Filters








544 Hits in 12.0 sec

Space-based Sub-THz ISAR for Space Situational Awareness Concept and Design

Emidio Marchetti, Andrew G. Stove, Edward G. Hoare, Mikhail Cherniakov, David Blacknell, Marina Gashinova
2021 IEEE Transactions on Aerospace and Electronic Systems  
A feasibility study is presented based on use case scenarios of the relative motion of monitoring satellite and observed objects.  ...  A simple electromagnetic modeling capability is proposed to create a comprehensive dataset of sub-THz ISAR images, with the orientation and aspect angles seen by the sensors, which can be used to train  ...  ACKNOWLEDGEMENT This work is sponsored by the Defense Science and Technology Laboratory (DSTL), United Kingdom, as part of the Defense and Security Accelerator (DASA) competition, contract number: DSTLX1000141364  ... 
doi:10.1109/taes.2021.3126375 fatcat:kakj6ybgebcwniful5dxphhnxy

New Opportunities for Forest Remote Sensing Through Ultra-High-Density Drone Lidar

James R. Kellner, John Armston, Markus Birrer, K. C. Cushman, Laura Duncanson, Christoph Eck, Christoph Falleger, Benedikt Imbach, Kamil Král, Martin Krůček, Jan Trochta, Tomáš Vrška (+1 others)
2019 Surveys in geophysics  
Analysis of surface elevation measurements on a heterogeneous target observed 51 days apart indicates that the realized range accuracy is 2.4 cm. The single-date precision is 2.1-4.5 cm.  ...  Low-altitude flight using drones enables the collection of ultra-high-density point clouds using wider laser scan angles than have been possible from traditional airborne platforms.  ...  Acknowledgements This research was funded by Brown University and the National Aeronautics and Space Administration of the United States of America.  ... 
doi:10.1007/s10712-019-09529-9 pmid:31395993 pmcid:PMC6647463 fatcat:cs2r4y52ive73mlibznn3tibhe

Passive localization of moving emitters using out-of-plane multipath

S.D. Coutts
2000 IEEE Transactions on Aerospace and Electronic Systems  
This is a novel localization technique that assumes no a priori knowledge of the location of the multipath sources.  ...  The Cramer-Rao lower bounds of the variances for each estimator are derived and used to study estimator performance for several scenarios.  ...  The Doppler terms computed in this report were based on a flat-earth approximation. Future work could include a reformulation of the geometry using site-specific digital elevation data.  ... 
doi:10.1109/7.845246 fatcat:i6pnfsjbkjf47gdiw4vv7vi6sm

Comparative Study of Optimal Multivariable LQR and MPC Controllers for Unmanned Combat Air Systems in Trajectory Tracking

Alvaro Ortiz, Sergio Garcia-Nieto, Raul Simarro
2021 Electronics  
For this purpose, a novel dynamic trajectory-planning algorithm is employed, which can obtain an appropriate trajectory by analyzing the environment as a discrete 3D adaptive mesh and performs a softening  ...  Guidance, navigation, and control system design is, undoubtedly, one of the most relevant issues in any type of unmanned aerial vehicle, especially in the case of military missions.  ...  Acknowledgments: The authors would like to thank the editors and the reviewers for their valuable time and constructive comments.  ... 
doi:10.3390/electronics10030331 fatcat:fk63nplvlfahloe3pvzvwtsumi

Full profile incoherent scatter analysis at Jicamarca

D. L. Hysell, F. S. Rodrigues, J. L. Chau, J. D. Huba
2008 Annales Geophysicae  
</strong> Incoherent scatter data from a hybrid long-pulse/double-pulse experiment at Jicamarca are analyzed using a full-profile analysis similar to the one implemented by Holt et al. (1992).  ...  Results for a 24 h interval in April of 2006 are presented, covering altitudes through 1600 km with 10 min time resolution, and compared with results from the NRL ionospheric model SAMI2.  ...  The Jicamarca Radio Observatory is a facility of the Instituto Geofisíco del Perú operated with support from NSF cooperative agreement ATM-0432565 through Cornell University. Topical Editor M.  ... 
doi:10.5194/angeo-26-59-2008 fatcat:2mk3b5eykrcbjidb6yjwzqbjre

2015 Index IEEE Transactions on Geoscience and Remote Sensing Vol. 53

2015 IEEE Transactions on Geoscience and Remote Sensing  
., +, TGRS Jan. 2015 324-334 A Self-Adaptive Wavelet-Based Algorithm for Wave Measurement Using Nautical Radar.  ...  ., +, TGRS March 2015 1355-1363 A Self-Adaptive Wavelet-Based Algorithm for Wave Measurement Using Nautical Radar.  ...  Radiofrequency interference A Methodology to Determine Radio-Frequency Interference in AMSR2 Observations.  ... 
doi:10.1109/tgrs.2015.2513444 fatcat:zuklkpk4gjdxjegoym5oagotzq

Compressed sensing application in interferometric synthetic aperture radar

Liechen Li, Daojing Li, Zhouhao Pan
2017 Science China Information Sciences  
A novel interferometric synthetic aperture radar (InSAR) signal processing method based on compressed sensing (CS) theory is investigated in this paper.  ...  By solving the CS inverse problem, the magnitude image and interferometric phase are generated at the same time. Results on both the simulated data and real data are presented.  ...  Conflict of interest The authors declare that they have no conflict of interest.  ... 
doi:10.1007/s11432-016-9017-6 fatcat:34i32zwzmjbgrlwr7ywpg4bcp4

A Unified Airspace Risk Management Framework for UAS Operations

Suraj Bijjahalli, Alessandro Gardi, Nichakorn Pongsakornsathien, Roberto Sabatini, Trevor Kistan
2022 Drones  
To address the existing gaps in the current airspace risk assessment models, this article proposes a comprehensive risk management framework, which relies on a novel methodology to model UAS collision  ...  This new risk assessment methodology is based on rigorous analysis of the CNS error characteristics and the transformation of the associated models into the spatial domain to generate a protection volume  ...  Acknowledgements: Parts of the study reported in this paper are derived from an Airspace Risk Modelling research report prepared by RMIT for the Civil Aviation Safety Authority (CASA) in 2020.  ... 
doi:10.3390/drones6070184 fatcat:j7e4oqb2sfawro5b4bhy5cpt3a

Alfvén waves underlying ionospheric destabilization: ground-based observations

Michael Hirsch, Joshua Semeter
2017 Zenodo  
A modified version of the algorithm is applied to topside ionospheric radar at Mars and broadcast FM passive radar. The fusion of data from coher [...]  ...  A network of tightly synchronized tomographic auroral observatories using model based iterative reconstruction (MBIR) techniques were developed in this dissertation.  ...  A method for solving such problems via brute force is the use of minimization algorithms (Semeter and Mendillo, 1997) .  ... 
doi:10.5281/zenodo.3239515 fatcat:k2iwfs6cwvewfel7cgw6rsfdd4

Generative Adversarial Networks Capabilities for Super-Resolution Reconstruction of Weather Radar Echo Images

Chen, Zhang, Liu, Zeng
2019 Atmosphere  
using GAN to tackle the problem of weather radar echo super-resolution to achieve better reconstruction performance (measured in peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM  ...  Using authentic weather radar echo data, we present the experimental results and compare its reconstruction performance with the above-mentioned methods.  ...  Acknowledgments: We want to acknowledge the Guangdong Meteorological Bureau and the Chinese Academy of Meteorological Sciences for providing the weather radar data used in this study.  ... 
doi:10.3390/atmos10090555 fatcat:5kvh5feqaff3zmc4q5u2p4eqze

National Center for Atmospheric Research

1999 Disaster Prevention and Management  
., 1998: On the minimum useful elevation angle for weather surveillance radar scans. J. Atmos. and Oceanic Technol., 15, 841-843. [Moderate impact, radar data quality issue for low elevation angles.  ...  The method was found to be useful when the radar data are available at a single or very few elevation angles.  ...  For rain this consistency can be used to calibrate the reflectivity (Z) of the radar to within 0.5 dB, providing the correct rain drop shape model is used.  ... 
doi:10.1108/dpm.1999.07308aag.036 fatcat:3ah6tzr4k5gilhcbhqlfzkzcfa

The National Center for Atmospheric Research

1999 Disaster Prevention and Management  
., 1998: On the minimum useful elevation angle for weather surveillance radar scans. J. Atmos. and Oceanic Technol., 15, 841-843. [Moderate impact, radar data quality issue for low elevation angles.  ...  The method was found to be useful when the radar data are available at a single or very few elevation angles.  ...  For rain this consistency can be used to calibrate the reflectivity (Z) of the radar to within 0.5 dB, providing the correct rain drop shape model is used.  ... 
doi:10.1108/dpm.1999.07308aag.035 fatcat:lys575gn4vcfhghzsruwmnjqy4

Monitoring of Soil Salinization in the Keriya Oasis Based on Deep Learning with PALSAR-2 and Landsat-8 Datasets

Adilai Abulaiti, Ilyas Nurmemet, Nuerbiye Muhetaer, Sentian Xiao, Jing Zhao
2022 Sustainability  
The random forest (RF)-integrated learning algorithm is used to select the optimal feature subset composed of eight polarimetric elements.  ...  The radar vegetation index (RVI) is calculated using PALSAR-2 data, while the normalized difference vegetation index (NDVI) and salinity index (SI) are calculated using OLI data.  ...  Acknowledgments: We extend our hearty gratitude to the anonymous reviewers of this manuscript for their constructive comments and helpful suggestions provided during the preparation.  ... 
doi:10.3390/su14052666 fatcat:f33p6kaiifgpjnup2zs4pksyzu

Integrated Sensor Systems and Data Fusion for Homeland Protection [chapter]

Alfonso Farina, Luciana Ortenzi, Branko Ristic, Alex Skvortsov
2014 Academic Press Library in Signal Processing: Volume 2 - Communications and Radar Signal Processing  
The first data fusion algorithms employed in real systems in the radar field go back to the early seventies, when they had been developed for multi-radar tracking (MRT) for netted sensors.  ...  Most of the algorithms developed for quantitative fusion are based on Bayes filter [3], as Kalman filter [4], information filter [5] and neural networks.  ...  Graziano (SELEX Sistemi Integrati) for the continuous and fruitful cooperation on the many topics described in the Chapter for years.  ... 
doi:10.1016/b978-0-12-396500-4.00022-3 fatcat:gwnm3a2l5nh4dhheaxc7su5eni

Fast Distributed Multiple-Model Nonlinearity Estimation for Tracking the Non-Cooperative Highly Maneuvering Target

Fansen Zhou, Yidi Wang, Wei Zheng, Zhao Li, Xin Wen
2022 Remote Sensing  
Compared with ground-based radars, satellite tracking platforms equipped with Synthetic Aperture Radars (SARs) have a wide detection range, and can keep the targets in custody, making them a promising  ...  This approach first requires each satellite to perform local filtering based on its own single model, and the corresponding fusion factor derived by the Wasserstein distance is solved for each local estimate  ...  As shown in Figure 1 , a single satellite can provide two measurements of the target through processing SAR images, consisting of the azimuth, φ, and the elevation angle, θ.  ... 
doi:10.3390/rs14174239 fatcat:luodgmkldfb7bpevqlks3fjajm
« Previous Showing results 1 — 15 out of 544 results