Linear terrestrial laser scanning using array avalanche photodiodes as detectors for rapid three-dimensional imaging

Abstract

As an active remote sensor technology, the terrestrial laser scanner is widely used for direct generation of a three-dimensional (3D) image of an object in the fields of geodesy, surveying, and photogrammetry. In this article, a new laser scanner using array avalanche photodiodes, as designed by the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences, is introduced for rapid collection of 3D data. The system structure of the new laser scanner is first presented, and a mathematical model is further derived to transform the original data to the 3D coordinates of the object in a user-defined coordinate system. The performance of the new laser scanner is tested through a comprehensive experiment. The result shows that the new laser scanner can scan a scene with a field view of 30° × 30° in 0.2 s and that, with respect to the point clouds obtained on the wall and ground floor surfaces, the root mean square errors for fitting the two planes are 0.21 and 0.01 cm, respectively. The primary advantages of the developed laser scanner include: (i) with a line scanning mode, the new scanner achieves simultaneously the 3D coordinates of 24 points per single laser pulse, which enables it to scan faster than traditional scanners with a point scanning mode and (ii) the new scanner makes use of two galvanometric mirrors to deflect the laser beam in both the horizontal and the vertical directions. This capability makes the instrument smaller and lighter, which is more acceptable for users.

Analytical and numerical approaches to study echo laser pulse profile affected by target and atmospheric turbulence

“…(3) The ELPP of the target with discontinuous shape is easier affected by atmospheric turbulence than that of the target with continuous shape. (4)The accuracy of the model is determined by the number of grids. Based on the discussions on echo pulse width vs tilt angle of the target, the optimal number of grids is obtained to study the ELPP.…”

“…With the fast development of pulse laser, many detecting sensors such as ranging sensors [1,2] and three-dimensional (3D) sensors [3,4] have been studied and developed. Moreover, target recognition based on pulse laser has attracted much attention these years due to its ability to acquire echo pulse with high accuracy and efficiency [5,6].…”

Plane-based self-calibration and improvement of three-dimensional multi-beam laser scanning with two-axis-mirror

“…In order to solve the problem of the limited resolution of these sensors and improve their acquisition efficiency, we referred to another MBLS in this investigation, which combines one laser emitter and multiple echoes detected by linear array avalanche photodiodes (APDs) or a plane array photomultiplier within the same optical path, and scanned with a two-axis galvanometric mirror to provide rapid and reasonably accurate 3D representation with a high resolution. For instance, Cai et al presented a mathematical model for this MBLS with 16-beam linear array APDs [8]; Liu et al presented a low-photon MBLS based on an 8 × 8 array silicon plane array photomultiplier to obtain 64 echoes with array fiber [9].…”

Spatially Adaptive Retina-Like Sampling Method for Imaging LiDAR

“…According to the type of imaging, these sensors can be divided into scanning and nonscanning types [8], [9]. For the scanning type, different scanners (e.g., MEMS mirror, galvanometer scanner) have been employed in the imaging LiDAR to obtain images with a large field of view (FOV) and high resolution [10], [11]. However, the information of target is obtained by point-by-point sampling through scanners.…”