[PROJ] Problem converting to State Plane Coordinates

[wayne at truwayllc.com]

Thanks everyone for your help. That got me going. As Greg pointed out the State Plane system was originally created around 1927 but was updated about 1983 coinciding with the adoption of NAD83. Fortunately for me all of the data I’m working with refers to SPCS 1983 and datum is NAD83 (2011) epoch 2010.0. As Greg also mentioned the projection type for SPSC can vary. There are three projection types, Transverse Mercator, Lambert Conformal Conic and Oblique Mercator. The only zone using the Oblique Mercator is Alaska zone (5010) that covers the Aleutian Islands. In Utah, three bands of East-West extent are used and the Lambert projection is used for each zone. Our neighbor to the South, Arizona, chose to use three zones of North-South extent, and the Transverse Mercator Projection is used. The goal in all cases is to keep the grid scale correction less that one part in 10,000. For those curious about this system, here’s a link to a great resource.

https://geodesy.noaa.gov/library/pdfs/NOAA_Manual_NOS_NGS_0005.pdf <https://geodesy.noaa.gov/library/pdfs/NOAA_Manual_NOS_NGS_0005.pdf>


Thanks Again,

Wayne

_________________
Wayne Anderson
Wayne at truwayllc.com
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