2019 QUARTER 03

A B C D E F G H I K L M N O P R S T U V W
DC-14 - Vector data extraction
  • Describe the source data, instrumentation, and workflow involved in extracting vector data (features and elevations) from analog and digital stereoimagery
  • Discuss future prospects for automated feature extraction from aerial imagery
  • Discuss the extent to which vector data extraction from aerial stereoimagery has been automated
CV-03 - Vector Formats and Sources
  • List the data required to explore a specified problem
  • Discuss the extent, classification, and currency of government data sources and their influence on mapping
  • List the data required to compile a map that conveys a specified message
  • Discuss the issue of conflation of data from different sources or for different uses as it relates to mapping
  • Describe a situation in which it would be acceptable to use smaller-scale data sources for compilation to compile a larger scale map
  • Describe the copyright issues involved in various cartographic source materials
  • Explain how data acquired from primary sources, such as satellite imagery and GPS, differ from data compiled from maps, such as DLGs
  • Explain how digital data compiled from map sources influences how subsidiary maps are compiled and used
  • Explain how geographic names databases (i.e., gazetteer) are used for mapping
  • Explain how the inherent properties of digital data, such as Digital Elevation Models, influence how maps can be compiled from them
  • Identify the types of attributes that will be required to map a particular distribution for selected geographic features
  • Determine the standard scale of compilation of government data sources
  • Assess the data quality of a source dataset for appropriateness for a given mapping task, including an evaluation of the data resolution, extent, currency or date of compilation, and level of generalization in the attribute classification
  • Compile a map using at least three data sources
AM-59 - Vector-to-raster and raster-to-vector conversions
  • Explain how the vector/raster/vector conversion process of graphic images and algorithms takes place and how the results are achieved
  • Create estimated tessellated data sets from point samples or isolines using interpolation operations that are appropriate to the specific situation
  • Illustrate the impact of vector/raster/vector conversions on the quality of a dataset
  • Convert vector data to raster format and back using GIS software
DM-51 - Vertical datums
  • Explain how a vertical datum is established
  • Differentiate between NAVD 29 and NAVD 88
  • Illustrate the difference between a vertical datum and a geoid
  • Illustrate the relationship among the concepts ellipsoidal (or geodetic) height, geoidal height, and orthometric elevation
  • Outline the historical development of vertical datums
CV-16 - Virtual and immersive environments
  • Discuss the nature and use of virtual environments, such as Google Earth
  • Explain how various data formats and software and hardware environments support immersive visualization
  • Compare and contrast the relative advantages of different immersive display systems used for cartographic visualization (e.g., CAVEs, GeoWalls)
  • Evaluate the extent to which a GeoWall or CAVE does or does not enhance understanding of spatial data
  • Explain how the virtual and immersive environments become increasingly more complex as we move from the relatively non-immersive VRML desktop environment to a stereoscopic display (e.g., a GeoWall) to a more fully immersive CAVE
CV-07 - Visual Hierarchy and Layout

Mapmaking, by digital or manual methods, involves taking complex geographic information and building a visual image with many components. Creating effective maps requires an understanding of how to construct the elements of the map into a coherent whole that executes the communicative purpose of the map. Visual hierarchy and layout are the cartographer’s tools for organizing the map and completing the map construction. The cartographer layers the mapped geography in an image into a visual hierarchy emphasizing some features and de-emphasizing others in vertical ordering of information. Likewise, the cartographer arranges the components of a map image—title, main map, inset map, north arrow, scale, legend, toolbar, etc.—into a layout that guides the reader’s eye around the horizontal plane of the map. The visual hierarchy and layout processes work together to create the structure of the map image.

CP-14 - Web GIS

Web GIS allows the sharing of GIS data, maps, and spatial processing across private and public computer networks. Understanding web GIS requires learning the roles of client and server machines and the standards and protocols around how they communicate to accomplish tasks. Cloud computing models have allowed web-based GIS operations to be scaled out to handle large jobs, while also enabling the marketing of services on a per-transaction basis.

A variety of toolkits allow the development of GIS-related websites and mobile apps. Some web GIS implementations bring together map layers and GIS services from multiple locations. In web environments, performance and security are two concerns that require heightened attention. App users expect speed, achievable through caching, indexing, and other techniques. Security precautions are necessary to ensure sensitive data is only revealed to authorized viewers.

Many organizations have embraced the web as a way to openly share spatial data at a relatively low cost. Also, the web-enabled expansion of spatial data production by nonexperts (sometimes known as “neogeography”) offers a rich field for alternative mappings and critical study of GIS and society.

PD-16 - Web GIS Programming

Web GIS programming involves creating, extending, utilizing, Web GIS or web mapping solutions to solve specific problems, build complete applications, or consume or produce data and geospatial processing services. With the expansion of the internet and availability of Web GIS or Web mapping options, web GIS programming is becoming a commonly required skill set in many organizations. Web GIS programming is a type of software development that provides a means of handling internet, browser-based software application development tasks which require unique solutions to web GIS or web mapping problems. In addition, a number of Web GIS software options offer application programming interfaces (APIs) that provide a means by which developers can leverage the published data and processing services of others to build and customize applications through standardized interfaces with external web GIS software, data, and services. Web GIS programming applies to mobile as well as desktop application development. A browser typically runs software applications by submitting Hypertext Transfer Protocol (HTTP) or Hypertext Transfer Protocol Secure (HTTPS) requests to a server hosting resources the application user wishes to access available through a Uniform Resource Locator (URL), and the server replies by providing resources or performing functions requested by the user. This entry reviews the fundamentals of web GIS programming, accompanying the Web Mapping and other entries in the Programming and Development section, the Web GIS entry in the Computing Platforms section, and the User Interface and User Experience (UI/UX) Design entry in the Cartography and Visualization section (Sack, 2017; Quinn, 2018; Roth, 2017).

CV-15 - Web Mapping

As internet use has grown, many paper maps have been scanned and published online, and new maps have increasingly been designed for viewing in a web browser or mobile app. Web maps may be static or dynamic, and dynamic maps may either be animated or interactive. Tiled web maps are interactive maps that use tiled images to allow for fast data loading and smooth interaction, while vector web maps support rendering a wide variety of map designs on the client. Web maps follow a client-server architecture, with specialized map servers sometimes used to publish data and maps as geospatial web services. Web maps are composed of data from a database or file on the server, style information rendered on either server or client, and optionally animation or interaction instructions executed on the client. Several graphic web platforms provide user-friendly web mapping solutions, while greater customization is possible through the user of commercial or open source web mapping APIs. When designing web maps, cartographers should consider the map’s purpose on a continuum from exploratory and highly interactive to thematic and less interactive or static, the constraints of desktop and/or mobile web contexts, and accessibility for disabled, elderly, and poorly connected users.

AM-89 - Weighting schemes
  • Evaluate a fuzzy weighting scheme in terms of uncertainty and error propagation

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