Quantification of the single layer mapping function error using NeQuick model

Kurzfassung

Ionosphere can be the largest source of error in Global Navigation Satellite System (GNSS) positioning and navigation. The error in satellite - receiver distance measurements is equivalent to so called Total Electron Content (TEC). This parameter is often converted between different satellite-receiver link geometries. The most common conversion uses single layer approximation of the ionosphere which can introduce an error to the estimation of the ionospheric delay. According to our study case which was modelled by the NeQuick model, the conversion error can reach value of 8 TECU in case elevation angles, underestimation of ionospheric height or high solar activity. In case two or all three are present, the error is even more severe. We also defined an asymmetry index which can be used to model the behavior of the mapping function error and potentially reduce its effect.