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Project

Summary

Projects spatial data from one coordinate system to another.

Usage

  • If the input feature class or dataset has an unknown or unspecified coordinate system, you can specify the input dataset's coordinate system with the Input Coordinate System parameter. This allows you to specify the data's coordinate system without having to modify the input data (which may not be possible if the input is a read-only format). Also, you can use the Define Projection tool to permanently assign a coordinate system to the dataset.

  • Coverages, VPF Coverages, raster datasets, and raster catalogs are not supported as input to this tool. Use the Project Raster tool to project raster datasets.

  • The tool's Geographic Transformation parameter is optional. When no geographic or datum transformation is required, no drop-down list will appear on the parameter and it is left blank. When a transformation is required, a drop-down list will be generated based on the input and output datums, and a default transformation will be picked.

    • For example, a geographic transformation is not required when projecting from GCS_North_American_1983 to NAD_1983_UTM_Zone_12N because both the input and output coordinate systems have a NAD_1983 datum. However, projecting from GCS_North_American_1983 to WGS_1984_UTM_Zone_12N requires a geographic transformation because the input coordinate system uses the NAD_1983 datum, while the output coordinate system uses the WGS_1984 datum.
      Tip:

      Transformations are bidirectional. For example, if converting data from WGS 1984 to NAD 1927, you can pick a transformation called NAD_1927_to_WGS_1984_3, and the tool will apply it correctly.

    • For a list of transformations and their area of use, see the following knowledge base article: 21327 (Esri Knowledge base article #21327).

  • The in_memory workspace is not supported as a location to write the output dataset.

  • When projecting the complex data types listed below, certain operations need to be performed on the resulting data:

    • A feature dataset containing a network dataset: the network dataset must be rebuilt.
    • A feature dataset containing a topology: the topology should be validated again.

  • If the input participates in relationship classes (as with feature-linked annotation), the relationship class will be transferred to the output. The exception to this rule relates to participating stand-alone tables.

  • Depending on the input feature's coordinates and the horizon (valid extent) of the output coordinate system, multipoint, line, and polygon may be clipped or split into more than one part when projecting them. Features that fall completely outside the horizon will be written to the output with a Null shape. These can be deleted using the Repair Geometry tool.

  • Feature classes participating in a geometric network cannot be projected independently—the entire feature dataset containing the network needs to be projected.

  • Many geoprocessing tools honor the output coordinate system environment setting, and in many workflows you can use this environment setting instead of using the Project tool. For example, the Union tool honors the output coordinate system environment setting, which means you can union several feature classes together, all of which are in a different coordinate system, and write the unioned output to a feature class in an entirely different coordinate system.

    Learn more about geoprocessing environments

  • Selection and definition query on layers are ignored by this tool—all features in the dataset referenced by the layer will be projected. If you want to project selected features only, consider using the Copy Features tool to create a temporary dataset, which will only contain the selected features, and use this intermediate dataset as input to the Project tool.

  • When a feature class within a feature dataset is used as input, the output cannot be written to the same feature dataset. This is because feature classes within a feature dataset must all have the same coordinate system. In this case, the output feature class will be written to the geodatabase containing the feature dataset.

  • The Preserve Shape parameter, when checked, creates output features that more accurately represent their true projected location. Preserve Shape is especially useful in cases where a line or polygon boundary is digitized as a long, straight line with few vertices. If Preserve Shape is not checked, the existing vertices of the input line or polygon boundary are projected, and the result may be a feature that is not accurately located in the new projection. When Preserve Shape is checked (preserve_shape="PRESERVE_SHAPE" in Python), extra vertices are added to the feature before projecting. These extra vertices preserve the projected shape of the feature. The Maximum Offset Deviation parameter controls how many extra vertices are added; its value is the maximum distance the projected feature can be offset from its exact projected location as computed by the tool. When the value is small, more vertices are added. Choose a value that suits your needs. For example, if your projected output is for general small-scale cartographic display, a large deviation may be acceptable. If your projected output is to be used in large-scale, small-area analysis, a smaller deviation may be needed.

  • To perform a vertical transformation, check the optional Vertical parameter on the dialog. By default, the Vertical parameter is disabled and is only enabled when the input and output coordinate systems have Vertical Coordinate System, and the input feature class coordinates have Z values. Also, additional data (Coordinate Systems Data) setup needs to be installed on the system.

    When you select the output coordinate system, you will be able to choose both the geographic or projected coordinate system and a vertical coordinate system (VCS). If the input and output vertical coordinate systems are different, an appropriate vertical and an optional geographic (datum) transformations is available. If a transformation should be applied in the opposite direction to its definition, choose the entry with the tilde (~) in front of the name.

Syntax

Project_management (in_dataset, out_dataset, out_coor_system, transform_method, {in_coor_system}, {preserve_shape}, {max_deviation}, {vertical})
ParameterExplanationData Type
in_dataset

The feature class, feature layer, or feature dataset to be projected.

Feature Layer; Feature Dataset
out_dataset

The output dataset to which the results will be written.

Feature Class; Feature Dataset
out_coor_system

Valid values are a Spatial Reference object, a file with a .prj extension, or a string representation of a coordinate system.

Coordinate System
transform_method
[transform_method,...]

This method can be used for converting data between two geographic coordinate systems or datums. This optional parameter may be required if the input and output coordinate systems have different datum.

Tip:

Transformations are bi-directional. For example, if converting data from WGS 1984 to NAD 1927, you can pick a transformation called NAD_1927_to_WGS_1984_3, and the tool will apply it correctly. If no transformation is provided, a default transformation is used. This default transformation is suitable for general mapping applications but may not be suitable for applications that require precise locational accuracy.

String
in_coor_system
(Optional)

The coordinate system of the input feature class or dataset. When the input has an unknown, or unspecified, coordinate system, this allows you to specify the data's coordinate system without having to modify the input data (which may not be possible if the input is in read-only format).

Coordinate System
preserve_shape
(Optional)

Adds vertices to the output lines or polygons so their projected shape is more accurate.

  • NO_PRESERVE_SHAPEDoes not add extra vertices to the output lines or polygons. This is the default.
  • PRESERVE_SHAPEAdds extra vertices to the output lines or polygons, as needed, so their projected shape is more accurate.
Boolean
max_deviation
(Optional)

Determines how far a projected line or polygon can deviate from its exact projected location when preserve_shape="PRESERVE_SHAPE". The default is 100 times the XY tolerance of the spatial reference of the output dataset.

Linear unit
vertical
(Optional)

The option is only applied when the input and output coordinate systems have a Vertical Coordinate System, and the input feature class coordinates have Z values. Also, many vertical transformations require additional data files that have to be installed on the computer using the ArcGIS Coordinate Systems Data installation package.

This option is not compatible with the Preserve Shape parameter.

  • NO_VERTICALProject tool ignores Z values of geometry coordinates. The Z values will be left unmodified. This is the default.
  • VERTICALApplies the transformation specified in Geographic Transformation parameter. Project tool transforms X, Y, and Z values of geometry coordinates.
Boolean

Code sample

Project example 1 (Python window)

The following Python window script demonstrates how to use the Project function in immediate mode.

import arcpy

# input data is in NAD 1983 UTM Zone 11N coordinate system
input_features = r"C:/data/Redlands.shp"

# output data
output_feature_class = r"C:/data/Redlands_Project.shp"

# create a spatial reference object for the output coordinate system
out_coordinate_system = arcpy.SpatialReference('NAD 1983 StatePlane California V FIPS 0405 (US Feet)')

# run the tool
arcpy.Project_management(input_features, output_feature_class, out_coordinate_system)
Project example 2 (stand-alone script)

The following stand-alone script demonstrates how to use Project in a stand-alone script.

# Name: Project_Example2.py

# Description: Project all feature classes in a geodatabase
# Requirements: os module

# Import system modules
import arcpy
import os

# Set environment settings
arcpy.env.workspace = "C:/data/Redlands.gdb"
arcpy.env.overwriteOutput = True

# Set local variables
outWorkspace = "C:/data/Redlands_utm11.gdb"

try:
    # Use ListFeatureClasses to generate a list of inputs 
    for infc in arcpy.ListFeatureClasses():
    
        # Determine if the input has a defined coordinate system, can't project it if it does not
        dsc = arcpy.Describe(infc)
    
        if dsc.spatialReference.Name == "Unknown":
            print('skipped this fc due to undefined coordinate system: ' + infc)
        else:
            # Determine the new output feature class path and name
            outfc = os.path.join(outWorkspace, infc)
            
            # Set output coordinate system
            outCS = arcpy.SpatialReference('NAD 1983 UTM Zone 11N')
            
            # run project tool
            arcpy.Project_management(infc, outfc, outCS)
            
            # check messages
            print(arcpy.GetMessages())
            
except arcpy.ExecuteError:
    print(arcpy.GetMessages(2))
    
except Exception as ex:
    print(ex.args[0])

Licensing information

  • ArcGIS Desktop Basic: Yes
  • ArcGIS Desktop Standard: Yes
  • ArcGIS Desktop Advanced: Yes

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