Space Plasma Exploration by Active Radar (SPEAR): an overview of a future radar facility

D M Wright,F Honary,S W H Cowley,R B Horne,P J Chapman,M Lester,T K Yeoman,E C Thomas,J A Davies,T R Robinson,A J Stocker

doi:10.1007/s00585-000-1248-7

D M Wright, F Honary + Show 9 more

Open Access

https://doi.org/10.1007/s00585-000-1248-7

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Abstract

Abstract. SPEAR is a new polar cap HF radar facility which is to be deployed on Svalbard. The principal capabilities of SPEAR will include the generation of artificial plasma irregularities, operation as an 'all-sky' HF radar, the excitation of ULF waves, and remote sounding of the magnetosphere. Operation of SPEAR in conjunction with the multitude of other instruments on Svalbard, including the EISCAT Svalbard radar, and the overlap of its extensive field-of-view with that of several of the HF radars in the SuperDARN network, will enable in-depth diagnosis of many geophysical and plasma phenomena associated with the cusp region and the substorm expansion phase. Moreover, its ability to produce artificial radar aurora will provide a means for the other instruments to undertake polar cap plasma physics experiments in a controlled manner. Another potential use of the facility is in 'field-line tagging' experiments, for coordinated ground-satellite experiments. Here the scientific objectives of SPEAR are detailed, along with the proposed technical specifications of the system.Key words: Ionosphere (active experiments) – Radio science (instruments and techniques) – Space plasma physics (instruments and techniques)

Highlights

It is realized that further improvements in our understanding of the ®eld of solar-terrestrial physics are only likely to result from better coordinated observing programmes involving a numberD
High-power radio waves, those of some 10 MW eective radiated power (ERP), can readily generate small-scale irregularities in both the Eand F-regions under a wide variety of conditions, as has been shown using the EISCAT heating facility at Tromsù (e.g. Robinson, 1989). Such arti®cially generated irregularities can act as targets for coherent scatter radars; this has been demonstrated on a number of occasions using the Finland and Iceland East radars of the CUTLASS facility, coverage of both of which includes the Tromsù heater (e.g. Bond et al, 1997; Robinson et al, 1997, 1998)
A wide variety of ULF and VLF oscillations can be stimulated by modulated heating of the high latitude ionospheric electrical current system (e.g. Stubbe et al, 1982)

Summary

Introduction

It is realized that further improvements in our understanding of the ®eld of solar-terrestrial physics are only likely to result from better coordinated observing programmes involving a number. Wright et al.: Space Plasma Exploration by Active Radar (SPEAR): an overview of a future radar facility Coherent radars, such as those of the SuperDARN network, play a vital role in imaging high-latitude dynamical processes by mapping plasma convection orthogonal to the geomagnetic ®eld, on a wide variety of spatial and temporal scales. Such arti®cially generated irregularities can act as targets for coherent scatter radars; this has been demonstrated on a number of occasions using the Finland and Iceland East radars of the CUTLASS facility, coverage of both of which includes the Tromsù heater

ULF modulation for magnetospheric sounding

Nonlinear interactions in the polar cap ionosphere

Summary