搜索结果: 1-15 共查到“工学 Doppler”相关记录28条 . 查询时间(0.046 秒)
WHIRL WIND DETECTION AND IDENTIFICATION IN INDONESIA UTILIZING SINGLE POLARIZATION DOPPLER WEATHER RADAR VOLUMETRIC DATA
whirl wind remote sensing weather radar radial velocity reflectivity spectral width
2016/12/1
Whirl wind occurrence frequency in Indonesia tends increasing in the last five years. Geospatial data from National Agency for Disaster Management (BNPB) recorded 72 cases with the impact of the two v...
二维光子晶体中反常Doppler效应的相位演变
光子晶体 反常Doppler效应 负折射 相位演变
2017/2/27
光在具有负等效折射率的二维光子晶体中传输时会产生反常Doppler现象，为了分析光在该反常效应中传输时的相位变化，首先用时域有限差分（FDTD）法仿真了光经过静止光子晶体时的负折射现象，然后对光子晶体中沿光传输方向的Bloch波做快速傅里叶（FFT）处理。对滤波后的频谱，用iFFT反演出各平面波分量，并通过分析各平面波分量的相位演变，分离出与负折射产生有关的后退波分量。然后，将实验中的连续运动过程...
Visualization of Space-borne Synthetic Aperture Radar (SAR) Doppler Parameter Estimation and Its Application in Topographic Surveying and Mapping
Remote Sensing SAR Image Correction Geodesy Application
2015/12/2
Synthetic Aperture Radar (SAR) image is not easy to interpretation because of its image unique characters, and there is a close relationship between the Doppler parameter and the quality of SAR image,...
Performance Analysis and Experimental Validation of a Doppler-Aided GPS/INS Receiver for JPALS Applications
Doppler-Aided GPS/INS Receiver JPALS Applications
2015/6/26
The Joint Precision Approach and Landing System (JPALS) is the next generation aircraft precision approach and landing system being sponsored by US Department of Defense. This GPS-based system will pr...
Performance of a Doppler-Aided GPS Navigation System for Aviation Applications under Ionospheric Scintillation
Performance Doppler-Aided GPS Navigation System Aviation Applications Ionospheric Scintillation
2015/6/25
Aircraft landing using the Global Positioning System (GPS) in equatorial regions is more difficult than in other regions because ionospheric scintillation is prevalent.Ionospheric scintillation causes...
Doppler on Wheels--the biggest 'dish' on the road!
Doppler on Wheels the biggest dish on the road
2015/5/25
For nearly a decade, with support from the National Science Foundation (NSF), Doppler on Wheels (DOW) has been doing its best work in dangerous weather, driving into the eye of the storm to gather sci...
JOINT OFFSHORE WIND FIELD MONITORING WITH SPACEBORNE SAR AND PLATFORM-BASED DOPPLER LIDAR MEASUREMENTS
SAR, Wind Energy Turbine Wake LiDAR
2015/5/7
The increasing demand for renewable energy resources has promoted the construction of offshore wind farms e.g. in the North Sea. While the wind farm layout consists of an array of large turbines, th...
针对实时动态PPP中常常会遇到卫星信号中断或大部分卫星发生周跳而导致重新初始化的问题，可以将GNSS信号短时间中断看作是全部卫星发生周跳，通过研究Doppler观测值在快速重新初始化中的观测模型，进而提出联合伪距、相位、Doppler观测值及电离层延迟变化约束信息的数学模型，对于发生周跳的卫星，通过将周跳参数固定为整数以实现动态PPP快速重新初始化。根据实际算例，从多个角度进行统计分析表明引入Do...
Assimilating Doppler radar radial velocity and reflectivity observations in the weather research and forecasting model by a proper orthogonal-decomposition-based ensemble, three-dimensional variational assimilation method
Assimilating Doppler radar radial velocity and reflectivity observations in the weather research and forecasting model proper orthogonal-decomposition-based ensemble three-dimensional variational assimilation method
2013/9/2
Doppler radar observations with high spatial and temporal resolution can effectively improve the description of small-scale structures in the initial condition and enhance the mesoscale and microscale...
GPS/Doppler导航随机模型的移动窗口实时估计算法
GPS/Doppler 随机模型 单位权方差 稳健估计
2011/8/1
GPS/Doppler随机模型对导航解算结果有重要影响，动态条件下需要实时估计随观测条件而变化的随机模型。本文引进了时间遗忘因子和观测冗余度因子，有效地平衡了移动窗口内不同时刻的观测数据及其冗余情况对单位权方差估值的贡献，改进了单位权方差的移动开窗实时估计算法；并采用载噪比模型确定观测权阵，等价权抗差估计方法处理粗差。实测车载GPS/Doppler数据的处理结果表明：采用本文算法显著提高了GPS/...
一种解大旋翼类雷达目标微Doppler模糊的方法
沿航迹干涉技术 时频变换 微多普勒模糊 旋转部件
2014/4/14
在单通道模式下，当雷达目标旋转半径比较大时，脉冲重复频率与微多普勒带宽之间可能会出现欠采样的情形，导致在时频面上发生微多普勒混叠，从而不能得到完整的微多普勒信息。针对此问题，提出了一种基于双通道干涉处理的解大旋翼类雷达目标微多普勒模糊的方法。文中详细推导了该模式下此类目标引起的微多普勒频率和微多普勒带宽的参数化表达式，分析表明其微多普勒带宽受一个正弦因子的调制而显著减小，从而使其满足香农采样定理，...
Vector Velocity Estimation In Doppler Radar Networks
Applied sciences Pure sciences Earth sciences Estimation Mesoscale Networks Radar Velocity Wind
2014/11/7
This document presents an approach using the maximum likelihood formulation to estimate vector velocities in real-time by a network of Doppler radars. Relationships between the estimated vector veloci...
Nonlinear dynamic analysis of mitral valve doppler signals: surrogate data analysis
Doppler mitral valve largest lyapunov exponent correlation dimension surrogate data ROC
2010/10/12
In our study, the nonlinear dynamics of mitral valve Doppler signals from 32 healthy and 28 patients with mitral valve stenosis was evaluated using by the computation of Lyapunov exponents, correlatio...
MEASUREMENT OF PHASE INTERACTION IN DISPERSED GAS-PARTICLE TWO-PHASE FLOW BY PHASE-DOPPLER ANEMOMETRY
phase-Doppler anemometry gas-particle turbulence
2009/10/14
For simultaneous measurement of size and velocity distributions of continuous and dispersed phases in a two-phase flow a technique phase-Doppler anemometry was used. Spherical glass particles with a p...
COMPARISON OF VELOCITY MEASUREMENTS BY HIGH TEMPERATURE ANEMOMETER AND LASER-DOPPLER ANEMOMETER WITH RESULTS OF CFD-SIMULATION
velocity measurement HTA LDA
2009/10/13
In the present work, results of gas velocity measurements with a newly developed vane anemometer (HTA - High-Temperature-Anemometer) are compared with results of measurements obtained from Laser Doppl...