USE OF EISCAT 3D FOR OBSERVATIONS OF SPACE DEBRIS

Abstract

We investigate the capabilities of the next generation ionospheric research radar EISCAT 3D (E3D) for observations of space objects. The radar is multi-static, and is therefore capable of observing instantaneous threedimensional vector velocity and position by observing round-trip delay and Doppler shift between the transmitter and three receiver sites. The radar is to be located in Northern Scandinavia, which provides a high revisitrate for high inclination objects. To model the performance of E3D for space object observations, we have included radar equation based analysis of object detectability as a function of range and size. To study the performance of the radar for orbital elements determination, we have used a linearized error covariance analysis for idealized Keplerian elements. The analysis includes range and range-rate errors due to signal-to-noise and ionospheric radio propagation. To estimate the fraction of total debris that can be observed with E3D, we have used the MASTER model [FGW+09]. E3D uses a relatively low VHF frequency (233 MHz), which experiences more radio wave propagation effects than more conventional higher frequency space surveillance radars. Our modeling shows that ionospheric ray-bending and group delay are severe enough that these effects need to be modeled in order to determine accurate orbital elements. As EISCAT 3D is an ionospheric research radar, there will be high quality ionospheric electron density measurements that can be utilized for radio propagation modeling. Our simulations indicate that the radar can be used for observations of orbital elements of objects down to 5 cm in diameter. It is therefore feasible that the radar could provide to be a useful source of accurate information of orbital elements of space debris.