How do they measure height of Mointains before electronic/GPS systems were avaiable?

Question

How do they measure height of Mointains before electronic/GPS systems were avaiable?

In: Other

Answer 1

Same way they do it with GPS

Good ol trigonometry.

Just instead of using theodolites as the measurement points we use a few satellites and a base station.

Alternatively you can use photogrammetry from pictures taken of the mountains as well. For heights you can use comparisons to objects of known dimensions or use the shadow it casts if you know longitude/latitude and time.