Satellite: A platform launched into close orbit around the Earth and used to carry electronic equipment that transmits information back to Earth. Some satellites are used to transmit pictures of the Earth from space back to Earth for remote sensing applications. The GPS uses 24 satellites that were made and launched specifically for transmitting signals to GPS receivers on Earth.

Scale mapping is a more sophisticated method of sketch mapping, aimed at generating geo-referenced data to facilitate discussions and allow community members to develop maps that can stand the scrutiny of adversarial parties. The method is based on effective selection of symbols and colours for depicting indigenous spatial knowledge on transparencies superimposed on a geo-coded and scaled map (source: Rambaldi et al, 2005).

Selection: A form of generalization that involves choosing which of a number of features (or which parts thereof) to show on a map while omitting others.

Selective availability: A procedure by which the United States Department of Defense (USDoD) deliberately and intermittently interferes with the signals from GPS satellites so that civilian and other non-USDoD GPS receivers cannot calculate extremely precise locations, but their own units can. The errors thus introduced must be taken into account (and perhaps strategically minimized) by civilian GPS users.

Scale: The relationship between distance on a map and on the Earth's surface, usually represented as a ratio (for example, 1:10,000) or with a graph scale.

Sideshot: Along a survey route, a short branch or spur made for the purpose of accurately recording an important feature located a short distance to one side of the route.

Simplification: A form of generalization that involves deleting some of the surveyed points that show the path of a line feature or the boundary of a polygon so as to remove excessive detail.

Sketch map: A method for mapping on paper. A drawing of a place or area, not drawn with accurate or measured scale or direction. Features are depicted by the use of natural materials or more frequently by coloured marker pens or chalk. Participants usually have a range of choices regarding what materials to use for the drawing and how to visualise desired items. Features are exaggerated in size to match the importance participants attach to them. If properly facilitated, the process is documented and records are kept in terms of the keys necessary for interpreting depicted symbols. The lack of a consistent scale and geo-referencing of the data leaves room for subjective interpretation of the final map. A scale sketch map is a sketch given scale by fitting it onto a topographic map. without a field survey. (source: Rambaldi et al, 2005).

Smoothing: A form of generalization that involves averaging (either by visual estimation or computation) the locations of the coordinates that define the surveyed path of a line feature or the boundary of a polygon so as to remove excessive detail, given the scale of the map, or to average measurement errors.

Slope Distance: A distance measured on sloping terrain that has not yet been converted to horizontal distance for plotting on a survey drawing or map.

Spatial Information Technologies (SIT): refer to Geographic Information Technologies (GIT)

SPOT: A specific kind of satellite image that covers a smaller area than a LANDSAT image and at a higher resolution (and usually at a higher cost per square kilometer).

Spot height: The exact height, shown with a number on a map of a particular place above some datum (usually mean sea level).

Station: A starting point or endpoint of a survey leg. Stations are where measurements of distance and bearings are taken and recorded, along with any relevant notes. The stations within each surveying project are sequentially numbered for identification.

Stereoscope: A device used to look at paired air (aerial) photography, making it possible to see features on the photographs in three-dimensional perspective.

Survey: To traverse a particular linear feature (such as a boundary or a river), or travel in some specific pattern across a particular area, with the purpose of recording the locations of features on the land and details about them for use in making a map. Surveying is often done with a compass and a meter tape: some surveys are done with a GPS receiver.

Survey chain: A surveying tool that consists of a nylon rope on which every tenth of a meter is marked by a metal clip.

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