GIS Dictionary

[physics] A measure of the reflectivity of an object or surface; the ratio of the amount of radiation reflected by a body to the amount of energy striking it.

[usability] A message that calls attention to a notable situation or informs users of changes in the state of a monitored situation.

1 [computing] An alternative name specified for fields, tables, files, or datasets that is more descriptive and user-friendly than the actual name. On computer networks, a single e-mail alias may … Read more

[graphics computing] The jagged appearance of curves and diagonal lines in a raster image. Aliasing becomes more apparent as the size of the raster pixels is increased or the resolution … Read more

1 [surveying] A peep sight mounted on a straightedge and used to measure direction. 2 [surveying] The part of a theodolite containing the telescope and attachments.

[ESRI software] A task that identifies the fields required for geocoding, such as address and city, when uploading data.

A drafting symbol that runs parallel to the baseline and indicates the true distance between beginning and ending dimension points.

[network analysis] In network analysis, the process of assigning entities or edges and junctions to features until the feature’s capacity or limit of impedance is reached. For example, streets may … Read more

1 [GPS] In GPS, a file transmitted from a satellite to a receiver that contains information about the orbits of all satellites included in the satellite network. Receivers refer to … Read more

[remote sensing] A remote-sensing tool with a line of many fixed sensors that record reflected radiation from the terrain along a satellite’s direction of movement, creating scan-line strips that are … Read more

[cartography] A grid of numbered rows and lettered columns (or vice versa) superimposed on a map, used to find and identify features. Alphanumeric grids are commonly used as a reference … Read more

[database structures] An attribute or set of attributes in a relational database that provides a unique identifier for each record and could be used as an alternative to the primary … Read more

[geocoding] A name for an address element, usually a street name, that is different from the official or most common name. For example, a highway number might be an alternate … Read more

1 [coordinate systems] The height or vertical elevation of a point above a reference surface. Altitude measurements are usually based on a given reference datum, such as mean sea level. … Read more