# Is there an equivalent term for average altitude like semi-major axis?

So if we have a satellite in a non circular orbit, can't state a time independent altitude (we can only state the altitude at a given time). We can however state a constant value for the semi-major axis (I'm ignoring orbit perturbations here). The semi-major axis is the in essence;

(perigee altitude + apogee altitude + 2 x radius of Earth)/2

So is there a term specifically for;

semi-major axis - radius of Earth

• It's sometimes referred to as "mean orbital altitude". I'm not aware of any other term for this. – TildalWave Jul 23 '15 at 17:47