[{"@context":"http:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/gnss-reflectometry-wikipedia\/#BlogPosting","mainEntityOfPage":"https:\/\/wiki.edu.vn\/en\/wiki24\/gnss-reflectometry-wikipedia\/","headline":"GNSS reflectometry – Wikipedia","name":"GNSS reflectometry – Wikipedia","description":"From Wikipedia, the free encyclopedia Earth observation technology GNSS reflectometry (or GNSS-R) involves making measurements from the reflections from the","datePublished":"2022-05-13","dateModified":"2022-05-13","author":{"@type":"Person","@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/author\/lordneo\/#Person","name":"lordneo","url":"https:\/\/wiki.edu.vn\/en\/wiki24\/author\/lordneo\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"Enzyklop\u00e4die","logo":{"@type":"ImageObject","@id":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","url":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/9\/98\/GNSS-R_system_diagram.svg\/300px-GNSS-R_system_diagram.svg.png","url":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/9\/98\/GNSS-R_system_diagram.svg\/300px-GNSS-R_system_diagram.svg.png","height":"260","width":"300"},"url":"https:\/\/wiki.edu.vn\/en\/wiki24\/gnss-reflectometry-wikipedia\/","about":["Wiki"],"wordCount":2975,"articleBody":"From Wikipedia, the free encyclopediaEarth observation technology  GNSS reflectometry (or GNSS-R) involves making measurements from the reflections from the Earth of navigation signals from Global Navigation Satellite Systems such as GPS. The idea of using reflected GNSS signal for earth observation became more and more popular in the mid-1990s at NASA Langley Research Center[1] and is also known as GPS reflectometry. Research applications of GNSS-R are found inAltimetry [2][3]Oceanography (Wave Height and Wind Speed)[4]Cryosphere monitoring[1][5]Soil moisture monitoring[6]GNSS reflectometry is passive sensing that takes advantage of and relies on separate active sources – the satellites generating the navigation signals. For this, the GNSS receiver measures the signal delay from the satellite (the pseudorange measurement) and the rate of change of the range between satellite and observer (the Doppler measurement). The surface area of the reflected GNSS signal also provides the two parameters time delay and frequency change. As a result, the Delay Doppler Map (DDM) can be obtained as GNSS-R observable. The shape and power distribution of the signal within the DDM is dictated by two reflecting surface conditions: its dielectric properties and its roughness state. Further derivation of geophysical information rely on these measurements.GNSS reflectometry works as a bi-static radar, where transmitter and receiver are separated by a significant distance. Since in GNSS reflectometry one receiver simultaneously can track multiple transmitters (i.e. GNSS satellites), the system also has the nature of multi-static radar. The receiver of the reflected GNSS signal can be of different kinds: Ground stations, ship measurements, airplanes or satellites, like the UK-DMC satellite, part of the Disaster Monitoring Constellation built by Surrey Satellite Technology Ltd. It carried a secondary reflectometry payload that has demonstrated the feasibility of receiving and measuring GPS signals reflected from the surface of the Earth’s oceans from its track in low Earth orbit to determine wave motion and windspeed.[4][7]Table of ContentsSee also[edit]References[edit]Further reading[edit]External links[edit]See also[edit]References[edit]^ a b Komjathy, A.; Maslanik, J.; Zavorotny, V.U.; Axelrad, P.; Katzberg, S.J. (2000). “Sea ice remote sensing using surface reflected GPS signals”. IGARSS 2000. IEEE 2000 International Geoscience and Remote Sensing Symposium. Taking the Pulse of the Planet: The Role of Remote Sensing in Managing the Environment. Proceedings (Cat. No.00CH37120). Honolulu, HI, USA: IEEE. 7: 2855\u20132857. doi:10.1109\/IGARSS.2000.860270. hdl:2060\/20020004347. ISBN\u00a0978-0-7803-6359-5. S2CID\u00a062042731.^ Semmling, A. M.; Wickert, J.; Sch\u00f6n, S.; Stosius, R.; Markgraf, M.; Gerber, T.; Ge, M.; Beyerle, G. (2013-07-15). “A zeppelin experiment to study airborne altimetry using specular Global Navigation Satellite System reflections: A ZEPPELIN EXPERIMENT TO STUDY AIRBORNE ALTIMETRY”. Radio Science. 48 (4): 427\u2013440. doi:10.1002\/rds.20049.^ Rius, Antonio; Cardellach, Estel; Fabra, Fran; Li, Weiqiang; Rib\u00f3, Serni; Hern\u00e1ndez-Pajares, Manuel (2017). “Feasibility of GNSS-R Ice Sheet Altimetry in Greenland Using TDS-1”. Remote Sensing. 9 (7): 742. Bibcode:2017RemS….9..742R. doi:10.3390\/rs9070742. ISSN\u00a02072-4292.^ a b Gleason, S.; Hodgart, S.; Yiping Sun; Gommenginger, C.; MacKin, S.; Adjrad, M.; Unwin, M. (2005). “Detection and Processing of bistatically reflected GPS signals from low Earth orbit for the purpose of ocean remote sensing”. IEEE Transactions on Geoscience and Remote Sensing. 43 (6): 1229\u20131241. Bibcode:2005ITGRS..43.1229G. doi:10.1109\/TGRS.2005.845643. S2CID\u00a06851145.^ Rivas, M.B.; Maslanik, J.A.; Axelrad, P. (2009-09-22). “Bistatic Scattering of GPS Signals Off Arctic Sea Ice”. IEEE Transactions on Geoscience and Remote Sensing. 48 (3): 1548\u20131553. doi:10.1109\/tgrs.2009.2029342. ISSN\u00a00196-2892. S2CID\u00a012668682.^ Rodriguez-Alvarez, Nereida; Camps, Adriano; Vall-llossera, Merc\u00e8; Bosch-Lluis, Xavier; Monerris, Alessandra; Ramos-Perez, Isaac; Valencia, Enric; Marchan-Hernandez, Juan Fernando; Martinez-Fernandez, Jose; Baroncini-Turricchia, Guido; Perez-Gutierrez, Carlos (2011). “Land Geophysical Parameters Retrieval Using the Interference Pattern GNSS-R Technique”. IEEE Transactions on Geoscience and Remote Sensing. 49 (1): 71\u201384. Bibcode:2011ITGRS..49…71R. doi:10.1109\/TGRS.2010.2049023. ISSN\u00a00196-2892. S2CID\u00a027516781.^ M. P. Clarizia et al., Analysis of GNSS-R delay-Doppler maps from the UK-DMC satellite over the ocean Archived 2011-06-06 at the Wayback Machine, Geophysical Research Letters, 29 January 2009.Further reading[edit]Zavorotny, Valery U.; Gleason, Scott; Cardellach, Estel; Camps, Adriano (2014). “Tutorial on Remote Sensing Using GNSS Bistatic Radar of Opportunity”. IEEE Geoscience and Remote Sensing Magazine. Vol.\u00a02, no.\u00a04. pp.\u00a08\u201345. doi:10.1109\/MGRS.2014.2374220. ISSN\u00a02168-6831.Larson, Kristine M.; Small, Eric E.; Braun, John; Zavorotny, Valery (2014). “Environmental Sensing: A Revolution in GNSS Applications”. InsideGNSS. Vol.\u00a09, no.\u00a04. pp.\u00a036\u201346. ISSN\u00a01559-503X. Archived from the original on 2016-03-15. Retrieved 2016-03-15.Cardellach, Estel (2015): E-GEM \u2013 GNSS-R Earth Monitoring; State of the Art Description Document Archived 2020-11-28 at the Wayback Machine.Emery, William and Camps, Adriano (2017): Introduction to Satellite Remote Sensing 1st Edition Atmosphere, Ocean, Land and Cryosphere Applications, Chapter 6:  Remote Sensing Using Global Navigation Satellite System Signals of Opportunity, Elsevier, 20th September 2017, Paperback ISBN\u00a09780128092545, eBook ISBN\u00a09780128092590A complete list of references maintained by the GNSS-R Community can be found at: https:\/\/www.ice.csic.es\/personal\/rius\/gnss_r_bibliography\/index.htmlExternal links[edit]  "},{"@context":"http:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/#breadcrumbitem","name":"Enzyklop\u00e4die"}},{"@type":"ListItem","position":2,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/gnss-reflectometry-wikipedia\/#breadcrumbitem","name":"GNSS reflectometry – Wikipedia"}}]}]