TAILIEUCHUNG - Construction of initial national quasi-geoid model VIGAC2017, first step to national spatial reference system in Vietnam

The orientation of the WGS-84 ellipsoid was accomplished under conditions of it’s best fitting to the Hon Dau local quasi-geoid and the parallelism of its axes to the corresponding axes of the national WGS-84 reference ellipsoid allows get national quasi-geoid heights and coordinate transformation parameters that have been used for conversion of the mixed quasi-geoid heights from the VIGAC2014 quasi-geoid model to the initial national quasi-geoid model VIGAC2017. | Vietnam Journal of Earth Sciences 39(2), 155-166, DOI: Vietnam Academy of Science and Technology (VAST) Vietnam Journal of Earth Sciences Construction of initial national quasi-geoid model VIGAC2017, first step to national spatial reference system in Vietnam Ha Minh Hoa Vietnam Institute of Geodesy and Cartography Received 08 March 2017. Accepted 31 March 2017 ABSTRACT Vietnam national WGS-84 reference ellipsoid was obtained in 1999 from results of an orientation of the global WGS-84 reference ellipsoid. However, usage of the broadcast satellite messages doest not give high accuracy in determination of national quasi-geoid heights. Based on the determined geopotential of the Hon Dau local geoid and constructed initial mixed quasi-geoid model VIGAC2014, this scientific article presents results of building of initial national quasi-geoid model VIGAC2017. Used data consisting of geodetic coordinates B, L, H of 164 first and second orders benchmarks of the national leveling networks was obtained from GPS data processing in ITRF according to global WGS-84 ellipsoid with satellite ephemeris accuracy at level of ± 2,5 cm, and the initial mixed quasi-geoid model VIGAC2014 was constructed from the EGM2008 model. The orientation of the WGS-84 ellipsoid was accomplished under conditions of it’s best fitting to the Hon Dau local quasi-geoid and the parallelism of its axes to the corresponding axes of the national WGS-84 reference ellipsoid allows get national quasi-geoid heights and coordinate transformation parameters dX 0 , dY0 , dZ 0 , that have been used for conversion of the mixed quasi-geoid heights from the VIGAC2014 quasi-geoid model to the initial national quasi-geoid model VIGAC2017. * Along withquasi-geoid heights , which were obtained from the initial national quasi-geoid model * * VIGAC2017, an estimation of the accuracy of differences ( ) shows that quasi-geoid heights have the .

• Địa Lý
• Vietnam Journal of Earth Sciences
• Construction of initial national quasi geoid model VIGAC2017
• First step to national spatial reference system in Vietnam
• Coordinate transformation parameters
• The WGS 84 ellipsoid
• General characteristics of rare earth
• Radioactive elements in Dong Pao deposit
• The natural tap and thermal waters
• Liquid scintillation counter
• Probabilistic seismic hazard assessment for the South Central Vietnam
• Probabilistic seismic hazard assessment
• The South Central Vietnam
• Recent seismotectonic and geodynamic
• Prediction of maximum earthquake magnitude for northern Vietnam region
• The gev distribution
• Maximum earthquake magnitude
• Generalized extreme value distribution
• The earthquake catalog of Northern Vietnam
• Continuous GPS network in Vietnam
• The total electron
• The South East Asian region
• The continuous GPS network
• The South East Asian equatorial ionization anomaly
• Upper Permian lower Triassic volcanic sequences
• The Hoa Binh area
• northwest Vietnam
• Insignificant cumulative displacement
• Oriented core samples
• An analysis of forest biomass changes
• Geospatial tools and ground survey data
• Yok Don national park
• Central Highlands of Vietnam
• SPOT HRV satellite
• The autumn precipitation
• Tropical cyclone activity
• Central Vietnam and its East Sea
• Sea surface temperature
• Adaptation plans anticipated
• Abnormal features of oceanographic characteristics
• Upwelling Vietnam waters under impact of El Niño events
• Deeper water layers during
• El Niño phase
• The relation between fault movement potential
• Seismic activity of major faults in Northwestern Vietnam
• Fault Movement Potential
• The nearly horizontal trend
• U Pb detrital zircon geochronology
• Sedimentary rocks in NE Vietnam
• Implication for Early and Middle Devoni an Palaeogeography
• LA SF ICP MS techniques
• The western Himalaya
• Preliminary study on phytogeography
• Dipterocarpaceae Blume family in Vietnam
• Dipterocarpaceae Blume family
• Tropical and or slightly passing
• The Mekong River deltas
• Impacts of climate change on erosion and water flow
• The soil and water assessment tool and gis
• Cau river basin in Vietnam
• oil and Water Assessment Tool
• Errors in determination of main parameters of earthquake hypocenter
• The national seismic network of Vietnam
• Main parameters of earthquake hypocenter
• The seismic stations
• The previous studies
• Sea level rise and resilience in Vietnam
• Sea level rise and resilience in the AsiaPacific
• Sea level rise and resilience
• Climate change induced sea level rise
• Spatial distribution of hot days in north central region
• Vietnam in the period of 1980 2013
• Hot days in north central region
• North Center Region
• Debris flow hazard in relation
• Geological environment changes in mountainous regions
• Geological environment changes
• Debris flows in Vietnam
• High arsenic concentration in groundwater related to sedimentary facies
• The Mekong River Delta
• High arsenic concentration
• AOAC laboratory Vietnamese standard
• Assessment of geomorphic processes and active tectonics
• Con Voi mountain range area
• The hypsometric curve analysis method
• The hypsometric curve
• Uptake capacity of metals by Vetiveria zizanioides
• Uptake capacity of metals
• Dong Xam metal production trade village
• Thai Binh province
• Metal production trade village
• Coralline Ba Ca ratios
• Luminescent line records
• Con Dao island
• Mekong river runoff
• Bright luminescent lines
• Simulation of long term variations
• The F2 layercritical frequency f0F2
• The northern tropical crest of ionization at Phu Thuy
• The thermosphere ionosphere electrodynamicsgeneral circulation model
• Long term variations
• Methodology of determining effective porosity
• Longitudinal dispersivity of aquifer
• The application to field tracer injection test in Southern Hanoi
• The groundwater flow
• New discovery of late early ordovician graptolites
• Discussion on stratigraphic sequence of paleozoic sediments
• The Dinh Ca Trang Xa section
• Vo Nhai disctrict
• A digital shoreline analysis system
• Mangrove shoreline changes along
• The Giao Thuy coastal area
• Mangrove shoreline changes and mangrove zoning