Today, 3D mapping has invaded several fields. It ranges from the construction of structures and planning of cities to the surveillance of the environment—and the management of disasters. Photogrammetry and LiDAR (Light Detection and Ranging) are the two leading technologies. That is being used to foster this revolution. However, each of them has its advantages. Utilizing the LiDAR data along with photogrammetry can lead to the creation of relatively accurate and dense DSMs. Combined, they promise each other’s strengths in terms of precision and resolution, which are hard to beat.
Understanding LiDAR and Photogrammetry
LiDAR employs the use of laser pulses to get the distance between the locations of the sensor and ground structures. These measurements produce a series of points or coordinates in the 3D environment. And a correct representation of the terrain and structures. LiDAR is particularly useful for gathering data in areas where vegetation is dense, which is why traditional photogrammetry can hardly succeed. Photogrammetry is the task of capturing several photographs with overlaps from different viewpoints. Then, we will perform a process that will result in 3D models. This method is especially effective in reproducing the color and Surface textures of objects. Thus creating a dense semantic backdrop for 3D maps.
Good For Its Synergy
The major advantage of using both LiDAR and photogrammetry is the fact that the two technologies complement each other in the data acquisition process.
Moving LiDAR data with photogrammetry benefits both methods in one way or another. Here are the key benefits:
- This is because while LiDAR provides accurate distance measurements, photogrammetry provides accurate texture and color data. Therefore, when employed collectively, the models are more accurate.
- Photogrammetry offers high levels of feature detail on the land. LiDAR can cover the vegetation and provide the vertical sections of the surface effectively. Making sure that all aspects are captured.
- Integrating both technologies can help cut down the time spent gathering data. It can also help to eliminate the need to conduct surveys repeatedly.
Its Value in LiDAR Applications
Integration, which is done to ensure the best results, requires LiDAR targets in most instances. Laser targets are unique objects that can be put on the ground to give direction to the actual procedure of data acquisition. These targets assist in eliminating any misplacement between the LiDAR data and photogrammetric images. Thus making the two dense point clouds compatible.
In practice, LiDAR land control targets are placed at various points of the surveyed area and, if possible, on distinguishable objects. In the process of data handling, they become control points that allow for the correction of all the distortions. And proper alignment of the datasets from both technologies. Especially when you need to generate a high-resolution 3D map. To provide the user with maximum accuracy and a realistic view.
Integrated 3D mapping can be defined as the use of developed integrated 3D mapping techniques in real-life situations. Involving new structure construction or structure redevelopment.
The integration of LiDAR and photogrammetry is transforming various industries:
Urban Planning
3D land maps aid city planning, infrastructure, and the conception of public spaces, including gardens and parks. They have a higher-quality image resolution than 2D maps.
Environmental Monitoring
3D maps are also used to track the rates and the process of deforestation. And for the assessment of the effects and consequences of natural disasters.
Construction
Planning and scheduling, needs assessment, and documentation are some of the many tasks. That 3D detailed mapping helps in developing and following through in the construction domain.
Archaeology
The integration of different types of 3D mapping technologies allows for the documentation of the measured area and its exploration with little impact on the landscape.
Challenges and Considerations
However, it is notable that while there are many advantages to integrating LiDAR and photogrammetry. There are also some challenges involved. Data formats, versioning of data, and the collection and reduction of big data require significant planning and experience. Moreover, in the case of LiDAR targets, it is always important to position them correctly together. Their measuring requires some time.
Still, there is progress in the techniques used to integrate these software packages. And processing algorithms are gradually enhancing the ease and feasibility of implementing these technologies. These are the most important challenges. Any professional can never face integrated 3D mapping. However, with modern tools and methods, such issues can be eliminated.
Conclusion
The combination of LiDAR data with photogrammetry can be viewed as much progress in the area of 3D surveying. This way, both methods complement each other and allow the creation of highly detailed 3D models. LiDAR targets, in particular, serve to define the integration of systems and make data accurate and consistent during the process. There is evidence to suggest that both LiDAR and photogrammetry are steadily progressing.
