| Research Works of Graduate Student |
content > Research Works of Graduate Student
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Research of Graduate Student was adopted by international conference. Abstract of study is as follows. |
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Collaboration of REAL TIME GIS and Spatial Data for Large Scale Map ISPRS Workshop 2005 |
| Aki OKUNO |
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Much local government has been utilizing the large scale digital map with Geographic Information System (GIS). GIS will be able to work efficiently and to reduce mapping costs. Furthermore, by sharing the data with their position in local government, it is possible to improve the service to a citizen. However, the maintenance and renewal of a map database need much labor and time. The updating method of a map is not established yet and, there are very few successful examples. The purpose of this study is establishment to update of the large scale map for local government using Remote Sensing, Global Positioning System (GPS), GIS and its collaboration. In this paper, large scale map and Remote Sensing means 1/500 to 1/1000 base map and high-resolution satellite imageries (HRSI) respectively. By overlay HRSI and base map with GIS, it is possible to find the changed houses at urban area in detail. The changed area is surveyed by using GPS. GPS is able to survey absolute position with high accuracy. And, it is possible that digital map data update at real time using cellular phone and Real-Time Kinematic Global Positioning System (RTK-GPS) which has simultaneity. In this study, it was defined as the REAL TIME GIS and, the collaboration of Remote Sensing, GPS and GIS is most important point. “REAL TIME GIS” is the system for real time mapping, and updating the map at the field site using RTK-GPS and GIS. It means that host computer with GIS database is able to connect by cellular phone or Internet which stored real time data. The measuring time per point by RTK-GPS measuring needed only a few seconds, and it was possible to survey by one person. Renewal of the map can be completed very quickly. For example, this concept is able to use the barrier-free map for physically handicapped persons. A barrier-free map means the map which displayed the road whose physically handicapped person is able to pass. Displayed road needs the most recent conditions. REAL TIME GIS using RTK-GPS is powerful tool to update road conditions. Government will provide comfortable living of social environment for handicapped person. However, some important restrictions exist. Measured RTK-GPS data is Japanese Geodetic Datum 2000 (JGD2000) of WGS-84, but most of the digital map of local government is still Tokyo Datum of old geodetic system. In order to correspond with two kinds of data which have different geodetic system, it is necessary to transform coordinates. Geographic Survey Institute of Japan (GSI) opened a website for the conversion parameters and programs. Measured GPS data is able to apply to digital map in small scale. However, Base Map and thematic map which has made the large scale (1/500 or 1/1000) on the old geodetic system did not get sufficient accuracy. In this research, High-Accuracy Regional Parameter (HARP) which changes from an old geodetic system to a new geodetic system using RTK-GPS was proposed. In the verification, Affine Transformation which the most general and simple method in various geometric conversions was used. Affine Transformation makes the three parameters. There are rotation, scale and parallel transformation. These parameters transform the geodetic system (x, y) to (x’, y’). Actual experiment was performed at two places in the narrow area at Kanazawa district in Japan. How much distance there was between the digital map and measured RTK-GPS data were verified. Accuracy of two HARP was compared. Local government has over 1000 digital maps which are 1/500 scale (300m×400m). It is better that the numbers of control points are few as much as possible, because of the maintenance, management and renewal of control points need much labor and money. In the research, we discussed what kind of method was appropriate as a coordinate transformation in the area. HARP was calculated by 11 methods which was different of number and place of control points. Base Map (BM) of local government was transformed from Tokyo Datum to JGD2000 using the parameter which located 4 points at the corner of unit. RTK-GPS measuring carried out on the road line of BM. It was verified how far there are differences between BM and RTK-GPS measuring data. The difference was 5~10cm and 30 cm at longitude and latitude respectively. The differences at latitude are not allowed in large scale digital map. However, distance of both differences can be improved more and more by using the adjustment of offset. Conclusions of study are listed below. This research suggested the conversion method of the large scale digital map for the local government using RTK-GPS. The new way will support the revise of Base Map at real time. The control points for the conversion are enough at 4 points, and it has to place at the corner of unit. If the local government introduces HRSI as a background of base map, government and general user can easily recognize the conditions. We recommend that local government introduce the system of “REAL TIME GIS” and Remote Sensing imageries for their work. The simplification of mapping process, reduction of mapping and updating cost, and understanding of accurate urban conditions are connected with the improvement of the service to the citizens. As a result, collaboration of Remote Sensing, GPS and GIS is useful tool for local government to renew large scale map. Key Words: REAL TIME GIS, GIS, GPS, RTK-GPS, Remote Sensing, Large Scale Map |
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Actual experiment of renewal system for barrier-free map IGARSS 2003 |
| Naoko MATSUDA |
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Improvement of barrier-free is required because the proportion of an advanced rapidly increases in Japan. The purpose of the study is to make the map of a barrier-free for physically handicapped persons. A barrier-free map is the map, which displayed the road for physically handicapped person is able to pass. This paper focused physically handicapped person with wheelchair. Wheelchair users are limited in terms of one’s action space depending on condition of road such as a bump or steep. Government has to consider a comfortable living for the wheelchair user in their social environment. The research described that wheelchair user use Remote Sensing (RS), Real-Time Kinematic-Global Positioning System (RTK-GPS) and Geographic Information System(GIS) support to make barrier-free map. Especially, Remote Sensing means high-resolution satellite imageries in the paper. The RTK-GPS is able to survey absolute position with high accuracy. Accuracy of horizontal distance obtained by the RTK-GPS has 1-3cm at latitude and longitude. Further, the map can be renewed at real time when measure of the RTK-GPS is performed well. If equipment of the RTK-GPS attached to wheelchair, barrier-free map will able to renew every day as the imageries on computer. Wheelchair users always can get the latest information of urban conditions. Proposed system will automatically make barrier-free map. In other words, it suggests that mapping process dose not need much labor and time. Any help of volunteers do not need to collect map database. In addition, the system as mentioned above makes more useful barrier-free map using Remote Sensing imageries as a background. We hope that they easily go out into the town from their home. Combination of Remote Sensing, RTK-GPS and GIS apply to barrier-free map prepared by local government improve rapidly living environment for wheelchair users. The actual experiment was performed on the campus of Kanazawa Institute of Technology (KIT) with RTK-GPS attached to a wheelchair. Communication from reference station to rover station for the RTK-GPS depends on radio broadcasts. The purpose of the experiment is to get absolute position data measured by the RTK-GPS and to display it on a computer screen. The experiment proved that the system can measure and display data in real time on the digital map of local government’s digital map. However, the experiment showed that it was difficult to obtain continuous data showing a path. The problem was caused by the effect of multi path and communication distance from reference station to rover station. To solve these problems, a gyroscope and Virtual Reference Station (VRS) system should be adopted to make the barrier-free map for practical applications. The experiment showed that, Remote Sensing, RTK-GPS and GIS are useful tools of renewal system for barrier-free map. This research makes it possible to quickly and easily produce barrier-free maps, in order to improve the lives of handicapped persons. |
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Management of Mapping in Local Government IGARSS 2002 |
| Chieko ARAI |
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Much local government has recently utilized the digital map for Geographic Information System(GIS). The key to the problem of the utilization for GIS in local government is accurate updating of the map data. However, local government does not have established technique to renew the map data at the present. It is difficult that local government obtain the latest urban conditions because of the revision of base maps require much time. The purpose of this study is to examine real-time revision of the base map data using Remote Sensing and RTK-GPS. In this paper, it defined “REAL TIME GIS”. In addition, we consider effect on cost reduction of REAL TIME GIS to apply local government. First, Remote Sensing with the High Resolution Satellite Imageries(HRSI) was introduced to REAL TIME GIS. Such HRSI is expected to identify individual houses in urban area. Current status of houses including changes can be systematically monitored by overlay of HRSI and base map. The base map was produced from an aerial photograph by the local government in the past. The procedure of renewal has a problem that the present digital data does not correspond with the base map used in the local government. The HRSI is able to obtain the image data every day theoretically. If the local government utilizes the HRSI, the base map will indicate the latest urban conditions. Second, RTK-GPS was introduced to find the changed area in real time with HRSI. Accuracy of horizontal distance obtained by RTK-GPS has 1-3 cm at latitude and longitude. RTK-GPS and mobile phone are operated for real time mapping and updating at the field sites. The obtained data by RTK-GPS have to send to virtual map server to correspond with the base map. The base map which the local government creates is generated with general coordinates. However, the position between the base map and measured data do not correspond completely. Affine transformation was adopted to two maps for correspond geometrically. As a result, we solve the problems. The REAL TIME GIS system is not established completely. Actual experiment using RTK-GPS and HRSI is carried out in Kanazawa city, Japan from February 2001 to March 2003. In the actual experiment, we introduced the system to facility management of local government tentatively and calculate cost reduction. As a result, it was found out that about 55% of the costs that affect map renewal could be reduced. The main results of the research are as follows. The Remote Sensing and RTK-GPS help to make a map more useful in real time. The simplification of mapping processes, reduction in mapping costs, and understanding of accurate urban conditions are connected with the improvement in the service of local government to the citizens. The system of REAL TIME GIS will affect powerfully for management of base map in local government. |
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Erosion Control and Environmental Assessment by Using
GIS and Remote Sensing
ERIM 1999 |
| Junko YAMASHITA |
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In our country natural force causes most of disasters. For example, it is heavy rain and an earthquake. Every year we have calamities of landslides, mud flow and snow-slides somewhere. A lot of lives were lost in those disasters. To prevent those disasters in mountainous areas skilled engineers have been practiced the plan of erosion control with their intuition and experience. Those plans need long time and much labor; and besides, most of them ignore the environmental assessments. Purpose of the study is easily simulates such as estimating the mass of earth and sand, extracting the watershed and locating the Sabo dam by using Geographic Information System (GIS) and Remote Sensing. (Sabo dam means debris dam in English) Therefore, developed system uses digital map data (DEM of 50m mesh was made by Geographic Survey Institute of Japan) for calculation of these operations. Next we proposed to use GIS for estimating parameters. A major purpose to use GIS technique is to be overlay the data like plan of erosion control, map of environmental assessment and Remote Sensing imageries. As a results we established the simulation algorithm to decide the location of Sabo dam considered with environment conditions. This paper also described that GIS technology will useful to evaluate the erosion control and disaster management. |