Beautiful, precise point clouds and meshes of buildings can be generated by adjusting the gimbal angle from within Site Scan Field. Oblique images can be used standalone or incorporated into the photogrammetry process to include the orthomosaic, mesh, or model that is generated as Nadir imagery is generally not sufficient to build an accurate point cloud of a site that contains vertical surfaces.
To perform a crosshatch survey, open the Site Scan field app and select “Crosshatch Survey” from the Flight modes screen.
You can then change the Survey altitude and Gimbal Angle directly from the Flight settings menu on the right by moving the sliders. When changing the Gimbal Angle, the closer you are to Nadir signifies how much will the camera point directly to the ground i.e. 0 degrees means it will face down.
Make sure you set the angle and altitude of your survey appropriately based on the structure of interest. In this example a crossahatch survey was done in an industrial park with factories so a 200 feet altitude with a 37 degree angle on the Gimbal was set. For oblique image acquisition it’s best to have the Gimbal anywhere between 37 and 45 degrees.
Once you’re done planning out your Crosshatch survey, hit the green “Fly Survey” button on the bottom, and after you go through the Pre Flight checklist, slide the button to the right to take off.
A progress bar on the bottom of the screen indicates the progress of the mission, while the numbers at the bottom shows the number of photos taken vs the number of photos required for the mission. During flight you can pause the mission by pressing the pause button on the bottom right of the screen. After the survey is complete, the aircraft will return straight to home.
After landing, the app will retrieve the flight data from the aircraft. This may take a few seconds to complete.
After the flight data has been retrieved, the app will display the number of photos taken and geotagged.
After the flight data is retrieved, hit the X on the upper left of the screen to go back to our Flight modes menu. Here you will find a notification on the upper left, clicking on this button will open the jobs page
You can rename the job by clicking on the ellipses (…) on the top right. To wirelessly retrieve the images from the camera, press the blue “Get Images” button at the bottom.
After the download is complete, the button changes to an “Upload to 3DR Cloud” button. Connect to the internet to upload the images. After the upload to 3DR is complete, white checkmarks will appear on all the images.
To process the job, log into sitescan.3dr.com and log in using your Site Scan account and select the desired project from the main page
Once the desired job has been selected, go into the “Job Data” tab –> click on “Process Job” and it will then move it over to “Active Processes” indicating processing has started.
Once it finishes the processing phase, you’ll find the results under “Job Data” along with a link in the far right to download each result.