function X_sat_rot = e_r_corr(traveltime, X_sat)
%E_R_CORR  Returns rotated satellite ECEF coordinates
%          due to Earth rotation during signal travel time

%Kai Borre 10-10-96
%Copyright (c) by Kai Borre
%$Revision: 1.0 $  $Date: 1997/09/26 $

Omegae_dot = 7.292115147e-5;           %  rad/sec

omegatau = Omegae_dot*traveltime;
R3 = [  cos(omegatau) sin(omegatau) 0;
       -sin(omegatau) cos(omegatau) 0;
           0               0        1];
X_sat_rot = R3*X_sat;
%%%%%%%% end e_r_corr.m %%%%%%%%%%%%%%%%%%%%%