Map to Map Transformation of Strings
There are many occasions when coordinates must be transformed from one coordinate system to another, e.g. from MGA to a local grid and vice versa. In addition, where survey data has been entered using an incorrect backsight, the data can be corrected by transforming the coordinate system onto the backsight that was used.
Another important occasion is when oblique sections have been taken through a DTM or string file using an axis. In this case, the resultant section string files have coordinates relating to the axis used. They can be easily transformed back to real world coordinates using this function.
This function allows you to perform a lauf transformation on a range of string files based on the input of several control points.
To run this function: Choose File tools > Transformations > Map to map transformation, or...
Define files to transform
Location, ID range and (O)bs or (S)tring files
Identify the files to be transformed by entering the Location and ID range.
Define files to create
Location
The output string files may have the same or different location.
Any Z correction
If you wish to alter the Z values as well as the X and Y coordinates, respond with Y here.
Transform AB axis
An axis will not be transformed unless specifically requested by entering Y here.
(A)ddition or (M)ultiplication
If you specify a Z correction in the preceding question, now specify whether you wish to add a constant to each Z value, or multiply it by a constant.
Correction factor
If Z corrections are to be applied then the constant which is to be used must be entered here.
This can be a negative number if a constant is to be subtracted.
Define transformation parameters
You must then enter the coordinates of at least four points whose coordinates are known in both systems. The more points used the greater the accurracy of the final results.
For each control point used fill in a row of the scroll block, entering the original y and x coordinates of the point and the transformed y and x coordinates of the point.