Where is NAD_1983_Albers projection?

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11-02-2011 08:50 AM
AlKomarek
New Contributor
Where do I find this projection in the ArcToolbox, "Define Projection" tool?

Projected Coordinate System:   NAD_1983_Albers
Projection: Albers
False_Easting: 0.00000000
False_Northing: 0.00000000
Central_Meridian: -98.00000000
Standard_Parallel_1:  34.00000000
Standard_Parallel_2:  36.50000000
Latitude_Of_Origin:    33.00000000
Linear Unit:  Meter

Geographic Coordinate System:   GCS_North_American_1983
Datum:  D_North_American_1983
Prime Meridian:  Greenwich
Angular Unit:  Degree

I am trying to project my new files to match some old files and I have looked under every category but cannot find just a plain NAD_1983 projection that includes Albers. 

Thanks in advance,
Al
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4 Replies
MelitaKennedy
Esri Notable Contributor
Hi Al,

ArcGIS doesn't support this definition. You should be able to 'import' the definition from your other data, otherwise, you'll have to create a new one, or modify an existing one. Modify is easier than creating a new one. Look in the projected coordinate systems, Continental and use one of the US Albers definitions.

By the way, is this definition a statewide coordinate system for Oklahoma? Is it government-sanctioned? If so, I'd like to add it. Any website you can point me to?

Melita
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AlKomarek
New Contributor
Thank you, Melita, very good suggestion; however, I have been away from ArcGIS for a while and cannot remember how to do a lot of the things I used to do.  I have been busy supporting other applications. 

It seems like every time I try to  'import' the definition from another shapefile, it changes the shapefile I'm working on into the one I copied the projection from.  Why?  I don't know. So I gave up on that idea.  I am even having trouble projecting the unprojected files I have with the ArcToolbox projection tool; every time I do, I get a little red X that pops up down in the corner of my screen and the projection fails.  Granted, I am trying to project the files I received via email from Arkansas, stating they were projected in NAD_83.  I have tried every possible NAD_83 for the area, both feet and meters.

I doubt the definition is a statewide coordinate system for Oklahoma and I'm quite sure that it is not government-sanctioned.  It's many years old (over 10) but the files that have this projection are the ones I need to work with again after all this time.  I would run them through "Projector" if I could get anything to work in ArcGIS 10.  I feel like loading my old ArcView 3.x and working with it instead.

Now I remember why I don't miss working with GIS... projection should start with a capital "P" for Pain!

Thank you for you reply,
Al
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MelitaKennedy
Esri Notable Contributor
Hi Al,

A little background! Please feel free to ignore it. We tried to change terminology in ArcGIS to make it more precise. "Projection" doesn't make sense if the data's in lat/lon, so we use geographic coordinate system (which includes a datum, angular unit, etc), projected coordinate system (includes a geographic coord sys, map projection, parameters, linear unit), and vertical coordinate system (must be defined in connection with a geographic/projected coord sys).

The Define Projection tool or a data's property page in ArcCatalog let you define its coordinate system. Both methods update the metadata only--it doesn't change the data's extent or coordinate values. The Projection Tool (hate the name) will create a copy of a dataset, in the target coordinate system. The source data must already have its coordinate system defined (and it must be correct!). Many, many people make the mistake of using the Define Projection tool when they want the Project tool.

I'm unable to reproduce your import problem. I'm trying it through the data's property page in ArcCatalog, XY coordinate system tab. All that happens is that the coordinate system definition is changed, nothing else about the shapefile.

Beyond the Albers data, you have some NAD83 data that you're trying to project in a different coordinate system? Are they in lat/lon, rather than a projected coordinate system?

I've attached a prj file for the NAD83 Albers definition. You'll need to rename the extension from .txt to .prj (I can't upload .prj) and place it in the coordinate systems, projected coordinate systems folder of the ArcGIS installation.

Melita
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RhondaJanos
New Contributor

I had a shapefile that needed to be re-projected from NAD 1983 Albers (feet) to NAD83 Minnesota State Planes, South Zone, US ft. I was not able to do it.  I did use the attached zip file to sucessfully define projection and then project into Albers, but could project into any of the other State Plane types.  Does anyone understand why that would be? 

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