Detection and correction of anomalous measurements and ambiguity resolution in a global navigation satellite system receiver

摘要

A global navigation system includes a first navigation receiver located in a rover and a second navigation receiver located in a base station. Single differences of measurements of satellite signals received at the two receivers are calculated and compared to single differences derived from an observation model. Anomalous measurements are detected and removed prior to performing computations for determining the output position of the rover and resolving integer ambiguities. Detection criteria are based on the residuals between the calculated and the derived single differences. For resolving integer ambiguities, computations based on Cholesky information Kalman filters and Householder transformations are advantageously applied. Changes in the state of the satellite constellation from one epoch to another are included in the computations.

主权项

1. A method for resolving ambiguities in a global navigation satellite system comprising a first navigation receiver located in a rover and a second navigation receiver located in a base station, the method comprising the steps of:
receiving a first plurality of measurements based on a first plurality of carrier signals received by the first navigation receiver from a plurality of global navigation satellites, the first plurality of measurements comprising a first plurality of pseudo-ranges and a first plurality of carrier phases; receiving a second plurality of measurements based on a second plurality of carrier signals received by the second navigation receiver from the plurality of global navigation satellites, the second plurality of measurements comprising a second plurality of pseudo-ranges and a second plurality of carrier phases, each carrier signal in the second plurality of carrier signals corresponding to a carrier signal in the first plurality of carrier signals, and each measurement in the second plurality of measurements corresponding to a measurement in the first plurality of measurements; calculating a plurality of single differences based on the first plurality of measurements and the second plurality of measurements; linearizing the plurality of single differences; determining an observation vector and an observation matrix based on the linearized single differences; filtering ambiguities based on the observation vector and the observation matrix, wherein the step of filtering ambiguities comprises the steps of:
generating a Cholesky information Kalman filter; andperforming a Householder transformation on the Cholesky information Kalman filter; estimating float ambiguities based on the filtered ambiguities; determining an integer ambiguities vector candidate based on the estimated float ambiguities; determining whether the integer ambiguities vector candidate meets fix criteria; and in response to determining that the integer ambiguities vector candidate meets the fix criteria, generating an estimate of integer ambiguities vector.