Patents by Inventor David H. Spradley

David H. Spradley has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5155490
    Abstract: An improved system and method for determining a position fix in space and time using the Global Positioning System (GPS) satellite network signals. The system comprises at least three fixed base stations each having a satellite receiver operating in conjunction with a highly accurate (atomic-standard) clock. Each base station's position is known with great accuracy. GPS satellite signals are collected over statistically significant periods of time at each base station and fitted to determine with the clock offset and drift of the station clocks, thus establishing a "network" of base station clocks that in the aggregate is of great accuracy and precision. An arbitrary number of mobile receiver stations similarly collect data for working periods of statistically significant duration; these data are used in conjunction with the base station data to compute position fixes for the mobile stations.
    Type: Grant
    Filed: October 15, 1990
    Date of Patent: October 13, 1992
    Assignee: GPS Technology Corp.
    Inventors: Lewis H. Spradley, Jr., John P. Wincelowicz, Jr., David H. Spradley