Analysis of GNSS‐R delay‐Doppler maps from the UK‐DMC satellite over the ocean

Clarizia, Maria Paola; Gommenginger, Christine; Gleason, Scott; Srokosz, Meric; Galdi, C.; Bisceglie, M. Di

doi:10.1029/2008gl036292

Cited by 149 publications

(67 citation statements)

References 9 publications

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“…Among the current spaceborne techniques, global navigation satellite system reflectometry (GNSS-R) is an effective and innovative remote sensing technique for the ocean, land and cryosphere [1,2]. It can be used to derive geophysical parameters based on the GNSS L-band signals that are reflected by the Earth's surface under all weather conditions [3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Spatiotemporal Evaluation of GNSS-R Based on Future Fully Operational Global Multi-GNSS and Eight-LEO Constellations

Gao

Wang

et al. 2018

Remote Sensing

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Spaceborne GNSS-R (global navigation satellite system reflectometry) is an innovative and powerful bistatic radar remote sensing technique that uses specialized GNSS-R instruments on LEO (low Earth orbit) satellites to receive GNSS L-band signals reflected by the Earth's surface. Unlike monostatic radar, the illuminated areas are elliptical regions centered on specular reflection points. Evaluation of the spatiotemporal resolution of the reflections is necessary at the GNSS-R mission design stage for various applications. However, not all specular reflection signals can be received because the size and location of the GNSS-R antenna's available reflecting ground coverage depends on parameters including the on-board receiver antenna gain, the signal frequency and power, the antenna face direction, and the LEO's altitude. Additionally, the number of available reflections is strongly related to the number of GNSS-R LEO and GNSS satellites. By 2020, the Galileo and BeiDou Navigation Satellite System (BDS) constellations are scheduled to be fully operational at global scale and nearly 120 multi-GNSS satellites, including Global Positioning System (GPS) and Global Navigation Satellite System (GLONASS) satellites, will be available for use as illuminators. In this paper, to evaluate the future capacity for repetitive GNSS-R observations, we propose a GNSS satellite selection method and simulate the orbit of eight-satellite LEO and partial multi-GNSS constellations. We then analyze the spatiotemporal distribution characteristics of the reflections in two cases: (1) When only GPS satellites are available; (2) when multi-GNSS satellites are available separately. Simulation and analysis results show that the multi-GNSS-R system has major advantages in terms of available satellite numbers and revisit times over the GPS-R system. Additionally, the spatial density of the specular reflections on the Earth's surface is related to the LEO inclination and constellation construction.

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Section: Introductionmentioning

confidence: 99%

Spatiotemporal Evaluation of GNSS-R Based on Future Fully Operational Global Multi-GNSS and Eight-LEO Constellations

Gao

Wang

et al. 2018

Remote Sensing

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“…An alternative signal source using Earth reflected GNSS signals as a means of sensing the ocean surface was proposed in 1988 [13]. Researchers subsequently used data from the GNSS-R experiment on the UK-DMC satellite to demonstrated that signal retrievals of sufficient signal-to-noise ratio (SNR) could be used to perform successful ocean wave and wind estimation [14] [15] [16]. These results show that it is possible to detect reflected GNSS signals from space across a range of surface wind and wave conditions using a modest instrument configuration thus enabling an alternative to active sensing ocean remote sensing using bi-statically reflected signals transmitted from global navigation satellites (Reference Figure 6).…”

Section: Application Example In Earth Weathermentioning

confidence: 99%

CubeSats to NanoSats; Bridging the gap between educational tools and science workhorses

Rose

Dickinson

Ridley

2012

2012 IEEE Aerospace Conference

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Since their initial development and launch in the early 2000's, the CubeSat platform has captured the imagination and energy of our next generation of spacecraft technologists around the world. Once thought of by the established space community as "toys" and educational novelties, the CubeSat has revolutionized the space-community and broken the acceptance barrier with proven development and on-orbit performance. Leveraging CalPoly's published specification, CubeSats have demonstrated the advantages of a common form factor that can be launched and deployed using a common deployment system by smashing the cost-to-orbit price-point while offering significant mission manifest flexibility. The challenge now lies in transitioning the strengths and success of the CubeSat to mainstream science investigations. While the CubeSat's successes combined with today's budget constraints have served to open the established space community to discussions of innovative ideas to reduce costs; it faces both perceived and real constraints related to mission applications,reliability, payload performance, communications, and operations. The CubeSat model must be evolved to penetrate the stigmas and applied appropriately to become an accepted tool in the world of mainstream science investigations. This paper identifies issues and presents potential solutions and lessons-learned regarding these issues based on several recent mission concept developments for potential real-world applications.

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“…The shape of the DDM is sensitive to the roughness of the scattering surface and, through various empirical models, the ocean surface winds [2], [3]. Ocean winds can be retrieved by fitting a scattering model to DDM observations, or identifying an observable, such as trailing or leading edge slopes or DDM power average exceeding a threshold, [4], [5]. A variety of such methods have been demonstrated with airborne experiments [3], [6], and [7].…”

Section: Introductionmentioning

confidence: 97%