Projecting in ArcMap by owm23003

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									                                                 Map Projections...
                                                Projecting in ArcMap

Introduction... Assigning a Coordinate System for your Data Frame

All data from DEP/BIS/GIS is stored in the same coordinate system. To display this data, all you need
to do is add it to ArcMap. No thought needs to go into whether or not the layers will overlay properly.

However, if you have collected data from a variety of sources, you will need to know what coordinate
system each dataset uses to ensure ArcMap can display them together.

When you add a layer to an empty data frame, that layer sets the coordinate system for the data frame;
you can change it later if necessary. As you add subsequent layers, they are automatically transformed
to the data frame’s coordinate system as long as there is enough information associated with the layer’s
data source to determine its current coordinate system.


If there is not enough information, ArcMap will be unable to align the data and display it correctly.
In this case, you will have to supply the necessary coordinate system information yourself. ArcMap
expects coordinate system information to be stored with the data source. For a layer in a geodatabase,
this information is part of the layer’s metadata. For coverages, shapefiles, and raster data, it is stored
on disk in a separate file named after the data source but with a .prj file extension. These files are
optional files, and you may still need to define the coordinate system for one of these data sources.



Note:    Changing the coordinate system of a data frame does not alter the coordinate
         system of the source data contained in it.
                                 Map Projections...
                       Using the Projector Mod! Extension




                               Map Projections...
                              Projecting in ArcMap
Step 1: Start ArcMap




                                                            ⇒   Right Click on the data
                                                                frame and choose Properties.
The Data Frame Properties dialog window opens...




                                                   ⇒ Click the Coordinate System Tab




                                                   The details of the current data frame
                                                   coordinate system display in the
                                                   dialog.




                                                   ⇒ Click New and Click Projected
                                                     Coordinate System
Step 2: Assigning the Data Frame a Coordinate System


                                                   ⇒ Type in a New name for your projected coordinate system


                                                   ⇒ Choose a Projection from the drop down list

                                                          Enter Values in for the for Parameters…

                                                                    DEP Users enter...
                                                       False_Easting   400,000       False_Northing 0

                                                       Central Meridian –84           Standard Parallel_1   24
                                                       Standard Parallel_2    31.5    Latitude of origin    24
                                                       Geographic Coordinate System –

                                                       GCS_North_American_1983 HARN

                                                       Datum-   D_North American_1983_HARN

                                                   ⇒ Choose the Linear Unit Name from the drop down list


                                                   ⇒ Click Select
⇒ Browse for the Coordinate System you want your data frame to be in.



                                                                        DEP Users... Our Data’s Geographic
                                                                        Coordinate System is North American
                                                                                   1983 HARN.


                                                                          If you want your data to display in
                                                                        that coordinate system follow the next
                                                                                        steps...



                                                                           ⇒ Double Click North America
⇒ Select North American 1983 HARN.prj




                                        ⇒ Click Add
    Your data frame is now set to the coordinate system
                     you specified.




⇒   Click OK
    The Coordinate System of your
     data frame has been defined




    To save the Projected Coordinate System...


⇒   Click Add to Favorites
Step 3... Option 1: Displaying Data with a Predefined Coordinate System

⇒   Right Click the data frame that you want to set
    the coordinate system of and Click Properties.




                                                                          You can have layers with different
                                                                          coordinate systems and projections in
                                                                          your data frame and can change your
                                                                          data frame to any of the coordinate
                                                                          systems or projections your layers are
                                                                          in. Or, you can change your data
                                                                          frame to any coordinate system or
                                                                          projection even if it differs from the
                                                                          ones your layers are in.
                                                                          Again, Changing the coordinate
                                                                          system of a data frame does not
                                                                          alter the coordinate system of the
                                                                          source data contained in it.
⇒ Click the Coordinate System tab




                                    ⇒   Double Click Predefined
Navigate through the folders until
 you find the coordinate system
     you want and click it.




⇒ Click OK
All layers in the data frame will now
be displayed with the pre-defined
coordinate system.
Option 2: Importing a data source with a defined coordinate system



⇒   Right Click on the data frame and choose Properties


                                                          ⇒   Click the Coordinate System




                                                          ⇒   Click Import
Browse to select a data source with a defined coordinate system
that you want your data frame to be in.




                                                                      Select a Data Source...




                                                                  ⇒    Click Add
The Data Frame has been updated to the
selected Coordinate System...




⇒   Click OK
Step 4: Modifying Coordinate System Parameters
                                                                Sometimes you may need to adjust the
                                                                Projection, Parameter Values or linear
⇒   Right Click on the data frame and choose Properties         units of your data.




                                                          ⇒    Click the Coordinate System tab




                                                          ⇒   Click Modify
⇒   Adjust the coordinate system properties
    as appropriate.




⇒   Click OK




Congratulations... This concludes the tutorial.

								
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