MRI: Development of Radio Array of Portable Interferometric Detectors (RAPID)

Northeast Radio Observatory Corp, Westford MA

Investigators

Abstract

The investigators will develop a Radio Array of Portable Interferometric Detectors (RAPID) investigations of ionospheric phenomena, solar radio emission, the Galactic synchrotron background, and ultra-high energy cosmic rays via airshower emission. The array will consist of 50-100 small, low-gain broadband antennas operating below 500 MHz. Unlike existing arrays, RAPID can be operated without any cabling between the antennas and a central location, and can be shipped, deployed and physically reconfigured quickly and easily with zero site infrastructure. This creates a unique capability to locate and configure an imaging radio interferometer array, highly customized to the specific science goal of any given field campaign, thereby supporting science investigations that hitherto have not been feasible. The system is based on voltage data capture with all processing performed offline in software at the home institutions of investigators, simplifying field operations and reducing equipment complexity. RAPID will revolutionize a range of ionospheric studies through high resolution interferometric imaging of ionospheric structures in equatorial and/or auroral regions, via coherent and enhanced scatter of signals from existing transmitters, both commercial (TV and radio) and scientific (incoherent scatter radar installations),. With its broad frequency coverage and the ability to customize the array layout to match the spatial scales in powerful solar coronal emissions of various kinds, RAPID will greatly advance solar imaging capabilities at these frequencies, shedding new light on a region intimately linked with space weather phenomena. The reconfigurability and excellent imaging properties of RAPID will enable all-sky maps of the Galactic synchrotron background emission with superior angular resolution compared to current data, while also incorporating high precision broadband spectral data spanning a decade in frequency. The RAPID system also offers the capability of studying intense nanosecond-scale pulses from cosmic ray airshowers, capturing full amplitude and phase information in response to external triggers, with user-selected aperture sampling, and with easy portability to the location of existing particle observatories. The project will introduce important innovations to the radio measurement community, and provide a technical foundation for subsequent development of larger, more powerful instruments of this type. We will bring together leading edge technologies and techniques from multiple branches of radio astronomy, the geospace radar community, and a rapidly advancing high-tech industry to create a truly portable system with unique capabilities for the detailed study of strong radio signals. The project also features extensive education and training opportunities for students and teachers through the NSF REU and RET programs, and the diverse science topics it addresses which can be communicated to the general public with a connecting theme of radio signals. The RAPID system elements are ideal as educational tools to demonstrate the principles of radio measurement at schools and colleges around the country.