Decimeter-Level Geolocation Accuracy Updated by a Parametric Tropospheric Model with GF-3.

Area of Science:

• Earth Observation
• Geodesy
• Atmospheric Science

Background:

• GaoFen-3 (GF-3) is a C-band synthetic aperture radar (SAR) satellite with 1-meter resolution.
• Current GF-3 geolocation accuracy is approximately 3 meters.
• Meter-level geolocation residuals persist due to atmospheric path delay, even with static tropospheric models.

Purpose of the Study:

• To improve GF-3 satellite geolocation accuracy.
• To compensate for residual geolocation errors caused by atmospheric path delay.
• To evaluate the effectiveness of a sophisticated tropospheric model using real meteorological data.

Main Methods:

• Implementation of a sophisticated tropospheric model utilizing real meteorological data.
• Compensation of atmospheric path delay residuals.
• Analysis of geolocation accuracy improvements on GF-3 data.

Main Results:

• The sophisticated tropospheric model achieved millimeter-level accuracy.
• Geolocation accuracy of GF-3 was enhanced to several decimeters.
• Significant reduction in meter-level geolocation residuals was observed compared to static models.

Conclusions:

• A sophisticated tropospheric model significantly improves GF-3 geolocation accuracy.
• Real meteorological data is crucial for accurate tropospheric delay compensation.
• The enhanced accuracy enables more precise Earth observation applications.