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Altitude Question

Discussion in 'Pro/Adv Discussion' started by MrTokens, Mar 31, 2016.

  1. MrTokens

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    This is probably the dumbest question of the day.

    when flying how can I know the exact altitude, it appears that the drone knows my altitude from the home point but if my home point is 300 feet high and I fly over a hill the drones distance to ground could be much less than the 300 feet.

    So what I'm asking is if I'm now 500 feet from my home point is there a way to know that I'm 200 feet from the ground.

    Is there a way to load a typography map as I'm flying to see the exact height I am at?

    Sorry for such a stupid question I've looked on the form and I cannot find an answer.

    MrTokens
     
  2. Air Ontario

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    I live in a slight depression with a large lake. It is over 150 ft from lake to highway 3/4 kilometer away.

    I look at the elevation of my yard(joining the lake) and take the lake elevation of say 800 ft(my take off point/yard) and look at the 950' elevation of the roadway 3/4 kilometer away.

    From those elevation figures it is plain to see if I launch and rise 150' and fly towards the highway I'm gonna be pooched, even if there were no obstacles, I would hit the asphalt road surface.

    So you have to look at an elevation map, get the difference in feet of elevation change, and then add a good measure of additional feet to clear trees(i use 150 ft AGL of that elevation) or whatever obstacle you have to deal with.

    So I may be flying 300 ft above the lake briefly but as I move inland towards the highway I may only be 150 ft AGL and only 50 ft above the trees as an example. My app will still show 300 ft all the way to the highway.
     
  3. spindrift

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    You should be able to obtain a contour map for your area that gives you the rough elevation of your surrounding landscape.
     
  4. spindrift

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    Keep in mind that the Phantom uses its takeoff location for elevation reference. I've flown in places where even with ceiling height set at max, I couldn't clear some obstacles.
     
  5. Trackman1

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    I use google earth on the computer. Use the ruler to draw a line from home point to where you want to go. Save the line with a name.
    Right click the name and show elevation. Put your mouse over the graph and you will see the changes in elevation along the line and at what distance.
     
  6. PrecisionAeroworks

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    What you want is coming, @MrTokens, hopefully pretty soon.

    Some of our fantastic 3rd party app developers are working on this now. It requires access to an Earth maps database that has good enough elevation data and some clever implementation on the developers part. Understand, however, that the elevation data (available at present) can be off by as much as 30m, particularly in areas where the elevation is changing rapidly.

    I think we will get mission planning with "true AGL" waypoints first. From there, an option to display a "live AGL" based on the drones position and and the Earth database is a smaller step.

    You can do this with a P3 right now with software system called UgCS, but it requires a PC for mission planning and then uses an app to fly the pre-planned missions.

    I would't hold my breath waiting for this on DJI GO, however.
     
  7. alokbhargava

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    Whenever I fly at a new place, I study Google Earth to figure out the elevations and then plan out my flights.

    If you have Litchi, you can import flight path from Google earth to it and fly out. I'm not sure about other apps though.
     
  8. MrTokens

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    Thanks to all... I was hoping For an elevation map live as I flew.

    seems to me if the drone has access to satellite data it would be fairly simple for DJI to relay the elevation based on the latitude and longitude I must be missing

    BTW I love this form
     
  9. MrTokens

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    going to have a look at Litchi now. Thanks much...
     
  10. sonof40

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