Land Surveyor Forum

Replies

• Student Surveyor

  James Wallace October 5, 2017 at 6:28pm

  Hi,

  I have a question regarding aerial surveys. A local Registered Surveyor asked me to demonstrate/prove the accuracy of the drone generated model.

  I have used Pix4d and Photoscan briefly in the past.

  What are some ways to demonstrate the accuracy?

  - include some GCP's that are not part of the processing and check their location/height in the model?

  - leave a staff flat on the ground at a fixed length and measure its length in the model? Maybe two at a 90 degree angle?

  Thanks,

  James
• Land Surveyor

  Burton Ngoma September 22, 2017 at 1:47am

  Hi Kevin,

  We use Ebee RTK Drones, easy to setup and work with. When we capture our imagines, we use PIX4D to process our images. PIX4D gives us very good point clouds which you can import in other software (i use maptek I-Site Studio to create contours, DTMs etc). PIX4D also generates very good contours which you can also import in other survey software (I use surpac). PIX4d has a volume function which can help you calculate cut and fill volumes. hope this helps :)
  • Not a Surveyor

    Kevin Sales > Burton Ngoma September 22, 2017 at 6:49am

    Hi Burton,
    Thanks for the info.
    I’ll certainly take a look at the software.
    We are using DJI phantom 4 pros, Matrice 210 and Matrice 600 drones.
• Land Surveyor

  WISDOM September 19, 2017 at 5:20am

  WHAT TO KNOW BEFORE COMMENCING FIELD OPERATION WITH A DRONE
  
  
  Before you send a flying robot into the sky, check your local law. In the US, for instance, FAA guidelines stipulate that drones and other model aircraft must stay less than 400 feet above the ground and not within 3 miles of an airport or air traffic.
  
  
  Now that you've done your research into local law, you can start the process of finding the perfect drone to suit your needs. Introductory models such as the $80 Blade Nano QX are ideal for people just learning how to fly, because they're cheap. You will likely crash the drone during your first few flight attempts, so you don't want to invest a lot initially.
  After you've practiced a bit, you can consider fully-assembled models such as the $750 3D Robotics' Iris or more popular models like DJI's Phantom series.
  Other drones worth considering include the Hubsan X4 micro quadcopter, Estes Proto X mini quadcopter, smartphone-controlled Parrot AR Drone 2.0, UDI U818A camera quadcopter, and STORM Drone 6 GPS. Keep in mind whether you want the aircraft to come with a camera, and if not, the amount of payload you want it to carry. You'll also want to look at how long-lasting the battery should be for your purposes and if you want to control the drone via a smartphone or remote.
  If you didn't select a drone with a built-in camera, you will need to get a video camera that will provide the best image quality for its size and weight. The GoPro Hero3 Black Edition is the standard when it comes to aerial videography and photography. Fancy camera is prohibited as long as you ensure there is no vibration, because that will completely ruin your footage quality. Though the drone itself may causes vibration through its engine. Air turbulence causes vibration too. To ease the possibility of vibration, you will need to use vibration isolators and gimbals. Fast lenses that are sharp at large aparture will help too.
  And finally, some drones, or rather specific applications of aerial photography, may require additional things like a specialized RC remote or even anti-gravity motors. You should thoroughly research all the drone accessories available and how they can aid you as an aerial photographer.
  
  TIPS TO COVER WHEN IT COMES TO PHOTOGRAPHY
  Use a shorter and fastest lens that has a fixed-focal length such as professional f/2.9 zoom lens, fast shutter speeds around 1/1,000 second at 200mm or even 1/500 at 100mm are necessary to ensure your footage is sharp.
  SAFETY ON OPERATION OF DRONES
  Always have in mind, whether you're just getting started or are a seasoned professional, there are some obvious safety rules you'll need to remember. Always think about what you might hit if your drone crashes. You should never fly over large crowds of people - unless you have a lot of experience and are confidence in your equipment.
  You should also avoid areas and altitudes where you could collide with manned aircraft or stumble upon unfriendly weather.
  Certain low-end and medium-end drones can't even operate in extremely high altitudes because of the thin air (and their motors tend to freeze), so you'll want to analyse all the types of environments that both you and your drone can handle before attempting any flight.
  However, it must be mentioned that as easy as these are to fly, common sense and care is a big part of aerial flying. It’s suggested you start with some limitations in place, easily set up on the smartphone app that runs the drone. This is usually along the lines of limiting the maximum height you can fly, and also how far away you can send the drone.
  Always start somewhere wide open, such as a local oval or park, and spend time getting a feel of the controls before you even think about pressing the shutter button. Always be aware of your location in relation to what’s around you. As these cameras usually have a wide angle lens (20mm equivalent) and it’s easy to mis-judge your positioning when in close proximity to objects such as tree
  • Land Surveyor

    WISDOM > WISDOM September 30, 2017 at 8:00pm

    You are welcome Surv. Kevin Sales. Hoping for the fulfilment of your promise.
  • Not a Surveyor

    Kevin Sales > WISDOM September 22, 2017 at 6:55am

    Hi Wisdom,
    Thanks for the detailed info. I’m certainly playing about the camera settings.
    We are just putting the finishing touches to our Operating Safety Case to be submitted to the UK CAA for your commercial operations but once it’s all through we will be using 3 different DJI drones and a range of cameras.
    Just need the clients now and a firm grasp of the right software (Agisoft/DroneDeploy or Pix4D being the main ones considered.
• Land Surveyor

  Eric Lindgren September 18, 2017 at 3:55pm

  Hello Kevin from the other side of the pond. We use a DJI Phantom 4 Pro drone. Our tablets in the field run Pix4D Capture to run the grids and collect the images (free software). We then process the images with Pix4DPro Mapper. This software requires a monthly/yearly subscription, or a one-time purchase fee and is pricey. 

  Pix4D mapper exports the orthomosaics, point clouds, etc. that we need. We are now flying almost every topo site that we do! I have seen as good as 0.5" resolution, and it is great to have the up-to-date imagery. 

  Hope that helps, feel free to ask questions if you have any. 

  -Eric Lindgren
  • Not a Surveyor

    Kevin Sales > Eric Lindgren September 19, 2017 at 3:24am

    Hi Eric/Rafael
    Thanks for the reply.
    I was about to start a 15day trial of Pix4D mapper. Can you measure volumes etc on that version? It was between mapper and Bim. Mapper seems to be comparable to DroneDeploys top package. Certainly price wise.
    As I've not have much experience with exports since I don't have any programmes to import the exported data to try it. Do you know if I export in various formats if my client could then use that data to measure his own volumes, area, cut/fill etc...
    So i basically just supply the raw data.
    
    Rafael,
    I'll be in touch, pretty much the same sort of question as I've just asked Eric above.
    
    Thanks
    Kevin.
  • Land Surveyor

    RAFAEL SILVA DE SOUSA > Eric Lindgren September 18, 2017 at 3:57pm

    Hello Kevin... We use DJI Phanton 4. We use Drone deploy in our handsets and to process the data we use Agisoft PhotoScan.

    U can send me a msg by what´s App and we can talk better.

    +5511993127262 or by e-mail adress: [email protected]

    See you.