Baro-aiding

Baro-Aiding: A Technique to Improve GPS Integrity

Baro-aiding is a method used to enhance GPS integrity solution by incorporating a nonsatellite input source, typically a barometer. The technique is aimed at reducing the errors caused by atmospheric uncertainties, such as ionospheric and tropospheric delays, satellite clock and ephemeris errors, and multipath effects. By combining the GPS measurements with barometric altitude information, baro-aiding can significantly increase the accuracy and reliability of GPS position, velocity, and time estimates.

To enable baro-aiding, the user needs to enter the current altimeter setting as instructed in the GPS receiver manual. The altimeter setting provides the reference pressure level, which is used to convert the measured barometric pressure into an altitude value. The barometric altitude is then fused with the GPS altitude to obtain a more accurate and robust height estimate. Additionally, baro-aiding can help in detecting and correcting GPS glitches, such as cycle slips, noise, and signal blockage, by providing an independent measure of position error.

Overall, baro-aiding is a useful technique to improve GPS integrity and performance, especially in challenging environments where satellite signals may be compromised or unavailable. Baro-aiding can be implemented in various forms, such as Kalman filtering, adaptive filtering, or neural networks, depending on the specific requirements of the application.