scholarly journals Monitoring of the particles above the unpaved road by lidar technique

2013 ◽  
Vol 13 (4) ◽  
pp. 309-316
Keyword(s):  
Atmospheric Aerosols ◽  
Light Detection And Ranging ◽  
Lidar System ◽  
Unpaved Road ◽  
Range Resolution ◽  
Advantages And Disadvantages ◽  
Maximum Range ◽  
Scanning Lidar ◽  
Basic Concepts ◽  
Elastic Backscattering

Basic concepts of laser-based technique LIDAR (LIght Detection and Ranging) are discussed in this article as well as advantages and disadvantages. Presented are measurements of relative particulate concentrations above an unpaved road which were performed in a rural area near the Iowa City, Iowa, USA. The LIDAR system used in these measurements is a small, scanning LIDAR that uses elastic backscattering to obtain information on the amount of atmospheric aerosols. In the elastic LIDAR, light scattered back towards the LIDAR system from molecules and particles in the atmosphere is collected by a telescope and is detected with a photodiode. A Big Sky Laser model CFR-200 Nd:YAG laser operating at 1.064 microns is used to generate the LIDAR's outgoing signal. The laser is attached directly to the top of a 26 cm, f/10 Cassegrian telescope. A series of pulses are summed to make a single scan. A series of scans is used to build up a twodimensional map of relative atmospheric aerosol concentrations. With a maximum range of about 6-8 km, a range resolution of 2.5 m, and a time resolution of 30 s, the LIDAR is capable of very detailed mapping of aerosols.

scholarly journals A new mobile and portable scanning lidar for profiling the lower troposphere

2015 ◽  
Vol 4 (1) ◽  
pp. 35-44 ◽  
Author(s):  
C.-W. Chiang ◽  
S. K. Das ◽  
H.-W. Chiang ◽  
J.-B. Nee ◽  
S.-H. Sun ◽  
...  
Keyword(s):  
Atmospheric Aerosols ◽  
High Speed ◽  
Stimulated Raman Scattering ◽  
Layer Structure ◽  
Lower Troposphere ◽  
Sea Breeze ◽  
Industrial Area ◽  
Atmospheric Pollutants ◽  
Lidar System ◽  
Scanning Lidar

Abstract. An in-house developed mobile and portable three-dimensional scanning lidar system is discussed in this work. The system uses a stimulated Raman-scattering technique for the continuous observation of atmospheric aerosols, clouds and trace gases. This system has a fast scanning technique with a high-speed data acquisition, and permits the real-time measurement of atmospheric pollutants with the temporal resolution of 1 min. This scanning lidar system provides typical horizontal coverage of about 8–10 km while scanning; however, in zenith mode, good quality backscattered signals can be from 20 km, depending upon the laser power and sky conditions. This versatile lidar system has also overcome the drawbacks which are popular in the traditional scanning lidar systems such as complicated operation, overlap height between laser beam and telescope field of view In this system, the optical damage is reduced by using an integral coaxial transmitter and receiver. Some of the initial results obtained from the scanning lidar system are also presented. This study shows that boundary-layer structure and land–sea breeze circulation can be resolved from the developed scanning lidar system. The application of this lidar system to measure the pollutants over an industrial area is also discussed.

scholarly journals Concurrent Firing Light Detection and Ranging System for Autonomous Vehicles

2021 ◽  
Vol 13 (9) ◽  
pp. 1767
Author(s):  
Gunzung Kim ◽  
Imran Ashraf ◽  
Jeongsook Eom ◽  
Yongwan Park
Keyword(s):  
Laser Pulse ◽  
Autonomous Vehicles ◽  
Measuring Method ◽  
Light Detection And Ranging ◽  
Walking Robots ◽  
Lidar System ◽  
Light Detection ◽  
Emission Channel ◽  
Scanning Lidar ◽  
Pulse Stream

We proposed a light detection and ranging (LIDAR) system that changes the measurement strategy from a LIDAR system of sequential emission and measuring method to a concurrent firing measuring method. The proposed LIDAR was a 3D scanning LIDAR method that consisted of 128 output channels in one vertical line in the measurement direction and concurrently measured the distance for each of these 128 channels. The scanning LIDAR emitted 128 laser pulse streams encoded by carrier-hopping prime code (CHPC) technology with identification and checksum. When the reflected pulse stream was received and demodulated, the emission channel could be recognized. This information could be used to estimate the time when the laser pulse stream was emitted and calculate the distance to the object reflecting the laser. By using the identification of the received reflected wave, even if several positions were measured at the same time, the measurement position could be recognized after the reception. Extensive simulations indicated that the proposed LIDAR could provide autonomous vehicles or autonomous walking robots with good distance images to recognize the environment ahead.

scholarly journals A new mobile and portable scanning lidar for profiling lower troposphere

2014 ◽  
Vol 4 (1) ◽  
pp. 165-190 ◽  
Author(s):  
C.-W. Chiang ◽  
S. K. Das ◽  
H.-W. Chiang ◽  
J.-B. Nee ◽  
S.-H. Sun ◽  
...  
Keyword(s):  
Atmospheric Aerosols ◽  
High Speed ◽  
Stimulated Raman Scattering ◽  
Layer Structure ◽  
Lower Troposphere ◽  
Data Retrieval ◽  
Air Pollutant ◽  
Lidar System ◽  
Vertical Range ◽  
Scanning Lidar

Abstract. We present and discuss on an indigenously developed mobile and portable 3-D scanning lidar system. The system utilizes a stimulated Raman-scattering technique for the continuous observation of atmospheric aerosols, clouds and trace gases. The system provides fast scanning technique with a high speed data acquisition, which permits the real-time measurement of air pollutant mobility. The temporal resolution of data retrieval is every one min. The scanning lidar system provides typical horizontal coverage of about 8–10 km when scanning, while the vertical range can be up to 20 km depending upon the laser power and sky conditions. This versatile lidar system has also overcome the drawbacks which are popular in the other scanning lidar system such as complicated operation; overlapping height between laser beam and telescope field of view; and damage of optic detectors for long duration measurement by using an integral coaxial transmitter and receiver. Some of the initial results obtained from the scanning lidar system are also presented. We have shown that the developed 3-D scanning lidar system can resolve the boundary layer structure and land-sea breeze circulation. Discussion is also made on the application of scanning lidar system to measure pollutant over industrial areas.

EVALUATION OF CIRCULARITY MEASUREMENT THROUGH LIMAÇON APPROXIMATION AND A LIGHT DETECTION AND RANGING (LiDAR) SYSTEM

2021 ◽  
Author(s):  
Vinicius Conti da Costa ◽  
Bruno Ziegler Haselein ◽  
Filipe Barbosa Veras ◽  
Manoel Kolling Dutra ◽  
Tiago Pinto
Keyword(s):  
Light Detection And Ranging ◽  
Lidar System ◽  
Light Detection

Aerosol density distribution in the boundary layer measured by a scanning LIDAR system

1993 ◽  
Author(s):  
Shlomo Fastig ◽  
Y. Benayahu ◽  
Abraham Englander ◽  
E. Glaser
Keyword(s):  
Boundary Layer ◽  
Density Distribution ◽  
Lidar System ◽  
Scanning Lidar

Epidemiology and biostatistics

2019 ◽  
pp. 52-67
Author(s):  
Nizam Damani
Keyword(s):  
Cohort Studies ◽  
Confidence Intervals ◽  
Prevalence Rate ◽  
Statistical Significance ◽  
Case Control ◽  
Statistical Process ◽  
Practical Advice ◽  
Advantages And Disadvantages ◽  
Basic Concepts ◽  
Healthcare Associated

This section includes a chapter on basic epidemiology and biostatistics as applied to healthcare-associated infections (HAIs). The epidemiology section summarizes various types of studies and outlines the advantages and disadvantages of case–control and cohort studies. It describes the incidence and prevalence rate and how to calculate the most common HAIs. Practical advice is also given on how to avoid bias and confounders. The chapter describes basic concepts in biostatistics and tests of statistical significance used in investigating an outbreak. It also provides guidance on how to calculate the sensitivity and specificity of the test and describes how to interpret confidence intervals and statistical process charts.

SNR Analysis under Multi Pulse Accumulation of Non-Scanning Lidar System

2012 ◽  
Vol 49 (5) ◽  
pp. 051401
Author(s):  
高峰 Gao Feng ◽  
杨进华 Yang Jinhua ◽  
姜成昊 Jiang Chenghao ◽  
朱彦 Zhu Yan
Keyword(s):  
Lidar System ◽  
Scanning Lidar

Depolarization Light Detection and Ranging Using a White Light LIDAR System

2006 ◽  
Vol 45 (No. 6) ◽  
pp. L165-L168 ◽  
Author(s):  
Toshihiro Somekawa ◽  
Chihiro Yamanaka ◽  
Masayuki Fujita ◽  
Maria Cecillia Galvez
Keyword(s):  
White Light ◽  
Light Detection And Ranging ◽  
Lidar System ◽  
Light Detection
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