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Inspire and GPS lock

Discussion in 'Inspire 1 Discussion' started by DaveMoi, May 18, 2015.

  1. DaveMoi

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    Hi everyone,


    I just got my Inspire 1 last week and have been flying with it as much as possible since :). Al has gone well, however yesterday I did have something odd happening. I was flying in an open field during the evening. I started the flight with 19 satellites lock and started to fly at about 30 meters altitude. After a few minutes, I decided to descent to about 10 or 8 meters above the ground in this open field. I decended and hovered in place for a few seconds and made the camera look straight down towards the ground. Just at that moment I got the app telling me that it switched to atti mode. U looked at the app an saw that I suddenly only had 6 seats? I decided to bring the bird in and during the landing all the stats came back. About 30" later I flew out again to the same area and never lost any sats...

    Has anyone have this happen to them? How many sats does the inspire need to remain in GPS mode?

    Thanks,

    David


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  2. The Editor

    The Editor Moderator
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    What firmware are you running?
    This very problem was addressed in the most recent couple of versions although they were released within a few days of each other.
    If you have just received your Inspire it is highly likely it was in transit before the release of the most recent FW.
     
  3. DaveMoi

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    Thank you for the fast reply :)

    I'm on the latest firmware. The shop where I bought the inspire updated the firmware prior to delivery. I also downloaded the latest firmware and put it on the microSD card in the camera in order to update the two extra batteries I bought a few days later.

    The app also states that I'm on the latest firmware.

    I've only had the drop once up till now but it doesn't make sense as there was nothing to obstruct the signal in the area when it happened.




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  4. The Editor

    The Editor Moderator
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    OK - That probably rules out firmware. Where abouts in the world are you? For instance, Northern part of Scotland in the UK would mean the majority of satellites would be south most of the time and can be near to the horizon.

    Try this -> http://www.calsky.com/cs.cgi

    Go to 'Satellites', 'GPS' Input your details and yesterdays date and it may shed some light on your anomaly.
     
  5. DaveMoi

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    I was in Zemst, Belgium at the time. The strange thing is that the loss of satellites only lasted a minute or so. Do you know how many satellites the Inspire needs for gps mode?

    Thanks,

    David


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  6. The Editor

    The Editor Moderator
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    As you probably know, The Inspire uses both GPS (Navstar) and Glonass constellations for a more accurate/reliable fix.
    Only four sats are required for a 3 dimensional fix.

    People get hung up on the number of satellites but what is more important is VDOP/HDOP (Vertical and horizontal dilution of precision) and how they are calculated and factored into the positional fix. In a way, it was a backwards step for DJI to reintroduce the number of satellite back into the display as it gives a false sense of security.
     
    Kilrah likes this.
  7. DaveMoi

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    You hit the nail on the head :) I didn't understand either why I didn't get a lock with 6 sats. I guess it all comes down to which satellites are being received? On the other hand, dropping from 19 sats to 6 is quite puzzling....


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