Which of the following are inputs to a satellite tracking program?
The correct answer is B: The Keplerian elements. The Keplerian elements are inputs to a satellite tracking program. These orbital elements (also called TLEs - Two-Line Elements) describe the satellite's orbit and are used to calculate its position, predict passes, and determine visibility. Keplerian elements include parameters like inclination, eccentricity, right ascension of ascending node, argument of perigee, mean anomaly, and mean motion. For amateur radio operators, updating Keplerian elements regularly ensures accurate tracking predictions. These elements are published by organizations like NORAD and AMSAT and need to be updated periodically as orbits change.
Exam Tip
Tracking program input = Keplerian elements. Think 'K'eplerian 'E'lements = 'K'ey 'E'nter data. Orbital elements (TLEs) are the standard input for calculating satellite positions and passes. Power and Doppler are outputs, not inputs.
Memory Aid
"Tracking program input = Keplerian elements. Think 'K'eplerian 'E'lements = 'K'ey 'E'nter data. Orbital parameters (TLEs) used to calculate satellite position and predict passes."
Real-World Application
You download the latest Keplerian elements (TLEs) for AO-91 and enter them into your tracking program. The program uses these elements to calculate the satellite's orbit and predict when it will be visible from your location, what the elevation and azimuth will be, and how much Doppler shift to expect. Without current elements, predictions become inaccurate as the orbit changes over time.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Satellite transmitted power is not an input to tracking programs - it's a satellite characteristic that doesn't affect orbit calculations. Tracking programs calculate position from orbital elements.
Option C: Incorrect. The last observed time of zero Doppler shift is not a standard input - tracking programs calculate Doppler from orbital elements and your location.
Option D: Incorrect. Since A and C are not correct inputs, 'all of the above' cannot be correct. Only Keplerian elements are the standard input.
题目解析
The correct answer is B: The Keplerian elements. The Keplerian elements are inputs to a satellite tracking program. These orbital elements (also called TLEs - Two-Line Elements) describe the satellite's orbit and are used to calculate its position, predict passes, and determine visibility. Keplerian elements include parameters like inclination, eccentricity, right ascension of ascending node, argument of perigee, mean anomaly, and mean motion. For amateur radio operators, updating Keplerian elements regularly ensures accurate tracking predictions. These elements are published by organizations like NORAD and AMSAT and need to be updated periodically as orbits change.
考试技巧
Tracking program input = Keplerian elements. Think 'K'eplerian 'E'lements = 'K'ey 'E'nter data. Orbital elements (TLEs) are the standard input for calculating satellite positions and passes. Power and Doppler are outputs, not inputs.
记忆口诀
Tracking program input = Keplerian elements. Think 'K'eplerian 'E'lements = 'K'ey 'E'nter data. Orbital parameters (TLEs) used to calculate satellite position and predict passes.
实际应用示例
You download the latest Keplerian elements (TLEs) for AO-91 and enter them into your tracking program. The program uses these elements to calculate the satellite's orbit and predict when it will be visible from your location, what the elevation and azimuth will be, and how much Doppler shift to expect. Without current elements, predictions become inaccurate as the orbit changes over time.
错误选项分析
Option A: Incorrect. Satellite transmitted power is not an input to tracking programs - it's a satellite characteristic that doesn't affect orbit calculations. Tracking programs calculate position from orbital elements. Option C: Incorrect. The last observed time of zero Doppler shift is not a standard input - tracking programs calculate Doppler from orbital elements and your location. Option D: Incorrect. Since A and C are not correct inputs, 'all of the above' cannot be correct. Only Keplerian elements are the standard input.
知识点
Keplerian elements, Orbital elements, Satellite tracking, TLEs
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.