Questions tagged [nad83]

North American Datum of 1983, a geocentric datum and geographic coordinate system based on the 1980 Geodetic Reference System ellipsoid (GRS80).

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Geographic Transformations in Alaska Between NAD83 and WGS84

I have done a ton of research on the most accurate transformation to use in mainland Alaska to convert between the NAD83 and WGS84 datums, but I just can't seem to find a definitive answer. ArcMap ...
9
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1answer
5k views

Is re-projection needed from SRID 4326 (WGS 84) to 4269 (NAD 83)SRID

I have US census data against state boundaries stored as SRID 4269, in an MSSQL DB. The input data used for calculations against that dataset is stored as SRID 4326. As far as I can infer from the ...
9
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1answer
6k views

Difference between datum and ellipsoid for geodetic coordinates?

Looking at the Wikipedia page for the North American Datum, it seems to imply that the datum is completely defined by the ellipsoid, which defines the major/semi-major axes, flattening, etc. For ...
3
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2answers
521 views

When is data created in datums other than WGS84?

I'm trying to understand why we need datums other than WGS84. Since GPS coordinates are relative to the WGS84 ellipsoid what is the advantage of having other datums like for example NAD83. I ...
2
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4answers
10k views

Convert PLSS (Section, Township, Range, Meridian) to Latitude and Longitude using R package or Python

I have data in the form of Section, Township, Range and meridian. I have 300,000 data points from all over the USA. Is there any way i can write R or python scripts to batch convert all the points to ...
2
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1answer
611 views

Shifting a CAD file from ATS77 MTM 5 to NAD83 CSRS UTM 20

Looking to make the coordinate system shift in ArcMAP (for Nova Scotia) between ATS77 MTM 5 and NAD83 CSRS...NTv2 file?
1
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0answers
540 views

Incorrect coordinates when reprojecting NAD27 to NAD83

I have some historic UTM coordinates as NAD27 (556787, 7169250) which I entered into a spreadsheet and have imported into QGIS. I assign them the projection Nad27 / UTM zone 12N (EPSG: 26712) I ...
0
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1answer
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Transform Shapefile from WGS84 to NAD83 using QGIS? [duplicate]

Possible Duplicate: How to reproject a vector layer in QGIS? I have some shapefiles whose CRS is WGS 1984 and I have some shapefiles whose CRS is NAD 1983 State Plane Illinois East. I want them ...