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39-415: RPF may refer to: Computing [ edit ] Raster Product Format, a GIS file format Reverse-path forwarding , a technique in multicast routing in networking Reverse power feeding , in broadband networking Medicine [ edit ] Renal plasma flow , a metric of the volume of blood delivered to the kidneys Retroperitoneal fibrosis ,

78-399: A feature dataset) stores information about discrete objects, using an encoding of the vector logical data model to represent the location or geometry of each object, and an encoding of its other properties that is usually based on relational database technology. Typically, a single dataset collects information about a set of closely related or similar objects, such as all of the roads in

117-471: A geographic information system that served as a milestone in the development of integrated mapping systems. The Laboratory influenced numerous computer graphic, mapping and architectural systems such as Intergraph , Computervision , and Esri . In 1963, during a training session held at Northwestern University , Chicago architect Howard T. Fisher encountered computer maps on urban planning and civil engineering produced by Edgar Horwood's group at

156-474: A Gaullist party Rassemblement pour la France , France (1999–2011), a right wing party Reformatorische Politieke Federatie , Netherlands (1975–2003), a Protestant Christian party Rwandan Patriotic Front , Rwanda (founded 1994), a major political party backed by Paul Kagame Other uses [ edit ] Radioisotope Production Facility , a facility in Inshas, Egypt Real person fiction ,

195-497: A city. The Vector data model uses coordinate geometry to represent each shape as one of several geometric primitives , most commonly points (a single coordinate of zero dimension ), lines (a one-dimensional ordered list of coordinates connected by straight lines), and polygons (a self-closing boundary line enclosing a two-dimensional region). Many data structures have been developed to encode these primitives as digital data, but most modern vector file formats are based on

234-464: A continuous space, raster data is most commonly used to represent geographic fields , in which a property varies continuously or discretely over space. Common examples include remote sensing imagery, terrain/elevation , population density , weather and climate , soil properties , and many others. Raster data can be images with each pixel (or cell) containing a color value. The value recorded for each cell may be of any level of measurement , including

273-536: A discrete qualitative value, such as land use type, or a continuous quantitative value, such as temperature, or a null value if no data is available. While a raster cell stores a single value, it can be extended by using raster bands to represent RGB (red, green, blue) colors, colormaps (a mapping between a thematic code and RGB value), or an extended attribute table with one row for each unique cell value. It can also be used to represent discrete Geographic features , but usually only in exigent circumstances. Raster data

312-650: A disease of the retroperitoneum Military [ edit ] Railway Protection Force , a railway police organisation in India Rohingya Patriotic Front , a Rohingya group active in the 1970s and 80s in Bangladesh Reichspfenning (1924–1948) (Rpf.), unit of the German Reichsmark Political parties [ edit ] Rassemblement du Peuple Français , France (1947–1955),

351-606: A dozen by 1972 as grants expired. The Odyssey project grew the Laboratory from about 12 people in 1977 to forty people by 1981. The Laboratory shrank significantly back to approximately half a dozen people from 1982 until its closure in June 1991. From 1979 the Laboratory was encouraged to develop external software sales and entered into licensing agreements for this purpose, most notably with Synercom and ISSCO Corporation (sold to Computer Associates in 1987) for Odyssey. However,

390-661: A genre of fanfiction about real people Rehabilitation Project Force , a Scientology program Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title RPF . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=RPF&oldid=1189268602 " Category : Disambiguation pages Hidden categories: Articles containing German-language text Articles containing French-language text Articles containing Dutch-language text Short description

429-399: Is based on a regular tessellation of space into a rectangular grid of rows and columns of cells (also known as pixels ), with each cell having a measured value stored. The major difference from a photograph is that the grid is registered to geographic space rather than a field of view. The resolution of the raster data set is its cell width in ground units. Because a grid is a sample of

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468-566: Is different from Wikidata All article disambiguation pages All disambiguation pages GIS file format The first GIS installations of the 1960s, such as the Canada Geographic Information System were based on bespoke software and stored data in bespoke file structures designed for the needs of the particular project. As more of these appeared, they could be compared to find best practices and common structures. When general-purpose GIS software

507-445: Is stored in various formats; from a standard file-based structure of TIFF, JPEG, etc. to binary large object (BLOB) data stored directly in a relational database management system (RDBMS) similar to other vector-based feature classes. Database storage, when properly indexed, typically allows for quicker retrieval of the raster data but can require storage of millions of significantly sized records. A vector dataset (sometimes called

546-537: The Census Bureau's Urban Atlas in 1975 inspired the Laboratory to develop an integrated suite of programs beneath by a common user interface and common data manipulation software. In 1978 this suite became the Odyssey project. The Odyssey project's aim was to produce a vector GIS that provided spatial analysis of many different forms within a single system. As of 1980, in addition to early Odyssey modules,

585-607: The Graduate School of Design , the Ford Foundation provided $ 294,000 over three years to seed the Harvard Laboratory for Computer Graphics. Working with programmer Betty Benson, Fisher completed SYMAP for distribution in 1966. Also under Fisher's direction, SYMVU and GRID programs were developed. A 1968 reorganisation followed Fisher reaching Harvard's mandatory retirement age and led to renaming as

624-526: The Open Geospatial Consortium (OGC) Simple Features specification, often directly incorporating its Well-known text (WKT) or Well-known binary (WKB) encodings. In addition to the geometry of each object, a vector dataset must also be able to store its attributes . For example, a database that describes lakes may contain each lake's depth, water quality, and pollution level. Since the 1970s, almost all vector file formats have adopted

663-596: The University of Washington . Fisher conceived a computer mapping software program, SYMAP (Synergistic Mapping), to produce conformant, proximal, and contour maps on a line printer. Fisher applied for a Ford Foundation grant to explore thematic mapping based on early SYMAP outputs, which was awarded in 1965. In association with Harvard providing facilities in Robinson Hall in Harvard Yard as part of

702-434: The relational database model, either in principle or directly incorporating RDBMS software. Thus, the entire dataset is stored in a table , with each row representing a single object that contains columns for each attribute. Two strategies have been used to integrate the geometry and attributes into a single vector file format structure: Geospatial topology is often an important part of vector data, representing

741-558: The CALYPSO module for the commercial Odyssey project and worked on the GLIB/LINGUIST table-driven language system in collaboration with Nick Chrisman and Jim Dougenik, which was based on automata theory and dynamic scoping. GLIB/LINGUIST provided an English-like user interface for Odyssey, BUILDER, and other HLCG software. The early period of the Laboratory saw staff numbers grow to approximately 40 in 1970, but shrink to half

780-775: The Esri Shapefile and most spatial databases ) includes no topology information, with each geometry being completely independent of all others. A topology dataset (often used in network analysis ) augments spaghetti data with a separate file encoding the topological connections. A topology rulebase is a list of desired topology rules used to enforce spatial integrity in spaghetti data, such as "county polygons must not overlap" and "state polygons must share boundaries with county polygons." Vector datasets usually represent discrete geographical features , such as buildings, trees, and counties. However, they may also be used to represent geographical fields by storing locations where

819-548: The Harvard Graduate School of Design sought less commercial work and an increased focus on research, though with reduced budgets. "But the timing of this burgeoning commercialism of the Lab's activities collided with the moment in history when Harvard's President Derek Bok set out to clarify the blurred lines between academic research and development on the one hand, and more clearly defined commercial activities on

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858-432: The Harvard Graduate School of Design. From 1978 to 1983, the Laboratory hosted a popular annual Harvard Computer Graphics Week. Geoffrey Dutton, a research associate at the Laboratory from 1969 through 1984, created the first holographic thematic map, "America Graph Fleeting" in 1978. This rotating strip of 3,000 holograms depicted an animated sequence of 3d maps showing US population growth from 1790 to 1970, generated by

897-469: The Harvard Laboratory for Computer Graphics and Spatial Analysis. From 1972, the Laboratory was based in Graduate School's newly built Gund Hall. The Laboratory's original and continuing goals were: SYMAP's ability to print cheap, albeit low quality, maps using readily available technology led to rapid adoption in the late 1960s. SYMVU software, developed in 1969 to illustrate surface displays,

936-654: The Laboratory sold the following programs for display and analysis of spatial data The 1982 release of Odyssey included seven programs for geographical analysis: Like most of the Laboratory's software, it was written in FORTRAN and operated on several platforms. The POLYPS and PRISM modules could draw maps on a variety of vector display devices. The Laboratory distributed software, and later data, at cost, thus encouraging experimentation. The Laboratory conducted correspondence courses, hosted numerous conferences, and worked on environmental planning and architectural projects with

975-485: The Laboratory's ASPEX program. Dutton also contributed the program DOT.MAP to the Laboratory's family of distributed software (1977). In 1977 James Dougenik, Duane Niemeyer, and Nicholas Chrisman developed contiguous area cartograms. Bruce Donald , working at the Laboratory from 1978 to 1984, wrote BUILDER, a program for computer-aided architecture. BUILDER produced plan and shaded perspectives that popularised computer-aided-design in architecture. Donald also wrote

1014-476: The inherent spatial relationships (especially adjacency) between objects. Topology has been managed in vector file formats in four ways. In a topological data structure , most notably Harvard's POLYVRT and its successor the ARC/INFO coverage, topological connections between points, lines, and polygons are an inherent part of the encoding of those features. Conversely, non-topological or spaghetti data (such as

1053-406: The licensing agreements had weak to non-existent technology exploitation and non-compete clauses, so potential purchasers were frustrated in attempting to license from a competitor often preferentially positioning its proprietary software. Potential purchasers often redeveloped Odyssey functions rather than wait for licenses. Meanwhile, having carved out the potential commercial interests, from 1981

1092-462: The other." Financial strain and the lack of commercial inspiration for projects led to the dispersal of many team members from 1981. Despite some further research during the late 1980s, the Laboratory closed in 1991. Odyssey became the template for subsequent GIS software, cited as an inspiration by numerous commercial efforts in mapping and architecture, such as M&S Computing (later Intergraph ), Computervision , and Geodat . The Laboratory

1131-507: The proliferation of web mapping; formats such as the Keyhole Markup Language (KML) and GeoJSON can be more easily integrated into web development languages than traditional GIS files. Over a hundred distinct formats have been created for the storage of spatial data, of which 20-30 are currently in common usage for different purposes. These can be distinguished in a number of ways: Like any digital image, raster GIS data

1170-449: The same database. Harvard Laboratory for Computer Graphics and Spatial Analysis The Harvard Laboratory for Computer Graphics and Spatial Analysis (1965 to 1991) pioneered early cartographic and architectural computer applications that led to integrated geographic information systems (GIS). Some of the Laboratory's influential programs included SYMAP, SYMVU, GRID, CALFORM, and POLYVRT. The Laboratory's Odyssey project created

1209-401: The spatially continuous field has been sampled. Sample points (e.g., weather stations and sensor networks ), Contour lines and triangulated irregular networks (TIN) are used to represent elevation or other values that change continuously over space. TINs record values at point locations, which are connected by lines to form an irregular mesh of triangles. The face of the triangles represent

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1248-463: The terrain surface. Formats commonly in current usage: Historical formats seldom used today: There are some important advantages and disadvantages to using a raster or vector data model to represent reality: Modern object–relational databases can now store a variety of complex data using the binary large object datatype, including both raster grids and vector geometries. This enables some spatial database systems to store data of both models in

1287-637: The wide variety of federal government data. Although this particular format failed to garner widespread support, it led to other standardization efforts, especially the Open Geospatial Consortium (OGC), which has developed or adopted several vendor-neutral standards, some of which have been adopted by the International Standards Organization (ISO). Another development in the 1990s was the public release of proprietary file formats by GIS software vendors, enabling them to be used by other software. The most notable example of this

1326-574: Was an enormous influence on the commercial Environmental Systems Research Institute, Esri , founded in 1969 by Jack Dangermond , a landscape architect graduate of Harvard Graduate School of Design who had worked as a research assistant at the Laboratory during 1968 and 1969. Scott Morehouse, the development lead for the Odyssey project, worked at the lab from 1977 to 1981. When revenues from Odyssey did not meet expectations, his team's resources started to dwindle, and Morehouse left to join Jack at Esri to build

1365-456: Was another popular product. GRID, CALFORM, and POLYVRT products further explored the raster versus vector approach to mapping. The Laboratory gained a reputation for solid output leading to several commercially successful projects and significant budgetary independence for a research institute . Some struggles with restructuring Geographic Base Files - Dual Independent Map Encoding (GBF-DIME files, an early vector and polygonal data structure) for

1404-621: Was developed in the 1970s and early 1980s, including programs from academic labs such as the Harvard Laboratory for Computer Graphics and Spatial Analysis , government agencies (e.g., the Map Overlay and Statistical System (MOSS) developed by the U.S. Fish & Wildlife Service and Bureau of Land Management ), and new GIS software companies such as Esri and Intergraph , each program was built around its own proprietary (and often secret) file format. Since each GIS installation

1443-536: Was effectively isolated from all others, interchange between them was not a major consideration. By the early 1990s, the proliferation of GIS worldwide and an increasing need for sharing data, soon accelerated by the emergence of the World Wide Web and spatial data infrastructures , led to the need for interoperable data and standard formats. An early attempt at standardization was the U.S. Spatial Data Transfer Standard , released in 1994 and designed to encode

1482-584: Was the emergence of free and open-source software libraries , such as the Geospatial Data Abstraction Library (GDAL) , which have greatly facilitated the integration of spatial data in any format into a variety of software. During the 2000s, the need for specialized spatial files was reduced somewhat by the emergence of spatial databases , which incorporated spatial data into general-purpose relational databases. However, new file formats have continued to appear, especially with

1521-481: Was the publication of the Esri Shapefile format, which by the late 1990s had become the most popular de facto standard for data sharing by the entire geospatial industry. When proprietary formats were not shared (for example, the ESRI ARC/INFO coverage), software developers frequently reverse-engineered them to enable import and export in other software, further facilitating data exchange. One result of this

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