Biomass End-to-End PErformance Simulator: Description of the ionosphere module

ESA's BIOMASS Earth Explorer mission aims at providing global above ground forest biomass. Its payload is a UHF synthetic aperture radar. At UHF ionospheric effects, notably the group delay and phase advance, the Faraday rotation, and the intensity and phase scintillations (or rapid fluctuations) are significant and have to be properly modelled to be compensated, to understand the limitations of the proposed technique, and to select the optimum observation conditions. This paper summarizes the structure and main characteristics of the ionospheric module of the BIOMASS end-to-end performance simulator (BEEPS-IOM).This work was supported by ESA/ESTEC project (DLR subcontract Nr. D/551/67282068) “BIOMASS Ionospheric Module for End-to-End Performance Simulator,” by the Spanish Ministry of Science, Innovation and Universities, "Sensing with Pioneering Opportunistic Techniques," grant RTI2018-099008-BC21/AEI/10.13039/501100011033, and by the Unidad de Excelencia Maria de Maeztu MDM-2016- 0600.Peer ReviewedPostprint (author's final draft

Improved characterization and modeling of equatorial plasma depletions

This manuscript presents a method to identify the occurrence of Equatorial Plasma Bubbles (EPBs) with data gathered from receivers of Global Navigation Satellite System (GNSS). This method adapts a previously existing technique to detect Medium Scale Travelling Ionospheric Disturbances (MSTIDs), which focus on the 2nd time derivatives of total electron content estimated from GNSS signals (2DTEC). Results from this tool made possible to develop a comprehensive analysis of the characteristics of EPBs. Analyses of the probability of occurrence, effective time duration, depth of the depletion and total disturbance of the EPBs show their dependence on local time and season of the year at global scale within the latitude belt from 35°N to 35°S for the descending phase of solar cycle 23 and ascending phase of solar cycle 24, 2002–2014. These results made possible to build an EPBs model, bounded with the Solar Flux index, that simulates the probability of the number of EPBs and their characteristics expected for a representative day at given season and local time (LT). The model results provided insight into different important aspects: the maximum occurrence of bubbles take place near the equatorial anomaly crests, asymmetry between hemispheres and preferred longitudes with enhanced EPBs activity. Model output comparisons with independent observations confirmed its soundness.Postprint (published version

Modeling of ionospheric scintillation

A signal, such as from a GNSS satellite or microwave sounding system, propagating in the randomly inhomogeneous ionosphere, experiences chaotic modulations of its amplitude and phase. This effect is known as scintillation. This article reviews basic theoretical concepts and simulation strategies for modeling the scintillation phenomenon. We focused our attention primarily on the methods connected with the random phase screen model. For a weak scattering regime on random ionospheric irregularities, a single phase screen model enables us to obtain the analytic expression for phase and intensity scintillation indices, as well as the statistical quantities characterizing the strength of scintillation-related fades and distortions. In the case of multiple scattering, the simulation with multiple phase screens becomes a handy tool for obtaining these indices. For both scattering regimes, the statistical properties of the ionospheric random medium play an important role in scintillation modeling and are discussed with an emphasis on related geometric aspects. As an illustration, the phase screen simulation approaches used in the global climatological scintillation model GISM is briefly discusse

Improved modelling of ionospheric disturbances for remote sensing and navigation

A generic software tool to evaluate the impact of ionospheric disturbances is presented, including low and high latitude physically-based models, and low and high frequency fluctuations. This tool has been developed specifically to assess the performance of navigation receivers, but it is ready to simulate other frequencies and even receivers in dynamic conditions, which allows it to be used in other applications such as communications, GNSS-R, radar altimetry or SAR.Peer ReviewedPostprint (published version

Improved modelling of ionospheric disturbances for remote sensing and navigation

A generic software tool to evaluate the impact of ionospheric disturbances is presented, including low and high latitude physically-based models, and low and high frequency fluctuations. This tool has been developed specifically to assess the performance of navigation receivers, but it is ready to simulate other frequencies and even receivers in dynamic conditions, which allows it to be used in other applications such as communications, GNSS-R, radar altimetry or SAR.Peer Reviewe