WGS84 and CGCS2000 Coordinate Converter Online

Online WGS84 and CGCS2000 coordinate conversion tool, supporting high-precision interconversion between WGS84 coordinates and CGCS2000 coordinates.

1. The CGCS2000 version and WGS84 version supported by this tool are as follows:

   Version	Release Time	Frame	Epoch	Major Improvements	Applicable Scenarios
   CGCS2000	2008	ITRF97	2000.0	Geocentric coordinate system for improved accuracy	China's nationally standardized coordinate system
   WGS84 (G2135)	2021	ITRF2020	2020.0	Enhanced multi-GNSS compatibility	Multi-system fusion positioning (GPS/BeiDou, etc.)
   WGS84 (G1762)	2015	ITRF2014	2015.0	Update speed modeling to support real-time kinematic	Real-time kinematic positioning (RTK)
   WGS84 (G1674)	2013	ITRF2008	2005.0	Aligned with ITRF2008, centimeter-level accuracy	Precision navigation, earth science research
   WGS84 (G1150)	2001	ITRF97	2001.0	Integration of additional ground-based observatory data	High-precision geographic information systems (GIS)
   WGS84 (G873)	1996	ITRF94	1997.0	Improvement of dynamic frame accuracy to the decimeter level	Commercial satellite positioning, mapping
   WGS84 (G730)	1994	ITRF91	1994.0	Introduction of satellite tracking data for the first time	Civilian GPS Enhancement

2. Input Coordinates ： Supports the input of Cartesian spatial rectangular coordinate system coordinates (ECEF coordinates, XYZ) and geodetic coordinates (geodetic longitude, geodetic latitude, geodetic height, LBH). Use comma-separated values to enter one set of coordinates per line. Multiple lines are supported. The spatial Cartesian coordinate format is X , Y , Z, the unit is the meter (m). The geodetic coordinate format is L , B , H, longitude and latitude are in degrees and elevation is in meters.
3. Basic Parameters : Sets the base parameters for WGS84 and CGCS2000 coordinate conversions.
   1. Convert Type : Select WGS84 to CGCS2000 or CGCS2000 to WGS84.
   2. WGS84 Version : Select the version of WGS84 coordinates, this tool supports WGS84 (G2135), WGS84 (G1762), WGS84 (G1674), WGS84 (G1150), WGS84 (G873), WGS84 (G730), and other versions. etc.
   3. WGS84 Epoch : Observation epoch for the input WGS84 coordinates.
   4. WGS84 Type : Select the type of WGS84 coordinates, XYZ - Geocentric and LBH - Geodetic coordinates are supported. If the selected coordinate type is geodetic, the ellipsoid parameter must be set, and the geodetic coordinates will automatically be converted to geocentric geoid coordinates for calculation during the coordinate conversion.
   5. CGCS2000 Version : Fixed to CGCS2000.
   6. CGCS2000 Epoch : Fixed to 2000.0 .
   7. CGCS2000 Type : Select the type of CGCS2000 coordinates, XYZ - Geocentric and LBH - Geodetic coordinates are supported. If the selected coordinate type is geodetic, the ellipsoid parameter must be set, and the geodetic coordinates will automatically be converted to geocentric geoid coordinates for calculation during the coordinate conversion.
4. Convert Parameters : Sets the frame conversion parameters and epoch calculation parameters for WGS84 and CGCS2000 coordinate conversions.
   1. Velocity Type : If the input observation epoch is different from the output result epoch, velocity information must be provided. This tool supports two ways to provide speed information:
      Velocity Vector : Directly fill in the vx, vy, vz velocity values in m/a, meters per year.
      Euler Vector : Fill in the Euler vectors Ωx, Ωy, Ωz in rad/Ma, radians per million years. Use the Euler vectors and station coordinates to calculate the velocity values.
   2. Custom : Clicking Custom displays the 14 parameters and reference epoch for the ITRF framework conversion. You can modify these parameter values to use custom parameter conversions.
   3. Input ITRF : the ITRF framework of the input coordinates.
   4. Output ITRF : the ITRF framework of the output coordinates.
   5. Selecting different conversion types and WGS84 versions automatically sets the input ITRF and output ITRF. This tool automatically fills the parameters and reference epoch associated with the coordinate transformation based on the input ITRF frame and the output ITRF frame. You can click the Custom button to view the filled parameter values. You can also modify the parameter values used for the conversion. The Input ITRF and Output ITRF are only used to automatically fill the parameters for the conversion between ITRF frames and are not involved in the actual calculation.
   6. ITRF Epoch : Reference epoch for ITRF framework conversion parameters.
   7. tx : X-axis translation, in millimeters.
   8. ty : Y-axis translation, in millimeters.
   9. tz : Z-axis translation, in millimeters.
   10. d : Scaling factor, in ppb, 10⁻⁹.
   11. rx : The X-axis rotation angle is measured in mas, milli-arcseconds.
   12. ry : The Y-axis rotation angle is measured in mas, milli-arcseconds.
   13. rz : The Z-axis rotation angle is measured in mas, milli-arcseconds.
   14. txv : The translation speed of the X-axis is measured in millimeters per year (mm/a).
   15. tyv : The translation speed of the Y-axis is measured in millimeters per year (mm/a).
   16. tzv : The translation speed of the Z-axis is measured in millimeters per year (mm/a).
   17. dv : Scaling factor change rate, unit: ppb/a, 10⁻⁹/year.
   18. rxv : The rotational angular velocity on the X-axis is measured in mas/a and in milli-arcseconds/year.
   19. ryv : The rotational angular velocity on the Y-axis is measured in mas/a and in milli-arcseconds/year.
   20. rzv : The rotational angular velocity on the Z-axis is measured in mas/a and in milli-arcseconds/year.
5. Open File : Support for opening UTF-8 encoded text files.
6. The process of calculation in this tool is as follows: a. Epoch calculation of conversion parameters between different ITRF frames b. Plate motion correction c. Coordinate conversion using seven parameters determined in step a. The accuracy of the coordinate conversion is highly dependent on the velocity field data provided. If there is no local high-precision velocity field information, you can use the 3x3 degree velocity field data of mainland China in the appendix of this tool, or use the Euler vector data of CGCS2000 plate. The conversion accuracy of using Mainland China 3x3 degree velocity field data is generally between millimeter and centimeter level.
7. Example of IGS station WGS84 to CGCS2000. Parameters used: WGS84 version - WGS84 (G1674), WGS84 epoch - 2005.0, WGS84 coordinate type - XYZ. CGCS2000 version - CGCS2000, CGCS2000 epoch - 2000.0, CGCS2000 coordinate type - XYZ . Velocity parameter source - Based on the XYZ coordinates, use the XYZ to LBH tool on this site to get the LBH coordinates. Then query the table Mean Velocity - Velocity Fields - CGCS2000 for Mainland China 3x3 Degree Grid to get the velocity data. The unit of velocity obtained from the table should be converted from mm/a to m/a, i.e. divided by 1000. The speeds of Urumqi, Changchun and Beijing stations are inverted as parameters.

   Station	WGS84 Coordinate			CGCS2000 Coordinate			Velocity			Calculated CGCS2000			Residual
   N/A	X (m)	Y (m)	Z (m)	X (m)	Y (m)	Z (m)	Vx (m/a)	Vy (m/a)	Vz (m/a)	X (m)	Y (m)	Z (m)	X (m)	Y (m)	Z (m)
   WUHN/Wuhan	-2267749.426	5009154.287	3221290.704	-2267749.263	5009154.311	3221290.709	-0.0315	-0.0085	-0.0116	-2267749.271778932	5009154.346067069	3221290.738206169	-0.008778932	0.035067069	0.029206169
   SHAO/Shanghai	-2831733.505	4675665.951	3275369.429	-2831733.363	4675666.015	3275369.466	-0.0298	-0.0101	-0.0132	-2831733.3608287573	4675666.016929227	3275369.471364079	0.0022	0.001929227	0.005364079
   LHAS/Lasa	-106938.0326	5549269.52	3139215.874	-106937.804	5549269.587	3139215.789	-0.0443	-0.0087	0.0115	-106937.80822647549	5549269.582272761	3139215.79246651	-0.0042	-0.004727239	0.00346651
   URUM/Urumqi	193030.6314	4606851.291	4393311.462	193030.540	4606851.298	4393311.455	0.0298	0.0023	-0.0014	193030.48642357028	4606851.295608156	4393311.448628469	-0.0536	-0.002391844	-0.006372
   CHAN/Changchun	-2674427.231	3757143.218	4391521.671	-2674427.313	3757143.205	4391521.625	0.0251	0.008	0.0102	-2674427.3606022364	3757143.1907928986	4391521.599623243	-0.0476	-0.01421	-0.025376757
   BJFS/Beijing	-2148744.083	4426641.273	4044655.927	-2148744.179	4426641.266	4044655.880	0.0293	0.0059	0.0107	-2148744.2322619907	4426641.2584007485	4044655.852110395	-0.05326	-0.0076	-0.027889605

8. Calculate Formula:
   1. Use Euler vectors to calculate station velocity formula:. In the formula, V_x, V_y, V_z are the calculated velocity value components. X, Y, Z are the coordinate of the station. Ω_x, Ω_y, Ω_z are the Euler vector of the plate where the station is located.
   2. Epoch calculation formula : from t₀ to t .
      
      In the formula, m_r = 4.84813681*10⁻⁹ , is the conversion factor from milli-arcseconds mas to radians rad.
   3. Correction formula for plate movement: . In the formula, t_c is the observation epoch. t is the epoch to be converted. X_tc, Y_tc, Z_tc is the coordinate at the observation epoch tc. X_s, Y_s, Z_s is the speed value of the station.
   4. Inter-frame coordinate formula: converts the coordinates of an ITRFyy frame to an ITRFzz frame.
      
      In formula [X Y Z]ITRF_zz are the coordinates in the target ITRF frame. [X Y Z]ITRF_yy are the coordinates in the input ITRF frame. T_x, T_y, T_z are the translation parameters. D is the scaling factor. R_x, R_y, R_z are the rotate parameters.
9. Parameters of the reference ellipsoid

   Name	Semi-major axis(a)	Flattening Inverse(rf)
   WGS84	6378137 m	298.257223563
   CGCS2000	6378137 m	298.257222101

10. Reference Documentation
    1. Transformation parameters between ITRF Solutions
    2. Mean velocity of 3x3 degree grid in mainland China - Velocity field - CGCS2000 . The statistical values of the difference between the calculated velocity values of the grid points and their reference values are ±1.81 mm/a, ±1.05 mm/a, ±1.55 mm/a, and the error of positional motion velocity ±2.61 mm/a, respectively. ±1.55 mm/a, and the error of positional motion velocity ±2.61 mm/a .
       
       
       
    3. Technical Specification for Coordinate Conversion of Geodetic Control Points (CH/T 2014-2016), which contains 20 plates of Euler vector tables for CPM-CGCS2000.
       
       
11. This tool has a certain frequency limit, please use this tool reasonably. Anonymous : 30/IP*Hour, Normal user : 30/Hour, VIP : 360/Hour, Senior VIP : 360/Hour.
    Anonymous and normal users can only enter one set of coordinates at a time, and batch conversion is not supported. VIP and advanced VIP users support batch conversion.