With the new Phantom 4 RTK, DJI has made sure that complex industrial tasks can be solved with ease. This model appeared in Ukraine quite recently; DroneUA was one of the first to use drones.
Drones are becoming an integral tool in industry, replacing the classical approach in collecting information, while significantly reducing time and manpower required. DroneUA has developed successful cases on the use of this drone model. Examples that can serve as basic ones for use.
Phantom 4 RTK is the first drone from the world leader DJI, which has a coordinate determination module with centimeter accuracy and a unique system for synchronizing the received corrections in real time.
This drone is intended for companies that work in the construction, mining, geodesy, topography sectors and use drones to create maps, orthophotos and 3D models.
Technical features:
- RTK module (GPS: L1/L2; GLONASS: L1/L2Galileo: E1/E5a
- 1-inch 20 megapixel CMOS sensor
- OcuSynk 2.0 HD digital image transmission technology
- TymeSync system ensures continuous synchronization of the flight controller, camera and RTK module
- Special application for route planning GS RTK APP/ PC GS PRO
Advantages:
- the number of required anchor points becomes equal to 0;
- work speed increases 4 times;
- the mapping process becomes easier and more efficient.
Use example
Task
- comparing the accuracy of data from Phantom 4 RTK with control points obtained using the RTK rover
Test site: Kiev, part of the street. Saksagansky
Equipment and software involved:
- Phantom 4 RTK quadcopter
- RTK-rover GNSS rover ELNAV i70
- Pix4Dmapper Software
Stages of work:
- Coordination of control points
To control the accuracy of the data obtained using the Phantom 4 RTK, 10 control points were coordinated using the GNSS rover ElNAV i70.
- Surveying terrain with Phantom 4 RTK
- 1 How Phantom 4 RTK works.
There are 2 options for obtaining corrections to coordinates to achieve the stated accuracy
— work from the base station DJI D-RTK 2 Mobile Station
— operation from a network of GNSS base stations-SystemNET.
To make the most efficient use of the Phantom 4 RTK positioning modules, TimeSync was created. It allows the drone to calculate the center of the image, combined with location, altitude, camera angle relative to the drone, and time. Thus, the coordinate of the center of photography is recorded in the EXIF of each image in real time, taking into account all corrections.
In addition, the camera is calibrated at the manufacturing plant, what in photogrammetry is called calibration of internal orientation elements (coordinates of the main point x0, y0 and focal length of the image f, and distortion). This data is recorded in the extended metadata of each photo.
2.2 Route planning features: Phantom 4 RTK comes with the GS RTK APP/PC GS PRO program fully integrated with the drone, which has all the necessary functionality for route planning and control of the drone.
Parameters with which measurements were performed:
- Shooting height 150m
- Resolution 4 cm/px
- Overlap 80 longitudinal/75 transverse
- Speed 10 m/s
3. Data processing
Thanks to the TimeSync system, the exact coordinates of the centers of the images are already recorded in EXIF, including the accuracy with which a particular coordinate was obtained. When uploading photos to the Pix4d mapper project, the program automatically recognizes that the data was received from the Phantom 4 RTK camera (FC6310R_8.8_5472x3648) and, in addition to the coordinates, takes into account the camera calibration data.
4. Comparison of data accuracy from Phantom 4 RTK with control points obtained using an RTK rover.
To compare accuracy, DroneUA pilots performed 4 test flights for this territory. The resolution with which the GSD measurement was performed — 4.4 cm/px, so the expected planning accuracy is up to 8 cm (2×GSD), height accuracy is up to 12 cm (3×GSD). As a result of the flights performed, the accuracy of the planned position of coordinates at control points does not exceed 3 cm, the accuracy of the altitude position of coordinates does not exceed 4 cm.
Results
Orthophotomap and 3D terrain model, data that can later be used to create topographic plans
Photogrammetric processing export formats
- Orthomosaic: (GeoTIFF, KML)
- Point cloud: (LAS, LAZ, PLY, XYZ)
- 3D mesh: (PLY, FBX, DXF, OBJ)
- Contours with a given relief section: (SHP, PDF, DXF)
- DEM: (GeoTIFF)
- DTM: (GeoTIFF)
- Elevation grid: (XYZ, LAS, LAZ)
DroneUA specialists were able to evaluate the capabilities of Phantom 4 RTK in practice, where in the process of data processing the results were obtained, which once again confirmed that this drone — this is one of the most effective solutions in industry and cartography.
DroneUA — leading integrator of unmanned technologies on the Ukrainian market. The company operates in the fields of energy and oil and gas industries, as well as in the fields of geodesy and topography. The main areas of work of Drone.UA are the development and implementation of industry solutions based on drone technology, the provision of services using UAVs, as well as the processing of data obtained using drones. Drone.UA technologies are used on more than 3.5 million hectares of cultivated areas in Ukraine.
