Projections in GRASS

[Irochka]

In info.grass.user you write:

>Olga, mozhno sprosit' kakie referenz-ellipsoidy sejcas v rasporjazhenii ?
>----
>In Mid-Europe we should have the posibility to change from "old"
>Krassowskij to "new" Bessel systems when using the GK-system.

>Frank Hoffmann /DD 23:35

Here is a copy of etc/ellipse.table file which containes all supported ellipsoids.

 this file contains ellipsoid parameters
 # format of the file is
 #  name  a=value   x=value     comments
 #
 # where name is a single word elliposid name, a is the equatorial radius
 # and x is one of
 #   b polar radius, f flattening, or e eccentricity squared
 #
 # x should be a defining parameter (as opposed to a derived parameter)
 # no spaces before or after the =


 # these are from [Snyder, Table 1, p.12]
 australian     a=6378160     f=1/298.25
 clark66       a=6378206.4   b=6356583.8
 grs80         a=6378137     f=1/298.257
 hayford       a=6378388     f=1/297
 international a=6378388     f=1/297
 krassovsky     a=6378245     f=1/298.3
 wgs72         a=6378135     f=1/298.26

 # this is from naval oceanographic lab
 wgs84         a=6378137     f=1/298.257223563


 # these are from [Seppelin, Table 9, p.35]
 bessel        a=6377397.155 e=.006674372
 airy          a=6377563.396 e=.006670540
 everest       a=6377276.345 e=.0066378466
 wgs66         a=6378145     f=1/298.25

 # Snyder.
 #      John P. Snyder, "Map Projections - A  Working  Manual,"
 #      U.S.  Government  Printing Office, Washington DC, 1989.
 #      U.S. Geological Survey Professional Paper 1395

 # Seppelin.
 #      Thomas O. Seppelin, "The  Department  of Defense World
 #      Geodetic System 1972," presented at the International
 #      Symposium  on Problems Related to the Redefinition if
 #      North American Geodetic Networks, Fredericton, New
 #      Brunswick,Canada in May, 1974.


 #these were added for g.setproj capabilities
 MERIT           a=6378137       f=1/298.257
 IAU76           a=6378140.0     f=1/298.257
 GRS67           a=6378160.0     f=1/247.247167
 clark80         a=6378249.145   f=1/293.4663
 hough           a=6378270.0     b=6356794.343479
 mercury         a=6378166.0     b=6356784.283666
 modif_airy      a=6377341.89    b=6356036.143
 modif_everest   a=6377304.063   b=6356103.039
 modif_merc      a=6378150.0     b=6356768.337303
 new_internatnl  a=6378157.5     b=6356772.2
 SEasia          a=6378155.0     b=6356773.3205
 walbeck         a=6376896.0     b=6355834.8467
 # sphere        a=6370997.0     e=0.0
 ~
 
Vsego dobrogo, Irina