METHOD OF SUPPRESSING MULTIPATH ERRORS IN SATELLITE NAVIGATION RECEIVER

摘要

FIELD: physics.;SUBSTANCE: method involves operations for searching for navigation satellites signals, receiving and processing complex signals from each satellite, tracking found signals with a following-up open loop and determining coordinates, receiver velocity and exact time based on measurements of direct and reflected signal delay. Delay and frequency predictions for orientation of a two-dimensional accumulated power grid according to delay and frequency are calculated based on navigation parameters. When forming grid elements, the complex signal is summed on the coherent accumulation interval synchronously with data bits of the given satellite, wherein the coherent accumulation time is matched with bit length. Corrections to delay and frequency predictions are calculated based on processing the accumulated power grid including its centring, and delay and frequency measurements are calculated as sum of predictions with corresponding corrections. Further, the obtained measurements are extrapolated to a given moment in time and pseudorange and pseudovelocity measurements are calculated, and based on measurements obtained from all satellites, coordinates and velocity of the receiver are determined. When calculating delay and frequency corrections, single-beam signal corrections are calculated using the centred accumulated power grid. It is determined whether multipath is present and if so, corrections are improved using weight coefficients. Improvement of corrections is carried out by forming a likelihood function based on a centred accumulated power vector, and correction is performed according to the found global maximum of the likelihood function.;EFFECT: suppressing multipath for weak signals from accumulated power grid data.;5 cl, 17 dwg