PAU/GNSS-R: Implementation, Performance and First Results of a Real-Time Delay-Doppler Map Reflectometer Using Global Navigation Satellite System Signals
Signals from Global Navigation Satellite Systems (GNSS) were originally conceived for position and speed determination, but they can be used as signals of opportunity as well. The reflection process over a given surface modifies the properties of the scattered signal, and therefore, by processing th...
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ftpubmed:oai:pubmedcentral.nih.gov:3675528 2023-05-15T18:18:52+02:00 PAU/GNSS-R: Implementation, Performance and First Results of a Real-Time Delay-Doppler Map Reflectometer Using Global Navigation Satellite System Signals Marchan-Hernandez, Juan Fernando Camps, Adriano Rodriguez-Alvarez, Nereida Bosch-Lluis, Xavier Ramos-Perez, Isaac Valencia, Enric 2008-05-06 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3675528 https://doi.org/10.3390/s8053005 en eng Molecular Diversity Preservation International (MDPI) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3675528 http://dx.doi.org/10.3390/s8053005 © 2008 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland. This article is an open-access article distributed under the terms and conditions of the CreativeCommons Attribution license (http://creativecommons.org/licenses/by/3.0/). CC-BY Article Text 2008 ftpubmed https://doi.org/10.3390/s8053005 2013-09-05T00:46:49Z Signals from Global Navigation Satellite Systems (GNSS) were originally conceived for position and speed determination, but they can be used as signals of opportunity as well. The reflection process over a given surface modifies the properties of the scattered signal, and therefore, by processing the reflected signal, relevant geophysical data regarding the surface under study (land, sea, ice…) can be retrieved. In essence, a GNSS-R receiver is a multi-channel GNSS receiver that computes the received power from a given satellite at a number of different delay and Doppler bins of the incoming signal. The first approaches to build such a receiver consisted of sampling and storing the scattered signal for later post-processing. However, a real-time approach to the problem is desirable to obtain immediately useful geophysical variables and reduce the amount of data. The use of FPGA technology makes this possible, while at the same time the system can be easily reconfigured. The signal tracking and processing constraints made necessary to fully design several new blocks. The uniqueness of the implemented system described in this work is the capability to compute in real-time Delay-Doppler maps (DDMs) either for four simultaneous satellites or just one, but with a larger number of bins. The first tests have been conducted from a cliff over the sea and demonstrate the successful performance of the instrument to compute DDMs in real-time from the measured reflected GNSS/R signals. The processing of these measurements shall yield quantitative relationships between the sea state (mainly driven by the surface wind and the swell) and the overall DDM shape. The ultimate goal is to use the DDM shape to correct the sea state influence on the L-band brightness temperature to improve the retrieval of the sea surface salinity (SSS). Text Sea ice PubMed Central (PMC) Sensors 8 5 3005 3019 |
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Article Marchan-Hernandez, Juan Fernando Camps, Adriano Rodriguez-Alvarez, Nereida Bosch-Lluis, Xavier Ramos-Perez, Isaac Valencia, Enric PAU/GNSS-R: Implementation, Performance and First Results of a Real-Time Delay-Doppler Map Reflectometer Using Global Navigation Satellite System Signals |
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Article |
description |
Signals from Global Navigation Satellite Systems (GNSS) were originally conceived for position and speed determination, but they can be used as signals of opportunity as well. The reflection process over a given surface modifies the properties of the scattered signal, and therefore, by processing the reflected signal, relevant geophysical data regarding the surface under study (land, sea, ice…) can be retrieved. In essence, a GNSS-R receiver is a multi-channel GNSS receiver that computes the received power from a given satellite at a number of different delay and Doppler bins of the incoming signal. The first approaches to build such a receiver consisted of sampling and storing the scattered signal for later post-processing. However, a real-time approach to the problem is desirable to obtain immediately useful geophysical variables and reduce the amount of data. The use of FPGA technology makes this possible, while at the same time the system can be easily reconfigured. The signal tracking and processing constraints made necessary to fully design several new blocks. The uniqueness of the implemented system described in this work is the capability to compute in real-time Delay-Doppler maps (DDMs) either for four simultaneous satellites or just one, but with a larger number of bins. The first tests have been conducted from a cliff over the sea and demonstrate the successful performance of the instrument to compute DDMs in real-time from the measured reflected GNSS/R signals. The processing of these measurements shall yield quantitative relationships between the sea state (mainly driven by the surface wind and the swell) and the overall DDM shape. The ultimate goal is to use the DDM shape to correct the sea state influence on the L-band brightness temperature to improve the retrieval of the sea surface salinity (SSS). |
format |
Text |
author |
Marchan-Hernandez, Juan Fernando Camps, Adriano Rodriguez-Alvarez, Nereida Bosch-Lluis, Xavier Ramos-Perez, Isaac Valencia, Enric |
author_facet |
Marchan-Hernandez, Juan Fernando Camps, Adriano Rodriguez-Alvarez, Nereida Bosch-Lluis, Xavier Ramos-Perez, Isaac Valencia, Enric |
author_sort |
Marchan-Hernandez, Juan Fernando |
title |
PAU/GNSS-R: Implementation, Performance and First Results of a Real-Time Delay-Doppler Map Reflectometer Using Global Navigation Satellite System Signals |
title_short |
PAU/GNSS-R: Implementation, Performance and First Results of a Real-Time Delay-Doppler Map Reflectometer Using Global Navigation Satellite System Signals |
title_full |
PAU/GNSS-R: Implementation, Performance and First Results of a Real-Time Delay-Doppler Map Reflectometer Using Global Navigation Satellite System Signals |
title_fullStr |
PAU/GNSS-R: Implementation, Performance and First Results of a Real-Time Delay-Doppler Map Reflectometer Using Global Navigation Satellite System Signals |
title_full_unstemmed |
PAU/GNSS-R: Implementation, Performance and First Results of a Real-Time Delay-Doppler Map Reflectometer Using Global Navigation Satellite System Signals |
title_sort |
pau/gnss-r: implementation, performance and first results of a real-time delay-doppler map reflectometer using global navigation satellite system signals |
publisher |
Molecular Diversity Preservation International (MDPI) |
publishDate |
2008 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3675528 https://doi.org/10.3390/s8053005 |
genre |
Sea ice |
genre_facet |
Sea ice |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3675528 http://dx.doi.org/10.3390/s8053005 |
op_rights |
© 2008 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland. This article is an open-access article distributed under the terms and conditions of the CreativeCommons Attribution license (http://creativecommons.org/licenses/by/3.0/). |
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CC-BY |
op_doi |
https://doi.org/10.3390/s8053005 |
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