Summary Journal of Geodesy and Cartography Vol 40 (6) year 2019

Cập nhật : 28/07/2019
Lượt xem: 42

IMPROVEMENT OF THE ACCURACY OF THENATIONAL QUASIGEOID MODEL BASED ON CONSTRUCTION OF THE NATIONAL SPATIALREFERENCE SYSTEM

Ha Minh Hoa, Vietnam Institute of Geodesy and Cartography   

                                                             

In a process of construcion of the national spatial reference system,based on a reorientation of the WGS84 national reference ellipsoid with purposeof the best it’s fitting to the national quasigeoid, we will can increase theaccuracy of the seven parameters of coordinate conversion from the ITRF to thenational spatial reference system, especially of the scale change parameterbetween two above mentioned coordinate systems. That allows us to accuratelyconvert the global geodetic height determined by GNSS technology from the WGS84to the  national spatial reference systemserving a construction of the highly accurate national quasigeoid model. Thisscientific article will prove a correctness of this approach.  


WEBGIS APPLICATION IN SUPERVISION OF MANAGEMENT AND USE OF LAND RESOURCES

Nguyen Phi Son, Institute of Geodesy and Cartography

Increasing public participation in the field of publicadministration has become a world trend. In land monitoring activities,people's participation will enhance the efficiency of land management and use.There are many ways for people to participate in monitoring activities, throughwhich the Websites function of the geographic information system (WebGIS) willincrease the convenience and quality of information. Not only is WebGISconducive to raising public awareness about land law policies, citizens' rightsand obligations towards national assets and resources, but it also contributesto promoting similarities. positive cooperation between public and privaterights of citizens. WebGIS system is built on the basis of ASP.net programminglanguage, spatial database is put into SQL Server 2016 management system and C#programming language library in ASP.NET environment is used. to design thewebsite. Based on the Web interface, users can obtain information about landresources and local land use. The main function of the Web is the informationchannel for people and communities to provide the management agency withinitial information on violations in land management and land use in thelocality. The webmaster will receive the information, will synthesize andsubmit it to the competent authorities for resolution. This is an effectivetool to support the state management of land.

The paper is built based on data and research results of thestate level project under the climate change program 16-20, climate changecode.10/16-20.


APPLICATION OF MACHINE LEARNINGMETHODS IN SPOT6 IMAGE SATELLITE CLASSIFICATION WITH THE STUDY AREA IN THEMANGROVE FOREST OF CA MAU PROVINCE

Pham Minh Hai, Institute of Geodesy and Cartography

The selection of suitable algorithms plays an importantrolein any applicationsof machine learning methods because of their manycriteria. Also, the understanding of the strengthen and weakness of algorithmsin machine learning methods is essential to bring high efficiency. Within thescope of this manuscript, the team conducted an algorithm of Machine Learningmethods called Random Forest in using the SPOT6 remote sensing for the mangroveforest classification with the test area in Ca Mau Province. The results of thestudy have achieved two new points: successfully applying Machine Learningmethod in remote sensing image classification, and classification of detailspecies of mangrove forests in the study area. In addition, the team hasexploited the potential of machine learning methods to identify patterns onremote sensing images based on the selected samples in order to extractthematic information in high accuracy.

                                                                                      

STUDY OFAPPLICATION OF GNSS-RTK TECHNOLOGYIN CONSTRUCTION OF SUPER HIGH-RISEBUILDINGS IN VIETNAM

Tran Viet Tuan, Hanoi University of Mining and Geology

Diem Cong Trang, Vietnam institute for science science and technology

Thecontent of the article presents the research results of GNSS-RTK technology application to arrange construction of super high-rise buildings in Vietnam.Theoretical basis of this technical solution and experimental measurement results are to assess the applicability of GNSS-RTK technology in the processof ensuring the construction of high-rise and super high-rise buildings in ourcountry.


USING THE HOPFIELD NEURON NETWORK ENHANCES THE ACCURACY OF IDENTIFYING OBJECTS SMALLER THAN 1 PIXEL IN THESPECTRAL IMAGE

Dang Thanh Tung, State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing (LIESMARS), Wuhan University, 129 Luoyu Road, Wuhan 430079, China/ Hanoi University of Natural Resources and Environment

Do Nhu Hiep, Pham Dinh Tinh, Hanoi University of Natural Resources and Environment

Do Manh Ha, Vietnam Department of Surveying and Geographic Information

Nguyen TheLuan,  Institute of Marine Geology and Geophysics – Vietnam Academy of Science and Technology

In the field of remotesensing, soft classification is considered to have higher accuracy than hard classification. For the super-resolution, the Hopfield neuron network was usedto perform an optimization problem in determining the position of the layer ineach pixel. This study evaluates the effectiveness of the new algorithm withthe 4 image and the new method can increase the accuracy of all layers,especially those of smaller 1 pixel.


IMPACT OF URBAN EXPANSION TO CULTURAL HERITAGE: THE CASE STUDY OF THE COMPLEX OF HUE MONUMENTS

Pham Van Manh, Nguyen Ngoc Thach, Bui Quang Thanh, Pham Vu Dong, University of Science, Vietnam National University

Pham Minh Hai, Insitute of Geodesy and Cartography

Rapidchanges in large scale urban have been becoming more challenging for land-useconservation and planning, especially in historical sites. With the expansionof city boundaries are usually beyond planning, the pace of development poses achallenge for urban planners. These issues can be resulted from (i) outdatedplanning database, (ii) unplanned urban growth models are not properlymeasured. This paper proposes an approach to address these challenges by usingmultitemporal remote sensing data to study land use/cover changes for nearlyhalf of century (1968-2016). This study uses SPOT satellite image datacombining with topology mapping from NIMA (Texas University librarypublication). Different urbanization indices measure a detailed analysis ofurban expansion. The results indicate that urban expansion causes large changesin land use and urban growth. This leads to significant impacts ln thelandscape. The results also show an incline in agricultural land and greenspace that lasts 48 years. From these results, it can be seen that theintegrated method between remote sensing is highly effective for analyzing thenotable changes in land use and urban expansion in different periods(1968-1995, 1995-2000, 2000-2005, 2005-2011, và 2011-2016).


ASSESSMENT OF THE IMPACTS OF URBANIZATION ON AGRICULTURAL LAND IN THE RED RIVER DELTA USING MULTI-TEMPORAL REMOTE SENSING DATA AND GIS


Luu The Anh, CentralInstitute for Natural Resources and Environmental Studies, Vietnam NationalUniversity

Pham Minh Hai, VietnamInstitute of Geodesy and Cartography

Vu Thi Hong Ha, VietnamInstitute of Geodesy and Cartography

Kieu Thi Thao, VietnamInstitute of Geodesy and Cartography

Nguyen Ngoc Thang, NguyenThanh Binh, Institute of Geography, Vietnam Academy of Science and Technology

The Red River Delta (RRD) is an important economic, political, cultural and socialregion with the highest population density in Vietnam. In recent years, therapid urbanization process has significantly changed the land use/land covermodel (LULC) of the region, in which agricultural land is the most stronglyaffected by urbanization. Analysis of these changes will help us betterunderstand the impact of urbanization on farmland as well as the interactionbetween the government policy and farmers' economic interests. This study aimsto assess urban and agricultural land changes in the RRD in the periods of1995, 2005 and 2015 by using Urban Land Index (UI), Urban Expansion Index (UX)and Landscape Expansion Index (LEI) based on the use of ESA Climate ChangeInitiative Landcover data (300 m resolution). The research results showsignificant changes in agricultural land due to urbanization process;agricultural land around the cities was converted into urban and bare landduring 1995-2015. In areas adjacent to construction site and cities center,urbanization is increasing rapidly and agricultural land decreases strongly;meanwhile in areas which are far from construction site and city centers, landshave been rapidly fragmented and drastically changed. The research results willprovide the basis for the Government to make reasonable policies to minimizethe negative impacts of urbanization and industrialization on the agriculturalland fund.


PROBLEM SOLVING BREAKLINE LINE ON TIN MODEL, USING DCEL STRUCTURE

Le Quang Hung1 , Tran Thuy Duong2, Vu­ Quang Hieu2,Le Huu Hue ­2

1 Resource Enviroment and Materials Technology Joinstock Company

2 University of Mining and Geology

Breakline lines are oftendescribed as objects that perform on topographic models such as mountain,ravine, level…. However, when studying cadastral maps, it is also possible toapply Breakline road handling principles to solve some cadastral problems onthe numerical model. The main content objects of the cadastral map include landplots and related geographic features such as transport systems, hydrology...The cadastral TIN model is built from the triangle of field measurements. Theparcel of land when included in the model is automatically fixed edges andsatisfy the condition of the edge of the triangular network is not cut. Thus,triangular networks need to edit and edit to handle intersections. DCEL datastructure has advantages in data storage chosen to solve this problem inaccordance with the proposed algorithm. The paper uses two methods of"Split edge" and "Diagram" of triangle applied Breakline processing.This problem is a preceding problem, creating a premise to solve the problem ofcreating Topology for regional objects on the cadastral map application model.


SPATIAL - TEMPORAL PATTERN OF LANDSURFACE TEMPERATURE IN THE VIETNAMESE MEONG RIVER DELTA

Phan Hien Vu, Nguyen Truong Ngan, Nguyen Trong Khanh

Departmentof Geomatics Engineering, Faculty of Civil Engineering, University ofTechnology, VNU-HCM

During the last decades, the land-use structure in the Vietnamese Mekong River Deltahas changed due to industrialization. Recently a trend of built-in areasincreases while vegetable areas have a decrease trend.These make land surfacetemperature (LST) increase in urban and industrial areas. The paper focuses onexploiting MODIS data products to determine a spatial pattern of LST changes indry seasons from 2000 to 2015. For each pixel, a temporal trend of LST changeshas been estimated by a linear regression. The results indicate that generallyLST in the Vietnamese Mekong Delta increase at an average rate of +0.1 0Cper year in dry season during the observed period. Approximate 52% of the totalarea has light variable or a temporal trend of LST changes equaling nearlyzero.The central areas have an increased trend of the LST changes, to be indicativeof becoming warmer, occupying about 43% of the total area. Inversely, themaritime provinces have few areas becoming cooler, shown by negative trends ofthe LST changes, occupying approximately 5%. The result is expected tocontribute usefully studies and understandings of drought and salinityintrusionin this region.