440 likes | 600 Views
Chapter 2: Geospatial and Space Technology. GST. Outline. Core Study Areas Data Sources Data Processing Potential Areas of Applications. Geodesy and Geodynamics.
E N D
Outline • Core Study Areas • Data Sources • Data Processing • Potential Areas of Applications
Geodesy and Geodynamics • Geodesy is the study of the geometry of the earth including its gravity field. The study of geodesy deals generally with the determination of the figure and size of the earth as well as with the study of the earth’s gravity field. • Geodynamics on the other hand is concerned with the study of the dynamics of the solid earth including the study and monitoring of plate tectonics, earthquakes, and volcanic eruptions. Geodetic methods are core to the study of geodynamics. Geodesy and geodynamics form the scientific foundation on which various aspects of geospatial engineering are based.
Positioning and Navigation • Positioning is about the determination of position of a point on or near the earth’s surface. Positioning is closely allied to navigation, which is concerned with the determination of the position of an object in motion. Both in positioning and in navigation, one requires well-established reference coordinate systems, in four-dimensional space, which comprises the definition of position in terms of place and time. The reference coordinate system provides a reference with respect to which the location of the point or object is to be given.
Shape of the Earth It is actually a spheroid, slightly bulged at the equator and flattened slightly at the poles We think of the earth as a sphere
ECEF Coordinate System • Orientation of the axes: • Origin is at the center of mass of the earth. • xy-plane is coincident with earth’s equatorial plane. • x-axis points in the direction of Greenwich meridian. • z-axis is chosen normal to the equatorial plane in the direction of the geographic north pole. • y-axis completes the right handed coordinate system
Geographic Coordinates (f, l, h) • Cartesian (ECEF) coordinates are cumbersome in daily use. • An alternative is to represent the position information in geodetic coordinates – latitude, longitude and height or elevation. • Latitude (f) and Longitude (l) defined using anellipsoid, (i.e.), an ellipse rotated about an axis. • Elevation (z) defined usinggeoid, a surface of constant gravitational potential. • Earthdatumsdefine standard values of the ellipsoid and geoid
Topometry and Measurement Systems • Topometry is simply the measurement of topography, taken in its broadest sense to cover the measurement of topography of any object. Topometry thus finds application in the measurement of topography of small artefacts such as bolts and nuts to the measurement of the topography of the earth and even of other planets. Topometric measurements rely on sophisticated measurement systems ranging from those required for precise, industrial, metrology to satellite positioning systems for the measurement of the topography of the earth and the planets. The knowledge in topometry finds application in such areas as in the design and construction of robots, in biomedical engineering, in civil engineering design and construction, in machine guidance and control, in precision industrial measurements, and in the modelling of the environment. The instruments used in Geospatial Engineering are almost exclusively sensor based. Thus this aspect of the discipline covers also the understanding of the working principles of geo-spatial sensors and instruments as well as with their design and construction.
Geoinformatics and Visualisation • Geoinformatics is concerned with the application of modern computer information systems to the analysis of geo-spatial phenomena and systems. It comprises particularly the disciplines of cartography, photogrammetry, remote sensing, and geo-spatial information systems (GIS). • Spatial data visualisation (SDV) on the other hand is concerned with the manipulation of graphic representation of geo-spatial data as to be able to realise three-dimensional visualisation of such data. Through SDV one is in a position to create virtual reality models of geo-spatial systems and objects.
Land Management and Infrastructure Management • This is a traditional area of land surveying which is concerned with policy issues in land management on one hand and the management of infrastructure on the other hand. It covers surveys for land management and the design, development, and use of land information systems (LIS) including digital and three-dimensional cadastres. Facility management on the other hand is a modern area of professional practice concerned with the application of information technology in the management of infrastructure. In both these cases, the question of ‘location’ is of critical importance, hence the consideration of this as an integral aspect of geo-spatial engineering.
Disaster Monitoring-Japan Before Earthquake After Earthquake
Forestry & GPS/GIS GPS and GIS technologies result in rapid collection and coding of data presentation of data in numerous formats • Text based tables • Colour maps GPS/GIS combination brings in analytical power. GIS is a great mapmaking tool GIS has the ability to analyze the information.
Mining Industry • GPS for open pit mining • Pseudolites • Shovels • Truck Management system • Surveying • Drilling blast holes precisely • Open pit mining equipment can be controlled using inputs provided by GPS • Fleet Management • Quarry Applications ( Cement factory – monitoring the vehicle and driver too )
LIDAR GPS for Airborne Mapping
GPS augmentation: personal navigation supported by the human locomotion model
Military Uses • PLGR GPS ReceiverThe Man pack was replaced in 1993 by the hand-held Precision Lightweight GPS Receiver (PLGR) • These units are similar to civilian receivers, but they can use higher-precision GPS signals.
Marine Navigation • Increased marine safety. • GPS and wireless communications deliver precise position information over wireless satellite links for emergency reports, navigation and tracking. • DGPS based systems place and maintain buoys, lights, and day markers that direct traffic in harbours, and on coastlines, rivers and lakes. • DGPS systems are used aboard competitors and committee boats, and provide precision placement for race course marks. • harbour, Inland Waterway • Traffic Service