초록 ▼

A system and method for increasing jamming immunity in a GPS/INS system. The system includes a signal processor for receiving and down-converting GPS signals to a baseband frequency to provide I and Q (sine and cosine) signals. An integrate and dump operation is performed on the I and Q signals to p

A system and method for increasing jamming immunity in a GPS/INS system. The system includes a signal processor for receiving and down-converting GPS signals to a baseband frequency to provide I and Q (sine and cosine) signals. An integrate and dump operation is performed on the I and Q signals to provide GPS range and range rate residuals which are uncorrelated from sample to sample. A Kalman filter estimates navigation state corrections from the GPS range and range rate residuals. A NAV function, responsive to the output of the Kalman filter and range error and velocity error signals, provides guidance information and signals for correcting at least one of earth centered earth fixed (ECEF) position, velocity, initial attitude and IMU alignment states which are dynamically calculated from the range and range rate measurements. A line of sight geometry function maps position and velocity vector information from the NAV function into geometric range and range rate scalar information and feeds the scalar information to the signal processor and circuitry to perform an integrate and dump operation.

대표청구항 ▼

[ We claim:] [1.] A system for increasing jamming immunity in a GPS/INS system, comprising:(a) a signal processor for receiving and down-converting GPS signals to a baseband frequency to provide I and Q (sine and cosine) signals;(b) means to perform an integrate and dump operation on said I and Q si

[ We claim:] [1.] A system for increasing jamming immunity in a GPS/INS system, comprising:(a) a signal processor for receiving and down-converting GPS signals to a baseband frequency to provide I and Q (sine and cosine) signals;(b) means to perform an integrate and dump operation on said I and Q signals to provide GPS range and range rate residuals which are uncorrelated from sample to sample;(c) a Kalman filter for estimating navigation state corrections from said GPS range and range rate residuals;(d) navigation means responsive to the output of said Kalman filter and range error and velocity error signals to provide guidance information and signals for correcting at least one of earth centered earth fixed (ECEF) position, velocity, initial attitude and Inertial measurement unit alignment states which are dynamically calculated from range and range rate measurements; and(e) line of sight means for mapping position and velocity vector information from said navigation means into geometric range and range rate scalar information and feeding said scalar information to said signal processor and to said means to perform an integrate and dump operation;wherein said means to integrate and dump includes coherently adding the I signals and the Q signals separately over a predetermined time period (Ti) to provide a summation for each of the I and Q signals over the time period Ti, forming from these summations cross and dot products at the Ti rate, summing the cross and dot products over a different time interval of length Tk to provide a pair of second summations, one for the cross product signal and one for the dot product signal, and taking an arctangent function of the summed cross products and dot products and dividing the arctangent function by the integration time (Ti) to obtain said residual directly.