Enhancing the precision limits of interferometric satellite geodesy missions

Area of Science:

• Earth Science
• Astrodynamics
• Geophysics

Background:

• Satellite geodesy is crucial for mapping Earth's gravitational field.
• The Gravitational Recovery and Climate Experiment (GRACE) Follow-On mission faces limitations from noise sources.
• Key noise sources include laser phase noise, accelerometer noise, and quantum noise.

Purpose of the Study:

• To investigate the precision limits of satellite geodesy measurements.
• To identify and model the primary noise sources affecting satellite geodesy.
• To propose methods for enhancing the signal-to-noise ratio in future missions.

Main Methods:

• Analysis of noise sources in the GRACE Follow-On mission.
• Application of time-delay interferometry to mitigate laser phase noise.
• Exploration of differential mass satellite formations for accelerometer noise reduction.
• Investigation of quantum optics techniques for quantum noise reduction.

Main Results:

• Time-delay interferometry can eliminate laser phase noise, improving signal-to-noise ratio by nearly three orders of magnitude.
• Differential mass satellite formations offer further signal-to-noise ratio enhancement by reducing accelerometer noise.
• Quantum optics techniques show potential for reducing quantum noise in alternative mission designs.

Conclusions:

• Proposed methods significantly enhance the performance of satellite geodesy missions.
• Future missions can achieve unprecedented precision in measuring Earth's gravitational field.
• Noise mitigation strategies are key to advancing satellite geodesy capabilities.