Space-based aperture array for ultra-long wavelength radio astronomy

Space-based aperture array for ultra-long wavelength radio astronomy

Rajan, R.T.
Boonstra, A.J.
Bentum, M.
Klein-Wolt, M.
Belien, F.
Arts, M.
Saks, N.
Van der Veen, A.J.

Electrical Engineering, Mathematics and Computer Science

Microelectronics

2015-12-15

The past decade has seen the advent of various radio astronomy arrays, particularly for low-frequency observations below 100 MHz. These developments have been primarily driven by interesting and fundamental scientific questions, such as studying the dark ages and epoch of re-ionization, by detecting the highly red-shifted 21 cm line emission. However, Earth-based radio astronomy observations at frequencies below 30 MHz are severely restricted due to man-made interference, ionospheric distortion and almost complete non-transparency of the ionosphere below 10 MHz. Therefore, this narrow spectral band remains possibly the last unexplored frequency range in radio astronomy. A straightforward solution to study the universe at these frequencies is to deploy a space-based antenna array far away from Earths’ ionosphere. In the past, such space-based radio astronomy studies were principally limited by technology and computing resources, however current processing and communication trends indicate otherwise. Furthermore, successful space-based missions which mapped the sky in this frequency regime, such as the lunar orbiter RAE-2, were restricted by very poor spatial resolution. Recently concluded studies, such as DARIS (Disturbuted Aperture Array for Radio Astronomy In Space) have shown the ready feasibility of a 9 satellite constellation using off the shelf components. The aim of this article is to discuss the current trends and technologies towards the feasibility of a space-based aperture array for astronomical observations in the Ultra-Long Wavelength (ULW) regime of greater than 10 m i.e., below 30 MHz. We briefly present the achievable science cases, and discuss the system design for selected scenarios such as extra-galactic surveys. An extensive discussion is presented on various sub-systems of the potential satellite array, such as radio astronomical antenna design, the on-board signal processing, communication architectures and joint space-time estimation of the satellite network. In light of a scalable array and to avert single point of failure, we propose both centralized and distributed solutions for the ULW space-based array. We highlight the benefits of various deployment locations and summarize the technological challenges for future space-based radio arrays.

radio astronomy
ultra-long wavelength
interferometry
feasibility study
system design

http://resolver.tudelft.nl/uuid:9e6a58de-eacd-4b8d-b56a-c3778112f97e

Springer

1572-9508

https://doi.org/10.1007/s10686-015-9486-6

Experimental Astronomy, 41 (1), 2016

Institutional Repository

journal article

© 2015 The Author(s)
This article is published with open access at Springerlink.com