GNSS+R observations from MAPHEUS sub-orbital flight: testing ionospheric E-layer resolution

Abstract

On November 11, 2024 a sounding rocket was launched from Esrange, Northern Sweden for a sub-orbital flight within the MAPHEUS program (MAterials PHysics Experiment Under weightlessnesS). The flight (MAPHEUS-15) contained a micro-gravity period that covered altitudes between 90 and 310 km. We used this opportunity to record GNSS data on the rocket for a study on ionosphere remote sensing. A key aspect of our study is to obtain profiles of the slant total electron content (TEC) on direct or reflected GNSS links (GNSS+R) in this hardly studied sub-orbital altitude regime. The profiles shall resolve E-layer contribution (at about 100 km altitude) that is often masked in terrestrial observations by dominating F-layer contribution (from 200 km upward). The enhancement of E-layer observation will contribute to a better understanding of ionosphere and space weather impact on navigation and communication signals. The development of innovative observation techniques is part of DLR's RESITEK project (RESIliente TEchnologien für den Katastrophenschutz).