Beyond the Incoherent Scatter Radar

Measurement of the near space environment of the Earth using incoherent scattering has been a powerful technique for developing a quantitative understanding of ionospheric structure, dynamics, and coupling to the larger Geospace environment. The incoherent scatter radar systems (ISR) that are used for scientific investigations have a wide range of implementations, performance characteristics, and measurement capabilities. A common characteristic is the need for a sufficiently large power-aperture per unit temperature to achieve useful measurement speed in the ionosphere. This leads to a relatively large physical scale for ISR facilities. Indeed, many of these facilities are unique and the episodic projects to develop new systems have also occurred in very different environments and faced radical changes in technology. For example, it is only recently that software radio technology evolved to the point where a full exploitation of even the existing systems has become possible. These advances have also enabled next generation facilities based on all digital phased array implementations with significantly more capable receive apertures. This sets the stage for new approaches to Geospace facility design and has the potential to result in vastly increased scientific capabilities. The capabilities emerge both from the ability to implement far more flexible instruments and from advances in signal capture, processing, and analysis that allow for simultaneous use of the radar apertures for multiple applications and in combination with other instruments. Geospace Radar facilities of the future may take different forms including distributed arrays for space weather monitoring, rapidly deployable systems, mobile airship radars, large scale simultaneous transmit and receive (STAR) apertures using conformal geometries, and space based radar systems. These instruments would have incoherent scatter capabilities as a subset of a much richer group of techniques that would enable studies of the lower atmosphere, magnetosphere, heliosphere, and astronomical space environment. Application to more applied missions such as space weather monitoring, near earth object characterization, and space surveillance would also be enabled.