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

• A. The Keplerian elements
• B. Satellite telemetry data
• C. Signal strength indicators
• D. Track and field observations

Answer: (A)

The correct answer is the Keplerian elements. These elements are a set of parameters used to describe the orbit of a satellite, including its size, shape, orientation, and position. They provide important information needed to predict the satellite's position in the sky over time, which is essential in satellite tracking.

Keplerian elements include data such as the semi-major axis, eccentricity, inclination, right ascension of the ascending node, argument of perigee, and mean anomaly, all of which define the satellite's orbit in a mathematical format. This information is crucial for calculating where the satellite will be at a specific time, allowing operators to track its movements effectively.

While other options may seem relevant, they do not serve the same fundamental purpose in satellite tracking. Satellite telemetry data is related to the satellite's operation and performance, and signal strength indicators may be used for assessing communication quality but do not provide necessary orbital information. Track and field observations refer to activities unrelated to satellite tracking and provide no input for determining satellite positions.