Surveying is an essential process in construction and civil engineering, used to determine the relative positions of points on the Earth’s surface. It helps in planning, designing, and executing various construction projects. There are two primary types of surveying: Plane Surveying and Geodetic Surveying. Understanding their differences is crucial for choosing the right method for a specific project. This blog explores these two types of surveying, their key differences, and relevant IS codes used in India.![]()
What is Surveying?
Surveying is the technique of measuring and mapping the Earth’s surface. It involves determining distances, angles, and elevations to create accurate maps and plans for construction, land development, and infrastructure projects. Surveying ensures that structures are built in the correct locations and align with design specifications.What is Plane Surveying?
Plane surveying is a method of surveying in which the Earth’s surface is considered flat. It is used for small areas where the effect of the Earth’s curvature is negligible. The calculations in plane surveying are simpler and do not involve complex mathematical corrections.Features of Plane Surveying:
- Assumes the Earth is a flat surface.
- Used for small-scale projects (less than 250 km²).
- Requires simple instruments like chains, tapes, and theodolites.
- Used in land surveying, road construction, and small building projects.
- Less accurate for large areas due to the neglect of the Earth’s curvature.
What is Geodetic Surveying?
Geodetic surveying is a method of surveying in which the Earth’s curvature is taken into account. It is used for large-scale projects where high precision is required. This type of surveying applies advanced mathematical models to correct for the Earth’s curvature.Features of Geodetic Surveying:
- Considers the Earth as a curved surface.
- Used for large-scale projects (above 250 km²).
- Requires advanced instruments like GPS, satellite imagery, and electronic distance measurement (EDM) devices.
- Used in railway construction, large infrastructure projects, and mapping national boundaries.
- Provides high accuracy and precision.
Differences Between Plane Surveying and Geodetic Surveying
| Feature | Plane Surveying | Geodetic Surveying |
|---|---|---|
| Consideration of Earth’s Shape | Assumes the Earth is flat | Takes Earth’s curvature into account |
| Area Covered | Small areas (< 250 km²) | Large areas (> 250 km²) |
| Instruments Used | Chains, tapes, theodolites | GPS, satellites, EDM devices |
| Accuracy | Moderate | High |
| Applications | Land surveys, road construction | National mapping, large infrastructure projects |
| Mathematical Corrections | Not required | Required for curvature correction |
Applications of Plane Surveying:
- Layout of buildings and roads.
- Small-scale topographic mapping.
- Agricultural land measurement.
- Local property boundary determination.
Applications of Geodetic Surveying:
- Large-scale infrastructure planning (highways, railways, and pipelines).
- Mapping continents and national borders.
- Satellite and GPS-based navigation.
- Establishing reference points for future surveys.
IS Codes for Surveying in India
Surveying in India follows specific standards set by the Bureau of Indian Standards (BIS). Some relevant IS codes include:- IS 1492:1970 – Code of practice for field surveying.
- IS 16479:2017 – Guidelines for the use of GPS in surveying.
- IS 14494:1998 – Geodetic control networks.
- IS 12285:1987 – Specifications for surveying and mapping.
- IS 9623:1980 – Specifications for total stations in geodetic surveying.