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GPS and Battery Changes
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<blockquote data-quote="mha1" data-source="post: 80436" data-attributes="member: 12174"><p>see <a href="https://en.m.wikipedia.org/wiki/Time_to_first_fix" target="_blank">Time to first fix - Wikipedia</a></p><p></p><p>The mentioned flash memory is integrated in the GPS receiver chip and is managed by the receiver chip itself.</p><p></p><p>PS: GPS satellites are not geostationary. They are in a 12540mls orbit with an orbital period of one half day. So the satellites are moving around you. This explains why you will see the number of visible (locked on is the wrong wording btw) satellites is changing even if you are stationary in a wide open field with unobstructed visibility horizon to horizon. Satellites vanish and show up in the receivers field of view. It also explains why it’s possible to have low accuracy even with a high number of (visible) satellites. Some might be close to the horizion and others in a bad relative position to each other in order to obtain a acceptable solution of the navigation equations. Google delution of precision (DOP). I am 100% sure this is what DJI is using to determine the availability of GPS. The number of satellites is nearly meaningless as 4 satellites in ideal positions are better than 12 in bad positions. Probably also explains why it sometimes drops out of GPS into ATTI with a seemingly good number of satellites. A high DOP tells you to not rely on the data. In navigation you‘d revert to dead reckoning. DJI obviously chose to degrade to a semi-manual mode until reliable GPS data (low DOP) is available again.</p></blockquote><p></p>
[QUOTE="mha1, post: 80436, member: 12174"] see [URL="https://en.m.wikipedia.org/wiki/Time_to_first_fix"]Time to first fix - Wikipedia[/URL] The mentioned flash memory is integrated in the GPS receiver chip and is managed by the receiver chip itself. PS: GPS satellites are not geostationary. They are in a 12540mls orbit with an orbital period of one half day. So the satellites are moving around you. This explains why you will see the number of visible (locked on is the wrong wording btw) satellites is changing even if you are stationary in a wide open field with unobstructed visibility horizon to horizon. Satellites vanish and show up in the receivers field of view. It also explains why it’s possible to have low accuracy even with a high number of (visible) satellites. Some might be close to the horizion and others in a bad relative position to each other in order to obtain a acceptable solution of the navigation equations. Google delution of precision (DOP). I am 100% sure this is what DJI is using to determine the availability of GPS. The number of satellites is nearly meaningless as 4 satellites in ideal positions are better than 12 in bad positions. Probably also explains why it sometimes drops out of GPS into ATTI with a seemingly good number of satellites. A high DOP tells you to not rely on the data. In navigation you‘d revert to dead reckoning. DJI obviously chose to degrade to a semi-manual mode until reliable GPS data (low DOP) is available again. [/QUOTE]
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GPS and Battery Changes