Innovations in GIS 4 ppt

[...]... as GIS are maturing’ or GIS are growing up’ In part, this push has been user-driven, with more and more application domains emerging with requirements to handle, manipulate and analyze spatio-temporal information The GIS research community has responded accordingly, by expanding its horizons to include emerging technologies such as remote sensing and global positioning systems, while continuing to... or objects, in terms of points, lines and polygons Polygons are defined by lists of lines, while lines are defined by lists of points Objects are defined by the polygon, line and point features from which they are made up In the original CDP, spatial access was facilitated by the hierarchical links between pyramid levels The MTSD replaces these links with an alternative structure consisting of two regular... the fact that individual data sets will often carry only incomplete information about the geology they are seeking to represent (Rhind, 1989; Kelk, 1989) This incomplete information can be attributed to the difficulties and high financial costs incurred when collecting geoscientific data The problem is exaggerated by the often complex nature of geological structures 8 INNOVATIONS IN GIS 4 In order to... by applying a constrained Delaunay triangulation algorithm to the data Initially, all terrain points and points forming part of geological outcrop objects are grouped together and Delaunay triangulated This is followed by the process of inserting into the triangulation the line parts from which the geological outcrop objects are made, as a series of constraining line segments The constraining technique... generating a second fault line Ft consisting of points (t1, t2, …,tm) Here it follows that the first and last points, t1 and tm, are equal to s1 and sm, respectively The intervening points, (t2, t3,…, rm-1) can be generated by offsetting the coordinates of each of the corresponding points (s2, s3,…, sm-1) in the direction of fault dip The size of each point’s offset will be in relation to that point’s... happen to be subsumed in the overall themes chosen for emphasis in this particular volume of Innovations in GIS Part I, Data modelling and spatial data structures, deals with issues that affect the data engines that underlie all GIS There has already been substantial research in this area into the modelling, storage, indexing and retrieval of spatially referenced entities that exist in space and through... triangulation, taken from De Floriani et al (19 84) , will be referred to as error-directed point insertion For the purpose of inserting constraining linear features into the pyramid, the method of classifying vertices by means of the vertical error criterion is inadequate, since no account is taken of lateral variation in shape It will often be the case that the constraining features have been derived from a... creating CDPsi In its application to subsurfaces, a minor alteration in how the CDP algorithm is applied is in the insistence that when objects are included in a subsurface pyramid, CDPsi, then the level at which their constituent point parts appear in the pyramid is governed by the level at which each point part appears in CDPg This ensures that there is consistency between constraining edges within... system to provide generic support for GIS Finally, in Chapter 4, Dean Lombardo and Zarine Kemp, also computer scientists at the University of Kent at Canterbury, focus on the requirement to extend the capabilities of GIS data engines to seamlessly handle multimedia data types This work is influenced by research into multimedia databases, including modelling, storage, indexing, management and retrieval of... elevation points constrain ing edges 5.0 168 216 227 49 71 70 Creation time (s) 16 INNOVATIONS IN GIS 4 Database Number Vertical Lateral Number Number name of levels error (m) error (m) of terrain of object points point parts Bl 2 3 B2 Number Number of subsurface of elevation points constrain ing edges Creation time (s) 317 515 161 317 515 150 289 737 25.5 B3 12.5 1.0 35.0 10.5 1.0 40 .0 7.5 0.5 3 3 2.5 1.0 . w0 h0" alt="" Innovations in GIS 4 Selected Papers from the Fourth National Conference on GIS Research UK (GISRUK) Innovations in GIS 4 Selected Papers. M.Atkinson 152 13 Towards a 4D GIS: four-dimensional interpolation utilizing kriging Eric J.Miller 170 14 Assessing the influence of digital terrain model