# The sorting of perturbational effects by the power

I have developed an orbital propagation tool, which considers the effects of Sun, Moon, Earth harmonics, SRP, drag, relativistic correction.

First question

Considering the LEO orbit, I would sort the perturbational effects in the following order:

1. Harmonics
2. Sun
3. Moon
4. Atmospheric drag
5. SRP
6. Relativity

Is it correct?

Second question

• Is there any other effect, which has an influence more than any of these?
• On which place would be the Earth solid and ocean tides effect? What would be the magnitude of the effect?
• thanks for your accept, but the question is only 3 hours old; hasn't even gone around the Earth once! If you give it a day or two you may discover that you receive even more and more useful answers. – uhoh Oct 25 '18 at 11:43
• @uhoh I would wait!) BTW, for the harmonics coefficients, I used the JGM-3 TideFree model. May be, the Tides are already implemented there? earth-info.nga.mil/GandG/wgs84/gravitymod/egm2008/… – Leeloo Oct 25 '18 at 11:46
• exactly the kind of answer you'd like to wait for, or even ask separately. – uhoh Oct 25 '18 at 11:59

Here is en excerpt from the question Questions about the Dynamic Solid Tide. There is more about those effects in the question and especially in the answers.

As you can see the strengths of several effects depend in different ways on the average distance from the Earth, as they would for other aspects of the orbit's parameters.

In other words, it doesn't really make sense to try to rank them without specifying a specific orbit.

I found the following plot in the book Satellite Orbits; Models, Methods, Applications by Oliver Montenbruck and Eberhard Gill, Springer, 2000. The figure and description can also be found in google books. It's a low quality snapshot but it's hard to capture a dozen different dependencies over 20 orders of magnitude without showing the whole thing.

If of help, from my old Orbital Mechanics courses we have this plot (in Spanish).

There are two plots for drag ($$R_{aer}$$) because it depends on the atmosphere of that day, but you can have an idea. The only remark I would made is that for LEO Moon effect is always higher than the Sun's ones. The bars of Shuttle and ISS denotes the range of altitudes for those.

Regarding Earth and ocean tides I am sure that they can be modelled as spherical harmonics also. Anyway I am pretty sure that their effect is at least lower than solar radiation pressure.