Abstract: A method for measuring mass storage system performance in which the mass storage system has a plurality of disk drive storage elements controlled by a disk drive controller, the controller typically having a cache memory, and the controller receiving commands and data from and returning at least data to a plurality of host computers, provides the flexibility of issuing commands to the controller in a variety of different configurations from a plurality of hosts in a time synchronized and organized fashion. Some significant post processing techniques for validation and correction of the data are enabled according to the invention.

Abstract: The position, orientation, velocity and acceleration of remote sensors is determined using magnetic fields. Multiple, arbitrarily oriented magnetic field transmitters are placed in one reference frame (source reference frame), and multiple, arbitrarily oriented magnetic field receivers are placed in a second reference frame (body reference frame). The spatially varying magnetic fields of the transmitters in the source reference frame are sensed by the magnetic field receivers in the body reference frame. The computer algorithm uses a physics-based extended Kalman filter to resolve the position; orientation, velocity and acceleration of the body relative to the source reference frame. The physics-based extended Kalman filter can accommodate the effects of metal in the source and body reference frames and thus allow the system to measure position, orientation, velocity and acceleration under conditions where eddy currents would normally hinder other magnetic position measuring systems.