The Mapping Section is one of four core sections of SMD. Its major responsibility is map production. The section is not responsible for carrying out ground survey works for map production. Where such services are required, Topographic and Geodetic Survey Section undertake it. The Mapping Section extends its support mainly in the area of planning of ground photo control requirements for photogrammetric mapping and carries out photo and image interpretation and identification of photo points in the field.

Functions

The core function of the Mapping Section is the preparation of base maps for urban and rural areas. The main mode of preparation of maps is by analogue methods. Digital mapping is progressively being introduced with the aim of phasing out analogue methods which are inefficient and inflexible to changes and cannot fully meet the ever changing and more diversified Customer needs. Introduction of digital mapping technology is progressing procuring new equipment/systems hand in hand with training of staff on full utilization of the technology. The Mapping Section is organised into four major sub-sections or units:-

Photogrammetry Unit:

It is responsible for initial compilation of base maps from aerial photographs through the processes of aerial triangulation, photogrammetric stereo restitution and plotting. The unit is also responsible for maintaining the national aerial photo library.

Cartographic Unit:

It is responsible for cartographic map compilation and preparation of fair drawings by colour separation in order to obtain original map reproduction materials for printing purposes.

Printing and Reproduction Unit:

It is responsible for lithographic reproduction and printing of maps and other documents.

Digital Mapping Sub-Unit:

It is responsible for computer aided cartographic map compilation, creation of digital map databases and deriving new products from the same. It has staff from both cartography and photogrammetry sections.

Maps

Maps are basic tools for planning, implementing and monitoring physical development on land and the impact of such developments on the environment. Topographic base maps in particular are the media and framework onto which to portray the spatial distribution and statistical data of every phenomenon taking place on the physical land whether man-made or natural. Thus land administration and environmental management programs cannot succeed without appropriate maps. Because of ever changing developments taking place on land as well as the environment, maps need to be continuously updated in order to portray the current situation at any one given time.

Main types of maps are as follows:-

• Topographic Maps
• Thematic Maps
• Township Maps
• Aerial Photographs
• Satellite image
• Orthophotomap