Difference between data photogrammetry and three-dimensional laser scanning

The content of digital photogrammetry is very wide, and both aerial photography and close-range photogrammetry can be called digital photogrammetry. Close-range photogrammetry and three-dimensional laser scanning belong to industrial measurement. Close-range photogrammetry uses two or more calibrated cameras to shoot the three-dimensional image pairs of the target, and then carries out adjustment processing through the space back intersection or self-checking comparison beam method to obtain the three-dimensional information of the measured object, with high accuracy, and the accuracy of the image pairs can reach one in a million. Three-dimensional laser scanner is a method to quickly obtain three-dimensional information of the target. It obtains the three-dimensional coordinates of the surface of the measured object by emitting laser scanning, and in principle it checks itself. Its data acquisition speed is fast, its accuracy is not as good as that of close-range photogrammetry, and its 3D laser scanner is expensive.