function [a,b,e2,finv]=refell(type)% REFELL  Computes reference ellispoid parameters.%   Reference: Department of Defence World Geodetic%   System 1984, DMA TR 8350.2, 1987.%   TOPEX Reference: <http://topex-www.jpl.nasa.gov/aviso/text/general/news/hdbk311.htm#CH3.3>% Version: 1 Jun 04% Useage:  [a,b,e2,finv]=refell(type)% Input:   type - reference ellipsoid type (char)%                 CLK66 = Clarke 1866%                 GRS67 = Geodetic Reference System 1967%                 GRS80 = Geodetic Reference System 1980%                 WGS72 = World Geodetic System 1972%                 WGS84 = World Geodetic System 1984%                 ATS77 = Quasi-earth centred ellipsoid for ATS77%                 NAD27 = North American Datum 1927 (=CLK66)%                 NAD83 = North American Datum 1927 (=GRS80)%                 INTER = International%                 KRASS = Krassovsky (USSR)%                 MAIRY = Modified Airy (Ireland 1965/1975)%                 TOPEX = TOPEX/POSEIDON ellipsoid% Output:  a    - major semi-axis (m)%          b    - minor semi-axis (m)%          e2   - eccentricity squared%          finv - inverse of flatteningtype=upper(type);if (type=='CLK66' | type=='NAD27')  a=6378206.4;  finv=294.9786982;elseif type=='GRS67'  a=6378160.0;  finv=298.247167427;elseif (type=='GRS80' | type=='NAD83')  a=6378137.0;  finv=298.257222101;elseif (type=='WGS72')  a=6378135.0;  finv=298.26;elseif (type=='WGS84')  a=6378137.0;  finv=298.257223563;elseif type=='ATS77'  a=6378135.0;  finv=298.257;elseif type=='KRASS'  a=6378245.0;  finv=298.3;elseif type=='INTER'  a=6378388.0;  finv=297.0;elseif type=='MAIRY'  a=6377340.189;  finv=299.3249646;elseif type=='TOPEX'  a=6378136.3;  finv=298.257;endf=1/finv;b=a*(1-f);e2=1-(1-f)^2;