Which of the following are inputs to a satellite tracking program?

The correct answer focuses on the Keplerian elements because they are a set of orbital parameters that define the orbit of a satellite and are essential for tracking its position in space. Keplerian elements include the semi-major axis, eccentricity, inclination, longitude of the ascending node, argument of periapsis, and true anomaly. These parameters allow tracking systems to predict where a satellite will be at a given time, making them a crucial component of satellite tracking programs.

In the context of the choices provided, while the transmitted power and last observed time of zero Doppler shift might be relevant in certain contexts (like determining signal strength or analyzing the satellite's orbital path), they don’t specifically provide the necessary orbital information that a satellite tracking program requires to determine the satellite’s position over time, which is primarily derived from Keplerian elements. Therefore, the focus on Keplerian elements as the correct input reflects the fundamental principles of orbital mechanics central to satellite tracking.