Spatial data structures pdf

Spatial data structures 3 data structures to store geometric information sample applications collision detection location queries chemical simulations rendering spatial data structures for ray tracing objectcentric data structures bounding volumes space subdivision grids, octrees, bsp trees speedup of 10x, 100x. Implement the rtree data structure and the packed rtree data structure. Different gis may contain information of value to the other, but. Spatial data models and spatial data structures this section focuses on the methods available for the actual implementation of geographic models within gis. Choice of an optimal data structure depends on the. In the raster world, we have grid cells representing real world features. Spatial data models and data structures sciencedirect. The great diversity of spatial data structures is one of the reasons why exchanging spatial data between gis is problematic. The data or information that identifies the geographic location of features and boundries. A data structure is the logical view, and a file structure is the actual physical arrangement of the data. Pdf highlevel spatial data structures for gis researchgate. Height field representation collision detection hierarchical bounding volumes surgical simulations finite element method rendering.

Analysis is an important part of gis which allows spatial operations with data e. Games, movie production rendering tools permitting faster realtime rendering, intersection testing, collision detection, ray tracing, global illumination. Pdf cosmic voids, spatial algorithms and data structures. Introduction to gis and spatial data vector and raster comparison vector raster compact data structure for homogenous areas. Spatial data structures computer data algorithms and data. Traditionally, there are two broad methods used to store data in a gis for both abstractions. Spatial data structures refer to the organization of spatial data in a form suitable for digital computers. As we shall see, the term quadtree has taken on a generic meaning. Cs6345 spatial data structures suggestions for term projects. Spatial data models and structures semantic scholar.

Nonhierarchical data structures almost all data structures used in rendering of complex scenes are hierarchical in nature however, for some simpler cases, or for some special purpose situations such as gpu rendering, it is occasionally useful to have nonhierarchical data structures one possible example is a uniform grid. How does the computer see my vector and raster files. Hierarc hical data structures are based on the principle of. Spatial data can represent vector and raster data models realworld features that have discrete boundaries such as roads, buildings, lakes, rivers, administrative boundaries as well as realworld phenomenafeatures that have nondiscrete boundaries such as precipitation and nutrient levels, terrain. In particular, w e fo cus on hierarc hical data structures.

This section presents two spatial data structures for storing point data in two or more dimensions. This paper proposes a division of data structure visualization into four levels of abstraction, and shows how these abstractions can be taken into account in the. University of freiburg institute of computer science computer graphics laboratory. The design and analysis of spatial data structures aw. Spatial data structuresspatial data structures data structures to store geometric information sample applications collision detection location queries chemical simulations rendering spatial data structures for ray tracing objectcentric data structures bounding volumes space subdivision grids, octrees, bsp. The basic spatial data model is known as arcnode topology. Introduction to gis basics, data, analysis case studies.

Spatial indexing structures data structures to accelerate queries of the kind. In all cases, the geometry of these data structures consists of sets of coordinate pairs x, y. Vector data structures represent geographic objects or phenomenon as distinct geometries with specific characteristics and may also include topology. Spatial data structures free download as powerpoint presentation. Spatial data, also known as geospatial data, is a term used to describe any data related to or containing information about a specific location on the earths surface. Spatial data structures umd department of computer science. Visualization of spatial data structures on different levels of. The term quadtr e is often used to describ e man y elemen ts of this class of data structures. Pdf the design and analysis of spatial data structures. Computer graphics, image processing and gis addisonwesley series in computer science samet, hanan on. Data structures and intersection algorithms for 3d spatial. One of the strengths of the vector data model is that it can be used to render geographic features with great precision however, this comes at the cost of greater complexity in data structures, which sometimes translates to slow processing speed.

Spatial data structures answer questions like\who is near me\. Lecture 1 intro to gis and gis vector and raster data models. Spatial data, as used in geographic information systems, gives rise to particular problems in deriving suitable data models and structures because of the diverse sources and applications of the data. The fo cus is on hierarc hical data structures, includin g a n um ber of v arian ts of quadtrees, whic h sort the data with resp ect to the space o ccupied b y it. Can overlay displays easily can easily manipulate data table can have many variables linked to one geographic file better suited for map output a simple data structure. Spatial data structures are structures that manipulate spatial data, that is, data that has geometric coordinates. Spatial data structures data structures that organize geometry in 2d or 3d or higher the goal is faster processing needed for most speedup techniques primary applications. Spatial data comes up in many areas of computer science, like geographic information systems gis, robotics, computer graphics, virtual reality, as well as in other disciplines like. Lets look more in depth at the differences between raster and vector. A printable pdf version of this project list is available here.

The most common solution, and the one that we focus on in the rest of this chapter, is to use data structures that are based on spatial occupancy. Attribute data the information linked to the geographic features spatial data describing them data layers are the result of combining spatial and attribute data. One such data structure is the quadtree octree in three dimensions. A framework is proposed consisting of spatial concepts. Spatial data types provide the information that a computer requires to reconstruct the spatial data in digital form. Pdf spatial data structures kristin stock academia. The state records administrator also provides direction and guidance on data release and fees. Spatial data model vector data model raster data model attribute data attribute aspatial information is the label name categorisation descriptiong associated with a spatial object the attributes can be as important as the spatial data themselves may be more complex than the spatial data may be a simple text label e. Spatial data structures spatial data structures describe the rules that are used to represent geographic data in geographic information systems gis. On earth, such as natural and construted features like ocean, lake, pond etc. Spatial data structures computer data algorithms and.

Fifth, those intersection algorithms that have been designed for 3d spatial objects require very tailormade internal data representations that are not suitable to implement other 3d operations. Spatial data structures and acceleration algorithms. Spatial data structures store data objects organized by position and are an important class of data structures used in geographic information systems, computer graphics, robotics, and many other. The gis spatial data model university of washington. Moreover, it contains kdtree implementations for nearestneighbor point queries, and utilities for distance computations in various metrics. In the vector world, we have points, lines and polygons that consist of vertices and paths. Pdf the chapter focuses on the semantics of spatial concepts and their formalizations. Real world objects can be divided into two abstractions. Consequently, their understanding is a prerequisite for an effective construction of important components of a spatial database system like spatial index structures, optimizers for spatial data, spa. Scribd is the worlds largest social reading and publishing site.

Essentially adding the attribute database to the spatial location. Spatial data structures carnegie mellon university. State records administrator the acting state records administrator, jan mccormick at 5038086655, is responsible for identifying any privacy issues related to spatial data. No matter what your interests are or what field you work in, spatial data is always being considered whether you know it or not. The focus is on hierarchical data structures, including a number of variants of quadtrees, which sort the data. Such methods decompose the space from which the spatial data is drawn e. An overview is presented of the use of spatial data structures in spatial databases. In this paper we define the spatial data structure and discuss the manipulation of a spatial database for answering queries and for structural matching. They are based on the principle of recursiv e decomp osition similar to divide and c onquer metho ds. High spatial variability is efficiently represented only raster can store image data e.