Filters








37 Hits in 8.2 sec

First Evaluation of Topography on GNSS-R: An Empirical Study Based on a Digital Elevation Model

Hugo Carreño-Luengo, Guido Luzi, Michele Crosetto
2019 Zenodo  
as a function of several topographic parameters derived from a digital elevation model (DEM).  ...  Understanding the effects of Earth's surface topography on Global Navigation Satellite Systems Reflectometry (GNSS-R) space-borne data is important to calibrate experimental measurements, so as to provide  ...  Acknowledgments: This research was carried out with the support grant of a Juan de la Cierva postdoctoral research fellowship from the Spanish Ministerio de Ciencia, Innovación y Universidades, reference  ... 
doi:10.5281/zenodo.3677079 fatcat:uresh3ir3jalznaa762xnv2aue

First Evaluation of Topography on GNSS-R: An Empirical Study Based on a Digital Elevation Model

Hugo Carreno-Luengo, Guido Luzi, Michele Crosetto
2019 Remote Sensing  
were evaluated as a function of several topographic parameters derived from a digital elevation model (DEM).  ...  Understanding the effects of Earth's surface topography on Global Navigation Satellite Systems Reflectometry (GNSS-R) space-borne data is important to calibrate experimental measurements, so as to provide  ...  Acknowledgments: This research was carried out with the support grant of a Juan de la Cierva postdoctoral research fellowship from the Spanish Ministerio de Ciencia, Innovación y Universidades, reference  ... 
doi:10.3390/rs11212556 fatcat:mi2cgsjvkrfd5lqeinh4lw66sy

Desert Roughness Retrieval Using CYGNSS GNSS-R Data

Donato Stilla, Mehrez Zribi, Nazzareno Pierdicca, Nicolas Baghdadi, Mireille Huc
2020 Remote Sensing  
This is based on a spatio-temporal analysis of variations in Cyclone Global Navigation Satellite System (CYGNSS) data, expressed as changes in reflectivity (Γ).  ...  The aim of this paper is to assess the potential use of data recorded by the Global Navigation Satellite System Reflectometry (GNSS-R) Cyclone Global Navigation Satellite System (CYGNSS) constellation  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/rs12040743 fatcat:canxynxsbbcpjpl6ptxbx2g6ou

Investigation on Geometry Computation of Spaceborne GNSS-R Altimetry over Topography: Modeling and Validation

Minfeng Song, Xiufeng He, Milad Asgarimehr, Weiqiang Li, Ruya Xiao, Dongzhen Jia, Xiaolei Wang, Jens Wickert
2022 Remote Sensing  
The results show that using the TanDEM-X 90 m Digital Elevation Model (DEM) as a reference, a slope of 0.6% at an elevation angle of 54 degrees can result in a geolocation inaccuracy of 10km and a height  ...  In this study, the effect of large-scale slope on the spaceborne GNSS-R technique is investigated.  ...  We are also grateful to the ICE/IEEC-CSIC for making the waveform data accessible at https://www.ice. csic.es/research/gold_rtr_mining (accessed on 1 July 2021).  ... 
doi:10.3390/rs14092105 fatcat:5n23xdryhzbbbnxxuuafqrwuaa

Initial results of China's GNSS-R airborne campaign: soil moisture retrievals

Wei Wan, Weihua Bai, Limin Zhao, Di Long, Yueqiang Sun, Xiangguang Meng, Hua Chen, Xiai Cui, Yang Hong
2015 Science Bulletin  
This paper presents a first comprehensive overview of China's airborne GNSS-R campaign conducted on May 30, 2014.  ...  The global navigation satellite system reflectometry (GNSS-R) technique has been proven to be a powerful tool for retrieving geophysical parameters of ocean and land/hydrology processes.  ...  Xinyi Shen from the University of Oklahoma and Dr. Peng Guo from the Shandong Agricultural University for their comments on discussing the vegetation effects.  ... 
doi:10.1007/s11434-015-0789-9 fatcat:mlswjrh7cjarjet5ecbqgvzofq

Geolocation, Calibration and Surface Resolution of CYGNSS GNSS-R Land Observations

Scott Gleason, Andrew O'Brien, Anthony Russel, Mohammad M. Al-Khaldi, Joel T. Johnson
2020 Remote Sensing  
Information on terrain topography is then compiled from the Shuttle Radar Topography Mission (SRTM) generated Digital Elevation Map (DEM) to generate a grid of local surface points surrounding the initial  ...  The resulting geolocation algorithm is first demonstrated using an example GNSS-R reflection track that passes over a variety of terrain conditions.  ...  Previous studies on GNSS-R land retrievals, coherent and incoherent scattering and the impact of topography on GNSS-R land observations can be found in [14] [15] [16] .  ... 
doi:10.3390/rs12081317 fatcat:y6px4hbvbrddphknj3bup4zvla

The IEEE-SA Working Group on Spaceborne GNSS-R: Scene Study

Hugo Carreno-Luengo, Adriano Camps, Chris Ruf, Nicolas Floury, Manuel Martin-Neira, Tianlin Wang, Siri Jodha Khalsa, Maria Paola Clarizia, Jennifer Reynolds, Joel Johnson, Andrew O'Brien, Carmela Galdi (+13 others)
2021 IEEE Access  
CRYOSPHERE At present, there is also an increasing number of GNSS-R applications in the cryosphere. 1) SNOW The first study on GNSS-R over thick dry snow masses was the theoretical investigation performed  ...  Simultaneously, the effects of swell on the EM bias were evaluated as a function of the elevation angle [72] .  ... 
doi:10.1109/access.2021.3089762 fatcat:4dx5adyg2fe7dnxeet62zjlcdi

First Results of a GNSS-R Experiment From a Stratospheric Balloon Over Boreal Forests

Hugo Carreno-Luengo, Adriano Camps, Jorge Querol, Giuseppe Forte
2016 IEEE Transactions on Geoscience and Remote Sensing  
This experiment has provided the first GNSS-R data set over boreal forests.  ...  The bistatic coherent reflectivity is also evaluated as a function of the elevation angle, showing a decrease of ∼6 dB when the elevation angle increases from 35 • to 70 • .  ...  In the case of GNSS-R bistatic reflections over a forest area, a scattering model considering both the coherent and incoherent fields was proposed [30] .  ... 
doi:10.1109/tgrs.2015.2504242 fatcat:3deciaanivd6haa6youdxzq4xq

Sensitivity of TDS-1 GNSS-R Reflectivity to Soil Moisture: Global and Regional Differences and Impact of Different Spatial Scales

Adriano Camps, Mercedes Vall·llossera, Hyuk Park, Gerard Portal, Luciana Rossato
2018 Remote Sensing  
The sensitivity of different GNSS-R observables to SM and its dependence on the incidence angle is analyzed.  ...  The potential of Global Navigation Satellite Systems-Reflectometry (GNSS-R) techniques to estimate land surface parameters such as soil moisture (SM) is experimentally studied using 2014–2017 global data  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/rs10111856 fatcat:67ac7kakzbfxbc6m47jgmgvahe

On the Synergy of Airborne GNSS-R and Landsat 8 for Soil Moisture Estimation

Nilda Sánchez, Alberto Alonso-Arroyo, José Martínez-Fernández, María Piles, Ángel González-Zamora, Adriano Camps, Mercè Vall-llosera
2015 Remote Sensing  
The Light Airborne Reflectometer for GNSS-R Observations (LARGO) observations, together with optical, infrared, and thermal bands from Landsat 8, were linked through a semi-empirical model to field soil  ...  The objective was to evaluate the combined use of GNSS-R observations with a time-collocated Landsat 8 image for soil moisture retrieval under semi-arid climate conditions.  ...  Marí a Piles and Mercè Vall-llosera provided the model rationale and contributed to the methodology and the results.  ... 
doi:10.3390/rs70809954 fatcat:a5vncxlie5g2tojvnausf4hhf4

Spaceborne GNSS Reflectometry

Kegen Yu, Shuai Han, Jinwei Bu, Yuhang An, Zhewen Zhou, Changyang Wang, Sajad Tabibi, Joon Wayn Cheong
2022 Remote Sensing  
This article presents a review on spaceborne Global Navigation Satellite System Reflectometry (GNSS-R), which is an important part of GNSS-R technology and has attracted great attention from academia,  ...  This article provides an overview of these studies with a focus on the basic methods and techniques in the retrieval of a number of geophysical parameters and the detection of several objects.  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/rs14071605 fatcat:k7kh5pb4tje3rhved3trrofabu

Airborne GNSS Reflectometry for Water Body Detection

Hamza Issa, Georges Stienne, Serge Reboul, Mohamad Raad, Ghaleb Faour
2021 Remote Sensing  
A GNSS-R setup on-board a carrier with reduced size and weight was developed for this application.  ...  This article is dedicated to the study of airborne GNSS-R signal processing techniques for water body detection and edge localization using a low-altitude airborne carrier with high rate reflectivity measurements  ...  Acknowledgments: The authors would like to acknowledge the Université du Littoral Côte d'Opale (ULCO) and the National Council for Scientific Research of Lebanon (CNRS-L) for granting a joint doctoral  ... 
doi:10.3390/rs14010163 fatcat:wfrjgdau3fcclf6axacvjtpix4

Comprehensive Evaluation of Using TechDemoSat-1 and CYGNSS Data to Estimate Soil Moisture over Mainland China

Ting Yang, Wei Wan, Zhigang Sun, Baojian Liu, Sen Li, Xiuwan Chen
2020 Remote Sensing  
This study is the first to compare and evaluate the performance of the only two spaceborne GNSS-R satellite missions whose data are publicly available, i.e., the UK's TechdemoSat-1 (TDS-1) and the US's  ...  Spaceborne Global Navigation Satellite System Reflectometry (GNSS-R) provides a new opportunity for land observation.  ...  Conflicts of Interest: The authors declare no conflicts of interest.  ... 
doi:10.3390/rs12111699 fatcat:4w6wn3ootrdche3oholth2ljci

Computation Approach for Quantitative Dielectric Constant from Time Sequential Data Observed by CYGNSS Satellites

Junchan Lee, Sunil Bisnath, Regina S.K. Lee, Narin Gavili Kilane
2021 Remote Sensing  
Data from the Cyclone Global Navigation Satellite System (CYGNSS) mission, an eight-nanosatellite constellation for GNSS-R, are used for computing dielectric constant.  ...  This paper describes a computation method for obtaining dielectric constant using Global Navigation Satellite System reflectometry (GNSS-R) products.  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/rs13112032 fatcat:rtotjx6hrvh6jkrbywp25lp5aa

Machine Learning-Based CYGNSS Soil Moisture Estimates over ISMN sites in CONUS

Volkan Senyurek, Fangni Lei, Dylan Boyd, Mehmet Kurum, Ali Cafer Gurbuz, Robert Moorhead
2020 Remote Sensing  
In addition, both a site-independent and a year-based validation techniques demonstrate satisfactory accuracy of the proposed ML model, suggesting that this SM approach can be generalized in space and  ...  Bistatic Global Navigation Satellite System (GNSS) Reflectometry (GNSS-R) has emerged in recent years as a new domain of microwave remote sensing with great potential for SM retrievals, particularly at  ...  The topographic information, known to greatly affect the reflectivity of GNSS-R signals [29] , is derived from the 1 km Digital Elevation Model GTOPO30 product.  ... 
doi:10.3390/rs12071168 fatcat:3h7opww2tbfhraleeju3esgauy
« Previous Showing results 1 — 15 out of 37 results