# Inclination Maneuver of GEO Satellite

I have performed inclination maneuver for GEO satellite at ascending or descending node. The inclination of the satellite is 0.05 deg. Then I performed the maneuver so the inclination change to 0.00001 deg. After the first maneuver, the satellite reach 0.05 deg inclination after 37 days. But after the second maneuver, the satellite reach 0.05 deg inclination after 27 days. And after the third maneuver, the satellite reach 0.05 deg inclination after 21 days. I read in a book (Li (2011)), the inclination secular period is linear. Its means, the days satellite reach the same inclination after each maneuver is must be the same. But it doesn't on my work. Did I miss something about the concept of inclination manuever?

• What gravity model did you use for Earth; only $J_2$ or something larger and more complete? The reason I ask is that for these very small changes on this very short time scale you may also be seeing other random effects. After your maneuver is the spacecraft still actually synchronous over the same spot on Earth or has it moved in longitude or is starting to drift? Are you including gravitational effects from the Moon and Sun or are those turned off?
– uhoh
May 31, 2020 at 1:50
• Thank you very much for your response. I used JGM-2 and lunisolar perturbation. After maneuver, the satellite is starting to drift. Evidently, the inclination drift caused by lunisolar not secular. The drift is secular if I just include the lunar perturbation. Jun 14, 2020 at 15:08
• That's great news! Please feel free to post an answer to your own question and if you like you can click accept unless you'd like to wait for additional answers. It will be helpful to future readers to see tgat an answer has been posted and you can pick up a few more reputation points as well.
– uhoh
Jun 14, 2020 at 22:53