8:45 AM - 9:00 AM
[G01-5-02] Continuing and Emerging Roles of National GNSS CORS as Geodetic Infrastructure: Case study of GEONET in Japan
invited
GEONET, the national GNSS Continuously Operating Reference Stations (CORS) network of Japan, has been operational since 1996, celebrating the 20th year anniversary. Here we review the past 20 year operation of GEONET, and discuss continuing and emerging roles as Geodetic infrastructure.
Currently GEONET consists of 1,318 stations covering whole Japan with about 20 km spacing, tracking signals from GPS, QZSS, GLONASS and Galileo with 1 Hz sampling. Observation data and products are open to the public to support surveying and mapping. Private companies provide network-based realtime kinematic positioning services using data from GEONET, now widely used for ICT constructions and precision farming. Crustal deformations are monitored by time series of baseline vectors, revealing secular, coseismic, and postseismic deformations as well as slow slip events. The realtime analysis system for rapid deformation monitoring (REGARD) is now in operation, aiming to assist Tsunami warning. Thus GEONET has become the social infrastructure for surveying, mapping, positioning, disaster mitigation and Earth science.
Because of large and complex nature of crustal deformation around Japan, maintenance of the national reference frame needs extreme cares. So far, GEONET identified nearly 100 crustal deformations associated with large earthquakes. The 2011 Tohoku earthquake (M 9.0) is the largest one, recording 5.3 meter horizontal displacement, and still causing post seismic deformation. We need GEONET to generate semi-dynamic correction parameters that account for accumulated crustal deformations after the revision of the Japanese Geodetic Datum in 2011.
Although relative positioning that forms a baseline to delete common positioning errors is the old and reliable method for GNSS surveys, Precise Point Positioning (PPP) and PPP-AR (Ambiguity Resolution) that do not form baselines are emerging. We show the new role of national CORS is to provide sufficient local data for quicker fix of PPP.
Currently GEONET consists of 1,318 stations covering whole Japan with about 20 km spacing, tracking signals from GPS, QZSS, GLONASS and Galileo with 1 Hz sampling. Observation data and products are open to the public to support surveying and mapping. Private companies provide network-based realtime kinematic positioning services using data from GEONET, now widely used for ICT constructions and precision farming. Crustal deformations are monitored by time series of baseline vectors, revealing secular, coseismic, and postseismic deformations as well as slow slip events. The realtime analysis system for rapid deformation monitoring (REGARD) is now in operation, aiming to assist Tsunami warning. Thus GEONET has become the social infrastructure for surveying, mapping, positioning, disaster mitigation and Earth science.
Because of large and complex nature of crustal deformation around Japan, maintenance of the national reference frame needs extreme cares. So far, GEONET identified nearly 100 crustal deformations associated with large earthquakes. The 2011 Tohoku earthquake (M 9.0) is the largest one, recording 5.3 meter horizontal displacement, and still causing post seismic deformation. We need GEONET to generate semi-dynamic correction parameters that account for accumulated crustal deformations after the revision of the Japanese Geodetic Datum in 2011.
Although relative positioning that forms a baseline to delete common positioning errors is the old and reliable method for GNSS surveys, Precise Point Positioning (PPP) and PPP-AR (Ambiguity Resolution) that do not form baselines are emerging. We show the new role of national CORS is to provide sufficient local data for quicker fix of PPP.