Technicians in this category are - independent of, in co-operation with or in support of engineers and professional personnel, concerned with the surveying as well as the gathering and processing of aerial, remotely sensed and terrestrial survey data and the interpretation thereof according to the discipline: Photogrammetry and Remote Sensing. Stereoscopic observations and interpretation thereof are done by precision photogrammetric- instrument measurements utilising aerial and terrestrial photography. Accurate map production is done by means of CAD-assisted Wild A7, A8 stereoplotters, a Wild BC2- PC analytical stereoplotter, two VIRTUOZO digital photogrammetry systems and a Usmart Softcopy (digital photogrammetric) system. Microstation CAD is utilised to gather and process digital map data. The maps produced are used in the planning and designing of new dams, canals and pipelines, rehabilitation of mine dumps and other water supply and sanitation projects as well as for the development of irrigation schemes and for the supply of bulk water to Industry. Photogrammetry is also utilised to support GIS in gathering large scale accurate DTM’s of dam basins for catchment analysis purposes.

In addition to the standard black and white aerial photography used for most mapping projects, colour, false colour and colour infra-red photography can be supplied and utilised for mapping and interpretive purposes, e.g. water pollution control. Information is also gathered using other remotely sensed data, namely satellite imagery. The data gathered in this manner is used primarily for the mapping and evaluation of water use and irrigation, done on a regional as opposed to local level. This is extremely useful for determining lawful water use, for abstraction control and for the monitoring of the licensing process.