Eurosense, a leading aerial surveying, geo-data, and remote sensing company in Europe, recently had the opportunity to conduct 3D laser scanning services on the iconic Croatian cities of Dubrovnik and Split.
This complex project required the use of both ortho imagery and lidar surveying tools. Therefore, this study presented a great opportunity to determine if combining medium-grade image, light detection, and ranging techniques can produce more efficient and effective results than high-resolution-based systems.
Both cities present distinctive obstacles for standard 3D mapping, including rapidly changing elevations, sheer and mountainous coastline, and lofty structures. Dubrovnik, in particular, sits in a basin between elevated cliffs at the coast and mountains on the eastern edge. In some places, the altitude of the ground adjacent to a building is taller than the topmost part of the structure itself.
A good array of surveying tools and instruments is essential to successfully acquire good laser and orthophotographic information in such a tough zone. Comprehensive virtual depiction of the compact metropolitan areas needs extremely detailed and precise surveying information, with exceptional surveillance for scanning slender roads and structure walls while minimizing the side-effects of shading.
Eurosense used the RIEGL VQ-1560II and VQ-1560i-DW, which are state-of-the-art surveying instruments that use complete spectrum computerization and rendering. Both setups utilize a full-range design allowing for surveying on approach, above and beyond, with a uniform and consistent measurement point for superior urban scanning using 3D laser scanning services.
Unique Applied Technologies Included In These 3D Laser Scanning Services
Eurosense had to use extremely accurate flight planning, improved level of detail modeling for buildings, accurate orthographic projection, and 3-dimensional mesh computer modeling to overcome the complex topography challenges in Dubrovnik and Split.
Due to the landscape’s rise and fall, repeated camera adjustments were needed in conjunction with lidar gathering to obtain the necessary corrections to the flight plan while data was processing. DTM was also leveraged to increase the precision of flight paths for PhaseOne imaging.
With their complicated roof structures, these compact metropolitan areas posed additional surveying problems. As such, special geometry-based techniques were used in these 3D scanning services to achieve correct layered cartography and a complete object-oriented building database so that each building could be treated as its own and separate polygonal structure.
Initially, a standard 10cm raster image was called for. However, due to the demanding formation of these cities, it was impossible to attain a high enough quality image. Therefore, the DSM was updated using angle design and lidar details, resulting in a significantly better raster image that perfectly matched the exported building angles.
Because the improved DSM developed a high-quality raster image, it was agreed to create a 3-dimensional mesh representation of the city utilizing the flight paths enriched by lidar details. Using the rich lidar and angle data resulted in significantly improved 3-dimensional mesh reference points.
Insights For Customized 3D Laser Scanning Services
Using both ortho imagery and lidar surveying tools resulted in increased exactness and linear spacing of measure for the final product, allowing for a faster, more cost-effective data service. The unique applied technologies used in these 3D laser scans allowed for higher quality polygonal structure from the medium-grade cameras. The pervading question remains, however, if the higher cost of such extra labor presents more cost-effective solutions to high-resolution based systems.
