Characterization of LEO satellites through ground-based Doppler observations

This paper presents some practical aspects regarding the characterization of satellite's orbit through ground-based Doppler observations. The monitoring focused on receiving telemetry signals from active university satellites placed on low-altitude circular orbits, which operate in the UHF amateur radio band. The experimental data was used for satellite orbital analysis with the main purpose of estimating basic orbital parameters of a LEO (Low Earth Orbit) satellite. The obtained data (Doppler curves) over multiple passes was used in order to estimate the orbital period, and from it, to derive other orbital parameters like altitude and velocity.