Real-time Tbps digital correlator in NTU-array (original) (raw)
Related papers
The Murchison Widefield Array Correlator
Publications of the Astronomical Society of Australia, 2015
The Murchison Widefield Array (MWA) is a Square Kilometre Array (SKA) Precursor. The telescope is located at the Murchison Radio-astronomy Observatory (MRO) in Western Australia (WA). The MWA consists of 4096 dipoles arranged into 128 dual polarisation aperture arrays forming a connected element interferometer that cross-correlates signals from all 256 inputs. A hybrid approach to the correlation task is employed, with some processing stages being performed by bespoke hardware, based on Field Programmable Gate Arrays (FPGAs), and others by Graphics Processing Units (GPUs) housed in general purpose rack mounted servers. The correlation capability required is approximately 8 TFLOPS (Tera FLoating point Operations Per Second). The MWA has commenced operations and the correlator is generating 8.3 TB/day of correlation products, that are subsequently transferred 700 km from the MRO to Perth (WA) in real-time for storage and offline processing. In this paper we outline the correlator design, signal path, and processing elements and present the data format for the internal and external interfaces.
Publications of the Astronomical Society of the Pacific, 2008
A new generation of radio telescopes is achieving unprecedented levels of sensitivity and resolution, as well as increased agility and field-of-view, by employing highperformance digital signal processing hardware to phase and correlate large numbers of antennas. The computational demands of these imaging systems scale in proportion to BM N 2 , where B is the signal bandwidth, M is the number of independent beams, and N is the number of antennas. The specifications of many new arrays lead to demands in excess of tens of PetaOps per second.
Hardware Correlator Development at SHAO
2018 Progress in Electromagnetics Research Symposium (PIERS-Toyama), 2018
Very Long Baseline Interferometry (VLBI) is an important radio astronomy technology, it has high spatial resolution, is widely used in deep space probes high precision measurements. Correlator is the VLBI core data pre-processing equipment, is a complex high speed signal processing system. In recent years, with the development of the Field Programmable Gate Array (FPGA) technology, a lot of high performance digital signal processing platforms based on FPGA chip have appear. In Shanghai astronomical observatory, we have designed a series of hardware correlators based on FPGA and used in Chinese lunar project Chang'E 1, Chang'E 2, Chang'E 3 and Chang'E 5T1 mission. In the following lunar project and further Mars project in China, multiple orbits spacecraft tracking will be widely used, the tracking will be more complex. But because of the limitation of the hardware platform, the real time processing speed and precision is limited, can not meet the requirements of the f...
High-speed Data Playback of the VLBI Hardware Correlator
2016
VLBI (Very Long Baseline Interferometry) is an important radio astronomy technique and is widely used in deep-space probes and high-precision measurements. The performance of the correlator, as the core data pre-processing equipment of VLBI, is very important. At present, the Chinese VLBI data acquisition system (CDAS) can collect 2 Gbps of data, and a multiband combination can reach 16/32 Gbps. To ensure that the requirements of high speed and high precision are met, Uniboard was used as the hardware platform, 10 G Ethernet was used as the data playback interface, and 1 G Ethernet was used as the control interface. Also research was done into the VLBI data playback, which reaches speeds up to 4 Gbps for a single CDAS, and a pre-processing method that provides data correction and data decoding specific to the VLBI data characteristics has been designed. Now we have finished the preliminary system, and here we will show the design and some results.
Arxiv preprint astro-ph/0702141, 2007
We describe the development of an FX style correlator for Very Long Baseline Interferometry (VLBI), implemented in software and intended to run in multi-processor computing environments, such as large clusters of commodity machines (Beowulf clusters) or computers specifically designed for high performance computing, such as multi-processor shared-memory machines. We outline the scientific and practical benefits for VLBI correlation, these chiefly being due to the inherent flexibility of software and the fact that the highly parallel and scalable nature of the correlation task is well suited to a multi-processor computing environment. We suggest scientific applications where such an approach to VLBI correlation is most suited and will give the best returns. We report detailed results from the Distributed FX (DiFX) software correlator, running on the Swinburne supercomputer (a Beowulf cluster of ∼300 commodity processors), including measures of the performance of the system. For example, to correlate all Stokes products for a 10 antenna array, with an aggregate bandwidth of 64 MHz per station and using typical time and frequency resolution presently requires of order 100 desktop-class compute nodes. Due to the effect of Moore's Law on commodity computing performance, the total number and cost of compute nodes required to meet a given correlation task continues to decrease rapidly with time. We show detailed comparisons between DiFX and two existing hardware-based correlators: the Australian Long Baseline Array (LBA) S2 correlator, and the NRAO Very Long Baseline Array (VLBA) correlator. In both cases, excellent agreement was found between the correlators. Finally, we describe plans for the future operation of DiFX on the Swinburne supercomputer, for both astrophysical and geodetic science.
Using many-core hardware to correlate radio astronomy signals
Proceedings of the 23rd international conference on Conference on Supercomputing - ICS '09, 2009
A recent development in radio astronomy is to replace traditional dishes with many small antennas. The signals are combined to form one large, virtual telescope. The enormous data streams are crosscorrelated to filter out noise. This is especially challenging, since the computational demands grow quadratically with the number of data streams. Moreover, the correlator is not only computationally intensive, but also very I/O intensive. The LOFAR telescope, for instance, will produce over 100 terabytes per day. The future SKA telescope will even require in the order of exaflops, and petabits/s of I/O. A recent trend is to correlate in software instead of dedicated hardware. This is done to increase flexibility and to reduce development efforts. Examples include e-VLBI and LOFAR.
A wideband analog correlator system for AMiBA
Millimeter and Submillimeter Detectors for Astronomy II, 2004
A wideband correlator system with a bandwidth of 16 GHz or more is required for Array for Microwave Background Anisotropy (AMiBA) to achieve the sensitivity of 10μK in one hour of observation. Double-balanced diode mixers were used as multipliers in 4-lag correlator modules. Several wideband modules were developed for IF signal distribution between receivers and correlators. Correlator outputs were amplified, and digitized by voltage-to-frequency converters. Data acquisition circuits were designed using field programmable gate arrays (FPGA). Subsequent data transfer and control software were based on the configuration for Australia Telescope Compact Array. Transform matrix method will be adopted during calibration to take into account the phase and amplitude variations of analog devices across the passband.
Broadband digital correlator design using vertex-2 FPGAs
2004 Asia-Pacific Radio Science Conference, 2004. Proceedings., 2004
This paper presents a design of a 2-bit, 4-level digital conelator iinpleinented with Xilins Vertex-2 FPGAs. A technique of serial-to-parallel conversion of the input streams is adopted to reduce the speed requirement of the colrelation circuits. The correlator can be used for autoand cross-correlation. and fully cascadable to form more lags with more FPGA chips. It can run at a clock of 250
Correlating Radio Astronomy Signals with Many-Core Hardware
International Journal of Parallel Programming, 2010
A recent development in radio astronomy is to replace traditional dishes with many small antennas. The signals are combined to form one large, virtual telescope. The enormous data streams are cross-correlated to filter out noise. This is especially challenging, since the computational demands grow quadratically with the number of data streams. Moreover, the correlator is not only computationally intensive, but also very I/O intensive. The LOFAR telescope, for instance, will produce over 100 terabytes per day. The future SKA telescope will even require in the order of exaflops, and petabits/s of I/O. A recent trend is to correlate in software instead of dedicated hardware, to increase flexibility and to reduce development efforts.