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PRJ editor

PRJ Editor is a tool that allows you to edit the coordinate system knowing the transition parameters. In order to use it you need to select "PRJ Editor" in the Tools panel.

PRJ Editor_1.jpg

Currently, a small amount of photogrammetry and laser scanning software supports affine transformations, so this tool does not support affine transformations in the same way.

In the window that opens, click the "Select" button and select the *.prj file you want to edit.

PRJ Editor_2.jpg

The table provides a description of the parameters

Projection name
 Russia-Moskovskaya oblast-MSK50 GOST-zone2 Projection name
Coordinate system Krassovsky Name of coordinate system
DATUM unknown Datum name
SPHEROID krass",6378245,298.3 Name of ellipsoid
TOWGS84
7 parameters of transition to WGS84
Delta 23.57, -140.95, -79.8 Displacement of the intermediate geocentric coordinate along the X, Y, Z axes. It is specified in meters, and the translation direction is indicated by the value sign.
Rotation 0,0.35,0.79 The amount of rotation about the X, Y, Z axes that applies to intermediate geocentric coordinates. It is specified in angular seconds, and the direction of translation is indicated by the sign of the value.
Scale -0.22 A scaling factor that applies to intermediate geocentric coordinates. The value is given in parts per million and is the difference between the actual scaling factor and one.
For example, a scale parameter value of -2.5 gives an actual scale factor of 0.9999985. That is, the actual scale factor used is obtained by multiplying the parameter value by 1.0x10-06 and adding the result (algebraically) to 1.0.
PRIMEM "Greenwich",0 Zero meridian, indicating the offset between the zero meridian of the declared coordinate system and the Greenwich coordinate system.
UNIT "degree",0.01745329251994328 The unit of measure of SC (degrees).
PROJECTION Transverse_Mercator Projection type
PARAMETERS

Latitude of origin 0 Initial latitude
Central meridian 38.48333333333 Central meridian
Scale factory 1 Scale factor
False easting 2250000 Shift east
False northing -5712900.566 Shift north
UNIT

metre

 Projection unit

Make all necessary changes to the parameters, click the "Save" button, specify the path to save and the file name.

PRJ Editor_3.jpg

The resulting file is shown below.

PROJCS["MSK 50 zona 2",
    GEOGCS["Krassovsky,
        DATUM["unknown",
            SPHEROID["Krassowsky 1940",6378245,298.3,
            TOWGS84[-118.754,-61.782,-93.237,-2.40896,-3.47502,1.29688,6.5177]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.01745329251994328]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",38.48333333333],
    PARAMETER["scale_factor",1],
    PARAMETER["false_easting",2250000],
    PARAMETER["false_northing",-5712900.566],
    UNIT["metre",1]]
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