WGS84 to BJ2000 Converter
About WGS84 Coordinate System
WGS84 (World Geodetic System 1984) is the global standard geodetic reference system used by GPS. It defines an Earth-centered, Earth-fixed coordinate system and geodetic datum.
Developed by the U.S. Department of Defense in 1984, WGS84 has undergone several refinements (WGS84(G730), WGS84(G873), WGS84(G1150), WGS84(G1762)) to improve accuracy through GPS satellite observations.
WGS84 is the default coordinate system for GPS receivers worldwide. It is used in aviation, maritime navigation, Google Maps, OpenStreetMap, GIS applications, and scientific research.
WGS84 is the native coordinate system of the Global Positioning System (GPS), ensuring direct compatibility with all GPS receivers and satellite navigation systems worldwide.
As the most widely adopted geodetic datum, WGS84 provides a consistent global reference frame for mapping, surveying, and geospatial data exchange across international boundaries.
With continuous refinements, WGS84 achieves centimeter-level accuracy globally, making it suitable for high-precision applications like surveying, drone navigation, and scientific research.
About BJ2000 Coordinate System
BJ2000 is China's modern geodetic reference system based on CGCS2000, established to replace BJ54.
BJ2000 was developed alongside CGCS2000 as part of China's geodetic infrastructure modernization.
BJ2000 is used for surveying, GIS, engineering projects, and scientific research in China.
BJ2000 uses the same reference ellipsoid as CGCS2000.
Converting between BJ2000 and WGS84 requires regional 7-parameter values.
WGS84 → BJ2000 Conversion Guide
// WGS84 → BJ2000 (7-parameter Helmert transformation)
// Between WGS84 ellipsoid and CGCS2000/GRS80 ellipsoid
// Step 1: Convert from WGS84 to geocentric Cartesian
// Using source ellipsoid: a = 6378137.0, 1/f = 298.257223563
N = a_source / √(1 - e²_source × sin²(φ))
X = (N + h) × cos(φ) × cos(λ)
Y = (N + h) × cos(φ) × sin(λ)
Z = (N × (1 - e²_source) + h) × sin(φ)
// Step 2: Helmert 7-parameter transform (WGS84 → BJ2000)
// Parameters: dx, dy, dz (m), rx, ry, rz (rad), s (ppm)
//
X' = ΔX + (1 + s)(X + Rz·Y - Ry·Z)
Y' = ΔY + (1 + s)(-Rz·X + Y + Rx·Z)
Z' = ΔZ + (1 + s)(Ry·X - Rx·Y + Z)
// Step 3: Convert back to geodetic using CGCS2000/GRS80 ellipsoid
// a = 6378137.0, 1/f = 298.257222101
p = √(X'² + Y'²)
θ = atan2(Z' × a_target, p × (1 - f_target))
φ' = atan2(Z' + e²_target × (1 - f_target) × a_target × sin³(θ),
p - e²_target × a_target × cos³(θ))
λ' = atan2(Y', X'){{from}} to {{to}} requires a full 7-parameter Helmert transformation because the two systems use different ellipsoids and different datum origins. The conversion accuracy depends on the quality of regional 7-parameter values used.
- Enter your WGS84 coordinates in the input field (latitude, longitude, one pair per line)
- Enter the appropriate 7-parameter Helmert values (dx, dy, dz, rx, ry, rz, s) for your region
- Click the Convert button to transform coordinates from WGS84 to BJ2000
- Review the converted BJ2000 coordinates in the output field
- Copy the results or save them as an XLSX file for further use
- Ensure coordinates are within valid ranges before conversion
- 7-parameter values are region-specific; obtain them from local surveying authorities
- Verify a sample of converted coordinates on your target platform
- All conversions are performed client-side for complete data privacy