Sharing and cooperation in geo-information technology

Aziz, T. Lukman

Bibliographic data

Monograph

Persistent identifier:: 856479470

Author:: Aziz, T. Lukman

Title:: Sharing and cooperation in geo-information technology

Sub title:: ISPRS Commission VI Symposium, April 15 - 17, 1999, Bandung, Indonesia

Scope:: 1 Online-Ressource (130 Seiten)

Year of publication:: 1999

Place of publication:: London

Publisher of the original:: RICS Books

Identifier (digital):: 856479470

Illustration:: Illustrationen, Diagramme

Language:: English

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2016

Document type:: Monograph

Collection:: Earth sciences

Chapter

Title:: WG VI/3: INTERNATIONAL COOPERATION AND TECHNOLOGY TRANSFER

Write comment:: Der Aufsatz "Promotion Of The General Understanding And Improvement Of Public Relations, [...] ist im Original nicht enthalten.

Document type:: Monograph

Structure type:: Chapter

Chapter

Title:: GIS TECHNOLOGY TO SUPPORT SURVEY DATA AND MANAGEMENT OF DIFFERENT QUARRY TYPOLOGIES. Carlo MONTI

Document type:: Monograph

Structure type:: Chapter

63 1.2.2 Mixed quarry The mixed quarries are characterised both from open fronts and from the superficial and the deep stratum. For the first one we remand to the last paragraph, only adding that is difficult to determine the fronts of discontinuity nearly to the immersion under the water, hi this case due to the high influence of the relevant under water part, which is more regularly than the open parts, the decrease of the accuracy of the volume estimation with the decreasing of the density of points is lesser respect to the case of total open quarry. In this case the optimal grid is attested on a 20x20m grid. A grid of 5x5m describe sufficiently the volume of extraction. For the under water sectors we remand to the following paragraph. Fig. 7 The detail survey of a mixed quarry (Cemusco sul Naviglio). 1.2.3 Under water quarry and sectors hi the case studio it has been surveyed 58933 points. For these cases is necessary to use a quality bathymeter: once guaranteed the accuracy on the measure of the deep , the problem is the georeferentiation of the data in the global datum of the quarry that is the national Gauss-Boaga datum RM40. Is fundamental to synchronise the bathymetric measure with the topographic measure of position. Particularly the bathymetric systems (in which is acquired in continuous the measure of the depth interpolating the position by the supposition of constant velocity of the ship along the course) are not reliable. The instrumentation considered optimal and then tested in the survey in the stratum is represented by an integrated system GPS-bathymeter that allows a regularly distribution of the points surveyed. In this case are used two antennas GPS, one positioned on a vertices of the fundamental network and the second on the ship. To survey the distance between the two antennas it isn’t requested the mutual visibility. Once defined the direction along which to trace the bathymetric sections, the system guides the course of the ship calculating in automatic the new courses in function of the density requested in the project of the survey. A PC allows to visualize in real time the points surveyed, the depth and the course traced shown by an arrow. The suggested characteristics of the instruments. The GPS modality adopted is the so called RTK (Real Time Kinematic), it has large diffusion, it is made by a Master station in correspondence of one vertices of the fundamental network and by a mobile antenna (Rover) positioned on the ship in correspondence of the bathymeter or in a position out of the centre but known. The only limits is the necessity of the mutual visibility of at least 5 satellites actually guaranteed during the day at our latitude. Tire two antennas are connected by a radio-modem and this allows to the rover receiver to calculate the position respect to the master and to the global datum in real time. Once predetermined the equidistant courses (5m for the interesting areas and 10 meters for remaining Fig. 8 The detail survey of an under water quarry (Peschiera Borromeo). areas) and introduced the data of the course in the navigation programme is obtained on video the directions which the ship has to follows in real time with GPS. Contemporary has been acquired the data position fixed in number of 2 per second and the data of the depth (obtained by the average of 5 observation of the echo sounder which measure every 2/10 of second. With this methodology it has been surveyed in the case studio: 58933 points for the precedent case 25396 points for the quarry totally under water. 2. The DTM and the calculation of the volume The calculation of the volumes has been obtained building Digital Terrain Model (DTM) and interpolating the detail points surveyed for each quarry: 50.000 surveyed points tor the under water quarry and 15.000 points for the open quarry. The DTM can be obtained interpolating the height of the points to obtain a regular grid or a TIN network. The Software Surfer has been used to build the DTM (ver. 6.01 Golden Software) through Kriging standard interpolation. On the DTM are obtained the contour line (2m equidistant) to describe the orographic shape of the terrain.

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