LiDAR, which stands for Light Detection and Ranging, is a remote sensing technology that uses laser pulses to measure distances and create highly accurate 3D models of the Earth’s surface. It works by emitting laser beams and measuring the time it takes for the light to bounce back after hitting an object. This data is then used to generate precise elevation models, point clouds, and digital terrain models. LiDAR is particularly useful in areas with dense vegetation or complex terrain, as it can penetrate through foliage and capture detailed information about the ground surface.
On the other hand, photogrammetry is a technique that uses overlapping aerial images captured by a camera to create 3D models of the Earth’s surface. It relies on the principles of triangulation, where the position of a point in space is determined by measuring the angles between it and multiple camera positions. By analyzing the overlapping images, photogrammetry software can reconstruct the geometry and texture of objects on the ground. Photogrammetry is widely used in applications such as topographic mapping, urban planning, and environmental monitoring.
When comparing drone LiDAR and photogrammetry, several factors need to be considered. Firstly, LiDAR provides highly accurate and precise elevation data, making it ideal for applications that require detailed terrain information, such as flood modeling or forestry management. Photogrammetry, on the other hand, can produce high-resolution orthophotos and textured 3D models, which are valuable for visualizing and analyzing surface features.
Secondly, LiDAR is less affected by lighting conditions and can be used during both day and night. It is also capable of capturing data through clouds and haze, making it suitable for various weather conditions. Photogrammetry, however, heavily relies on good lighting conditions and clear skies to capture high-quality images. Shadows, reflections, and poor lighting can affect the accuracy and quality of the photogrammetric outputs.