Wind speed measurement using forward scattered GPS signals

Garrison, James L.; Komjáthy, A.; Zavorotny, Valery U.; Katzberg, Stephen J.

doi:10.1109/36.981349

Cited by 295 publications

(151 citation statements)

References 20 publications

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“…The model used in our implementation is based on Zavorotny and Voronovich (2000), Garrison et al (2002), and Martín-Neira et al (2011). The complex Y x and Y y signals are divided into consecutive coherent integration periods of length T c = 1 ms, to compute the complex cross-correlation Z xy as defined in Eq.…”

Section: Signal Modelmentioning

confidence: 99%

Altimetry with GNSS-R interferometry: first proof of concept experiment

et al. 2011

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The Global Navigation Satellite System Reflectometry (GNSS-R) concept was conceived as a means to densify radar altimeter measurements of the sea surface. Until now, the GNSS-R concept relied on open access to GNSS transmitted codes. Recently, it has been proposed that the ranging capability of the technique for ocean altimetric applications can be improved by using all the signals transmitted in the bandwidth allocated to GNSS, which includes open access as well as encrypted signals.The main objective of this study is to provide experimental proof of this enhancement through a 2-day experiment on the Zeeland Bridge (The Netherlands). In the experiment, we used a custom built GNSS-R system, composed of high gain GPS antennas, calibration subsystem, and an FPGAbased signal processor which implemented the new concepts, an X-band radar altimeter and a local geodetic network. The results obtained indicate that the new approach produces a significant improvement in GNSS-R altimetric performance.

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Section: Signal Modelmentioning

confidence: 99%

Altimetry with GNSS-R interferometry: first proof of concept experiment

et al. 2011

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“…There are different data acquisition techniques [5]: Conventional GNSS-R (cGNSS-R) [6], interferometric GNSS-R (iGNSS-R) [7], and reconstructed-code GNSS-R (rGNSS-R) [8]. At present, data collected by the Surrey Satellite Technology Ltd SSTL's TechDemoSat-1 mission [9] are being processing by the community.…”

Section: Introductionmentioning

confidence: 99%

First Polarimetric GNSS-R Measurements from a Stratospheric Flight over Boreal Forests

et al. 2015

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Abstract:The first-ever dual-frequency multi-constellation Global Navigation Satellite Systems Reflectometry (GNSS-R) polarimetric measurements over boreal forests and lakes from the stratosphere are presented. Data were collected during the Swedish National Space Board (SNSB)/European Space Agency (ESA) sponsored Balloon Experiments for University Students (BEXUS) 19 stratospheric balloon experiment using the P(Y) and C/A ReflectOmeter (PYCARO) instrument operated in closed-loop mode. Maps of the polarimetric ratio for L1 and L2 Global Positioning System (GPS) and GLObal Navigation Satellite System (GLONASS), and for E1 Galileo signals are derived from the float phase at 27,000 m height, and the specular points are geolocalized on the Earth's surface. Polarimetric ratio (Γ /Γ ) maps over boreal forests are shown to be in the range 2-16 dB for the different GNSS codes. This result suggests that the scattering is taking place not only over the soil, but over the different forests elements as well. Additionally to the interpretation of the experimental results a theoretical investigation of the different contributions to the total reflectivity over boreal forests is performed using a bistatic scattering model. The simulated cross-(reflected Left Hand Circular Polarization LHCP) and co-polar (reflected Right Hand Circular Polarization RHCP) reflectivities are evaluated for the soil, the canopy, and the canopy-soil interactions for three different biomass densities: 725 trees/ha, 150 trees/ha and 72 trees/ha. For elevation angles larger than the Brewster angle, it is found that the cross-polar OPEN ACCESSRemote Sens. 2015, 7 13121 signal is dominant when just single reflections over the forests are evaluated, while in the case of multiple reflections the co-polar signal becomes the largest one.

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“…[7,8]) and for sensing nearly all surfaces, such as sea state and wind over sea (see e.g. [9][10][11][12][13]), snow (see e.g. [14][15][16]), vegetation coverage (see e.g.…”

Section: Introductionmentioning

confidence: 99%

Detection of buried objects using reflected GNSS signals

Notarpietro

Mattia

Campanella

et al. 2014

EURASIP J. Adv. Signal Process.

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The use of reflected Global Navigation Satellite System (GNSS) signals for sensing the Earth has been growing rapidly in recent years. This technique is founded on the basic principle of detecting GNSS signals after they have been reflected off the Earth's surface and using them to determine the properties of the reflecting surface remotely. This is the so-called GNSS reflectometry (GNSS-R) technique. In this paper, a new application regarding the detection of metallic buried objects is analyzed and it is validated through several experimental campaigns. Although the penetration depth of GNSS signals into the ground is not optimal and depends on the soil moisture, GNSS signals can likely interact approximately with the first 10 cm of the ground and therefore can be reflected back by any metallic object buried on the first terrain layer. A very light and low-cost GNSS receiver prototype based on a software-defined radio approach was developed. This receiver can be used as a payload on board small drones or unmanned aerial systems to detect metallic objects (mines or other explosive devices). A signal processing tool based on an open-loop GNSS signal acquisition strategy was developed. The results of two experiments which show the possibility of using GNSS-R signals to detect buried metallic objects and to provide an estimate of their dimensions are discussed.

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Wind speed measurement using forward scattered GPS signals

Cited by 295 publications

References 20 publications

Altimetry with GNSS-R interferometry: first proof of concept experiment

Altimetry with GNSS-R interferometry: first proof of concept experiment

First Polarimetric GNSS-R Measurements from a Stratospheric Flight over Boreal Forests

Detection of buried objects using reflected GNSS signals

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