dvdoug / PHPCoord

            case RefEll::wgs84():

                return; //do nothing

            case RefEll::airy1830(): // values from OSGB document "A Guide to Coordinate Systems in Great Britain"

                $tx = 446.448;

                $ty = -125.157;

                $tz = 542.060;

                $s = -0.0000204894;

                $rx = deg2rad(0.1502 / 3600);

                $ry = deg2rad(0.2470 / 3600);

                $rz = deg2rad(0.8421 / 3600);

                break;

            case RefEll::airyModified(): // values from OSI document "Making maps compatible with GPS"

                $tx = 482.530;

                $rz = deg2rad(0.8421 / 3600);

                break;

            case RefEll::airyModified(): // values from OSI document "Making maps compatible with GPS"

                $tx = 482.530;

                $ty = -130.596;

                $tz = 564.557;

                $s = 0.00000815;

                $rx = deg2rad(1.042 / 3600);

                $ry = deg2rad(0.214 / 3600);

                $rz = deg2rad(0.631 / 3600);

                break;

            case RefEll::clarke1866(): // assumes NAD27, values from Wikipedia

                $tx = -8;