Airborne Streak Tube Imaging LiDAR Processing System: A Single Echo Fast Target Extraction Implementation

Abstract

In this paper, a ground target extraction system for a novel LiDAR, airborne streak tube imaging LiDAR (ASTIL), is proposed. This system depends on only a single echo and a single data source, and can achieve fast ground target extraction. This system consists of two modules: Autofocus SSD (Single Shot MultiBox Detector) and post-processing. The Autofocus SSD proposed in this paper is used for object detection in the ASTIL echo signal, and its prediction speed exceeds that of the original SSD by a factor of three. In the post-processing module, we describe in detail how the echoes are processed into point clouds. The system was tested on a test set, and it can be seen from a visual perspective that satisfactory results were obtained for the extraction of buildings and trees. The system mAPIoU = 0.5 is 0.812, and the FPS is greater than 34. The results prove that this ASTIL processing system can achieve fast ground target extraction based on a single echo and a single data source.

A Calibration Method for Time Dimension and Space Dimension of Streak Tube Imaging Lidar

“…Differently from the push broom scanning used in traditional STIL, we used a pendulum broom scanning method [21]. Due to the fact that the streak tube detection system could be seen as a linear array detector, the point cloud was composed of individual bands.…”

“…After the same data processing operation as below, filtering noise, calibrating the installation angle of the inertial measurement unit and optical system, and correcting the inherent error in distance measurement, we compared the data of the 3D point cloud before and after the time and angle calibration proposed in this paper. The results are shown in Figures 12 and 13 Differently from the push broom scanning used in traditional STIL, we used a pendulum broom scanning method [21]. Due to the fact that the streak tube detection system The aircraft flew at an altitude of about 2000 m and a speed of about 70 m/s; the terrain was relatively flat, with an elevation of about 100 m, and the surveying area was a small town in northern China.…”