garmin support) 

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    Thierry CHARLÈS

    Hello,

    If your GPS do no see the sky (The GPS must always see God eyes!), you go to kinds of thoses issues:

    - First the GPS cannot compute correctly your position. Let us imagine a direct line betwwen your GPS antenna and the satellite, if the path of this line is not a perfect strait line, the computation of the distance is wrong. Your GPS must compute four strait lines to four differents satellites, this is the requirement to be able to compute your position. The four satellites choise to be traked par your GPS are not to the zenith, but near the horizon line to provide four very differents transit time (Distance). If transits times or distances is too close, the position computation will be wrong.

    - Second problem: The set of datas of the constelaltion (Ephemerides and almanac'h) will not be refresh when the GPS do not receive the signal. The signal received from satellites by a GPS have a very very low level, (it is not as a Smart phone place at a few kilometers from the antenna relais), if the antenna of your GPS do not see the sky or if an object is placed between the antenna and the satellite, the signal received will be more lower or loss. In this case satellites datas are not refreshed correctement, satellites position too old, wrong, or unvaialble the position computing will be wrong.

    In the Garmin GPS the A-GPS function update constellation data when the GPS is connected to your PC thrue Garmin Connect. For TwoNav GPS the A-GPS function is available in the GPS chipset but this function is not used by TwoNav Sofware.

    Good Hikes

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