Assessment of the Higher Order Ionosphere Error on Position Solutions

This paper presents an assessment of the impact of the higher order ionosphere error on GPS position solutions. Prior studies of higher order ionosphere error are based on simplified ionosphere models, and there is a lack of understanding of their temporal and spatial structures. In this paper, we apply the Appleton-Hartree formula in the computation of the higher order errors by combining vertical electron density profiles obtained from the Arecibo incoherent scatter radar, the International Reference Ionosphere model, total electron content maps derived from the International GNSS Service database, and the International Geomagnetic Reference Field model. The 24-slot GPS baseline constellation is used to compute a receiver position error based on higher order range error. The position error at the Arecibo radar site on a quiet day is used as an example to demonstrate the magnitude, sign, and daily variation patterns of higher order ionosphere induced position error.