Ionospheric lensing and diffraction from a travelling ionospheric disturbance observed using LOFAR

Ben Boyde, Alan Wood, Gareth Dorrian, RA Fallows, David Themens

Research output: Contribution to conference (unpublished)Paperpeer-review

Abstract

The ionosphere is a region of plasma in the Earth’s upper atmosphere, which contains variations in plasma density with horizontal scales of up to 1000s of km. The LOw Frequency ARray (LOFAR) is a radio telescope centred in The Netherlands with stations spread across western and central Europe, intended for astronomical observations of the early universe. Signals from astronomical radio sources are disrupted by the ionosphere before they are recorded by LOFAR, and so these signals can be used to infer the presence and morphology of ionospheric structures along the line of sight. Modelling indicates that some of the ionospheric signatures in LOFAR observations are a result of small-scale travelling ionospheric disturbances (SSTIDs).

The features described here were observed from the UK LOFAR station (lat. 51.1⁰N, lon. 1.4⁰W) between 10:15 and 11:48 UT on the 15th of September 2018. These features repeated with a period of approximately ten minutes over roughly an hour. They were strongly frequency dependent, being much broader in time at lower frequencies. By modelling the ionosphere as a thin phase screen with a wave-like perturbation, representing the effect of a TID passing across the line of sight, it is possible to qualitatively replicate many of the features. This modelling suggests that the features observed here require the TID to have a short wavelength (
Original languageEnglish
Publication statusPublished - Jul 2022
EventThe National Astronomy Meeting (NAM) 2022 - University of Warwick, Warwick, United Kingdom
Duration: 11 Jul 202215 Jul 2022

Conference

ConferenceThe National Astronomy Meeting (NAM) 2022
Country/TerritoryUnited Kingdom
CityWarwick
Period11/07/2215/07/22

Fingerprint

Dive into the research topics of 'Ionospheric lensing and diffraction from a travelling ionospheric disturbance observed using LOFAR'. Together they form a unique fingerprint.

Cite this