[GRASS-user] Latitude/Longitude vs UTM

[Hamish]

Glynn wrote:
> The SW fragment of NH which is in zone 18 is only around half a
> degree; projecting that into zone 19 isn't really an issue.
> Or you could just use a custom transverse Mercator projection
> with the central meridian at e.g. 71d30'W.

... and of course there will be a state plane projection designed
for each state already, for NH they use 71d45'W. EPSG code(s):

# NAD83(HARN) / New Hampshire
<2823> +proj=tmerc +lat_0=42.5 +lon_0=-71.66666666666667 +k=0.999966667 +x_0=300000 +y_0=0 +ellps=GRS80 +units=m +no_defs  <>

# NAD83(NSRS2007) / New Hampshire
<3613> +proj=tmerc +lat_0=42.5 +lon_0=-71.66666666666667 +k=0.999966667 +x_0=300000 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs  <>

# NAD83 / New Hampshire
<32110> +proj=tmerc +lat_0=42.5 +lon_0=-71.66666666666667 +k=0.999966667 +x_0=300000 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs  <>

... and several more US survey ft variants.


Hamish