Real-Time GPS and LORAN-C Dynamical Performance for Critical Marine Applications

With system biases removed both LORAN-C and GPS can provide excellent real time position fixing for low-dynamics platforms. Nevertheless it is wise to understand the fundamental limitations which exist for each system in real-time applications. In addition to emitter geometry, the receiver/navigator architecture and user platform model must be incorporated. In this paper a new statistical error analysis approach is employed which accounts for these factors, and which allows determination of error dynamics experienced during signal faults. The approach enables a direct comparison of LORAN-C and GPS under identical dynamical conditions. A brief overview of the analytical technique is given, and normal and signal fault results presented for aided and unaided rho-rho LORAN-C processors, and for sequential and parallel GPS processors. GPS performance is based on the 6 × 3 18 satellite GPS constellation. LORAN-C performance is for the Northeast chain.