Abstract: Non-invasive methods for detecting arterial disease in vivo include obtaining acoustic signals from a sensor held on an external body region proximate an artery. A complex frequency grid of frequencies and associated lifetimes of the obtained acoustic signals is generated. A predictive model of complex frequencies associated with peak-perturbation acoustic signals attributed to boundary perturbations in vivo that occur with early stage arterial disease is provided. A predictive model of complex frequencies associated with line-perturbation acoustic signals attributed to boundary perturbations in vivo that occur with later stage arterial disease and thickening of arterial junctions is also provided. It is determined whether peak and/or line-perturbation acoustic signals of the predictive models are present to detect whether the subject has arterial disease.

Abstract: The effect of changing satellite geometry on the achievable accuracy of GPS relative positioning under the full GPS constellation has been researched. A mathematical model has been developed for the quantitative analysis of the accuracy of GPS relative positioning with respect to the changing satellite/station configuration, observation starting time and session length. A method based on modeling the relative dilution of precision (RDOP) has been developed for the optimum design of GPS relative positioning with carrier phase observable. The RDOP surface, a mathematical surface, has been generated based on the broadcast almanac file. The optimum observation windows, optimum session starting time and optimum observation session length have been derived from the study of the RDOP surface.The method and mathematical model based on the RDOP are compared with those based on the PDOP (position dilution of precision) for application purposes.

Abstract: A system for correlating electronic distance measurement and aerial photography where an airborne electronic location station is photographed as it passes over an area to be surveyed. The position of the airborne station is precisely measured as it moves and this information is included in the final image processing.