Relativistic Dynamics of Relative Motions (I): Post-Newtonian Extension   of the Hill-Clohessy-Wiltshire Equations
  With continuous advances in technologies related to deep space ranging and satellite gravity gradiometry, corrections from general relativity to the dynamics of relative orbital motions will certainly become important. In this work, we extend,in a systematic way, the Hill-Clohessy-Wiltshire Equations to include the complete first order post-Newtonian effects from general relativity. Within certain short time limit, post-Newtonian corrections to general periodic solutions of the Hill-Clohessy-Wiltshire Equations are also worked out. 
Peng Xu and Li-E Qiang
astro-ph.EP physics.geo-ph