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Comunicación expuesta online en el CYGNSS Science Team Summer Meeting celebrado del 27 al 29 de julio de 2021

BeiDou navigation satellite system is currently the only system which the whole constellation offers triple-frequency observation data, triple-frequency observation is conducive to carrier phase ambiguity fixing quickly and accurately. The algorithm of triple-frequency integer ambiguity resolution between BDS network RTK reference stations is proposed. The observation of B2 frequency and B3 frequency and the strict criterion of ambiguity fixing are used to determine extra-wide-lane integer ambiguity. The linear relationship between fixed extra-wide-lane integer ambiguity and other wide-lane integer ambiguity is selected as constraint conditions, then the wide-lane integer ambiguity, relative zenith tropospheric delay error and ionospheric delay error are estimated and the wide-lane integer ambiguity can be fixed by search mode. There is a kind of integer linear relationship between fixed wide-lane integer ambiguity and triple-frequency carrier phase integer ambiguity, this linear relationship is added to the observation model of carrier phase ambiguity parameter estimation and the integer ambiguity can be fixed. This algorithm is tested by the measured triple-frequency data of BDS CORS network. The results indicate that triple-frequency carrier phase ambiguity can be fixed accurately and effectively with the method.

System Erde; 8, Geodesy aims to determine the geometric figure and the gravitational field of the Earth, as well as its orientation in space. Steadily increasing accuracies, with which these tasks are being solved, are based on corresponding improvements in geodetic measuring data, both, on the quantitative as well as the qualitative level. Similar developments in the acquisition, processing and analysis of observation data, which have always been at the limit of the technically and scientifically feasible, are witnessed in the fields of seismology and geomagnetism as well. Recently however, innovative developments, building on Big Data approaches, are emerging with the combination of diverse data streams into integrated processing environments. Geodetic, seismological and geomagnetic observation data are fundamental for a better understanding of Earth system processes. The combination of these geoscience data collected by ground- and space-based sensors, their consistent processing, validation and assimilation into complex Earth system models contribute in an essential way to the future implementation of GGOS, the Global Geodetic Observing System.

System Erde; 7, Along with cell phones and the internet, satellite navigation is an integral part of everyday life. However, satellite navigation signals provide much more than precise information on user locations. Even before the GPS was declared fully operational in 1995, the potential for these globally and continuously available navigation signals for Earth observation and geoscientific applications was recognized. Such applications include the precise monitoring of continental plate movements with sub-mm/year accuracy (now used in real-time as part of early earthquake warning systems), regional and global atmospheric and ionospheric sounding to improve weather forecasts and climate change predictions, and for monitoring of water, ice, and land surfaces. The Earth observation prospects and related spectrum of applications are continuously growing, mainly stimulated by the transition from a single constellation (GPS) to Multi-GNSS (Global Navigation Satellite System) with the Russian GLONASS, Chinese BeiDou and European Galileo satellites and by the increasing number of GNSS receivers available both on the ground and aboard Low Earth Orbiting satellites.

GeoSHM (GNSS and Earth Observation for Structural Health Monitoring) is a feasibility study project funded under the Integrated Application Promotion (IAP) program of the European Space Agency (ESA) in August 2013. Through integrated use of GNSS, Remote Sensing technologies and environmental data, GeoSHM can offer bridge owners an effective tool to assess the operational conditions of their assets. A reference system that consists of four GNSS receivers and two anemometers was installed on the Forth Road Bridge (FRB) in Scotland. This first stage monitoring system is producing precise 3D real-time displacements under different loading conditions. It can also provide essential land movement information to assess potential threats due to underground water extraction, geo-hazards and other industrial activities. The GeoSHM Feasibility Study has proved that even a small scale monitoring system can make possible for the Bridgemaster of the FRB to fully understand the loading and response effect of the bridge, and identify unusual deformations under extreme weather conditions (wind gust, etc.). Furthermore, EO data has proved to be extremely useful for the subsidence detection, as the SAR interferometry images have shown that there is no significant subsidence of the towers of the FRB or in the surrounding area. Gathering real-time GNSS data has produced continuous and accurate estimation of the displacement time-series of the structure. The issues and gaps identified from GeoSHM FS will form a solid foundation for the next stage development of GeoSHM service – demonstration, which is a two-year project and have started in February 2016. A new consortium of GeoSHM has been formed, focusing on significant refinements to the system reliability, sensor integration, data acquisition, data transmission, data fusion and SHM information extraction. This further developed GeoSHM system will be installed on a few Chinese bridges and the reference monitoring system on the FRB will be expanded as a pre-operational system.