AHRS using DCM filter. No direct gyro bias estimation, but also compensates for attitude drift. Uses GPS speed for heading. Compensation of centrifugal force via GPS speed (to fly in circles with a fixedwing). Careful, it doesn't handle all BODY_TO_IMU rotations (mounting positions) correctly! The algorithm was developed by William Premerlani and Paul Bizard. The algorithm is also used in the AHRS systems of the AdruIMU. The name DCM for the algorithm is really a misnomer, as that just means that the orientation is represented as a DirectionCosineMatrix (rotation matrix). But since people already know it under that name, we kept it.

ifdef SECONDARY_AHRS ifneq (,$(findstring $(SECONDARY_AHRS), dcm float_dcm)) # this is the secondary AHRS $(TARGET).CFLAGS += -DAHRS_SECONDARY_TYPE_H=\"subsystems/ahrs/ahrs_float_dcm_wrapper.h\" $(TARGET).CFLAGS += -DSECONDARY_AHRS=ahrs_dcm else # this is the primary AHRS $(TARGET).CFLAGS += -DAHRS_TYPE_H=\"subsystems/ahrs/ahrs_float_dcm_wrapper.h\" $(TARGET).CFLAGS += -DPRIMARY_AHRS=ahrs_dcm endif else # plain old single AHRS usage $(TARGET).CFLAGS += -DAHRS_TYPE_H=\"subsystems/ahrs/ahrs_float_dcm_wrapper.h\" endif