What is the role of SBAS corrections in tightly coupled GNSS/INS processing?

• A. Provide corrections to improve accuracy
• B. Provide temperature compensation
• C. Provide satellite health data only
• D. Provide raw GNSS measurements

Answer: (D)

SBAS corrections improve GNSS measurement quality, which is crucial for a reliable tightly coupled GNSS/INS solution. In this setup, the navigation filter fuses GNSS observations with inertial data to estimate position, velocity, and attitude while constraining INS drift. When SBAS corrections are applied, the GNSS measurements used by the estimator have reduced errors from satellite orbits and clocks, ionospheric delays, and they carry integrity information. This makes the corrected GNSS inputs more accurate and trustworthy, so the combined navigation solution converges faster and remains more precise over time. It’s not about temperature compensation, nor solely about health data, nor about providing raw measurements—the corrections are applied to improve the GNSS data that the INS/GNSS estimator uses.