GIS Dictionary

[mathematics] The average for a set of values, computed as the sum of all values divided by the number of values in the set.

[spatial statistics use for geostatistics] The location of a single x,y coordinate value that represents the average x-coordinate value and the average y-coordinate value of all features in a study … Read more

[geodesy] The average height of the surface of the sea for all stages of the tide over a nineteen-year period, usually determined by averaging hourly height readings from a fixed … Read more

[spatial statistics use for geostatistics] In geostatistics, a property of a spatial process in which a spatial random variable has the same mean value at all locations.

[linear referencing] In linear referencing, either one or two fields in a table that describe the position of an event along a route.

[standards] An observed numerical value that is an appraisal of size, extent, or amount according to a set criteria.

[surveying] In surveying, the noise that is expected in every measurement. It occurs because the observer makes estimates and uses measuring equipment that is unpredictable in an environment that is … Read more

[surveying] The difference between a measured quantity and its theoretical true value as determined during each iteration of a least-squares adjustment.

1 [mathematics] The middle value of a set of values when they are ordered by rank. Half the values in a set are higher than the median, and half are … Read more

[spatial statistics use for geostatistics] A location representing the shortest total distance to all other features in a study area.

[printing] A printing device capable of producing an image on paper or other media sized between 15 and 35 inches (38 and 90 centimeters) wide. Medium-format printers typically use inkjet … Read more

1 [programming] Refers collectively to the properties and methods, or functions, of an interface or class. 2 [Internet] In ArcGIS Online, ArcGIS users who have registered for ArcGIS Online. Members … Read more

[computing] In ArcGlobe, the amount of system memory that the application will use.

[computing] In computer programming, the loss of computer memory that occurs when an application or component fails to free a section of computer memory when it has finished using it. … Read more

[mental maps] A person’s perception of a place. A mental map may include the physical characteristics of a place, such as boundaries of a neighborhood, or the attributes of a … Read more

[software] A list of available commands or operations displayed on a computer screen from which a user can make a selection.

[software] An item in a list of commands displayed on a menu.

[surveying] Establishing a boundary relative to ground features present at the time of a survey.

[ESRI software] In geodatabases, rules that dictate what happens to the respective attributes of features that are merged together during editing in ArcMap. A merge policy can be set to … Read more

[analysisgeoprocessing] Combining features from multiple data sources of the same data type into a single, new dataset.

A great circle on the earth that passes through the poles, often used synonymously with longitude. Meridians run northsouth between the poles. By convention, meridians are labeled with positive numbers … Read more

Information that describes the content, quality, condition, origin, and other characteristics of data or other pieces of information. Metadata for spatial data may describe and document its subject matter; how, … Read more

[data transfer] A unit of information within metadata, used to describe a particular characteristic of the data.

[ESRI software] A Web application, developed using the ArcIMS Java Connector, that can be used to view metadata included in an ArcIMS metadata service.

[standards] A modification of an existing metadata standard to adapt to data issues, cultural issues, or both. A profile is typically a subset of a base standard that tailors the … Read more

[ESRI software] A public ArcIMS virtual server that provides the capability to manage and search a central metadata repository. Data producers can publish their metadata to the repository while data … Read more

[ESRI software] A service that uses the spatial server metadata capabilities, allowing users to publish and share metadata documents over the Internet or an intranet.

A surveying method in which the limits of a parcel are identified as relative distances and bearings from landmarks. Metes and bounds surveying often resulted in irregularly shaped areas.

[programming] In object-oriented programming, an action that an object is capable of performing. Objects that belong to the same class all have the same methods. For example, all Visual Basic … Read more

[federal government] A geographic entity defined by the U.S. Office of Management and Budget for use by federal statistical agencies, including the U.S. Census Bureau. A metropolitan statistical area is … Read more