Patent ID: 9557418
Date: 2017-01-31
CPC Classifications: G01S

Claim:
1. A processing module to monitor a horizontal delay gradient in satellite signals representative of an ionospheric delay gradient, the processing function comprising: a satellite differencing module configured to receive carrier phase measurements for at least two satellites from at least three reference receivers, the at least two satellites including a monitored satellite and at least one other satellite, wherein the at least three reference receivers have a known geometric relationship to each other, and wherein the satellite differencing module determines differences in the carrier phase measurements between signals from the monitored satellite and at least one of the at least one other satellite; a double differencing module configured to: a parity test module configured to input the averaged compensated double differences when the average of the compensated double differences over the other satellites among the at least two satellites exceed a parity enable threshold; and a gradient estimator module configured to estimate a magnitude of the horizontal delay gradient based on a set of the averaged compensated double-differences input from the parity test module.