## NAME

m.region.ll - Converts Universal Transverse Mercator (UTM) coordinates falling within the current geographic region from UTM coordinates to geographic (latitude/longitude) coordinates.
(GRASS Data Import/Processing)

## SYNOPSIS

m.region.ll
m.region.ll help
m.region.ll spheroid=name

## DESCRIPTION

m.region.ll takes current geographic region settings in UTM coordinates, and converts them to geographic coordinates (i.e., latitudes and longitudes). It also prints the length (in meters) of one arc-second at each of the four edges of the geographic region. The user must enter the spheroid upon which to base the geographic coordinates.

The list of spheroids available is somewhat dynamic. It may not contain exactly the ones listed below. To determine the current list of possible spheroids, simply type in:

  m.region.ll help

A list of available spheroids will be printed on the screen.

### AVAILABLE SPHEROIDS

(The on-line listing includes only the spheroid names.)

    Spheroid:	Semi-major axis	Eccentricity sqrd (e),	Commonly used for:
    		(Equatorial Radius)	Flattening (f),
    		(a):	or Polar Radius (b):
    _
    airy          	a=6377563.396 e=.006670540
    australian    	a=6378160     f=1/298.25		Australia
    bessel        	a=6377397.155 e=.006674372		Japan
    clark66       	a=6378206.4   b=6356583.8		N. America
    everest       	a=6377276.345 e=.0066378466		India, Burma
    grs80         	a=6378137     f=1/298.257
    hayford       	a=6378388     f=1/297
    international 	a=6378388     f=1/297			Europe
    krasovsky     	a=6378245     f=1/298.3
    wgs66         	a=6378145     f=1/298.25		worldwide coverage
    wgs72         	a=6378135     f=1/298.26		worldwide coverage
    wgs84         	a=6378137     f=1/298.257223563		worldwide coverage

## EXAMPLE

  m.region.ll spheroid=clark66

Results:

    WINDOW 4928000.00N 609000.00E ZONE 13
           4914000.00S 590000.00W

    	 44.30.06N 44.29.57N
    	103.52.04W 103.37.44W

    	 44.22.32N 44.22.23N
    	103.52.13W 103.37.55W

    	At northern edge 1 arc-second longitude=22.088500m

    	At southern edge 1 arc-second longitude=22.135998m

    	At western edge 1 arc-second latitude=30.860285m

    	At eastern edge 1 arc-second latitude=30.863082m

The values for the geographic coordinates are rounded to the nearest second in this example. They would be more precise in the actual output that is printed on the screen.

## SEE ALSO

m.datum.shift
m.ll2u
m.u2ll
r.in.ll

## AUTHOR

Michael Shapiro, U.S.Army Construction Engineering Research Laboratory

Last changed: $Date: 2002/01/25 05:45:33 $