Coordinate System

A coordinate system is a mathematical system that allows uniquely describing point locations in space or on a plane using numerical values (coordinates). In geodesy and surveying, coordinate systems are a fundamental basis for all measurements.

Types of coordinate systems:

• Geographic system - latitude and longitude in degrees (φ, λ)
• Rectangular system - X, Y coordinates in meters
• Polar system - distance and angle from origin point
• Spatial system - X, Y, Z coordinates in 3D space

Coordinate systems used in Latvia:

• LKS-92 - Latvian geodetic coordinate system (official)
• WGS-84 - global system used by GPS
• ETRS89 - European Terrestrial Reference System
• UTM - Universal Transverse Mercator projection

LKS-92 characteristics:

• Transverse Mercator projection (TM)
• Central meridian: 24° east longitude
• Scale factor at central meridian: 0.9996
• Unit: meter
• GRS-80 ellipsoid

Coordinate transformation:

Different data sources may have different coordinate systems, requiring transformation:

• From GPS (WGS-84) to LKS-92
• From old systems to LKS-92
• From local systems to national system

Height systems:

• LAS-2000.5 - Latvian normal height system
• BHS-77 - Baltic Height System 1977
• Ellipsoidal heights - from GNSS measurements

Significance in surveying:

Correct coordinate system use ensures:

• Measurement compatibility with other data
• Precise object positioning
• Data exchange between different institutions
• Long-term data usability