INS Implementations

This sections contains ins implementations mechanized in different frames with different attitude represenations. Furthermore, system models representing the propagation of errors on the corresponding INS mechanizations are also presentented.

correctnav_Cen_v000.m Corrects the navigation states (i.e. position, velocity and attitude) using the Kalman generated error values. This function can be used for both PHI and PSI formulated Kalman filters.
geoparam_v000.m Re, Rn, G etc. for NED mechanization.
geoparam_v001.m Computes the curvature matrix (Elipsoidal radious of Earth) and the gravity. This is a non-singular implementation which must be used for polar navigation.
la_imu_v000.m lever arm computations INS+IMU
la_sen_v000.m Lever arm computations for sensor outputs only (subset of la_imu)
mdl_ecef_dcm_v000.m Wrapper for the sys_ecef_dcm (TO BE DEPRECIATED) (See:imu_err_defs)
mdl_ned_dcm_v000.m Wrapper for the sys_ned_dcm (this is called by the KF, this implicity calls sys_ned_dcm) (TO BE DEPRECIATED) (See:imu_err_defs)
strapdown_bckwrd_Cen_quat_v000.m Backward implementation of strapdown_Cen_quat (used in 2-filter smoothers)
strapdown_bd_dcm_v000.m Body frame mechanization of strapdown equations with DCM
strapdown_Cen_dcm_v000.m Wander-Azimuth implementation with position defined as Cen (singular)
strapdown_Cen_quat_v000.m Wander-Azimuth implementation with position defined as Cen and attitude mechanized as quaternion
strapdown_ecef_dcm_v000.m ECEF frame mechanization of strapdown equations with DCM
strapdown_ecef_quat_v000.m ECEF frame mechanization of strapdown equations with quaternions
strapdown_ned_dcm_v000.m NED frame mechanization of strapdown equations with DCM
strapdown_ned_quat_v000.m NED frame mechanization of strapdown equations with quaternions
strapdown_pln_dcm_v000.m Navigation in Planar Non-rotating Earth
strapdown_wander_dcm_v000.m Wander-Azimuth implementation (Singular)
strapdown_wander_quat_v000.m Wander-Azimuth implementation with quaternions (Non-Singular)
sys_bd_dcm_v000.m error propagation model for strapdown_bd_dcm
sys_ecef_dcm_v000.m error propagation model for sys_ecef_dcm_v000
sys_llh_phipsi_v000.m System model for geodetic navigation frame mechanization for both phi and psi parametrization. This model can be used for both DCM and quaternion mechanizations. (e.g. strapdown_ned_quat_v000, strapdown_ned_dcm_v000). Position errors are modelled as delta_llh.
  • The phi model of this script is equivalent to sys_ned_dcm_v000.
  • The only difference between this and sys_metric_phipsi_v000 is the position error parameterization.
sys_metric_phipsi_v000.m System model for geodetic navigation frame mechanization for both phi and psi parametrization. This model can be used for both DCM and quaternion mechanizations. (e.g. strapdown_Cen_dcm_v000, strapdown_Cen_quat_v000, strapdown_ned_dcm_v000). Position errors are modelled as delta_x (metric).
sys_ned_dcm_v000.m error propagation model for strapdown_ned_dcm
sys_ned_dcm_v001.m Similar to sys_ned_dcm_v000. However, this is modified for imu_err_defs usage.
sys_pln_dcm_v000.m error propagation model for strapdown_pln_dcm
sys_wander_dcm_v000.m System model for wander azimuth implementation (for strapdown_wander_dcm)
sys_wander_largeheading_v000.m System model for large heading uncertainties (for strapdown_wander_dcm)
sys_wander_psi_v000.m System model for wander azimuth implementation (for strapdown_wander_quat and strapdown_Cen_dcm)