GPS/INS Integration: From Modern Methods of Data Acquisition fo New Applications
This paper presents a new approach to GPS/INS data acquisition and synchronization for the most popular sensors adopted by the mapping industry for direct-georeferencing; the tactical-grade FOG/silicon-based inertial sensors and generic dual frequency GPS receivers. Contrary to most industry solutions, no dedicated timing boards or industrial PCs with real-time OS kernels are needed. The somewhat inconvenient SDLC communication and synchronization of the 400Hz inertial data is handled by a small interface that is connected to a conventional laptop via Ethernet. This PC performs data storage and/or loosely coupled integration with GPS data coming over RS232 serial link. The laptop can use Windows or other standard Operating Systems (OS) as varying processing latency is no longer critical. The same laptop can also handle voluminous (10 kHz) airborne laser scanning data coming over the same Ethernet port or data arriving from high resolution digital camera (fire-wire). Altogether this small-size, low-weight navigation system opens door to new and affordable mapping applications of high precision.