First results from the REAL-time Transient Acquisition backend (REALTA) at the Irish LOFAR station

Abstract

Modern radio interferometers such as the LOw Frequency ARray (LOFAR) are capable of producing data at hundreds of gigabits to terabits per second. This high data rate makes the analysis of radio data cumbersome and computationally expensive. While high performance computing facilities exist for large national and international facilities, that may not be the case for instruments operated by a single institution or a small consortium. Data rates for next generation radio telescopes are set to eclipse those currently in operation, hence local processing of data will become all the more important. Here, we introduce the REAL-time Transient Acquisition backend (REALTA), a computing backend at the Irish LOFAR station (I-LOFAR) which facilitates the recording of data in near real-time and post-processing. We also present first searches and scientific results of a number of radio phenomena observed by I-LOFAR and REALTA, including pulsars, fast radio bursts (FRBs), rotating radio transients (RRATs), the search for extraterrestrial intelligence (SETI), Jupiter, and the Sun.

Observing Jupiter's radio emissions using multiple LOFAR stations: a first case study of the Io-decametric emission using the Irish IE613, French FR606 and German DE604 stations

“…At the DE604 and FR606 stations, raw data packets were written to disk after lossless compression (using the Zstandard algorithm). At the IE613 station, the REALTA (REAL-time Transient Acquisition, Murphy et al 2021) backend was used. Similar successes have already been achieved with these different backends and used to conduct comparative studies (see e.g., Grießmeier, J.-M. et al 2021).…”

“…We have demonstrated the predictive power of the ExPRES simulations and the probability maps (gathered on the Jupiter Radio Probability Tool), the observing capability of the LOFAR network, and the data analysis methods enabled by software support (e.g., RE-ALTA Murphy et al 2021) and domain knowledge (e.g., the search for millisecond bursts in the high resolution data stream). We now highlight several future avenues for the exploitation of this rich LO-FAR dataset.…”

Simulating Solar Radio Bursts Using Generative Adversarial Networks

“…The dynamic spectra are composed of 488 frequency channels, and this data can be recorded at a rate of several TeraByte (TB) per hour. The I-LOFAR team has recently built a high-performance computing system for the purpose of processing and recording raw beamformed data Murphy et al (2021). Due to the high volume of data, automated algorithms are required to sort and classify any phenomena of interest.…”

udpPacketManager: An International LOFAR Station Data (Pre-)Processor

“…The software has supported ongoing observations of the Sun, Pulsars and Rotating Radio Transients (McKenna et al, 2023;Murphy et al, 2021) in Ireland since early 2020, alongside multi-site work with Breakthrough Listen in the search for extraterrestrial life (SETI) in coordination with the Swedish LOFAR station at Onsala since 2021 (Johnson et al, in prep. ) and observations of Jupiter in coordination with the French LOFAR station and one of the German LOFAR stations, at Postdam, in 2022 (Louis et al, 2022).…”

“…Previous work in this regard includes the LOFAR und MPIfR Pulsare (LuMP) Software (Anderson, 2013), an open-source recorder that saves data to a PUMA2-derived data format that can be parsed using the DSPSR (van Straten & Bailes, 2011) ecosystem, and the ARTEMIS system (Serylak et al, 2012), a hardware-software package for online transient observations derived from the source-available PELICAN LOFAR backend (Mort et al, 2021). These were found not to be sufficiently flexible to account for peculiar ways of utilising the telescope hardware, such as supporting multi-mode observations (McKay-Bukowski, 2013), nor work within some constraints of the REALTA compute cluster (Murphy et al, 2021). Consequently, udpPacketManager was built to better facilitate observations with the telescope.…”