Abstract Anomalous systematic position offsets have been noted in GNSS time series from a variety of locations around the globe. In many regions, these time series anomalies coincide with the presence of cloud streets in visible satellite imagery, implicating atmospheric lee waves as the source of the position offsets. We report here on seasonal anomalous position offsets from the San Bernardino Basin of southern California that occur during clear skies. Modeling of the troposphere on days with anomalous positions shows the presence of atmospheric lee waves. Ray tracing through these tropospheric models suggests that atmospheric lee waves create low elevation perturbations to microwave refractivity of as much as 10 %. These regions of perturbed refractivity reoccur in consistent locations over the San Bernardino Basin and, from the perspective of individual GNSS antenna, alter the refractivity to mimic spatial offset of the antenna phase center. This refractivity pattern is unlike the pattern estimated using linear and higher-order atmospheric gradients during GNSS position processing and results in apparent position offsets in the GNSS time series correlated with the orientation of the lee waves.
Szeliga et al. (Thu,) studied this question.