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Other The Quadcopter/Drone/Multirotor Thread

Discussion in 'General' started by Byron C, 4 Mar 2017.

  1. [ZiiP] NaloaC

    [ZiiP] NaloaC Well-Known Member

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    I use the drone for surveying areas of land that we're going to be using for the construction of "Integrated Constructed Wetlands" for wastewater treatment.


    So, I take whatever drone (previously a Mavic Pro, now a Phantom 4 RTK+D-RTK2), plan out a mission using Pix4D Mapper, then it flies an autonomous mission in a grid pattern. Each photo has georeference data relating to it, which also includes camera angle and other bits of info. Then I put them all into Pix4D and put it through 3 phases of processing (initialisation, Point Cloud generation, DSM rendering).

    From the Pix4D processing, I get a fully 3D model of the site, contour lines (for use by our CAD technician for design drawings) and a few other bits.

    The Mavic Pro was great for quickly surveying sites where I just needed to get a rough (+/- a few metres) layout of a site for design and planning, but the RTK unit can get me down to ~3-5cm accuracy in all 3 axis. There's a little bit of throw, since I have to convert everything to bloody Irish Transverse Mercator instead of GPS positioning, but it's not too bad. The main issue is elevation. GPS will log it at X, but ITM is usually ~56m below that value.

    The software does an awesome job of taking each of the photos, relative to its position in the grid that it flew, cross-referencing each image against others and finding keypoints in each photo. From this, the algorithms will use these key points to generate a 3D frame, then flesh it out with a point cloud to fill out the rest, then create a texture, DSM/DTM (digital terrain map - terrain without vegetation) and contours at whatever interval I want.

    What I surveyed in an hour of flight-time would have taken someone 1-2 days to do by hand, easily. The only shortfall I have, is that the software for the D-RTK2 base station does not allow for it to act as a mobile rover yet. Thankfully, for this particular site, I had an old survey of a yard that is part of the survey area, from which I got accurate and meaningful elevation data for 5 of my 7 control points (markers laid out on the ground by me), which in turn gave me a correction value to adjust the other 2 with confidence.

    All in all, I think I managed to get this down to 3cm accuracy, and this is only for machine work in a field, so that's an order of magnitude more than I needed. :D
     
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  2. David

    David Take my advice — I’m not using it.

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    A flying theodolite, but significantly more advanced. Very cool.

    I used to survey rock faces with a laser to create a 3D model for blast design - purely a safety measure to ensure explosives were not placed too close to the face prior to drilling and blasting, to eliminate flyrock incidents (sending a chunk of rock on a ballistic trajectory towards roads/public areas etc..) - it used to take forever and I can see your work as a viable application for that.

    Thanks for taking the time to explain. :)
     
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  3. Byron C

    Byron C Probably isn't Hitler, but definitely a muppet

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    So... I'm getting rid of my drone projects :(. I just don't have the time or patience for all the tinkering and building any more; I need to just get a Mavic or similar that I can just get in the air quickly without having to spend hours tinkering with calibration & settings. Thread in the for sale section here if you're interested - includes frame, motors, ESCs, TX/RX, LiPo charger, gimbal, etc...

    That sounds very complicated but very cool...

    Surveying rock faces to create 3D models for blast design also sounds very complicated but very cool!
     
  4. [ZiiP] NaloaC

    [ZiiP] NaloaC Well-Known Member

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    I did get the opportunity to record a blasting in a quarry a couple of years ago with the Mavic.

    I would ask those who watch this to NOT share it around please, thank you.

     
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  5. David

    David Take my advice — I’m not using it.

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    It does look better on an overcast day, when you can see the NONEL flashtube initiating the dets like that.

    We used to drop about 20,000 tonnes of rock with four tonnes of explosives. About once a month we'd get a school visit - all the kids stood at the other side of the quarry - "where should I be looking, I don't want to miss it". Don't worry, you won't. Then "crump" - three days of surveying, planning, drilling and charging all over in three seconds, and they're like "oh wow, do it again". :lol:
     
    Last edited: 15 Sep 2019
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  6. David

    David Take my advice — I’m not using it.

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    Well, I didn't crash it!

    I used up all three batteries, which meant a little over an hour. Didn't use any of the advanced modes like follow, orbit, selfie gestures etc.. I just concentrated on flying around and getting a feel for the controls. Landing/taking off manually, shhoting video and stills, testing RTH and generally playing around. The fact of having something simply capable af holding it's altitude absolutely transforms drone flying.

    Sport mode is scary fun - you can buzz around at 30-40mph, ten feet off the ground.
     
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  7. Byron C

    Byron C Probably isn't Hitler, but definitely a muppet

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    Not crashing is always a good first step :grin:.

    I briefly flew a mate's Mavic a couple of months ago, and it's in a different league compared to the flight controller I was using...
     
  8. David

    David Take my advice — I’m not using it.

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    The practise drone will be going back, if it ever arrives. It's well beyond the 4-9 shipping days promised at checkout - so maybe I can use that. If not, I'll flog it and take the hit.
     
  9. David

    David Take my advice — I’m not using it.

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    The practise drone turned up, very late. The Banggood seller wasn't interested - sorry it's late but we wont accept a return for that. Tw@t.

    Rather than piss around, I chucked it on ebay and made a healthy profit - I listed it high as a "buy it now" with offers accepted in the hope I could take a reduced offer but still get my money back, but somebody bought it outright. It isn't readily available in the UK yet, so he was obviously willing to pay over the odds to get his hands on it fast.
     
    Last edited: 6 Oct 2019
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  10. Byron C

    Byron C Probably isn't Hitler, but definitely a muppet

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    What was the practise drone you bought? I'm sure you posted in the purchases thread, but it'll be long buried by now...
     
  11. David

    David Take my advice — I’m not using it.

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    It was an Eachine E520S with 4K camera, 5G wifi, GPS and three batteries. Budget Mavic clone.

    [​IMG]

    Amazon have it for silly money - I paid about £87 shipped
     
  12. Arboreal

    Arboreal Keeper of the Electric Currants

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    I had a go at flying a Mavic Pro Platinum today, what a bit of kit!
    I've only played with painfully unstable cheap indoor drones, and it put me off.
    This was amazing.
    The guy flying it came to my work as he needed to photograph a site nearby, and I could provide a private safe location to fly from.
    I should have a memory stick in a couple of days of aerials of my workplace and the neighbouring buildings.
    Apparently, he's coming back for another go, as he didn't quite get all he needed today.
    I was seriously impressed about its stability, ease of use and the reduced noise and lower pitch on the Platinum.
    Much less intrusive than anything else I've heard.
    I'll post some images when they get in.
    Off to find elderly relatives/spare body parts to sell to fund an expensive potential new habit....
     
  13. David

    David Take my advice — I’m not using it.

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    I love my Mavic Pro, and I've only just scratched the surface. I'm currently learning Divinci Resolve to process and cut up video - it's early days but I'm having fun.
     
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  14. Arboreal

    Arboreal Keeper of the Electric Currants

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    I need help choosing the best Mavic to buy.
    I have been thinking about the Mini Fly More bundle, as it's not expensive, is small and easy to get going with.
    However, my background is photographic, and the lack of exposure / WB control and raw files, is offputting.
    The guy I mentioned above now has a Mini alongside his Pro Platinum, and says it's good, but too soon to say whether it's really good.
    He's been feeding me local ads and FB Marketplace ads, to help my addiction along.
    There's a Mavic Pro for £350 5 mins down the road, only one photo, and no description of condition or other accessories above the basics.
    This appeals, as I'd have the image control, but am I running before I can walk?
    The other downsides would be:
    No warranty / Care option
    Unknown battery condition / hidden or repaired damage
    Will have to register with the CAAa nd do my test - no great problem

    May have to buy a device* to run the app on - probably a refurb iPad Mini 4 - supposedly iOS support is better on DJI and better have a dedicated device than using your phone

    Help me guys, pleeeeeease...
     
  15. David

    David Take my advice — I’m not using it.

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    Mavic Pro is my first real drone - I don't regret it. £350 is v cheap, but the Mini might be dragging used values down a bit. Still worth giving it a good dose of looking at.

    I thought you could still control wb/exposure through your phone on the mini?

    Bear in mind you'll be looking at a cellular iPad, if you're not using your phone.

    The 2.7k camera is impressive, but the 4K on the Pro allows for greater room to stabilise and crop in post.

    I know I'm not making things any easier - just spewing out thoughts as they trickle into my grey(ish) matter.
     
  16. Arboreal

    Arboreal Keeper of the Electric Currants

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    Thanks David, good to hear from you. Keep on streaming the consciousness over, it does add to the decision making.

    Do I need cellular for stuff other than if I've moved my position or want to do self follow?
    I read you could use a phone hotspot; for that matter, I could use my phone for follow etc. where GPS is vital.

    I thought a bigger screen would be good and also the tablet wouln't be distracted by all the other stuff going on in my phone.

    Just read about 4K crop benefits, that's really handy. Also watched a Pro vs Air video and seen how th efootage looks different from the same res cameras.

    AFAIK, the Mini has no exposure override or WB at all, so your highlights/shadows are lost and no recourse via raw stills.

    Need to see if the £350 Pro is good vslue, or cheap for a reason. I've been told the guy's short of cash, so may be a genuine price to move it.

    Now to con a relative on FB to contact him, and see if I can get a look in daylight...
     
  17. David

    David Take my advice — I’m not using it.

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    I hadn't considered tethering to the phone - you're gunna end up costing me more money.

    The Air captures video at 100MB/s compare to the Pro's 60MB/s, so 4K video typically looks smoother - I think it's the one desirable feature it has. It's frikkin LOUD though - met a guy flying one a few weeks back and the noise difference between it and my Pro was astonishing, and that was without my low noise props; of which I'm not a huge fan even though they do make a marked difference.

    If that Pro is genuine, it'll be gone PDQ.
     
  18. Arboreal

    Arboreal Keeper of the Electric Currants

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    The Platinum was pleasingly quiet when it was up at work, the Air was noisy as you say, and that would be a minus for me.
    Which low noise props did you get?
    I'll ask in the morning about the Pro, you never know on FB.
     
  19. David

    David Take my advice — I’m not using it.

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    They were the DJI low noise props. They might be quiet but they increase vibration - you can see what's known as the jello effect in some of the video footage. It's very slight but, once you see it, you can't ignore it.
     
  20. mrlongbeard

    mrlongbeard Well-Known Member

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    Taken and passed the CAA drone test (rocket surgery it isn't) so I now have an operator and flyer ID should the need arise.
     
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