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 (
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 language | English |
---|---|
Publication status | Published - Jul 2022 |
Event | The National Astronomy Meeting (NAM) 2022 - University of Warwick, Warwick, United Kingdom Duration: 11 Jul 2022 → 15 Jul 2022 |
Conference
Conference | The National Astronomy Meeting (NAM) 2022 |
---|---|
Country/Territory | United Kingdom |
City | Warwick |
Period | 11/07/22 → 15/07/22 |