earth.h

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/*
 *----------------------------------------------------------------------
 * @(#) earth.h 1.0 30 Mar 93   <shc>
 *  Copyright (c) 1993, CSIRO Division of Oceanography.
 *----------------------------------------------------------------------
 *
 * Definitions of some basic earth-related constants.
 *
 * EMK      Gravitational constant (m**3 / s**2)
 * J2-J5    First four zonal gravitational harmonics
 * FLT      Flattening
 * FLTINV   1 / FLT
 * EQRAD    Equatorial radius (m)
 * POLRAD   Polar radius (m)
 * AEMEAN   Mean radius (m)
 * EAROT    Rotation rate in radians/sec
 * TEARTH   Minutes per revolution
 * ECCSQ    Eccentricity squared
 * NSPD     Number of seconds per (24 hour) day
 * NMPD     Number of minutes per (24 hour) day
 */
 
#ifndef __EARTH__
#define __EARTH__
 
#define EMK (3.986004415e14)
#define J2 (1.0862583e-3)
#define J3 (-2.5338975e-6)
#define J4 (-1.623821e-6)
#define J5 (-2.2963180e-7)
#define FLT (3.35281317789691443e-3)
#define FLTINV (298.257)
#define EQRAD (6378136.3)
#define POLRAD (EQRAD * (1 - FLT))
#define AEMEAN ((EQRAD + POLRAD)/2)
#define EAROT (7.2921159e-5)
#define TEARTH (1436.068176e0)
#define ECCSQ (FLT * (2 - FLT))
#define NSECPD (86400)
#define NMINPD (1440)
 
#endif /* __EARTH__ */