Abstract: A method of generating a synthetic pressure altitude is disclosed. The method includes providing a static air temperature to a data processing device. The method also includes receiving a geometric altitude from a geometric altitude sensing device and performing a numerical integration based on the static air temperature and the geometric altitude resulting in a synthetic pressure altitude. The method further includes receiving a pressure altitude from a pressure altitude sensing device, comparing the pressure altitude and the synthetic pressure altitude and generating an average of the pressure altitude and the synthetic pressure altitude. The method still further includes providing selectively, based on the comparing step, the average as output.

Abstract: Methods of measuring phase angle and decoding a pseudo-random noise (PRN) code by applying High Resolution Correlators, having three or more correlators signals, where at least two signals, or multiples of two, are equally distanced advanced or delayed signals from the PRN signal with the option of one signal substantially in sync with the PRN signal. A phase tracking error is computed when measuring phase angle or adjusting the relative timing difference by adjusting the phase of the locally generated PRN signals when the error signal has a non-zero magnitude, in a manner to drive said error signal to zero when decoding the PRN code.

Abstract: An apparatus and method for mitigating multipath interference in a spread spectrum ranging/positioning system receiver is disclosed. Improved peak tracking in the presence of multipath interference is accomplished with an improved discrimiriant. The discriminant may be developed from a curvilinear function based on a minimal number of correlators. Also disclosed is an open loop measurement compensation innovation that compensates for a multipath-induced shift of the correlation function peak. The positioning system receiver may have either one or both of the mitigation features.

Abstract: Attitude of a spinning vehicle is determined by observing at least one of the apparent amplitude modulation and the apparent phase modulation of a navigation signal received from a navigation source. Vectors describing the direction from the vehicle to the navigation source are computed and used to determine attitude relative to the navigation source. Inertial sensors are demodulated to remove rotation artifacts and used to anticipate rapid maneuvers.

Abstract: A method of generating a differentially corrected pseudorange residual in a differential global positioning system includes tracking at a base station first and second GPS signals, having first and second frequencies, from a first satellite. At the base station, a first pseudorange measurement is determined from the tracked first GPS signal. At the base station, a first smoothed pseudorange measurement is calculated from the determined first pseudorange measurement as a function of both the first and second GPS signals. The first smoothed pseudorange measurement is provided to a remote GPS receiver. The remote GPS receiver calculates the differentially corrected pseudorange residual as a function of the first smoothed pseudorange measurement provided by the base station.

Abstract: An apparatus is described permitting rapid rehanging of fallen freight bracing bulkheads and trolleys, comprising a movable shaft mounted on the existing trolley tracks, a portable winch for raising detached bulkheads, and a ceiling jack, attachable to said movable shaft, causing the apparatus to be suitable for raising fallen bulkhead trolleys.