The wideband ionospheric sounder cubesat experiment (WISCER)

This paper describes a preliminary design study to assess the possibility of flying a wideband ionospheric sounder cubesat experiment (WISCER). WISCER comprises a wideband (∼100 MHz) beacon on a low cost cubesat designed to measure and evaluate the ionospheric channel in anticipation of the development of operational, space-based, low frequency (i.e. around 450MHz) synthetic aperture radar (SAR) systems

Initial results from DAMSON-a system to measure multipath, Doppler spread and Doppler shift on disturbed HF channels

The performance of beyond line-of-sight (BLOS) high frequency (HF) communication systems is dependent on how well the system is matched to the propagation environment. In this respect issues such as antenna gain and transmitter power are very important. Deserving equal or greater attention, however, is the issue of the match between the signalling waveform and the time and frequency spread characteristics of the propagation path. This paper briefly describes a channel sounder known as DAMSON (Doppler and multipath sounding network) which has been developed to characterise the disturbed narrow band channel (3 kHz) by measuring its scattering function. The real time nature of the DAMSON processing makes it unique in the frequency range but, in its approach to measuring the channel its operation is similar to that of Wagner et al. (1988)

Space weather opportunities from the Swarm mission including near real time applications

Sophisticated space weather monitoring aims at nowcasting and predicting solar-terrestrial interactions because their effects on the ionosphere and upper atmosphere may seriously impact advanced technology. Operating alert infrastructures rely heavily on ground-based measurements and satellite observations of the solar and interplanetary conditions. New opportunities lie in the implementation of in-situ observations of the ionosphere and upper atmosphere onboard low Earth orbiting (LEO) satellites. The multi-satellite mission Swarm is equipped with several instruments which will observe electromagnetic and atmospheric parameters of the near Earth space environment. Taking advantage of the multi-disciplinary measurements and the mission constellation different Swarm products have been defined or demonstrate great potential for further development of novel space weather products. Examples are satellite based magnetic indices monitoring effects of the magnetospheric ring current or the polar electrojet, polar maps of ionospheric conductance and plasma convection, indicators of energy deposition like Poynting flux, or the prediction of post sunset equatorial plasma irregularities. Providing these products in timely manner will add significant value in monitoring present space weather and helping to predict the evolution of several magnetic and ionospheric events. Swarm will be a demonstrator mission for the valuable application of LEO satellite observations for space weather monitoring tools

Ionosphere Monitoring

Global navigation satellite system (GSSS)-based monitoring of the ionosphere is important in a twofold manner. Firstly, GNSS measurements provide valuable ionospheric information for correcting and mitigating ionospheric range errors or to warn users in particular in precise and safety of life (SoL) applications. Secondly, spatial and temporal resolution of ground- and space-based measurements is high enough to explore the dynamics of ionospheric processes such as the origin and propagation of ionospheric storms. It is discussed how ground- and space-based GNSS measurements are used to create globalmaps of total electron content (TEC) and to reconstruct the highly variable three-dimensional (3-D) electron density distribution on global scale under perturbed conditions. Thus, the monitoring results can be used for correcting ionospheric errors in single-frequency applications as well as for studying the driving forces of space weather-induced perturbation features at a broad range of temporal and spatial scales. Whereas large- and mediumscale perturbations affect accuracy and reliability of GNSS measurements, small-scale plasma irregularities and plasma bubbles have a direct impact on the continuity of GNSS availability by causing strong and rapid fluctuations of the signal strength, known as radio scintillations. It is discussed how better understanding of space weather-related phenomena may help to model and forecast ionospheric behavior even under perturbed conditions. Hence, ionospheric monitoring contributes to the successful mitigation of range errors or performance degradation associated with the ionospheric impact on a broad spectrum of GNSS applications