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Spatial and Geographic Databases Course outlines Fundamentals of GIS - Overview Spatial and Geographic Data(bases) Why Study GIS? What is GIS? What’s in a GIS? GIS vs. Other Systems - How GIS differs from Related Systems GIS System-Architecture and Components GIS Spatial Data Model GIS Spatial and Attribute Data How a GIS Organizes Spatial Data? Raster and Vector data Model - Spaghetti & Topologic Vector Data Model Representing Surfaces – DEM, TIN, Contour (isolines) Lines File Formats for Raster and Vector data models Spatial Database Management? Querying Data & Indexing of Spatial Data Sources of Geographic Data Appendix - GIS Software Packages, GIS File Formats Fundamentals of GIS - Overview Spatial and Geographic Data(bases) Spatial databases store information related to spatial locations, and support efficient storage, indexing and querying of spatial data. “Special index structures are important for accessing spatial data, and for processing spatial join queries.” Examples of geographic/spatial data map data for vehicle navigation distribution network information for power, telephones, water supply, and sewage Vehicle navigation systems store information about roads and services for the use of drivers: Spatial data: e.g, road/restaurant/gas-station coordinates Non-spatial data: e.g., one-way streets, speed limits, traffic congestion Global Positioning System (GPS) unit utilizes information broadcast from GPS satellites to find the current location of user with an accuracy of tens of meters. increasingly used in vehicle navigation systems as well as utility maintenance applications. Geographic databases store geographic information (e.g., maps): often called geographic information systems or GIS. 2 Why Study GIS? 80% of local government activities estimated to be geographically based plats, zoning, public works (streets, water supply, sewers), garbage collection, land ownership and valuation, public safety (fire and police) A significant portion of state government has a geographical component natural resource management, highways and transportation Businesses use GIS for a very wide array of applications retail site selection & customer analysis logistics: vehicle tracking & routing natural resource exploration (petroleum, etc.) precision agriculture, civil engineering and construction Military and defense Battlefield management Satellite imagery interpretation Scientific research employs GIS geography, geology, botany anthropology, sociology, economics, political science Epidemiology, criminology 3 Knowledge Base for GIS Computer Science/MIS graphics visualization database system administration security GIS Geography and related: cartography geodesy photogrammetry landforms spatial statistics. Application Area: public admin. planning geology mineral exploration forestry site selection marketing civil engineering criminal justice surveying The convergence of technological fields and traditional disciplines. 4 Applied GIS - Examples Urban Planning, Management & Policy Zoning, subdivision planning Land acquisition, Economic development Code enforcement Housing renovation programs Emergency response Crime analysis, Tax assessment Environmental Sciences Monitoring environmental risk Modeling storm-water runoff Management of watersheds, floodplains, wetlands, forests, aquifers Environmental Impact Analysis Hazardous or toxic facility siting Groundwater modeling and contamination tracking Political Science Redistricting Analysis of election results Predictive modeling Civil Engineering/Utility Locating underground facilities Designing alignment for freeways, transit Coordination of infrastructure maintenance Business Demographic Analysis Market Penetration/ Share Analysis Site Selection Education Administration Attendance Area Maintenance Enrollment Projections School Bus Routing Real Estate Neighborhood land prices Traffic Impact Analysis Determination of Highest and Best Use Health Care Epidemiology Needs Analysis Service Inventory 5 What is GIS? Defining Geographic Information Systems (GIS) A powerful set of tools for collecting, storing, retrieving, transforming, and displaying spatial data from the real world. (Burroughs, 1986) A computerized database management system for the capture, storage, retrieval, analysis and display of spatial (locationally defined) data. (NCGIA, 1987) A decision support system involving the integration of spatially referenced data in a problem solving environment. (Cowen, 1988) …intuitive description A map with a database behind it. A virtual representation of the real world and its infrastructure. A consistent “as-built” of the real world, natural and manmade queried to support on-going operations summarized to support strategic decision making and policy Which is formulation analyzed to support scientific inquiry 6 GIS overview… What’s in a GIS? GIS had three main components: a Database Management System; a Spatial Analytical Toolkit; a Mapping Package. GIS technology integrates common database operations (such as query and statistical analysis) with the unique visualisation and geographic analysis benefits offered by maps. Database Management System route finding buffering polygon overlay Spatial Analysis Tool kit attributes GIS Mapping Package points, lines, areas features layers 7 GIS vs. Other Systems How GIS differs from Related Systems DBMS - typical MIS data base contains implicit but not explicit locational information city, county, zip code, etc. but no geographical coordinates is 100 N. High around the corner or across town from 200 E Main? Automated mapping (AM) - primarily two-dimensional display devices thematic mapping (choropleth,etc such as SAS/GRAPH, DIDS, business mapping software) unable to relate different geographical layers (e.g zip codes and counties) automated cartography--graphical design oriented; limited database ability Facility management (FM) systems - lack spatial analysis tools CAD/CAM (computer aided design/drafting) - primarily (engineering design) & display systems 3-D graphic creation don’t reference via geographic location (CAD sees the world as a 3D cube, GIS as a 3D sphere) limited (if any) database ability (especially for non-spatial data) Scientific visualization systems - sophisticated multi-dimensional graphics, but: lack database support lack two-dimensional spatial analysis tools 8 GIS as a computer system GIS System-Architecture and Components Data input subsystem collects and processes spatial data from various sources, allows user to import, create, and edit spatial and tabular data Sub-system definition of GIS Data storage and retrieval subsystem provides storage, retrieval, updating and editing capabilities. Data manipulation & analysis subsystem provides to tools to examine characteristics of the data and model building capabilities (classification, modeling functions). A reporting subsystem provides tools for designing/displaying maps, graphics, text, and tabular reports Query-Input Geographic Database “Data-Storage” GIS main functions Data acquisition (spatial and non-spatial) & processing (data management) Data storage (Store data more efficiently) Data querying & analysis (Spatial & statistical) most important tool Data output - Visualization Data-Input Output: Display and Reporting ? Transformation and Analysis 9 GIS engineering… We have to deal with: GIS Adapted Spatial Data Models, formats Data acquisition, collecting, importing, creating, and editing Asking about the more powerful data management tool(s) GIS Querying Data manipulation Spatial & statistical analysis Query-Input Geographic Database “Data-Storage” A reporting & Visualization End-user interface Web-based front-end… Data-Input Output: Display and Reporting ? Transformation and Analysis 10 GIS Spatial Data Model Allowing Data acquisition, collecting, importing, creating, and editing Asking about the More powerful Spatial Data Management tools The GIS Data Model GIS Spatial Data Model – an overview allows the geographic features in real world locations to be digitally represented and stored in a database so that they can be abstractly presented in map (analog) form, and can also be worked with and manipulated to address some problem map Real world ? 12 GIS Spatial and Attribute Data GIS includes Spatial data (specifies location; where). Spatial data can be stored-in/obtained-from a shape (digital) files or maps images Coordinate system Latitude (Ø) and longitude () A planar coordinate system is defined by a pair of orthogonal (x,y) axes drawn through an origin (Øo, o) Descriptive data (Øo, o) (Attribute; specifies characteristics at that location (what, how much, when). Descriptive data can be stored in a database table or obtained from reports, statistical outcomes, etc. GIS systems traditionally maintain spatial and attribute data separately, then “join” them for display or analysis. 13 The GIS Data Model How a GIS Organizes Spatial Data? A GIS can model the world in a layered ways. The ‘layered’ approach where data is held (organized by) in thematic layers i.e. all water features will be contained in a Hydrology layer, etc. In this approach a GIS stores information about the world as a collection of thematic map layers Layers are integrated using explicit location on the earth’s surface, they can be linked together by geography. The thematic layer approach allows us to organise the complexity of the real world into a simple representation to help facilitate an understanding of natural relationships. AdministrativeBoundaries Zoning Buildings Parcels Hydrology Streets Digital Orthophoto … GIS Data 14 The GIS Data Model An example Here we have three layers or themes: Roads longitude roads, hydrology (water), topography (land elevation) They can be related because precise geographic coordinates are recorded for each theme. Layers are comprised of two data types hydrology Spatial data which describes location (where) Attribute data specifying what, how much, when Layers may be represented in two ways: in vector format as points and lines in raster (or image) format as pixels topography All geographic data has 4 properties: projection, scale, accuracy and resolution 15 Projection, Scale, Accuracy and Resolution the key properties of spatial data Projection: the method by which the curved 3-D surface of the earth is represented by X,Y coordinates on a 2-D flat map/screen distortion is inevitable Scale: the ratio of distance on a map to the equivalent distance on the ground in theory GIS is scale independent but in practice there is an implicit range of scales for data output in any project Accuracy: how well does the database info match the real world Positional: how close are features to their real world location? Consistency: do feature characteristics in database match those in real world is a road in the database a road in the real world? Completeness: are all real world instances of features present in the database? Are all roads included. Resolution: the size of the smallest feature able to be recognized for raster data, it is the pixel size 16 Representing Data with Raster and Vector Models Raster Model (Location-based) area is covered by grid with (usually) equal-sized, square cells attributes are recorded by assigning each cell a single value based on the majority feature (attribute) in the cell, such as land use type. Image data is a special case of raster data in which the “attribute” is a reflectance value from the geomagnetic spectrum (cells in image data often called pixels “picture elements”) Vector Model (Object-based) The fundamental concept of vector GIS is that all geographic features in the real work can be represented either as (because representation depends on shape) : points or dots (nodes): trees, poles, fire plugs, airports, cities lines (arcs): streams, streets, sewers, areas (polygons): land parcels, cities, counties, forest, rock type line point polygon Vector format often used to represent map data. Roads can be considered as two-dimensional and represented by lines and curves. rivers, may be represented either as complex curves or as complex polygons, depending on whether their width is relevant. Features such as regions and lakes can be depicted as polygons. 17 The Raster and Vector data model An example of Real World containing: Trees, River, Houses Real World Digital representation Raster Representation Vector Representation 18 Vector Data Model Spaghetti Vector Data Model Each point, line, or polygon is stored as a record in a file that consists of that entity’s ID and a list of coordinates that define geometry. ID Coordinates p1 p2 5,6 19,17 l1 l2 (2,1), (11,8), (13,20) (13,2), (18,1), (20,5) a1 a2 (2,12), (8,13), (5,19) (14,7), (20,8), (19,12), (16,11) Advantages Disadvantages For points p2 l1 15 a1 For lines 10 a2 For polygons p1 5 l2 0,0 simple efficient for display and plotting 5 10 15 inefficient for most types of spatial analysis 19 Vector Data Model Topologic Vector Data Model Composed of points, lines, and polygons Node: a point at the intersection of three or more lines n1 In addition to coordinate locations, the topologic relationships among geometric features are explicitly recorded a3 C a4 Arc a1 a2 a3 a4 Start End n1 n2 n1 n2 n1 n2 n2 n1 Arc a1 a2 a3 a4 Left Right A A B C C B StartXY 4,5 4,5 4,5 4,3 Arc Topology a1 n2 Planar Enforcement: No two individual features can overlap. There are no ‘holes’ or ‘íslands’ that are not themselves features. Every feature is represented as a record in the attribute table. Node Topology Node Arcs n1 a4, a2, a1, a3 n2 a2, a4, a3, a1 A B a2 Arc Coordinate Data IntermediateXY EndXY (4,8), (8,8), (8,1), (4,1) 4,3 (6,7), (6,3) 4,3 (1,3) 4,3 4,5 Polygon Topology ID A B C Arcs a1, a2 a2, a4 a3, a4 20 Raster, Vector Data Model Vector layers Examples Land Parcels layer: polygons Street Network layer: lines Raster (image) Layer: Digital Ortho Photograph Layer Overlay based on Common Geographic Location 0 1500 3000 Feet Example Digital Ortho photo: combines the visual properties of a photograph with the positional accuracy of a map, in computer readable form. Projection: Resolution: Accuracy: Scale: State Plane, North Central Texas Zone, NAD 83 0.5 meters 1.0 meters see scale bar 21 Representing Surfaces – an overview Surfaces involve a third elevation value (z) in addition to the x,y horizontal values Surfaces are complex to represent since there are an infinite number of potential points to model Three (or four) alternative digital terrain model approaches available: z x y Raster-based digital elevation model - Regular spaced set of elevation points (z-values) Vector based triangulated irregular networks - Irregular triangles with elevations at the three corners Vector-based contour lines - Lines joining points of equal elevation, at a specified interval Massed points and breaklines The raw data from which one of the other three is derived Massed points: Any set of regular or irregularly spaced point elevations Breaklines: point elevations along a line of significant change in slope (valley floor, ridge crest) 22 Representing Surfaces – DEM Digital Elevation Model (DEM or MNT) A sampled array of elevations (z) that are at regularly spaced intervals in the x and y directions. Two approaches for determining the surface z value of a location between sample points. In a lattice, each mesh point represents a value on the surface only at the center of the grid cell. The z-value is approximated by interpolation between adjacent sample points; it does not imply an area of constant value. A surface grid considers each sample as a square cell with a constant surface value. Advantages Simple conceptual model Data cheap to obtain Easy to relate to other raster data Irregularly spaced set of points can be converted to regular spacing by interpolation Real World 2124 … 2011 2012 … 2022 … 1230 2123 … … DEM Visualization Disadvantages Does not conform to variability of the terrain Linear features not well represented 23 Representing Surfaces – TIN Triangulated Irregular Network (TIN) a set of adjacent, nonoverlapping triangles computed from irregularly spaced points, with x, y horizontal coordinates and z vertical elevations. 24 Representing Surfaces – TIN Triangulated Irregular Network (TIN) Surface Points Polygons Node # X Y Z 1 0 999 1456 2 525 1437 1437 3 631 886 1423 etc Elevation points (nodes) chosen based on relief complexity, and then their 3-D location (x,y,z) determined. 2 1 A D 6 B 3 C 4 H E G F 5 Polygon Node #s Topology A 1,2,4 B,D B 2,3,4 A,E,C C 3,4,5 B,F,G D 1,4,6 A,H etc Elevation points connected to form a set of triangular polygons; these then represented in a vector structure. Advantages over raster: Attribute Info. Database Poly gons Var 1 A 1473 B 1490 C 1533 D 1486 etc. Var 2 15 100 150 270 Attribute data associated via relational DBMS (e.g. slope, aspect, soils, etc.) fewer points captures discontinuities (e.g ridges) slope and aspect easily recorded Disadvantages: Analysis involving comparison with other layers difficult Representing Surfaces – Isolines Contour (isolines) Lines Contour lines, or isolines, of constant elevation at a specified interval, Advantages Familiar to many people Easy to obtain mental picture of surface Close lines = steep slope Uphill V = stream Downhill V or bulge = ridge Circle = hill top or basin Disadvantages Poor for computer representation: no formal digital model Must convert to raster or TIN for analysis Contour generation from point data requires sophisticated interpolation routines, often with specialized software such as Surfer from Golden Software, Inc., or ArcGIS Spatial Analyst extension 26 Storing data issues… File Formats for Raster Spatial Data The generic raster data model is actually implemented in several different computer file formats: GRID is ESRI’s proprietary format for storing and processing raster data Standard industry formats for image data such as JPEG, TIFF and MrSid formats can be used to display raster data, but not for analysis (must convert to GRID) Georeferencing information required to display images with mapped vector data (mapping raster to vector…) - Requires an accompanying “world” file which provides locational information Image Image File World File TIFF image.tif image.tfw Bitmap image.bmp image.bpw BIL image.bil image.blw JPEG image.jpg image.jpw Although not commonly encountered, a “geotiff’ is a single file which incorporates both the image and the “world” information is a single file. 27 Storing data issues… File Formats for Vector Spatial Data Generic models above are implemented by software vendors in specific computer file formats Coverage: vector data format introduced with ArcInfo in 1981 multiple physical files (12 or so) in a folder proprietary no published specs & ArcInfo required for changes Shape ‘file’: vector data format introduced with ArcView in 1993 comprises several (at least 3) physical disk files (with extension of .shp, .shx, .dbf), all of which must be present openly published specs so other vendors can create shape files Geodatabase: new format introduced with ArcGIS 8.0 in 2000 Multiple layers saved in a singe .mdb (MS Access-like) file Proprietary, “next generation” spatial data file format Shapefiles are the simplest and most commonly used format 28 Building a GIS Information Spatial Database Management? How do we incorporate spatial data into a computer application system? SPATIAL OBJECT Usually by using a relational Data Base Management System (DBMS) GIS systems traditionally maintain spatial and attribute data separately, then “join” them for display or analysis. The spatial data can be store in vector or raster format ATTRIBUTE SPATIAL DBMS Vector format represents data in a series of (X,Y) coordinates Raster format represent data in a series of columns and rows-Matrix (Pixel, cell) GIS Database Accuracy Vector data are accurate and takes less storage, but take long time e.g. digitization Raster data are inaccurate and takes large storage, but takes short time e.g. scanning (1) SPATIAL OBJECT Hybrid vs. Integrated Approaches Hybrid Approach: ATTRIBUTE stores spatial data and attribute data in different data models (typically relational data model for attribute data and proprietary data structure for spatial data). Integrated Approach: stores spatial and attribute data using the same data model (typically using the relational data model in a single RDBMS). SPATIAL DBMS GIS Database (2) 29 Spatial Database Management System Spatial Database Management System (SDBMS) provides the capabilities of a traditional database management system (DBMS) while allowing special storage and handling of spatial data. SDBMS: Works with an underlying DBMS Allows spatial data models and types Supports querying language specific to spatial data types Provides handling of spatial data and operations SDBMS Three-layer Structure SDBMS works with a spatial application at the front end and a DBMS at the back end SDBMS has three layers: Interface to spatial application Core spatial functionality Interface to DBMS Spatial application Interface to spatial application Core Spatial Functionality Taxonomy, Data types Operations, Query language Algorithms, Access methods Interface to DBMS DBMS 30 Querying Data A GIS must provide tools for finding specific features based on their location or attributes. Queries, which are often created as logical statements or expressions, are used to select features on the map and their records in the database. A common GIS query is to determine what exists at a particular location. the user knows where the features of interest are, but wants to know what characteristics are associated with them. This can be accomplished with a GIS because geographic features on the map display are linked to their attributes stored in the database. Another type of GIS query is to determine which location or locations satisfy certain conditions. In this case, the user knows what characteristics are important and wants to find out where the features are that have these characteristics. 31 Querying Data… Spatial Queries How many elderly in Richardson live further than 10 minutes at rush hour from ambulance service? Nearness queries request objects that lie near a specified location. Nearest neighbor queries, given a point or an object, find the nearest object that satisfies given conditions. Region queries deal with spatial regions. e.g., ask for objects that lie partially or fully inside a specified region, that compute intersections or unions of regions. Spatial join of two spatial relations with the location playing the role of join attribute. Graphical user interface – constituting the front-end Spatial data is typically queried using a graphical query language; results are also displayed in a graphical manner. Extensions of SQL with abstract data types, such as lines, polygons and bit maps, have been proposed to interface with back-end. Queries can use spatial conditions (e.g. contains or overlaps). Queries can mix spatial and nonspatial conditions 32 Querying Data… Spatial Query Language Number of specialized adaptations of SQL Spatial query language Temporal query language (TSQL2) Object query language (OQL) Object oriented structured query language (O2SQL) Spatial query language provides tools and structures specifically for working with spatial data SQL3 provides 2D geospatial types and functions Spatial Query Language Operations - Three types of queries: Basic operations on all data types (e.g. IsEmpty, Envelope, Boundary) Topological/set operators (e.g. Disjoint, Touch, Contains) Spatial analysis (e.g. Distance, Intersection, SymmDiff) 33 Querying Data… Example Spatial Query County (Name, State, Population, Shape); River (Name, Source, length, Shape); Find all the counties that border on Contra Costa county SELECT C1.Name FROM County C1, County C2 WHERE Touch(C1.Shape, C2.Shape) = 1 AND C2.Name = ‘Contra Costa’; Find all the counties through which the Merced river runs SELECT C.Name, R.Name FROM County C, River R WHERE Intersect(C.Shape, R.Shape) = 1 AND R.Name = ‘Merced’; Analysis How County and River entities could implemented How the above Touch and Intersect operation could be implemented… One approach : the Object Orientation facilities may provide the more adequate support. 34 Querying Data… Analysis Data Table Photographic Image 35 More examples… High yaw contraction requires spatial intersection analysis Dam contraction requires 3D analysis 36 Radar location 37 3D studding Area- risk analysis Providing “Building permits” requires spatial analysis – flooding risk analysis 38 Spatial indexing-an overview Indexing of Spatial Data k-d tree - early structure used for indexing in multiple dimensions. Each level of a k-d tree partitions the space into two. choose one dimension for partitioning at the root level of the tree. choose another dimensions for partitioning in nodes at the next level and so on, cycling through the dimensions. In each node, approximately half of the points stored in the subtree fall on one side and half on the other. Partitioning stops when a node has less than a given maximum number of points. The k-d-B tree extends the k-d tree to allow multiple child nodes for each internal node; well-suited for secondary storage. 39 Spatial indexing-an overview Division of Space by Quadtrees Each line in the figure (other than the outside box) corresponds to a node in the k-d tree the maximum number of points in a leaf node has been set to 1. The numbering of the lines in the figure indicates the level of the tree at which the corresponding node appears. Each node of a quadtree is associated with a rectangular region of space; the top node is associated with the entire target space. Each non-leaf nodes divides its region into four equal sized quadrants correspondingly each such node has four child nodes corresponding to the four quadrants and so on Leaf nodes have between zero and some fixed maximum number of points (set to 1 in example). 40 Spatial indexing-an overview Quadtrees (Cont.) PR quadtree: stores points; space is divided based on regions, rather than on the actual set of points stored. Region quadtrees store array (raster) information. A node is a leaf node is all the array values in the region that it covers are the same. Otherwise, it is subdivided further into four children of equal area, and is therefore an internal node. Each node corresponds to a sub-array of values. The sub-arrays corresponding to leaves either contain just a single array element, or have multiple array elements, all of which have the same value. Extensions of k-d trees and PR quadtrees have been proposed to index line segments and polygons Require splitting segments/polygons into pieces at partitioning boundaries Same segment/polygon may be represented at several leaf nodes 41 R-Trees Supported in many modern database systems, along with variants like R+-trees and R*-trees. R-trees are a N-dimensional extension of B+-trees, useful for indexing sets of rectangles and other polygons. Basic idea: generalize the notion of a one-dimensional interval associated with each B+ -tree node to an N-dimensional interval, that is, an N-dimensional rectangle. A rectangular bounding box is associated with each tree node. Bounding box of a leaf node is a minimum sized rectangle that contains all the rectangles/polygons associated with the leaf node. The bounding box associated with a non-leaf node contains the bounding box associated with all its children. Bounding box of a node serves as its key in its parent node (if any) Bounding boxes of children of a node are allowed to overlap A polygon is stored only in one node, and the bounding Will consider only the box of the node must contain the polygon case (N = 2) A set of rectangles (solid line) and the bounding boxes (dashed line) of the nodes of an R-tree for the rectangles. The R-tree is shown on the right. 42 Sources of Geographic Data Land surveys and GPS Aerial photography and photogrammetry Satellite remote sensing U. S. Census Existing paper maps Sources of Geographic Data Land Surveys Specifies boundaries, rights-of-way, and other legal descriptions Surveyors use optical and electronic instruments to measure precise control point locations established by geodesists High quality data, but takes a lot of time GPS Global Positioning Systems Earth-orbiting satellites broadcast precisely timed radio signals GPS receivers determine positions on the ground by calculating distances from three or more satellite transmitters More expensive than traditional optical and electronic methods 44 Sources of Geographic Data Aerial Photography and Photogrammetry Field concerned with producing geographic data from aerial photographs Orthophoto: aerial photograph in which scale variations have been rectified. Satellite Remote Sensing Technologies and procedures used to measure and record energy emitted by the Sun, and reflected or emitted by the Earth Help predict the behavior of Earth's environmental systems Census Primary sources of demographic attribute data Valued by businesses, direct mail, and trade area analyses, and by social scientists who seek to understand the behavior of social systems 45 Building an end-user map… Land Surveys inspection GPS Census Aerial/Satellite Photography; Orthophoto Satellite Remote Sensing Existing Paper Maps 46 Appendix GIS Software Packages And GIS File Formats Software for GIS: The Main Players ESRI, Inc., Redlands, CA clear market leader with about a third of the market originated commercial GIS with their ArcInfo product in 1981 privately owned by Jack Dangermond, a legend in the field Strong in gov., education, utilities and business logistics The main two “pure GIS” companies. MapInfo, Troy N.Y. Aggressive newcomer in early 1990s, but now well-established. Strong presence in business, especially site selection & marketing, and telecom Intergraph (Huntsville, AL) origins in proprietary CAD hardware/software Older UNIX-based MGE (Modular GIS Environment) evolved from CAD Current GeoMedia was the first true MS Windows-based GIS strong in design, public works, and FM (facilities management), but weakening Bentley Systems (Exton, PA) Autodesk MicroStation GeoGraphics, originally developed with Intergraph, is now their exclusive and main product.. Strong in engineering; advertises itself as “geoengineering” (San Rafael, CA) Began as PC-based CAD, but now the dominant CAD supplier First GIS product AutoCAD Map introduced in 1996 Primarily small business/small city customer base 48 ESRI Product Line-up: ArcGIS client products (Fall 2007) ArcReader (“adobe acrobat” for maps) & ArcExplorer (spatial data viewer) Free viewers for geographic data. ArcGIS 9.x Desktop: two primary modules (MS only) ArcMap: for data display, map production, spatial analysis, data editing ArcCatalog: for data management and preview ArcToolbox, for specialized data conversions and analyses, available as a window in both Available capabilities within these modules are “tiered” in three levels ArcView: viewing, map production, spatial analysis, basic editing: ArcEditor: ArcView, plus specialized editing: ArcInfo: ArcView & ArcEditor plus special analyses and conversions: Extensions: for special apps.: Spatial Analyst, 3D Analyst, Geostatistics, Business Analyst, etc. ArcObjects: to build specialized capabilities within ArcMap or ArcCatalog using VB for Applications ArcGIS Workstation (for UNIX and MS) - the old command line ArcInfo 7.1 ArcGIS Engine (MS NT/2000/XP) Set of embeddable GIS components (ArcObjects software objects) for use in building custom applications Runs under Windows, Unix and Linux, with support for Java, C++, COM and .NET Replaces MapObjects which were based upon a previous generation of GIS objects Notes: ArcView 3.3 the only GUI option for UNIX. ArcGIS 8 released 2000 to integrate two previous standalone products: ArcView and ArcInfo ArcGIS 9 released 2004 providing the full capability that should have been in ArcGIS 8!!! --full support for all data types (coverages, shapefiles, geodatabases) --full support for all previous geoprocessing analyses --Modelbuilder for scripting and repetitive processing --ArcEngine for building custom applications 49 ESRI Product Line-up: ArcGIS server products (Fall 2007) ArcGIS Server: three tiers of capability Data services: ArcSDE (Spatial Database Engine) middleware to support spatial data storage in standard DBMS on server Supports all major industry databases: Oracle, SQL-Server, IBM DB2, Ingres Map services: ArcIMS (Internet Map Server) Provides maps and simple query to a user without a desktop GIS Accessed via web interface Analytic services: Permits the creation of server-based specialized GIS applications Provides full range of GIS capabilities to a user without a desktop GIS Accessed via web interface (prior to 9.2 these were sold as three separate products) ArcGIS On-line Services On-line services made available on the Internet with a subscription Normally charged on a “per transaction” basis, but can be flat fee built and operated by ESRI (or other others), usually based on ArcGIS Server 50 ESRI ArcGIS System c:\ ArcGIS Workstation ArcInfo ArcEngine/ ArcObjects Application Development & Customization ArcPad Clients ArcEditor ArcMap ArcCatalog ArcToolbox ArcMap ArcCatalog ArcToolbox ArcView Consistent interface Increasing capability ArcExplorer Browser ArcMap ArcCatalog ArcToolbox ArcServer Services Full GIS analysis ArcIMS Services Map display & query ArcSDE Services Database storage/access Internet Files (Personal Geodatabase, Shapefiles, Coverages, Grids, tins, etc) Handheld/Wireless Source: ESRI with modifs. Databases Multi-user Geodatabases (in Oracle, SQL Server, IBM DBII, etc) 51 Future Generic GIS Internet Enterprise Applications Browsers Web Web Server Broker Services ( built on .Net, SOAP/XML, Java API) Dallas Delhi Durban Databases 52 Vendor Implementation of GIS Data Structures: file formats Raster, vector, TIN, etc. are generic models for representing spatial information in digital form GIS vendors implement these models in file formats or structures which may be Proprietary: useable only with that vendor’s software (e.g. ESRI coverage) Published: specifications available for use by any vendor (e.g ESRI shapefile, or the military vpf format) Transfer formats: intended only for transfer of data Between different vendor’s systems (e.g. AutoCAD .dxf format, or SDTS) between different users of same vendors’ software (e.g. ESRI’s E00 format for coverages) One GIS vendor may be able to read another file format: By translation, whereby format is converted externally to vendors own format Usually requires user to carry out conversion prior to use of data On-the-fly, whereby conversion is accomplished internally and “automatically” No user action needed, but usually no ability to change data Natively, or transparently, which normally implies No special user action needed ability to read and write (change or edit) the data 53 Common GIS & CAD File Formats ESRI AutoCAD Coverages (vector--proprietary) E00 (“E-zero-zero”) for coverage exchange between ESRI users Shapefiles (vector--published) .shp Geodatabase (proprietary) .gdb Based on current object-oriented software technology GRID (raster) AutoCAD .DWG (native) AutoCAD .DXF for digital file exchange Intergraph/Bentley Bentley MicroStation .DGN Intergraph/Bentley .MGE Spatial Data Transfer Standard (SDTS) – US federal standard for transfer of data – Federal agencies legally required to conform – embraces the philosophy of self-contained transfers, i.e. spatial data, attribute, georeferencing, data quality report, data dictionary, and other supporting metadata all included – Not widely adopted ‘cos of competitive pressures, and complexity and perceived disutility derived from philosophy 54 ESRI Vector File Formats: “Georelational” Shape ‘file’: native GIS data structure for a Coverage: native GIS data structure for vector layer in ArcView a vector layer in ArcInfo not fully topological fully topological better suited for large data sets limited info about relationship of features better suited for fancy spatial analyses one to another comprises multiple physical files (12 or so) draw faster per coverage not as good for some fancy spatial analyses is a ‘logical’ file which comprises several (at least 3) physical disk files, all of which must be present for AV to read the theme each coverage saved in a separate folder named same as the coverage physical file set differs depending on type of coverage (point, line, polygon). coverage folders stored in a “workspace” directory with an info folder for tracking attribute tables stored there also layer.shp (geometric shape described by XY coords) layer.shx (indices to improve performance) ARC/INFO required to make changes layer.dbf (contains associated attribute data) proprietary: no published specs. layer.sbn layer.sbx not really a database, although ArcView presents files to user via relational concepts openly published specs so other vendors can develop shape files and read them E00 Export Files: format for export of coverages to other ESRI users IMPORT71 utility in ArcView Start Menu can read E00 files and convert them back to coverages Must convert to shapefile or AutoCAD .dxf format to transfer to a non-ESRI GIS system