Back-Projected Signal-Based Self-Interferometric Phase Analysis Technique for Sea Surface Observation Using a Single...

Area of Science:

• Oceanography
• Remote Sensing
• Signal Processing

Background:

• Existing Doppler frequency methods for sea surface observation using scatterometers struggle with weak signal strength at high incident angles (>30°).
• Conventional interferometry requires auxiliary systems or channels, posing practical challenges for moving sea surface observation.

Purpose of the Study:

• To introduce a self-interferometric phase analysis technique for improved sea surface observation with a single scatterometer system.
• To address the limitations of existing methods in measuring sea surface parameters at high incident angles.

Main Methods:

• Developed a phase-based analysis using consecutive signals from a single scatterometer.
• Utilized the back-projection algorithm to project radar signals onto a fixed reference point.
• Derived a theoretical model for extracting self-interferometric phase from radar-received signals processed with back-projection.

Main Results:

• The self-interferometric phase analysis technique demonstrated superior performance for wind velocity estimation at high incident angles (40° and 50°).
• Achieved a correlation coefficient >0.779 and root-mean-square error (RMSE) <1.69 m/s, outperforming the existing method (correlation <0.62, RMSE >2.46 m/s).

Conclusions:

• The proposed self-interferometric phase analysis technique offers a robust solution for sea surface observation, particularly at high incident angles.
• This single-system approach provides a practical advancement over conventional interferometric methods for dynamic oceanographic monitoring.