Hong Kong 1980 Grid (Hong Kong 1980 Coordinate System | EPSG:2326)
Jan 23,2026

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Introduction

Hong Kong 1980 Grid (Hong Kong 1980 Coordinate System | EPSG:2326) is a regional projected coordinate system specially designed for Hong Kong's urban surveying and mapping needs during the late 20th century. Developed as part of Hong Kong's territorial surveying framework, this system employs a transverse Mercator projection centered on the region's specific geographical characteristics. Although now supplemented and partially superseded by modern geocentric systems, it remains crucial for processing legacy engineering plans, cadastral records, and historical urban data from Hong Kong's development boom period.

Coordinate System Composition

Hong Kong 1980 Grid (EPSG:2326) is a projected coordinate system using the Transverse Mercator projection based on the International 1924 ellipsoid. The system employs a central meridian set at 114°10' East and a scale factor of 1.0, with false easting and northing values optimized for Hong Kong's compact territory. Coordinates are expressed in meters, providing convenient measurement units for detailed urban mapping and engineering applications across Hong Kong's islands and mainland areas.

Pros

Optimized Local Accuracy: Specially designed for Hong Kong's geographical extent, providing high positional accuracy for detailed urban surveying and large-scale mapping
Practical Engineering Applications: Meter-based coordinate units enable direct measurement for construction, planning, and cadastral applications without unit conversion
Standardized Regional Framework: Established a unified coordinate reference for Hong Kong's surveying community during the territory's rapid development period
Compatibility with Legacy Systems: Maintains backward compatibility with Hong Kong's earlier surveying practices while introducing modern projection techniques

Cons

Regional Limitations: Designed exclusively for Hong Kong territory, with rapidly decreasing accuracy outside the region's boundaries
Non-Geocentric Foundation: Based on the International 1924 ellipsoid rather than modern geocentric reference systems, creating compatibility issues with GPS and global datasets
Progressive Obsolescence: Being replaced by WGS84-based systems (like HK1980 Grid based on WGS84) in modern surveying applications
Limited International Interoperability: Requires transformation for integration with mainland China's coordinate systems or international geospatial frameworks

Application Scenario

Hong Kong 1980 Grid is primarily used in historical data processing and legacy system maintenance contexts. It serves as the reference system for interpreting and converting engineering drawings, cadastral plans, and topographic maps produced during Hong Kong's major infrastructure development period (1980s-1990s). The coordinate system enables the integration of historical urban planning documents, land registration records, and transportation network plans into modern GIS environments, supporting applications such as property boundary verification, infrastructure renovation planning, heritage conservation studies, and urban development pattern analysis. It remains particularly relevant for legal and administrative purposes when dealing with historical land transactions and property rights documentation established under this coordinate framework.