NGO (Non-Governmental Organization): An organization, usually with humanitarian or environmental protection objectives, that is not controlled by a government, though it may

operate with the assistance of government funding. Many NGO projects are intended to aid indigenous peoples to protect or improve their quality of life.

North line: A line drawn on a map so as to align with a north meridian. It provides a refer­ence line by which to measure bearings by using a compass or protractor.

Northing: The part of a coordinate (such as the latitude) that gives the north-south position.

Offset: The perpendicular distance from a traverse line to a parallel line or to a point.

Orientation: The positioning of a map so that its north line points to the Earth's true north.

Orthophoto: A perspective aerial photograph contains image displacements caused by the tilting of the camera and terrain relief (topography). It does not have a uniform scale. Distances cannot be measured on a conventional aerial photograph like one can do on a map. In an orthophoto the effects of tilt and relief are removed from the aerial photograph by the rectification process. Therefore an orthophoto is a uniform-scale photograph or photographic map. Since an orthophoto has a uniform scale, it is possible to measure directly on it like other maps. An orthophoto may serve as a base map onto which other map information may be overlaid (Source: U.S. Geological Survey)

Overlay map: A thematic map on tracing-paper (or on a plastic sheet) that is used in conjunction with a base map.

Panorama sketch: A landscape sketch made from a location that has a view of the surround­ing terrain for a fair distance.

Parallel (of latitude): A circle on the Earth's surface that is parallel to the equator, but smaller and either to the north or south of it. A line of latitude.

Participatory 3D Modelling (P3DM): This method integrates indigenous spatial knowledge with data on elevation of the land and depth of the sea to produce stand-alone, scaled and geo-referenced relief models. Essentially based on indigenous spatial knowledge, land use and cover, and other features are depicted by informants on the model by the use of pushpins (points), yarns (lines) and paints (polygons). On completion, a scaled and geo-referenced grid is applied to facilitate data extraction or importation. Data depicted on the model are extracted, digitised and plotted. On completion of the exercise the model remains with the community (Source: Rambaldi and Callosa-Tarr, 2002)

Participatory GIS (PGIS) is an emergent practice in its own right. It is a result of merger between Participatory Learning and Action (PLA) methods with Geographic Information Technologies (GIT). PGISfacilitates the representation of local people’s spatial knowledge using two- or three-dimensional maps. These map products can be used to facilitate decision-making processes, as well as support communication and community advocacy. PGIS practice is geared towards community empowerment through tailored, demand-driven and user-friendly applications of these geo-spatial technologies. Good PGIS practice is flexible and adapts to different socio-cultural and biophysical environments. It often relies on the combination of ‘expert’ skills with local knowledge. Unlike traditional GIS applications, PGIS places control on access and use of culturally sensitive spatial data in the hands of those communities who generated it.

PGIS spatial analysis uses the functionality and data associated with GIS technology to explore community driven questions. In the process, local spatially referenced as well as non-spatial data are integrated and analysed to support discussion and decision-making processes. The spatial analytic functionalities allow much easier and rapid analysis by the users, of e.g. time and cost functions, of separation and contiguity, and of the effects of barriers and buffers (source: Rambaldi et al, 2005).

Photographic map: see orthophoto.

PDOP (Precision Dilution of Position): PDOP is an estimate of the accuracy of a GPS position fix based on the quality of the satellite signals (which is a result of the satellite distribution at the time of the determination).

POC (Point of Commencement): The starting point for a survey route.

Point feature: Something - such as a sacred rock, house, or special tree that is too small to be drawn to scale on a particular map so it is instead represented by a standardized symbol that may be either abstract or stylized.

Polygon: A bounded area on a map that represents something (an area feature such as a lake, field, forest type, or hunting area) on the land that is large enough to be shown to scale. A polygon can be identified through the use of a particular color, pattern, or code.

Position Averaging: A method for improving the accuracy of GPS data that requires just one GPS receiver, which is set up to take a series of readings over a period of time.

PPGIS (Public Participation GIS): see ppgis

Practical ethics focuses on understanding and addressing difficult and controversial social issues arising in such fields as politics, economics, technology, healthcare, business, environmental conservation and education. Ethics more broadly investigates the meaning of the good, emphasising the role of values in raising and critically responding to questions of deep and abiding personal and common concern. Practical ethics requires resource managers who engage in mapping to follow clear protocols for explaining complex consequences of mapping to rural communities. This protocol requires outside actors to communicate clearly with each community, clarifying the purpose/objectives of collecting information, agreeing with villagers on what information can be mapped, and explaining potential consequences of recording the community's spatial information on maps that can then be copied and distributed outside the community. Most importantly, outside facilitators must communicate to villagers that they can agree to accept or reject the mapping exercise.

Prime meridian: Zero degrees longitude. Also known as the Greenwich Meridian because it was established at the Greenwich Observatory near London, England.

Projection: See map projection.

Protractor: A device, usually of clear plastic and circular or D-shaped, used to measure angles.

PRA (Participatory Rural Appraisal): A set of techniques for including the local people in the documentation and analysis of local land issues.

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