ICEBEAR: An All‐Digital Bistatic Coded Continuous‐Wave Radar for Studies of the E Region of the Ionosphere

Abstract

The Ionospheric Continuous-wave E region Bistatic Experimental Auroral Radar (ICEBEAR) is a coherent scatter ionospheric radar. It operates at a frequency of 49.5 MHz, which is ideal for observing E region coherent echoes. The radar is located in Saskatchewan, Canada, and is operated by the University of Saskatchewan. The ICEBEAR system uses a continuous-wave (CW) signal and requires isolation between the receiving and transmitting arrays. This was accomplished through a bistatic setup, where the receiver and transmitter are ≈240 km apart. Currently, the ICEBEAR system implements a pseudo random noise phase modulation on this CW signal to obtain 3-km range resolution and 5-s integration time images of E region ionospheric irregularities over a 600 km × 600 km field of view. The center of the field of view is located at ≈58 • N, 106 • W. The radar design allows for future improvements to temporal and/or spatial resolutions. Each site consists of a linear phased array with 10 equally spaced antennas. This, combined with modern digital radio hardware, provides azimuthal angle of arrival measurements at the receiving array and azimuthal transmission control at the transmitting array. This publication describes the radio hardware and signal processing used by the ICEBEAR radar and emphasizes the unique capabilities of the radar. First ICEBEAR observations from a Kp ≥ 4 event on 10 March 2018, are presented and shown to produce simultaneously the four types of previously characterized E region coherent scatter echoes.

Multistatic Specular Meteor Radar Network in Peru: System Description and Initial Results

“…This approach has a maximum unambiguous range which remains at 6000 km, with range-aliasing converted into an increase of flat noise by the pseudo random nature of the code, and an unaliased Doppler extent of ± 230 km/s (Nyquist frequency = 50 kHz). We note that a very similar approach has been applied successfully to E region plasma irregularity studies using the radar aurora system called ICEBEAR (e.g., Huyghebaert et al, 2019).…”

Determination of the Azimuthal Extent of Coherent E‐Region Scatter Using the ICEBEAR Linear Receiver Array

“…The preliminary result depicts a better representation of the size of the scattering volume than was previously performed in Huyghebaert et al. (2019) where only the azimuthal angle of arrival derived from single wavelength baselines to map the ionospheric scatter were used.…”

“…The processing speed of the cross‐spectra has been improved from previous operations described in Huyghebaert et al. (2019) by implementation of a graphics processing unit (GPU). The transition from a single i7 core to a modern GPU provided a reduction in processing time of ∼48x.…”

“…Chau and St.‐Maurice (2016) measured E‐region coherent scatter during an extremely active event with a radar optimized for meteor detection resulting in novel high resolution measurements of E‐region coherent scatter during active ionospheric periods. Building on previous discoveries, ICEBEAR was designed by using modern radio techniques to obtain simultaneous high temporal and spatial resolutions over a FOV located in the terrestrial auroral zone to expand upon the understanding of the Farley‐Buneman instability (Huyghebaert et al., 2019).…”

“…ICEBEAR is a recently deployed E‐region coherent scatter radar that has been operated on a campaign basis (Huyghebaert et al., 2019). It makes coherent scatter measurements of the E‐region ionosphere over a 600 × 600 km FOV and used a 10‐antenna one‐wavelength (1 λ ∼6.06 m for ICEBEAR) spaced linear receiving array from December 2017 to May 2018.…”