Question

What is datum? Explain how WGS84 is better than any local datum used in GIS.

Hint:

WGS84 enables consistent coordinates for global navigation and mapping.

Answer 1

A datum is a reference framework for defining Earth's shape, size, and coordinate systems used in mapping and spatial analysis.
It comprises an ellipsoid, a mathematical representation of Earth's form, and its alignment with Earth's center of mass.
Datums are categorized as either local or global.
Local datums, exemplified by the Everest Datum in India, provide precise fits for particular regions but may exhibit discrepancies globally.
WGS84 (World Geodetic System 1984) is a global datum engineered for GPS and comprehensive worldwide mapping.
WGS84 achieves superior accuracy by employing satellite measurements to encompass the entire Earth, aligning with its center of mass and ensuring uniform global coordinates.
Consequently, it is optimal for GPS navigation, global datasets, and cross-border data integration.
In contrast to local datums, which can exhibit regional variations, WGS84 facilitates the seamless exchange and overlay of geospatial data from diverse worldwide sources.
Therefore, WGS84's inherent global consistency renders it more dependable than any local datum in contemporary GIS applications.