Results 31 to 40 of about 19,851 (292)

Simulation Analysis of the Geometric Positioning Accuracy for MEO- and HEO-SAR Satellites

Remote Sensing, 2023
Due to the long synthetic aperture time, the large squint angle, and the large imaging width of medium Earth orbit (MEO) and high Earth orbit (HEO) SAR satellites, it is difficult to simulate the geometric positioning accuracy of MEO- and HEO-SAR ...
Ruishan Zhao, Ning Yang, Guo Zhang, Liang Pei, Jiguang Dai, Bing Zhang   +5 more
doaj   +1 more source

INS, cross sensing loop, Doppler radar, and GNSS positioning data.

, 2023
INS, cross sensing loop, Doppler radar, and GNSS positioning data.
Yiwei Xu (6651245), Qian Hu (205735), Kuangang Fan (17468338), Haoqi Guo (13878812)   +3 more
core   +1 more source

Semi-dynamical Doppler satellite positioning

Bulletin Géodésique, 1976
In semi-dynamical satellite geodesy, the satellite orbit is determined beforehand by dynamical methods, and tracking station coordinates are determined geometrically from satellite observations and the accepted satellite coordinates. This paper analyzes the use of the U.S.
J. Kouba, D. E. Wells
openaire   +2 more sources

Structure and Performance Analysis of Signal Acquisition and Doppler Tracking in LEO Augmented GNSS Receiver

Sensors, 2021
Due to the low signal power, the Global Navigation Satellite System (GNSS) signal is vulnerable to interference and even cannot be captured or tracked in harsh environments.
Li Cheng, Yonghong Dai, Wenfei Guo, Jiansheng Zheng   +3 more
doaj   +1 more source

Research on Multi-Parameter Optimization of Indoor WiFi Positioning Technology [PDF]

Jisuanji gongcheng, 2021
The existing WiFi-based indoor positioning technology is affected by the number of antennas and channel bandwidth, and has the problems of low positioning accuracy and frequent tracking failures.To address the problem, a multi-parameter indoor passive ...
WANG Yingying, CHANG Jun, WU Hao
doaj   +1 more source

Precise Position Estimation Using Smartphone Raw GNSS Data Based on Two-Step Optimization

Sensors, 2023
This paper presents a high-precision positioning method using raw global navigation satellite system (GNSS) observations from smartphones in the Google smartphone decimeter challenge (GSDC).
Taro Suzuki
doaj   +1 more source

Doppler measurement integration for kinematic real-time GPS positioning [PDF]

, 2010
The present paper discusses the advantages of the use of Doppler shift measurements in a Kalman filter estimator in order to improve the kinematic stand-alone global positioning system positioning performance.
Gianluca Marucco, DE AGOSTINO, MATTIA, Mattia De Agostino, Marucco G., Ambrogio Manzino, MANZINO, AMBROGIO   +5 more
core   +1 more source

False-positive diagnosis of pulmonary hypertension by Doppler echocardiography [PDF]

European Respiratory Journal, 1998
A 37-yr-old female presented with a history of several months of exertional dyspnoea. A diagnosis of primary pulmonary hypertension was suspected on the basis of a negative extensive cardiorespiratory work-up with a systolic pulmonary artery pressure of 41-46 mmHg calculated from repeated measurement of the maximum velocity of tricuspid regurgitation ...
Vachiery, Jean-Luc, Brimioulle, Serge, Crasset, Vincent, Naeije, Robert   +3 more
openaire   +3 more sources

XLVII. The Doppler effect in positive rays [PDF]

The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 1909
n ...
openaire   +1 more source

A novel drifter designed for use with a mounted Acoustic Doppler Current Profiler in shallow environments

, 2013
We present a novel design for a surface drifter, mounted with a pulse-coherent Acoustic Doppler Current Profiler (ADCP) for measuring near-surface (depths 0.18-1 m) flows.
Mullarney, Julia C., Henderson, Stephen M.   +1 more
core   +1 more source