TOPODRONE DJI Matrice 200/210 PPK + RX1RII 42Mp – new high precision and efficient tool for professional surveyors

TOPODRONE team brings to your attention a new product line of survey-grade drones TOPODRONE DJI MATRICE 210 L1/L2 PPK with a mount for a professional high-resolution cameras.

The TOPODRONE DJI MATRICE 210 L1/L2 PPK 42 Mp is the most versatile survey drone, equipped with a water-resistant body, heated power cells, advanced obstacle avoidance system, powerful dust-resistant and water-resistant motors, L1/L2/L5 186-channel multispectral receiver onboard, 3-axis gimbal and a professional 42 Mp SONY RX1 RM2 camera .

Img. 2. TOPODRONE DJI Matrice 210 V2 L1/L2/L5 RTK/PPK + 42Mp.

The reliability of TOPODRONE DJI MATRICE 200/210 has been proved on practice by our customers under the hardest weather conditions. Here are some examples:

• Our customer Eduardo Fernandez from Costa-Rica got caught by a heavy tropical rain during the aerial survey. His drone has completed the mission and performed a successful landing in  normal mode.
  
•  During the aerial survey in an upland area the drone has lost its connection to the remote-control device. The drone has performed an automatic landing on a flat section of the road with the use of its obstacle sensors.
• A mining facility in Kazakhstan regularly performs aerial surveys under wind speeds higher than 15m/s – 20m/s.

The technology of aerial surveying with UAV TOPODRONE DJI Matrice 210 V2 L1/L2/L5 RTK/PPK

In this article we will show you how to perform precise aerial survey of large areas with our new product TOPODRONE DJI MATRICE 210 L1/L2 PPK, equipped with a professional SONY RX1 RM2 42 Mp camera on a practical example. The accuracy of such modelling is about 3-5 cm in the plane and in height.

We have started from the mission planning in UGCS software. It allows to prepare the flying route following the local terrain on the PC, export it into kml file and upload to the DJI CrystalSky remote controller.

Img. 3. Creating the flight route with UgCS.

We have created a route at an altitude of 270m, with 80% and 60% overlap respectively and covering an area of more than 100 ha.

After that we have performed the flight in an automatic mode at the speed of 15 m/s. The mission took 21 minutes and only one power cell kit.

Following the aerial survey, we have carried out the quality control of the images. The GSD was 3.5 cm per pixel approximately, whereas the image quality was comparable to the images from DJI Phantom4 PRO at the altitude of 100-120 m.

TOPOSETTER 2.0 PRO – precise and simple GNSS data postprocessing

We have downloaded static Rinex data files from the base at a distance of 13km to process GNSS data.

The GNSS data postprocessing and image geotagging were executed in the TOPOSETTER 2.0 PRO software. We have set the folder with images, selected the drone UBX file and the base Rinex file. This program automatically uploads precise base coordinates for the postprocessing.

We have selected the output coordinate system to have our base coordinates automatically recalculated into it.

After setting the base antenna height, the antenna-to-camera offset, the folder with the results, we have initiated the process of automatic GNSS data postprocessing and image geotagging.

Img. 7. Antenna offset and base height parameters in TOPOSETTER 2.0 Pro

This program creates the following data set:

1. A folder with images that have precise coordinates and their accuracy written into EXIF tags.
   
2. Text files with image coordinates in WGS84 and in local map projection.
   

You can find more information on TOPOSETTER 2.0 Pro usage here.

The aerial survey data processing in Pix4Dmapper 4.5.6 has become faster

We have uploaded images into Pix4Dmapper. This software reads the coordinates and their horizontal and vertical accuracy from the image EXIF tags.

The next step is choosing the coordinate system. One can import a PRJ file with a custom coordinate system for that purpose. After that we have uploaded precise image centers in local map projection.

The image locations are shown on an interactive map. We initiate the process of photogrammetric adjustment of image blocks, input the calibrated focal length (32.9421 mm) and begin creating the dense point cloud and the orthophotomap.

We have performed the processing in the new Pix4Dmapper 4.5.6 software. The developers claim that it is much faster in aerial triangulation, calibrating camera and creating a dense point cloud and we approve it with our experience of using.

After creating the dense point cloud in Pix4Dmapper we have performed an automated classification and labeled buildings, constructions, roads, terrain and flora in different colours.

The detailed results allow to clearly locate the fences and the power line poles. These objects can be automatically classified as well.

We have created a terrain model and horizontals with the classified point cloud.

Img. 13. Created in automated mode horizontals, based on the classified point cloud.

It should be noted that the result objects are created in the custom coordinate system. There is no need to use a third-party software to transform the coordinates from WGS 84 to map projection.

The accuracy of the digital surface model has been examined with 20 ground control points, uniformly distributed around the area of interest. The position accuracy was 3-6 cm

The advantages of using TOPODRONE technologies for aerial survey

TOPODRONE DJI Matrice 210 V2 L1/L2/L5 RTK/PPK + 42Mp is a professional survey-grade drone that is highly effective for the aerial survey under the worst weather conditions.

Excellent flight performance and a high course speed up to 15 m/s allow performing a survey of areas up to 100ha per flight without any problems and doing large-scale mapping projects up to 1:500 scale with the efficiency around 1000ha per day.

A wide light spectrum of SONY RX1 RM2 camera creates a detailed low-noise point cloud under any illumination conditions, whereas the mechanical shutter and the stable image geometry provide a high quality of created models.

A new model of 186-channel multispectral L1/L2/L5 15Hz GNSS receiver gets the precise image coordinates and operates the 3-axis camera gimbal as well.

TOPOSETTER 2.0 Pro, included with all TOPODRONE survey drones, has easy-to-use tools for postprocessing GNSS data in different coordinate systems and for initial image processing automatization:

• multiple flight batch processing
• automatic image renaming
• writing coordinates into EXIF tags
  
• calculating actual focal length
  

You can examine the quality of the point cloud and the orthophotomap here as well: