GEODETIC AND GIS DIVISION

The Division is responsible for the following tasks:-

1. National Geodetic Control Surveys

Geodetic control surveys involve accurate determination of ground positions and heights above mean sea level of points suitably distributed throughout the country. These points are used as datum reference for all subsequent land surveys for various purposes. The methods that have been used include triangulation, traverse, trilateration, Doppler Positioning and recently the Global Positioning System (GPS). About two thirds of the country is covered by a network of horizontal control points and one-third by precise vertical control points. Hydrographic surveys are virtually non-existent while gravity surveys are scanty with no national network.

2. Aerial Photography

Involves Planning, acquisition and provision of aerial photographs for the following purposes:-

• Preparation of various topographical maps varying from the large scales mapping used for urban planning to the medium scale basic mapping of the country at scale 1:50,000. Preparation and supply of enlarged aerial photographs for land adjudication surveys at the scale of 1:12500 which is then enlarged to 1:2500 used in the field for identification and demarcation of land parcel boundaries. Various studies in forests, land use, soil conservation, environmental studies and human settlement.

• For use by Department of Defence and educational institutions.
  

3. Topographical Base Maps

Production of basemaps for physical planning of urban centers, settlement schemes and land consolidation surveys. These maps, prepared using photogrammetric methods, are also used for engineering, agricultural and other development projects.


4. National and International Boundaries
   
   

Inspection and maintenance of international and national (District and Provincial) boundaries in liaison with the office of the president.


5. Geographical Information System

The section is responsible for provision of digital data through digitization, scanning and vectorization. It is also responsible for conversion and cataloguing of existing topographical maps into digital forms to create National Topographical Data Base (NTDB). 78 map sheets at scale 1:50,000 and 31 map sheets at scale 1:250,000, have been digitized. The work is in progress to cover the whole country.