Google has announced the Fused Orientation Provider (FOP) API, which provides “quality and consistent device orientation by fusing signals from accelerometer, gyroscope and magnetometer.”
Unlike the existing Android Rotation Vector, FOP is implemented by Google Play Services, which allows it to provide more consistent behavior by eliminating implementation variances among device makers. It can also offer better accuracy by incorporating algorithm updates more quickly and compensating for lower-quality sensors or quirks in OEM implementations.
The FOP API is designed to be similar to the AOSP Rotation Vector to make transitions easy, and in some cases, it can return values piped through the Rotation Vector but with magnetic declination applied. It’s available on Android 5.0+ but the output rate is limited to 200Hz on Android 12+ unless your app is granted the HIGH_SAMPLING_RATE_SENSORS permission.
Google Maps uses FOP to better cope with magnetic disturbances, improving the reliability of the cone for users.