Pre-solution of the perturbed motion of artificial satellite
  The authors try to find a good solution of an artificial satellite motion under the influence of J2 gravity in terms of KS variables by using Picard Iterative Method. The result shows that there are many solutions for this problem depends on the initial guess solutions, so the choice of correct and convince initial guess is very difficult. Applications of the method applied on many satellites. 
Inalds A. Hassan, Hayman Z. Metwally and Mohammad A. F. Basha
astro-ph.IM