[NorthMountain]

I know how they measure it

Your own words, to which I responded, contradict that claim.

The onus is on you: If you know how mean sea level is measured, prove it.

lighten up.

That's already on my list of "BS Words and Phrases", but thank you anyway.

[enumerated]

Satellites measure from Earth’s center of mass - which is calculated from four surface points.

Here’s another opportunity to have no sense of humor:

The following is proof that a warm beer is better than a cold beer:

Given: Nothing is better than a cold beer.
Given: A warm beer is better than nothing.

Ergo: A warm beer is better than a cold beer.

Now, you have a choice:

A) expose the fallacy in my proof, and reveal that you have no sense of humor, or
B) lighten up.