Ionospheric Delays in PRETTY Mission Data: An Opportunity to study Ionospheric F-layer Structure

Kurzfassung

This paper presents initial results of a GNSS reflectometry study that uses code delay data of ESA's PRETTY cubesat mission. Focus of the satellite mission lies on ocean and sea-ice altimetry using grazing angle reflections. An important factor to reach the altimetric goals is precise modeling and a detailed understanding of atmospheric delays at grazing angles. Here, ionospheric delays are analyzed that occur along ray paths of direct and reflected signals. The electron content is retrieved as a profile of the reflected signal relative to the direct signal. Profile plots vs. the tangent height of the direct ray indicate changes of ionospheric conditions when the direct ray approaches Earth. The PRETTY data results are compared to model-based results and show excellent agreement. A deeper analysis of profiles' shape and location reveals a sensitivity to parameters of the ionospheric F-layer structure. An F-layer peak height of roughly 300 km is estimated from the given example data.