Abstract
The Integration of GPS with additional position technologies, such as Inertial Navigation Systems (INS), is an area of research that is well developed. The complimentary properties of the two systems, the long term stability and accuracy of GPS with the reliability and high data rates of the INS system, have meant they have been ideal candidates for integration in order to obtain a more robust and reliable navigation solution than either system can provide alone. Research to date has focused on integrating these two systems using a variety of data fusion techniques such as the Extended Kalman filter or other non-linear filtering techniques to utilize the strengths of each individual system. This has typically involved the need to design a system that takes into account both the GPS and INS systems when designing the overall system architecture. This paper proposes a different approach to the problem of integrating these two systems, from the constraint of having an existing GPS processing software suite that has been developed over many years and would require significant reengineering in order to modify sufficiently to enable the acceptance of both GPS and INS measurements. The method proposed here is to instead form virtual satellites, or ‘virtuaLites’ based on aiding position information, be it from an INS system or alternate source, that can be processed alongside the GPS satellites using the existing processing software for application in a precision agriculture environment. This paper examines the details in implementing this approach; it presents three different strategies for the implementation of the virtuaLite concept and examines the quality of aiding position information necessary for this implementation to be effective.