GIS Dictionary

[cartography] A rectangular map bounded by lines of latitude and longitude, often a map sheet in either the 7.5-minute or 15-minute series published by the U.S. Geological Survey. Quadrangles are … Read more

1 [coordinate systems] In a rectangular coordinate system, any of the quarters formed by the central intersection of x and y axes that divide a plane into four equal parts. … Read more

[spatial statistics use for geostatistics] In spatial sampling, one of a set of identically-sized areas, often rectangular, within which the members of a population are counted. The size, number, and … Read more

[spatial statistics use for geostatistics] Comparison of the statistically expected and actual counts of objects within spatial sampling areas (quadrats) to test for distribution patterns such as randomness and clustering.

A method for encoding raster data that reduces storage requirements and improves access speeds by storing values only for homogeneous regions rather than for every pixel. The raster is recursively … Read more

[data structures] Data classified or shown by category, rather than by amount or rank, such as soil by type or animals by species.

[quality assurance] A process used to verify the quality of a product after its production.

[ESRI software] In ArcGIS Survey Analyst, when used together, the F test and W test are called the B method of testing, for which a power can be defined. This … Read more

[quality control] A process used during production of a product to ensure its quality.

[statistics] In a data distribution, a value representing a class break, where classes contain approximately equal numbers of observations. The p-th quantile, where p is between 0 and 1, is … Read more

A data classification method that distributes a set of values into groups that contain an equal number of values.

[data structures] Data grouped or shown by measurements of number or amount, such as population per unit area.

[geography] The application of mathematical and statistical concepts and methods to the study of geography.

[programming] A request to select features or records from a database. A query is often written as a statement or logical expression.

A type of expression that evaluates to a Boolean (true or false) value, that is typically used to select those rows in a table in which the expression evaluates to … Read more

[ESRI software] A client may request a reference to a different interface on an object by calling the QueryInterface method of the IUnknown interface.

[computing] A language for storing, retrieving, and editing data in a database.

[ESRI software] A private ArcIMS virtual server that works with an image server to support query functions. When a viewer requests an identify or find operation, the query server returns … Read more

[database structures] A table containing results from a query.