In the last few years, Input/Output (I/O) bandwidth limitation of legacy computer architectures forced us to reconsider where and how to store and compute data across a large range of applications. This shift has been made possible with the concurrent development of both smartNICs and programmable switches with a common programming language (P4), and the advent of attached High Bandwidth Memory within smartNICs/FPGAs. Recently, proposals to use this kind of technology have emerged to tackle computer science related issues such as fast consensus algorithm in the network, network accelerated key-value stores, machine learning, or data-center data aggregation. In this paper, we introduce a novel architecture that leverages these advancements to potentially accelerate and improve the processing of radio-astronomy Digital Signal Processing (DSP), such as correlators or beamformers, at unprecedented continuous rates in what we have called the "Atomic COTS" design. We give an overview of this new type of architecture to accelerate digital signal processing, leveraging programmable switches and HBM capable FPGAs. We also discuss how to handle radio astronomy data streams to pre-process this stream of data for astronomy science products such as pulsar timing and search. Finally, we illustrate, using a proof of concept, how we can process emulated data from the Square Kilometer Array (SKA) project to time pulsars.

The Boolardy Engineering Test Array (BETA) is the first prototype of the Australian Square Kilometer Array Pathfinder (ASKAP), a new radio telescope that is pioneering the use of Phased Array Feed (PAF) technology in radio astronomy to provide instantaneous wide field-of-view imaging. BETA consists of six 12 meter parabolic antennas, each equipped with a 188-element PAF at the focus and a signal processing system capable of imaging an instantaneous 7 square degree field-of-view with a bandwidth of 300MHz at a resolution of 18kHz. In this paper we describe the architecture of the digital signal processing chain and its implementation on reconfigurable hardware based on Field-Programmable Gate Array (FPGA) technology. We present early engineering results taken by the instrument during commissioning trials at the Murchison Radio Observatory (MRO) in remote Western Australia. In particular, we present the first multi-beam image of an astronomical source captured with a PAF-based interferometer.

The Australia SKA Pathfinder (ASKAP) is a new telescope under development as a world-class high-dynamic-range wide-field-of-view survey instrument. It will utilize focal plane phased array feeds on the 36 12-m antennas that will compose the array. The large amounts of data present a huge computing challenge, and ASKAP will store data products in an archive after near real-time pipeline processing. This powerful instrument will be deployed at a new radio-quiet observatory, the Murchison Radio-astronomy Observatory in the midwest region of Western Australia, to enable sensitive surveys of the entire sky to address some of the big questions in contemporary physics. As a pathfinder for the SKA, ASKAP will demonstrate field of view enhancement and computing/processing technology as well as the operation of a large-scale radio array in a remote and radio-quiet region of Australia.

Corruption of C-band microwave brightness observations by radio-frequency interference (RFI) has been reported in recent data from orbiting radiometers; methods for mitigating these effects are of great importance for the design of future spaceborne microwave radiometers. One approach that has been suggested involves the use of multiple subchannels at C-band as opposed to a single channel; the use of multiple subchannels allows RFI to be detected and mitigated by analyzing relationships among subchannel brightnesses. While this approach has been utilized in previous airborne measurements, demonstrations of the RFI mitigation performance achieved have been difficult to obtain. To address this issue, an enhanced airborne system for observing radio-frequency interference effects on C-band microwave radiometers was developed, and is described in this paper. The system includes a traditional microwave radiometer with four C-band subchannels, so that RFI removal is possible using a subchannel mitigation algorithm. In addition, the system includes a digital receiver with the capability of providing high temporal and spectral resolution observations of interference. This high-resolution data allows improved understanding of RFI sources to be obtained, and also allows analysis of subchannel mitigation algorithm performance. Observations using the system in a test flight near Wallops Island, VA are described. Results show the four subchannel approach generally to be effective in mitigating the observed RFI sources, although examples are also illustrated using the digital receiver data to demonstrate failure of this approach. While studies of the digital receiver data alone could be performed to demonstrate further improvements in RFI mitigation, issues with this initial dataset limit the extent of such studies. Nevertheless, the results obtained still demonstrate qualitatively the improved RFI mitigation that can be achieved in brightness observations through the use of digital receivers

An airborne system for observing radio frequency interference at C-band is described. The digital receiver included has the capability of providing high temporal and spectral resolution of interference, as well as implementing simple mitigation strategies. Plans for observations with the system are discussed.

Microwave radiometers operating outside protected portions of the frequency spectrum can be adversely impacted by radio frequency interference. In this paper, we describe a new radiometer which coherently samples 100 MHz of spectrum and applies real-time RFI mitigation techniques using FPGAs. Experiments currently in progress to demonstrate the system are also detailed

Abstract — We describe measurements of radio frequency interference (RFI) in the 1200–1800 MHz band as observed from NASA’s P-3 research aircraft during a flight along the Mid-Atlantic coast of the U.S. at altitudes of 2,000 and 20,000 ft. Both power spectra and coherently-sampled waveform data were obtained. Our results indicate that the spectrum below 1400 MHz is typically dominated by pulses from ground based radars, which, while very strong, individually have transmit duty cycles of on the order of 0.1%. We detect but are unable to identify some relatively weak intermittent RFI inside the 20 MHz protected band centered at 1413 MHz. We detect no significant RFI above 1420 MHz, but the limited sensitivity of this particular experiment makes it impossible to rule out the presense of RFI at levels damaging to total power radiometry. Implications for radiometer design, including possible active countermeasures for RFI mitigation, are discussed. I.

Abstract — For increased sensitivity in L-band radiometry, bandwidths on the order of 100 MHz are desirable. This will likely require active countermeasures to mitigate RFI. In this paper, we describe a new radiometer which coherently samples 100 MHz of spectrum and applies real-time RFI mitigation techniques using FPGAs. A field test of an interim version of this design in a radio astronomy observation corrupted by radar pulses is described. I.