Summary Journal of Geodesy and Cartography Vol 46 (12) year 2020

Cập nhật : 09/04/2021
Lượt xem: 121

ACCURACY OF PRECISEPOINT POSITIONING WITH AMBIGUITY RESOLUTION USING GALILEO ONLY

Nguyen Ngoc Lau - Departmentof Geomatics Engineering, Ho Chi Minh City University of Technology

Vietnam National University Ho Chi Minh City

From GPS week 2034, the France CentreNational d’Etudes Spatiales (CNES) started to provide accurate products ofephemerides and clock corrections for GALILEO satellites with ambiguityresolution capability. We investigated the accuracy of precise pointpositioning with ambiguity resolution using only GALILEO at 12 IGS permanentstations in the European region. The results show that the accuracy of 24-hourstatic solution is (2.4, 3.8, 7.4) mm and kinematic solution (9.7, 8.8, 26.8)mm in the North, East and Up components. Compared with GPS only, the East andthe Up components of GALILEO static solution are still less accuracy than ½.Meanwhile, the accuracy of GALILEO’s kinematic position is not much differentfrom GPS.


THEINFLUENCE OF CHANGING LAND COVER AND HABITAT FRAGMENTATION IN LANDSCAPECONNECTIVITY: USING REMOTE SENSING MOTHOD AND MORPHOLOGICAL MEASUREMENT

                                     

Pham Van Manh, Do Thi Ngoc Anh, Nguyen Ngoc Thach - VNU University of Science, Vietnam National University, Hanoi

Pham Minh Hai - Vietnam Institute of Geodesy and Cartography, Ministry of Natural Resources and Environment

The built - up areas, especially urbanand peri-urban infrastructure, can reduce the natural vegetation cover.Maintaining landscape connectivity has become the subject of ecologicalresearch and conservation. The structural connection is estimated using onlyoverlays, which is a simple approach with great potential with less datarequirements for the protection corridor planning. The objective of this studyis to analyze fragmentation for the landscape connection of Hue city - WorldCultural Heritage by using spatial metrics such as LPI, PAFRAC, DCAD, TECI,LSI, DIVISION and SHDI


TECHNICAL DATABASE SOLUTION FOR AUTOMATIC DERIVATION OF GEOGRAPHIC BASE DATABASES AND TOPOGRAPHIC MAPS

Dong Thi Bich Phuong,  Tran Thi Minh Duc - Vietnam Intitude of Geodesy and Cartography

The article points out the necessityand proposes solutions to build technical database for deriving geographicbasic databases and topographic maps of various scales. The solution is builton the principles of data enrichment, automatic map generalization andrestructuring System of national geographic basic databases and topographicmaps.


UAV PHOTOGRAMMETRY FOR TOPOGRAPHICAL MAPPING BASED ON SCALE-INVARIANT FEATURETRANSFORM AND STRUCTURE FROM MOTION

Nguyen Dai Dong - Department of Survey, Mapping and Geographic information Vietnam

Bui Ngoc Quy - Hanoi University of Mining and Geology

The article about scientific basis of UAV photogrammetry for topographical mapping based on Scale-Invariant Feature Transform and Structure from Motion.


DESIGNING ANDMANUFACTURING THE TERRESTRIAL CAMERA SYSTEM BASED ON PHOTOGRAMMETRY TECHNOLOGYTHAT ACQUIRES GEOGRAPHIC INFORMATION DATA AND CREATE TOPOGRAPHIC MAPS

Dang Xuan Thuy, Luu Hai Au, Ngo Thi Lien - Vietnam Intitude of Geodesy and Cartography

Luu Hai Bang - Institute of TransportScience and Technology      

Nowaday, the application of photogrammetry technology in collecting geographicinformation data and making topographic maps has become popular in the worldand in Vietnam base on the advantages of this technology such as reducing timeconstruction, reducing labor therefore bringing high economic benefits. Thephotogrammetry technology is assessed that it has great applicability, but itoften has to be combined with direct measurement in the process of collectinggeographic information data and creating topographic maps due to limitationsthat cannot be engraved in practice such as: lack of topographic and terraindata in high coverage areas, limited vertical data collection of the terrain...Therefore, in order to complete the process of applying photogrammetrytechnology in collecting geographic information data and creating topographicmaps, studies are needed to overcome the above disadvantages. The authorsresearched based on the application of photogrammetry technology to overcomethe above disadvantages. This paper introduces the Terrestrial Camera systembased on photogrammetry technology that integrated by a digital camera, a GNSSand an IMU device. Besides, the paper investigates the accuracy of this systemin collecting geographic information data and creating topographic maps


THE APPLICATION OFREMOTE SENSING IN DETERMINING OCEAN WAVE DIRECTION AND SIGNIFICANT WAVE HEIGHTIN THE NORTHERN COASTAL REGION OF VIETNAM

Nguyen Ha Phu, Tran Tuan Ngoc, Nguyen Thi Phuong Hoa - National Remote Sensing Department

Nong Thi Oanh - The Hanoi University of Geodegy and Mining

Oceanwave direction and significant wave height are one of the most importantparameters of ocean waves that are often determined to study ocean processes aswell as to serve the coastal integrated management such as the establishment ofa coastal protection corridor. In this study, Sentinel2 optical satellite imagedata and Jason-3 satellite altimetry data will be used respectively todetermine wave direction and significant wave height in the Northern coastalregion of Vietnam. The results show that wave direction and significant waveheight determined by the above method have a great similarity with the seahydrographic data.


RESEARCH ON VECTOR TILESAND NODEJS FRAMEWORK FOR DEVELOPING VECTOR TILES SERVICES

Nguyen Hoang Long, Đinh Bao Ngoc, Tran Thi Hai Van - Hanoi University of Mining and Geology

Nguyen Dinh Ky, Lê Thị Kim Thoa - Vietnam Academy Of science and technology

Optimizingthe visualization and query function of web GISs needs to be considered whendeveloping any web GIS application. Tiled map, especially raster tile has beenprovided by serveral GIS servers, such as ArcGIS server and GeoServer with theaim of increasing the visualization performance. Nevertheless, raster tilescould only provide data in the form of images. It leads to difficulties whilequerying data. Vector tile was proposed to improve those drawbacks of rastertiles. This paper presents the backgrounds of tiled map, including both rastertiles and vector tiles. The process of developing vector tiles services usingan open sources software (PostgreSQL) and two frameworks (NodeJS and MapNik) isalso introduced.


DROUGHT MONITORINGDURING THE DRY SEASON BY NDDI INDEX ON GOOGLE EARTH ENGINE, A CASE STUDY AT DAKNONG PROVINCE

Tong Thi Huyen Ai, Nguyen Phuc Hai - Technology Institute, Vietnam Academy ofScience and Technology,

Le Huu Dung - Branch of Land Registration Office, Co Do District, Can Tho City,Can Tho Province

Vo Hong Hien - Environment and Natural Resource Department of Ben Tre Province

PhamThi Lan - Faculty of Geomatics and Land Administration, Hanoi University ofMining and Geology

                                                   

Inthis study, the authors analyzed the relationship between the NDVI, NDWI, NDDIindexes and drought condition of Dak Nong province. Landsat images data in dryseason from 2005-2019 quickly collected, pre-processed and calculated on GoogleEarth Engine. The results showed that NDWI and NDDI are more sensitiveindicatior for drought than NDVI. In which, NDDI value > 0.8 and NDWI


ABILITY OF SOIL MAPPINGESTABLISHMENT BY REMOTE SENSING TECHNOLOGY FOLLOWING IPCC TECHNICAL REGULATIONSERVING FOR CARBON EMISSION ESTIMATION IN VIETNAM

Vu Thi Phuong Thao - Hanoi University of Mining and Geology, MOET

Carbonstock in soil is an important part of the continent’s carbon sink. To calculatethe amount of carbon emissions from the soil, it is required to identify othersoil objects. Following the recommendations of the Intergovernmental Panel onClimate Change (IPCC), the use of soil classification system would be servedfor carbon emission’s estimation. Besides, carbon stocks vary by climateregions and soil types. Remote sensing technolog with transparency, multi-timeand wide coverage is useful in this direction. The article focuses on abilityof soils mapping establisment using remote sesing technology according toipcc’s technical specifications for calculating carbon emissions in Vietnam..The result was used in the second times of Vietnam biennial update report tothe United Nations Framework Convention on Climate Change that includedcontent, updated information of greenhouse gas emission.