Back to dictionary
General Terms
Elevation/Height
The vertical distance from a defined reference level (usually sea level) to a specific point on the Earth's surface.
Elevation/Height in geodesy is the vertical distance of a point from a defined reference level. In Latvia, the Baltic Sea level is used as the reference (Baltic Height System 1977 - BHS-77).
Types of height:
- Absolute height - height above mean sea level
- Relative height - height difference between two points
- Ellipsoidal height - height above the mathematical Earth model (ellipsoid)
- Orthometric height - height determined by leveling
Importance of height in surveying:
Precise height information is essential in many cases:
- Construction - for proper placement of buildings and infrastructure
- Drainage - for designing water drainage systems
- Road construction - for planning the vertical profile of routes
- Topographic surveying - for representing terrain
- Flood risk assessment - for identifying critical zones
Height determination methods:
- Geometric leveling - highest precision, uses a level instrument
- Trigonometric leveling - with total station, lower precision
- GNSS measurements - fast method with good precision
- LiDAR - mass height data acquisition
Latvian height system:
Latvia officially uses the Latvian Normal Height System LAS-2000.5, based on the European Vertical Reference System (EVRS). Heights are determined with millimeter precision using state leveling network points.