GS50 projection
{{Short description|Conformal map projection}}
File:GS-50 projection with lines of constant scale.svg
GS50, also hyphenated as GS-50,{{cite journal
| last1 = Snyder
| first1 = John Parr
| year = 1987
| title = Map Projections: A Working Manual
| url = https://pubs.usgs.gov/pp/1395/report.pdf
| format = PDF
| publisher = United States Geological Survey
| accessdate = 8 December 2023
| pages = 205
| journal = Professional Paper
| volume = 1395
}} is a map projection that was developed by John Parr Snyder of the USGS in 1982.
The GS50 projection provides a conformal projection suitable only for maps of the 50 United States. Scale varies less than 2% throughout the area covered. Distortion is very low as well. It is not a standard projection in the sense that it uses complex polynomials (of the tenth order) rather than a trigonometric formulation, though it was developed from an oblique stereographic projection.{{cite journal
| last1 = Snyder
| first1 = John Parr
| year = 1985
| title = Computer-assisted map projection research
| url = https://pubs.er.usgs.gov/publication/b1629
| format = PDF
| pages = 79–92; 147–51
| publisher = United States Geological Survey
| journal = Bulletin
| volume = 1629
| accessdate = 26 March 2013
}}