Patent ID: 8447517

Claim:
An apparatus comprising: an integration filter for a sensor-assisted global navigation satellite system (GNSS) receiver; a GNSS measurement engine for providing GNSS measurement data to said integration filter; an inertial measurement unit (IMU); and an inertial navigation system (INS) block for calculating INS navigation information using a plurality of inertial sensor outputs, wherein said integration filter uses a speed scale-factor and/or a heading bias in the INS measurement as state variables and performs a blending operation for combining said GNSS measurement data and said INS navigation information, and for estimating and compensating said speed scale-factor and said heading bias in the INS measurement, wherein said integration filter processes an INS user velocity data from said INS in a measurement equation of said integration filter using a method comprising: a plurality of INS measurements in a local navigation coordinate are included in said measurement equation in a way that said INS measurements are a function of velocity variables and speed scale-factor and/or heading bias variables of an integration filter state with a plurality of measurement noises.