What are the different methods for calculating satellite altitude?

[trunet]

Hi,

I'd like to know how it's possible to calculate the altitude of a satellite using some kind sensor.

I know that near-space(28~30km) you can still read a very low pressure so I can calculate the altitude using pressure. But and after this? I read that you can use gravity so, can I use an accelerometer? How's the math/formulas on this?

 

[Lsos]

Radar?

A satellite can't feel any acceleration so that's not going to work afaik.

 

[enigma]

Satellites will typically use some combination of Earth sensors, sun sensors, star trackers, directed antennas or lasers from the ground, and accelerometers. Low Earth orbit also gives you the ability to use GPS.