Results 31 to 40 of about 467 (182)

A Comparison of Atmospheric Boundary Layer Height Determination Methods Using GNSS Radio Occultation Data

Atmosphere, 2023
The accurate determination of Atmospheric Boundary Layer Height (ABLH) is crucial in various atmospheric studies and practical applications. In this study, we present a comprehensive comparative analysis of five distinct methods for estimating ABLH using
Cong Qiu, Xiaoming Wang, Haobo Li, Kai Zhou, Jinglei Zhang, Zhe Li, Dingyi Liu, Hong Yuan   +7 more
doaj   +1 more source

Ionospheric S4 Scintillations from GNSS Radio Occultation (RO) at Slant Path [PDF]

Remote Sensing, 2020
Ionospheric scintillation can significantly degrade the performance and the usability of space-based communication and navigation signals. Characterization and prediction of ionospheric scintillation can be made from the Global Navigation Satellite System (GNSS) radio occultation (RO) technique using the measurement from a deep slant path where the RO ...
openaire   +2 more sources

Tropical tropopause in Tibet: Insights from ground‐based global navigation satellite system and space‐based radio occultation observations

Meteorological Applications, 2022
Changes in the tropopause can explain regional and global weather and climate. In Tibet, there are few radiosonde stations, and the detection height is not high enough.
Guangwei Jiang, Yingying Shan, Chunxi Guo, Hong Zhao, Bin Wang, Dajiang Zhao   +5 more
doaj   +1 more source

Performance assessment of radio occultation data from GeoOptics by comparing with COSMIC data

Earth, Planets and Space, 2022
Responding to the ever-growing demand for environmental information, the National Oceanic and Atmospheric Administration (NOAA) seeks to enter into contracts to purchase Global Navigation Satellite System (GNSS) radio occultation (RO) observations ...
Hyeyeon Chang, Jiyun Lee, Hyosang Yoon, Y. Jade Morton, Alex Saltman   +4 more
doaj   +1 more source

A Machine Learning-Based Method for Wind Fields Forecasting Utilizing GNSS Radio Occultation Data

IEEE Access, 2022
With the development of computer technology and expanding environmental issues, machine learning has received more and more attention in the field of weather forecasting.
Xuezhao Chu, Weihua Bai, Yueqiang Sun, Wei Li, Congliang Liu, Hongqing Song   +5 more
doaj   +1 more source

Review of Assimilating Spaceborne Global Navigation Satellite System Remote Sensing Data for Tropical Cyclone Forecasting

Remote Sensing
Global Navigation Satellite System (GNSS) Radio Occultation (RO) and GNSS Reflectometry (GNSS-R) are the two major spaceborne GNSS remote sensing (GNSS-RS) techniques, providing observations of atmospheric profiles and the Earth’s surface. With the rapid
Weihua Bai, Guanyi Wang, Feixiong Huang, Yueqiang Sun, Qifei Du, Junming Xia, Xianyi Wang, Xiangguang Meng, Peng Hu, Cong Yin, Guangyuan Tan, Ruhan Wu   +11 more
doaj   +1 more source

Deep Reinforcement Learning Based Autonomous Decision‐Making for Cooperative Uncrewed Aerial Vehicles: A Search and Rescue Real World Application

Journal of Field Robotics, EarlyView.
ABSTRACT This paper presents the first end‐to‐end framework that combines guidance, navigation, and centralized task allocation for multiple UAVs performing autonomous search‐and‐rescue (SAR) in GNSS‐denied indoor environments. A twin delayed deep deterministic policy gradient controller is trained with an artificial potential field (APF) reward that ...
Thomas Hickling, Maxwell Hogan, Abdulla Tammam, Nabil Aouf   +3 more
wiley   +1 more source

Supervised Detection of Ionospheric Scintillation in Low-Latitude Radio Occultation Measurements

Remote Sensing, 2021
Global Navigation Satellite System (GNSS) Radio Occultation (RO) has provided high-quality atmospheric data assimilated in Numerical Weather Prediction (NWP) models and climatology studies for more than 20 years.
Vinícius Ludwig-Barbosa, Thomas Sievert, Anders Carlström, Mats I. Pettersson, Viet T. Vu, Joel Rasch   +5 more
doaj   +1 more source

Linear System Identification and Control of a Low‐Cost High‐Performance Omnidirectional Marine Surface Vehicle for Swarming Applications

Journal of Field Robotics, EarlyView.
ABSTRACT Marine operations traditionally rely on human intervention, a costly and disruptive method. Autonomous surface vehicles (ASVs) offer a powerful alternative, capable of operating autonomously, for extended periods, and with various sensors for various missions.
Ayman El Qemmah, Gianni Cario, Alessandro Casavola, Marco Lupia, Francesco Tedesco   +4 more
wiley   +1 more source

Stratospheric gravity waves in a post-limb sounder era: can GNSS-RO be used to extend the SABER QBO-driving record? [PDF]

Atmospheric Measurement Techniques
The quasi-biennial oscillation (QBO) is a slowly repeating cycle of winds which dominates tropical lower-stratospheric dynamics and has been described as the “heartbeat of the stratosphere”. However, it is challenging to represent in weather and climate
M. Almowafy, M. Almowafy, C. J. Wright, N. P. Hindley   +3 more
doaj   +1 more source