scholarly journals Platform-Motion Correction of Velocity Measured by Doppler Lidar

2008 ◽  
Vol 25 (8) ◽  
pp. 1369-1382 ◽  
Author(s):  
Reginald J. Hill ◽  
W. Alan Brewer ◽  
Sara C. Tucker
Keyword(s):  
Motion Correction ◽  
Research Laboratory ◽  
Doppler Velocity ◽  
Doppler Lidar ◽  
Earth System ◽  
System Research ◽  
Velocity Data ◽  
Velocity Measurements ◽  
Platform Motion ◽  
Coherent Doppler Lidar

Abstract The NOAA/Earth System Research Laboratory (ESRL) has two coherent Doppler lidar systems that have been deployed on board research vessels to obtain data during several experiments. The instruments measure the wind velocity relative to the motion of the lidar; therefore, correction for the motion of the platform is required. This article gives a thorough analysis of the correction for lidar velocity measurements. The analysis is general enough to be applied to Doppler velocity measurements from all monostatic ship- and aircraftborne lidars and radars, and generalization to bistatic systems is achievable. The correction is demonstrated using miniature master-oscillator power-amplifier (mini-MOPA) Doppler velocity data obtained during the Rain in Cumulus over the Ocean (RICO) experiment.

scholarly journals Estudo da Temperatura da Superfície do Mar para os Oceanos Atlântico e Pacífico Utilizando a Técnica de Análises de Componente Principal e de Agrupamento (Study of Sea Surface Temperature for the Atlantic and Pacific Oceans Using the Technique of...)

2011 ◽  
Vol 4 (2) ◽  
pp. 264
Author(s):  
Madson Tavares Silva ◽  
Stephany C. F. Do Egito Costa ◽  
Manoel Francisco Gomes Filho ◽  
Daisy B. Lucena
Keyword(s):  
Principal Component Analysis ◽  
Cluster Analysis ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Research Laboratory ◽  
Principal Component ◽  
Component Analysis ◽  
Sea Surface ◽  
Earth System ◽  
System Research

Apresenta-se neste estudo a avaliação da metodologia de Análises Multivariadas: Análises em Componente Principal (ACP) e de Agrupamento (AA), aos dados de Temperatura da Superfície do Mar (TSM) para os Oceanos Atlântico (Norte (NATL), Tropical (TROP) e Sul (SATL)) e Pacifico (NIÑO1+2, NIÑO3.4, NIÑO3 e NIÑO4). Foram utilizados dados mensais de janeiro de 1950 a dezembro de 2010 de TSM obtidos na NOAA (National Oceanic and Atmospheric Administration/Earth System Research Laboratory). As regiões TROP e NIÑO4 apresentam as maiores TSM para os meses entre dezembro-julho. A região NATL apresenta no período de agosto-outubro seu maiores valores de TSM. A região NIÑo1+2 apresentou os menores valores de TSM. Os resultados da Análise em Componente Principal (ACP) identificaram maiores pesos na variação total explicada pelas duas primeiras componentes, que representam cerca de 100% da variância total dos dados de TSM. A Análise de Agrupamento (AA), pelo método Ward, permitiu o agrupamento das estações em três grupos homogêneos. Palavras - chave: Análises Multivariadas, Mudanças climáticas, Aquecimento Global.   Study of Sea Surface Temperature for the Atlantic and Pacific Oceans Using the Technique of Principal Component Analysis and Cluster   ABSTRACT Presented in this study was to evaluate the methodology of Multivariate Analysis: Principal Component Analysis (PCA) and cluster analysis (CA), the data of sea surface temperature (SST) for the Atlantic (North (NATL), Tropical (TROP) and South (Satler)) and Pacific (+2 NIÑO1, NIÑO3.4, and NIÑO3 NIÑO4). We used monthly data from January 1950 to December 2010 SST obtained from NOAA (National Oceanic and Atmospheric Administration / Earth System Research Laboratory). TROP and NIÑO4 regions have the highest SST for the months from December to July. NATL The region has in the period August-October SST your highest values +2 NIÑo1 The region had the lowest values of TSM. Results on Principal Component Analysis (PCA) identified higher weights in the total variation explained by the first two components, which represent about 100% of the total variance of SST. The Cluster Analysis (AA), the Ward method, allowed the grouping of stations into three homogeneous groups. Keywords: Multivariate Analysis, Climate Change, Global Warming.

scholarly journals Velocity Error for Coherent Doppler Lidar with Pulse Accumulation*

2004 ◽  
Vol 21 (6) ◽  
pp. 905-920 ◽  
Author(s):  
Rod Frehlich
Keyword(s):  
Observation Error ◽  
Doppler Lidar ◽  
Engineering Analysis ◽  
Sampling Errors ◽  
Velocity Measurements ◽  
Instrument Error ◽  
Velocity Error ◽  
Velocity Estimate ◽  
Coherent Doppler Lidar ◽  
Total Observation

Abstract The random estimation or instrument error of coherent Doppler lidar velocity estimates with pulse accumulation (multiple lidar shots per velocity estimate) is determined with computer simulations for general conditions. The sampling errors for overlaid lidar tracks and tropospheric wind field conditions are also calculated for space-based operation. These results permit useful engineering analysis based on the total observation error of the velocity measurements.

scholarly journals UAV-borne coherent doppler lidar for marine atmospheric boundary layer observations

2018 ◽  
Vol 176 ◽  
pp. 02012
Author(s):  
Songhua Wu ◽  
Qichao Wang ◽  
Bingyi Liu ◽  
Jintao Liu ◽  
Kailin Zhang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Motion Correction ◽  
Wind Profile ◽  
Layer Structure ◽  
Doppler Lidar ◽  
Marine Atmospheric Boundary Layer ◽  
Preliminary Results ◽  
Design Specifications ◽  
Coherent Doppler Lidar

A compact UAV-borne Coherent Doppler Lidar (UCDL) has been developed at the Ocean University of China for the observation of wind profile and boundary layer structure in Marine Atmospheric Boundary Layer (MABL). The design, specifications and motion-correction methodology of the UCDL are presented. Preliminary results of the first flight campaign in Hailing Island in December 2016 is discussed.

A influência da temperatura da superfície do mar do oceano Pacífico na precipitação pluvial de Penedo-AL

2018 ◽  
Vol 2 (2) ◽  
pp. 8
Author(s):  
Eliane Barbosa Santos ◽  
Gildo Rafael De Almeida SANTANA
Keyword(s):  
Research Laboratory ◽  
Earth System ◽  
System Research

Estudos climáticos da ocorrência de precipitações extremas têm importante papel socioeconômico, pois longos períodos secos e chuvosos acarretam prejuízos para a infraestrutura das cidades. Com isso, o objetivo desse estudo é analisar as tendências dos índices dependentes da precipitação pluvial diária para o Município de Penedo, assim como, analisar suas relações com as Temperaturas da Superfície do Mar (TSM) das regiões dos Niños (1+2, 3, 3.4 e 4), no período de 1948 a 2007. Os dados de precipitação foram obtidos através da Agência Nacional de Águas (ANA) e os dados referentes às TSM das regiões dos Niños foram obtidos no site do Earth System Research Laboratory. O software utilizado no processamento e controle de qualidade dos dados de precipitação diária foi o RClimdex 1.9.0. Com base nos resultados encontrados, foram observadas tendências de aumento do número de dias secos consecutivos e uma diminuição do número de dias úmidos consecutivos, assim como, uma diminuição em dias com precipitação igual ou acima de 50 mm. As correlações estatisticamente significativas entre os índices de precipitação e as TSM foram negativas, indicando que um aumento nas TSM das regiões dos Niños leva a uma diminuição dos eventos extremos de chuva e do número de dias úmidos consecutivos na região em estudo. Das regiões dos Niños, as TSM dos Niños 1+2 e 3 foram as que apresentaram melhores relações com os índices de precipitação do Município de Penedo.

Characterization of turbulent wake of wind turbine by coherent Doppler lidar

2014 ◽  
Author(s):  
Songhua Wu ◽  
Jiaping Yin ◽  
Bingyi Liu ◽  
Jintao Liu ◽  
Rongzhong Li ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbulent Wake ◽  
Doppler Lidar ◽  
Coherent Doppler Lidar

scholarly journals Low-Level Wind Shear Identification along the Glide Path at BCIA by the Pulsed Coherent Doppler Lidar

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 50
Author(s):  
Hongwei Zhang ◽  
Xiaoying Liu ◽  
Qichao Wang ◽  
Jianjun Zhang ◽  
Zhiqiang He ◽  
...  
Keyword(s):  
Wind Shear ◽  
Vertical Direction ◽  
Small Scale ◽  
Observation Data ◽  
Doppler Lidar ◽  
Low Level ◽  
Glide Path ◽  
Coherent Doppler Lidar ◽  
Scanning Strategies ◽  
Meteorological Phenomenon

Low-level wind shear is usually to be a rapidly changing meteorological phenomenon that cannot be ignored in aviation security service by affecting the air speed of landing and take-off aircrafts. The lidar team in Ocean University of China (OUC) carried out the long term particular researches on the low-level wind shear identification and regional wind shear inducement search at Beijing Capital International Airport (BCIA) from 2015 to 2020 by operating several pulsed coherent Doppler lidar (PCDL) systems. On account of the improved glide path scanning strategy and virtual multiple wind anemometers based on the rang height indicator (RHI) modes, the small-scale meteorological phenomenon along the glide path and/or runway center line direction can be captured. In this paper, the device configuration, scanning strategies, and results of the observation data are proposed. The algorithms to identify the low-level wind shear based on the reconstructed headwind profiles data have been tested and proved based on the lidar data obtained from December 2018 to January 2019. High spatial resolution observation data at vertical direction are utilized to study the regional wind shear inducement at the 36L end of BCIA under strong northwest wind conditions.

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