DJI copters provide a very good solution for 3D reconstruction of various environments (buildings, fields, etc.) and they are appropriate to generate various outputs with Pix4Dmapper: 3D Textured Mesh, DSM, Orthomosaic, etc. A major advantage of DJI copters is the flexibility with the camera tilting and the ability to fly around objects. This is even more suitable for mapping facades for instance.
For an optimal image acquisition plan to achieve the best results with Pix4Dmapper, it is recommended to use the Pix4Dcapture mobile app that allows the drone to autonomously fly and take images (not videos). There are several types of missions available: (Android, iOS) Which type of mission to choose. For more information about the supported DJI drones: (Android, iOS) Which drones are supported by Pix4Dcapture.
To start using the app: Android, iOS (Pix4Dcapture - Getting Started).
For high accuracy results, Ground Control Points (GCPs) should be measured on the field and imported into the project: Using GCPs.
The accuracy of the reconstruction is also affected by the precision of the images, i.e. the pixel size that is called Ground Sampling Distance (GSD).
For more information about the model accuracy: Accuracy of Pix4D outputs.
I have a project that is 5 miles by 4 miles that I need to produce an ortho photo.
I'm wondering what is the minimum front and side overlap that I might be able to use.
I will be flying at 400 feet using a Sony RX II 43 mega pixel camera with a 28 mm lens.
Normally I fly 75% side and 70% front/back. I'm hoping to reduce the number of pictures needed.
Ron
Hi Ron. It's difficult to give you a specific overlap as it depends not just on the parameters you mentioned but the terrain you are mapping. Whether the area is hilly, snowy, covered in water or sand, can all influence the overlap required. I would recommend you test a few missions with different overlaps to see what calibrates in Pix4D Mapper. I would maybe think you could push it down to 65-60 minimum but that isn't for sure.
Thanks for the feed back.
Would PIX4D be able to create an ortho photo that contains 12 thousand photos that are 18,000 kb in size?
Hi Ronald. Pix4D can handle larger datasets but it is a more advanced process that requires an experienced user and more powerful hardware. Check out some of the links below and I would suggest you take a look at our personal training options with one of our trainers if you are considering taking on larger projects.
https://support.pix4d.com/hc/en-us/articles/202558579-Processing-Large-Datasets
https://support.pix4d.com/hc/en-us/articles/360021755152-Pix4D-Hardware-FAQ
https://www.pix4d.com/services/training-certification