Strapdown inertial navigation integration algorithm design Part 2: Velocity and position algorithms

This series of two papers (Parts 1 and 2) provides a rigorous comprehensive approach to the design of the principal software algorithms utilized in modern-day strapdown inertial navigation systems: integration of angular rate into attitude, acceleration transformation/integration into velocity, and integration of velocity into position. The algorithms are structured utilizing the two-speed updating approach originally developed for attitude updating; an analytically exact equation is used a moderate speed to update the integration parameter (attitude, velocity, or po sition) with input provided from sr high-speed algorithm measuring rectified dynamic motion within the parameter update time interval [coming far attitude updating, sculling for velocity updating, and scrolling (writer's terminology) for high-resolution position updating]. The algorithm design approach accounts for angular rate/specific force acceleration inputs from the strapdown system inertial sensors, as well as rotation of the navigation frame used for attitude referencing and velocity integration. The Pare 1 paper (Savage, P. G., "Strapdown Inertial Navigation Integration Algorithm Design Part 1: Attitude Algorithms," Journal of Guidance Control, and Dynamics, Vol. 21, No, 1, 1998, pip 19-28) defined the overall design requirement for the strapdown inertial navigation integration function and developed the attitude updating algorithms. This paper, Part 2, deals with design of the acceleration transformation/velocity integration and position integration algorithms. Although Parts I and 2 often cover basic concepts, the material presented is intended for use by the practitioner who is already familiar with inertial navigation fundamentals.