Title
A roadmap towards a space-based radio telescope for ultra-low frequency radio astronomy
Author
Bentum, M. J. (Eindhoven University of Technology; Netherlands Institute for Radio Astronomy (ASTRON))
Verma, M. K. (Student TU Delft)
Rajan, R.T. (TU Delft Signal Processing Systems) 
Boonstra, A. J. (Netherlands Institute for Radio Astronomy (ASTRON))
Verhoeven, C.J.M. (TU Delft Electronics)
Gill, E.K.A. (TU Delft Space Engineering)
van der Veen, A.J. (TU Delft Signal Processing Systems)
Falcke, H. (Netherlands Institute for Radio Astronomy (ASTRON); Radboud Universiteit Nijmegen)
Gurvits, L. (TU Delft Astrodynamics & Space Missions; Joint Institute for VLBI ERIC)
Department
Space Engineering
Date
2020
Abstract
The past two decades have witnessed a renewed interest in low frequency radio astronomy, with a particular focus on frequencies above 30 MHz e.g., LOFAR (LOw Frequency ARray) in the Netherlands and its European extension ILT, the International LOFAR Telescope. However, at frequencies below 30 MHz, Earth-based observations are limited due to a combination of severe ionospheric distortions, almost full reflection of radio waves below 10 MHz, solar eruptions and the radio frequency interference (RFI) of human-made signals. Moreover, there are interesting scientific processes which naturally occur at these low frequencies. A space or Lunar-based ultra-low-frequency (also referred to as ultra-long-wavelength, ULW) radio array would suffer significantly less from these limitations and hence would open up the last, virtually unexplored frequency domain in the electromagnetic spectrum. A roadmap has been initiated by astronomers and researchers in the Netherlands to explore the opportunity of building a swarm of satellites to observe at the frequency band below 30 MHz. This roadmap dubbed Orbiting Low Frequency Antennas for Radio Astronomy (OLFAR), a space-based ultra-low frequency radio telescope that will explore the Universe's so-called dark ages, map the interstellar medium, and study planetary and solar bursts in the solar system and search them in other planetary systems. Such a radio astronomy system will comprise of a swarm of hundreds to thousands of satellites, working together as a single aperture synthesis instrument deployed sufficiently far away from Earth to avoid terrestrial RFI. The OLFAR telescope is a novel and complex system, requiring yet to be proven engineering solutions. Therefore, a number of key technologies are still required to be developed and proven. The first step in this roadmap is the NCLE (Netherlands China Low Frequency Explorer) experiment, which was launched in May 2018 on the Chinese Chang'e 4 mission. The NCLE payload consists of a three monopole antenna system for low frequency observations, from which the first data stream is expected in the second half of 2019, which will provide important feedback for future science and technology opportunities. In this paper, the roadmap towards OLFAR, a brief overview of the science opportunities, and the technological and programmatic challenges of the mission are presented.
Subject
Nanosatellite
OLFAR
Satellite swarms
Ultra-long wavelength astronomy
Ultra-low frequency radio astronomy
To reference this document use:
http://resolver.tudelft.nl/uuid:2d6d772d-7767-45a8-b229-a137e038db20
DOI
https://doi.org/10.1016/j.asr.2019.09.007
Embargo date
2021-10-01
ISSN
0273-1177
Source
Advances in Space Research, 65 (2), 856-867
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Part of collection
Institutional Repository
Document type
journal article
Rights
© 2020 M. J. Bentum, M. K. Verma, R.T. Rajan, A. J. Boonstra, C.J.M. Verhoeven, E.K.A. Gill, A.J. van der Veen, H. Falcke, L. Gurvits, More Authors