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National Atlas Coordinate System

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#1
razornole

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Does anybody know what the coordinate system is for shapefiles from the NationalAtlas.gov/rawdata? I can open the files in ArcMAP 9.3, but the coordinates are undefined.

Thanks,
kru
"Ah, to see the world with the eyes of the gods is geography--to know cities and tribes, mountains and rivers, earth and sea, this is our gift."
Strabo 22AD

#2
Nick H

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Does anybody know what the coordinate system is for shapefiles from the NationalAtlas.gov/rawdata? I can open the files in ArcMAP 9.3, but the coordinates are undefined.


The shapefiles are geographic, WGS84 lat/lon.

Regards, N.
Caversham, Reading, England.

#3
razornole

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Thanks a lot Nick, I gave up searching after an hour or so.

kru
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Strabo 22AD

#4
François Goulet

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I just downloaded some shapefiles for a project and there's a text file in the .zip...

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.000278
Longitude_Resolution: 0.000278
Geographic_Coordinate_Units: Decimal degrees
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: GRS1980
Semi-major_Axis: 6378137
Denominator_of_Flattening_Ratio: 298.257222

I'd say NAD83 lat/long instead...

#5
Nick H

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I'd say NAD83 lat/long instead...


My mistake, I'd sort of got used to the 'NAD83/WGS84' idea, but what's a metre between friends? :). Actually, it can be a lot sometimes, so my apologies to Razornole.

Regards, N.
Caversham, Reading, England.

#6
razornole

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I'd say NAD83 lat/long instead...


My mistake, I'd sort of got used to the 'NAD83/WGS84' idea, but what's a metre between friends? :). Actually, it can be a lot sometimes, so my apologies to Razornole.

Regards, N.


No apologies needed, thanks for the help, both of you. I didn't get that text file with my layer. This was for a 2.5'x4' map that covers an area ~400 miles. That meter doesn't make a bit of difference. The map works well regardless.

Thanks,
kru
"Ah, to see the world with the eyes of the gods is geography--to know cities and tribes, mountains and rivers, earth and sea, this is our gift."
Strabo 22AD




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