Procedure: enp_crib.pro Purpose: A crib showing how to transform data from ENP coordinates to GEI coordinates and vice versa E: sat to earth (in orbtial plane) N: east (in orbital plane) P: north (perpendicular to orbtial plane). Defined relative to another coordinate system: P_sat = spacecraft position in geocentric inertial coordinate system V_sat = deriv(P_sat) (spacecraft velocity in the same coordinate system.) P_enp = P_sat cross V_sat E_enp = -P_sat N_enp = P_enp cross P_sat Notes: $LastChangedBy: egrimes $ $LastChangedDate: 2014-02-11 08:33:06 -0800 (Tue, 11 Feb 2014) $ $LastChangedRevision: 14275 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/cotrans/special/enp/enp_crib.pro $