Some Design Aspects of Lidar System for Measurement of Atmospheric Aersosols

1986 ◽  
Vol 15 (1) ◽  
pp. 21-25
Author(s):  
P. C. S. Devara ◽  
D. R. Jadhav ◽  
P. Ernest Raj
Keyword(s):  
Lidar System

Registration and Fusion of UAV LiDAR System Sequence Images and Laser Point Clouds

2020 ◽  
Author(s):  
Jiayong Yu ◽  
Longchen Ma ◽  
Maoyi Tian, ◽  
Xiushan Lu
Keyword(s):  
Point Cloud ◽  
Image Data ◽  
Point Clouds ◽  
Optical Image ◽  
Point Cloud Data ◽  
Feature Points ◽  
Lidar System ◽  
Registration Accuracy ◽  
Cloud Data ◽  
Intensity Image

The unmanned aerial vehicle (UAV)-mounted mobile LiDAR system (ULS) is widely used for geomatics owing to its efficient data acquisition and convenient operation. However, due to limited carrying capacity of a UAV, sensors integrated in the ULS should be small and lightweight, which results in decrease in the density of the collected scanning points. This affects registration between image data and point cloud data. To address this issue, the authors propose a method for registering and fusing ULS sequence images and laser point clouds, wherein they convert the problem of registering point cloud data and image data into a problem of matching feature points between the two images. First, a point cloud is selected to produce an intensity image. Subsequently, the corresponding feature points of the intensity image and the optical image are matched, and exterior orientation parameters are solved using a collinear equation based on image position and orientation. Finally, the sequence images are fused with the laser point cloud, based on the Global Navigation Satellite System (GNSS) time index of the optical image, to generate a true color point cloud. The experimental results show the higher registration accuracy and fusion speed of the proposed method, thereby demonstrating its accuracy and effectiveness.

Flexible Lidar system for the mobile and UAV-based use Flexibles Lidar-System für den mobilen und UAV-Basierten Einsatz

GIS Business ◽  
2017 ◽  
Vol 12 (5) ◽  
pp. 34-35
Author(s):  
Fürst, C ◽  
Amon, P ◽  
Teufelsbauer, H
Keyword(s):  
Lidar System

Flexible Lidar system for the mobile and UAV-based use Flexibles Lidar-System für den mobilen und UAV-Basierten Einsatz

scholarly journals Development and Performance Evaluation of a Very Low-Cost UAV-Lidar System for Forestry Applications

2020 ◽  
Vol 13 (1) ◽  
pp. 77
Author(s):  
Tianyu Hu ◽  
Xiliang Sun ◽  
Yanjun Su ◽  
Hongcan Guan ◽  
Qianhui Sun ◽  
...  
Keyword(s):  
Forest Inventory ◽  
Low Cost ◽  
Canopy Cover ◽  
Tree Height ◽  
Flying Height ◽  
Tree Level ◽  
Forest Site ◽  
Lidar System ◽  
Individual Tree ◽  
Gap Fraction

Accurate and repeated forest inventory data are critical to understand forest ecosystem processes and manage forest resources. In recent years, unmanned aerial vehicle (UAV)-borne light detection and ranging (lidar) systems have demonstrated effectiveness at deriving forest inventory attributes. However, their high cost has largely prevented them from being used in large-scale forest applications. Here, we developed a very low-cost UAV lidar system that integrates a recently emerged DJI Livox MID40 laser scanner (~$600 USD) and evaluated its capability in estimating both individual tree-level (i.e., tree height) and plot-level forest inventory attributes (i.e., canopy cover, gap fraction, and leaf area index (LAI)). Moreover, a comprehensive comparison was conducted between the developed DJI Livox system and four other UAV lidar systems equipped with high-end laser scanners (i.e., RIEGL VUX-1 UAV, RIEGL miniVUX-1 UAV, HESAI Pandar40, and Velodyne Puck LITE). Using these instruments, we surveyed a coniferous forest site and a broadleaved forest site, with tree densities ranging from 500 trees/ha to 3000 trees/ha, with 52 UAV flights at different flying height and speed combinations. The developed DJI Livox MID40 system effectively captured the upper canopy structure and terrain surface information at both forest sites. The estimated individual tree height was highly correlated with field measurements (coniferous site: R2 = 0.96, root mean squared error/RMSE = 0.59 m; broadleaved site: R2 = 0.70, RMSE = 1.63 m). The plot-level estimates of canopy cover, gap fraction, and LAI corresponded well with those derived from the high-end RIEGL VUX-1 UAV system but tended to have systematic biases in areas with medium to high canopy densities. Overall, the DJI Livox MID40 system performed comparably to the RIEGL miniVUX-1 UAV, HESAI Pandar40, and Velodyne Puck LITE systems in the coniferous site and to the Velodyne Puck LITE system in the broadleaved forest. Despite its apparent weaknesses of limited sensitivity to low-intensity returns and narrow field of view, we believe that the very low-cost system developed by this study can largely broaden the potential use of UAV lidar in forest inventory applications. This study also provides guidance for the selection of the appropriate UAV lidar system and flight specifications for forest research and management.

scholarly journals AEROSOLS OBSERVATIONS BY AN ELASTIC LIDAR SYSTEM OVER THE CITY OF SÃO PAULO, BRAZIL

2001 ◽  
Vol 32 ◽  
pp. 407-408
Author(s):  
E. LANDULFO ◽  
A. PAPAYANNIS ◽  
A. ZANARDI DE FREITAS ◽  
M.P.P.. M. JORGE ◽  
N.D. VIEIRA JÚNIOR
Keyword(s):  
Sao Paulo ◽  
São Paulo ◽  
Lidar System ◽  
The City

Simplified Homodyne Detection for Linear FM Lidar

2008 ◽  
Vol 1076 ◽  
Author(s):  
Peter Adany ◽  
Chris Allen ◽  
Rongqing Hui
Keyword(s):  
Field Experiment ◽  
Local Oscillator ◽  
Homodyne Detection ◽  
Lidar System ◽  
Receiver Sensitivity ◽  
Sensitivity Estimation

ABSTRACTA fiber based lidar system is developed which simplifies the processing of linear FM pulses by using a modulated local oscillator power in the coherent detector. Experiments were conducted on lidar systems with direct, heterodyne and simplified homodyne detection to compare receiver sensitivity. A field experiment using the homodyne system verified the sensitivity estimation on a building target at 370-m range.

Development of a mobile Doppler lidar system for wind and temperature measurements at 30–70 km

2017 ◽  
Vol 188 ◽  
pp. 52-59 ◽  
Author(s):  
Zhaoai Yan ◽  
Xiong Hu ◽  
Wenjie Guo ◽  
Shangyong Guo ◽  
Yongqiang Cheng ◽  
...  
Keyword(s):  
Temperature Measurements ◽  
Doppler Lidar ◽  
Lidar System
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