Seven-parameter Solution

Summary

Use Bursa model to calculate the seven parameters for the transformation among different coordinate systems according to three or more pairs of tie-points. The parameters include three translation parameters, dx, dy, dz, three rotation parameters, rx, ry, rz, and a scaling factor, m. The calculation formula is shown below. Bursa seven parameters formula can be written as follow:

Convert the above formula to a equation set, which is:

In the equation set, there are seven unknown parameters. If there are three or more than pairs of tie-points, these seven parameters can be solved through the above equation set using the least square method.

Usage

Click Data Management > Projections and Transformations > Seven-parameter Solution

Settings

Source File: Select the file containing the source coordinates of control points. File should be in .txt format. Please refer to seven parameters inputs for detailed information.
Target File:Select the file containing the targeted coordinates of control points. File should be in .txt format. Please refer to seven parameters inputs for detailed information.
Swap: Swap the source file and target file with each other.
XYZ (Checked by default): The inserting points' coordinates should be in spatial Cartesian coordinate system.
BLH (Optional): The inserting points' coordinates should be in geographic coordinate system.
- Unit (Degree by default): Either degree, or degree: minute: second.
- Ellipsoid (WGS84 by default): Ellipsoidal coordinate systems including WGS 1984, Xi'an 1980, and Beijing 1954 are provided.
Output Path: Save the report of the solved results to a user-defined path.

Seven-parameter Solution