Northrop Grumman Guidance and Electronics Company, Inc.

Gang Kevin Liu

Robert John Buchler

Charles P Bruner

A method for estimating a probability of failure of a least-squares ambiguity decorrelation adjustment (LAMBDA) method is provided. The LAMBDA method is used for estimation of double difference carrier phase integer ambiguity. A plurality of condition sets are selected. Each condition set comprises a probability of failure (P) for a boot-strap method of estimation of the double difference carrier phase integer ambiguity, a number of space vehicles (N), and a ratio test tolerance for the LAMBDA method. A plurality of Monte Carlo simulations are run on the plurality of condition sets to obtain a plurality of result sets. Each result set comprises a probability of lambda fail (P) and a probability of lambda reject (P) for one condition set of the plurality of condition sets. A lookup table is created with the plurality of result sets. A value of Pfor given values of P, P, and Nis estimated through employment of the lookup table.

Estimation of probability of lambda failure through employment of lookup table

An apparatus comprising a position system configured to determine a global positioning (GPS) change vector, and an inertial navigation system (INS) change vector. The position system is configured to determine a relative position between a first platform and a second platform based on the GPS change vector and the INS change vector, and the position system is configured to correct a GPS position calculation error based on the GPS change vector and the INS change vector.

Ins based GPS carrier phase cycle slip detection and repairing

A first navigation unit of an apparatus in one example comprises a hybrid global positioning system (GPS)/inertial navigation system (INS) component. The hybrid GPS/INS component provides first GPS information and first INS information for the first navigation unit. The first navigation unit is configured to receive second GPS information and second INS information from a second navigation unit. The second navigation unit comprises a GPS component configured to determine a double-differenced GPS carrier phase measurement through employment of the first GPS information and the second GPS information. The first navigation unit comprises a relative Kalman filter configured to update an INS error estimate for an estimate of a relative position between the first and second navigation units based on the double-differenced GPS carrier phase measurement and the first and second INS information.

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Simi Valley, CA, United States of America

Gang Kevin Liu