Base Map Preparation

A digital base map is a primary element for developing a Geographic Information System for organized urban development. Base map forms the framework for overlaying other relevant details related to infrastructure, land base, utility networks, property details etc. to create any intelligent GIS map. An accurate base map can lay the foundation for efficient infrastructure planning, monitoring and management. Our systematic approach for base map preparation ensures accuracy and effectiveness.

BASE MAP PREPARATION

Data Sources

We utilize multiple data sources for the preparation of geo-referenced vectorized base maps. These sources include the following:
Existing hard copy maps (administrative maps, cadastral sheets etc.)
High-resolution satellite imagery and aerial images
Field survey mainly to validate the existing data and to collect landmarks
In addition to spatial information, our surveyors also collect attribute information to make the base map more reliable and useful.
pipeline GIS for water utilities Data Sources

Approach

The base maps we create undergo a series of steps for development. Here's a quick look:
Fixation of area of interest including demarcation of administrative boundaries
Scanning and mosaicking of the existing hardcopy maps
GCP collection to geo-reference the administrative maps and satellite imagery
 
Superimposition of scanned maps over Satellite Imagery
Field validation of the same mainly using DGPS to ensure accuracy
Digitization of relevant layers from geo-referenced scanned maps including administrative layers like corporation/ municipality boundaries, ward boundaries etc.
Extraction of spatial layers from the satellite imagery including roads, railways, water bodies and other relevant features.
Ground-truthing to validate the prepared map via attribute data collection
DGPS/ GPS survey to collect points of interest
This is followed by integration of the field output for further enhancement of the base map.
So far, we have developed more than 150 base maps for town planning.
GIS in gas pipeline network Base Map