constmath.m

NORAD公布的两行星历数据计算轨道参数模型

% ------------------------------------------------------------------------------
%
%                           function constmath
%
%  this function sets constants for mathematical operations. 
%
%  author        : david vallado                  719-573-2600    2 apr 2007
%
%  revisions
%
%  inputs        : description                    range / units
%    none
%
%  outputs       :
%    rad, twopi, halfpi;
%    ft2m, mile2m, nm2m, mile2ft, mileph2kmph, nmph2kmph;
%
%  locals        :
%                -
%
%  coupling      :
%    none.
%
% constmath;
% ------------------------------------------------------------------------------

        small = 0.00000001;

        infinite  = 999999.9;
        undefined = 999999.1;

        % -------------------------  mathematical  --------------------
        rad    = 180.0 / pi;
        twopi  = 2.0 * pi;
        halfpi = pi * 0.5;

        % -------------------------  conversions  ---------------------
        ft2m    =    0.3048;
        mile2m  = 1609.344;
        nm2m    = 1852;
        mile2ft = 5280;
        mileph2kmph = 0.44704;
        nmph2kmph   = 0.5144444;