In the field of 3D scanning and surveying, Emesent´s real-time kinematics (RTK) solution for Hovermap stands out. By eliminating or reducing the need to lay out and georeference ground control points (GCPS), RTK significantly accelerates the process from scanning to actionable insights, and overcomes scenarios where placing ground control targets is impractical. Emesent has now advanced this capability even further.
As every surveyor knows, manually georeferencing and aligning large scans is a time-consuming and labour-intensive process, and locating control points within a survey can be challenging. Emesent’s RTK solution for the Hovermap Lidar mapping system addresses this by automating high-accuracy georeferencing and drift correction, streamlining workflows and minimizing the potential for error. Accuracy is further enhanced by intelligently leveraging a combination of both RTK and SLAM technologies to optimize results and ensure the most reliable, robust point cloud.
Intelligent georeferencing
Emesent's processing and visualization software, Aura, intelligently balances RTK and SLAM data based on the best position quality to deliver the highest–quality results. Aura chooses RTK when corrections are favourable and automatically switches to SLAM when they are not. This has the additional benefit of providing a more accurate result in environments that are traditionally challenging for SLAM, such as very large areas with limited features or long linear repetitive environments.
The integration of 360–degree colourization adds further context to the point cloud, uncovering richer insights and aiding stakeholder understanding. The same scan can be used to extract 360–degree images which can be viewed side by side with the point cloud. Images are automatically georeferenced, making it easier to draw up the point cloud into building information modelling (BIM) software such as Revit.
Designed with versatility in mind
Hovermap has been designed with versatility in mind, enabling the same device to be deployed in multiple ways to address any scanning requirement. Similar principles have been extended to Emesent’s RTK solution for Hovermap, allowing RTK to be leveraged on a drone, vehicle and backpack, giving clients flexible deployment options and enabling them to choose the best RTK platform for their environment. Clients can also monitor RTK quality in real time in the Commander app, providing confidence that a high–quality output will be achieved.
Validated results
To provide clients with the confidence to use the RTK solution on their highest-accuracy projects, Emesent partnered with Orion Spatial Solutions to independently validate the accuracy of the Vehicle RTK Kit. This seamlessly connects the Emlid RS2/2+ and the latest RS3 to the Hovermap and attaches securely to any vehicle via magnetic or suction cup feet. Data was captured along a 2km stretch of road in Brisbane, Australia, with the Vehicle RTK Kit mounted to the back of a van to give good visibility of the road surface. Six passes were completed in either direction at approximately 50km/h, with a total capture time of 50 minutes. The baseline length was a maximum of 1km, with the Emlid RS3 rover connected to a local base station. The data was reprojected to GDA2020 MGA Zone 56 and a geoid applied (AHD). No ground control was used in the processing of the dataset. The dataset was compared against 75 quality control points which Orion Spatial Solutions established on the 2km stretch of road using a Leica TS13 total station and Leica LS15 digital level, in accordance with Queensland Government Transport and Main Roads Surveying Standards. The results are shown in Figure 1.
For use cases where speed and ease of capture is more important than accuracy, the Emesent Backpack RTK Kit has been launched. This allows georeferencing in GPS–denied environments by starting a scan outdoors using RTK and then seamlessly transitioning to SLAM capture indoors during the same scan, without requiring indoor setup of control points using a total station to georeference the point cloud. This method of capture is also beneficial in forestry applications, construction progress tracking, and any project where small areas of the site have limited or no GPS.
Real-life applications
Today, RTK is being successfully leveraged across multiple applications, including:
• Change detection and repeatability for mapping and surveying: RTK streamlines the survey process by reducing time and improving accuracy. Its georeferencing capability enables easy overlay of repeat scans, facilitating insights into environmental changes and site developments.
• Faster, easier scanning for forestry and topographic mapping: In expansive and rugged terrains where deploying numerous GCPs is challenging, RTK offers a practical solution by removing the need for such targets.
• Enhanced accuracy for large, featureless environments: RTK excels in featureless environments such as open fields, stadiums and quarries, where traditional SLAM techniques might struggle due to the lack of distinct features.
• Safer scanning in high-risk or challenging areas: RTK is particularly advantageous in hazardous locations, like coastal areas with eroded edges, where placing targets would be unsafe or impractical.
• Scanning in inaccessible areas: In urban environments or areas with drone restrictions, RTK–equipped vehicles offer a viable alternative, enabling effective data collection where drones cannot operate.
• Large project areas: For extensive projects such as roadway developments, road condition inspections, urban planning and civil engineering, RTK provides the necessary accuracy and efficiency.
• Rapid results in case of natural disasters: When responding to events such as landslides or coastal erosion, RTK facilitates swift and safe scanning, allowing for prompt analysis and response for first responders.
Leveraging the best of RTK and SLAM
Delivering automated georeferencing and drift correction, Emesent’s RTK solution represents a step forward in geospatial mapping technology, providing a robust, efficient and highly accurate surveying solution for diverse scanning needs.
More Information: www.emesent.com