Broadband Receiver for VLF On-Orbit Wave-Particle Interaction Experiments

Abstract

A broadband, multi-channel Very Low Frequency (VLF) radio receiver (BBR), developed as a sensitive analog, vector wave receiver for whistler-mode signals in the VLF range, was successfully flown on the Air Force Demonstration Science Experiment (DSX) Mission to Mid-Earth Orbit (Johnston et al., 2023, https://doi.org/10.1029/2022JA030771). The BBR is a radiation resistant, 5 × 2 channel receiver, integrated into the Wave Induced Precipitation of Electron Radiation (WIPER) instrument package on DSX. The BBR accepts electric wave signal inputs from (a) an 81.6 m tip-to-tip dipole VLF antenna on the DSX Y-boom, (b) a 16.3 m tip-to-tip dipole antenna on the DSX Z-boom, and (c) signals from a Tri-Axial Search Coil (TASC), an three-orthogonal axes magnetic wave search coil magnetometer mounted on the DSX + Z boom. The electric and magnetic VLF signals are processed in the BBR by two independent, radiation hardened five channel receivers: (a) a receiver of heritage design with commercial off-the-shelf components (COTS), and (b) a micro-receiver incorporating custom, radiation resistant, micro-electronics. The bandwidth of all five channels in both the heritage and micro designs covers from 10 Hz to 50 kHz. A software “receiver”, SRx, running in the on-board flight computer, the ECS, manages the BBR's data flow and data delivery to the ground. The SRx additionally computes supporting science data products such as Fourier transforms, multi-band filters and cross correlations among the BBR's electric and magnetic field channels to facilitate production of VLF wave normals.