Improving strapdown inertial navigation system (SINS) with velocity information of active radar seeker (ARS)

We deal with turning into actual design the potential of ARS to aid SINS. We utilize the ARS velocity information. We design a new Kalman filter to implement such utilization of ARS velocity information. The two key problems are: (1) the compensation for the difference between SINS velocity and ARS velocity: (2) the design of measurement construction and then the derivation of the observation equation. After suitable compensation, the SINS velocity can be transformed into equivalent ARS velocity and the observation quantity is the difference between ARS velocity and equivalent ARS velocity. Thus we derive the observation equation using the ARS body coordinate system instead of the usual navigation coordinate system as reference. The results of two numerical examples show that: (1) the velocity accuracy is improved to within 1 m/s and 2.5 m/s respectively; (2) the position error is suppressed to about 500 m and 3000 m respectively. Our research means ARS velocity information can improve SINS navigation performance without extra equipment and cost.