Radio frequency self-interference from a data processing centre at a radio telescope site

2009 ◽  
Vol 27 (3) ◽  
pp. 121-130 ◽  
Author(s):  
Roberto Ambrosini ◽  
Pietro Bolli ◽  
Claudio Bortolotti ◽  
Francesco Gaudiomonte ◽  
Filippo Messina ◽  
...  
Keyword(s):  
Data Processing ◽  
Radio Frequency ◽  
Radio Telescope ◽  
Processing Centre

scholarly journals Radio Frequency Interference Mitigation and Statistics in the Spectral Observations of FAST

2021 ◽  
Author(s):  
Chuan-Peng Zhang ◽  
Jin-Long Xu ◽  
Jie Wang ◽  
Yingjie Jing ◽  
Ziming Liu ◽  
...  
Keyword(s):  
Data Processing ◽  
Radio Frequency ◽  
Radio Telescope ◽  
Radio Astronomy ◽  
Interference Mitigation ◽  
Statistical Data ◽  
Radio Frequency Interference ◽  
Test Results ◽  
Baseline Fitting ◽  
Statistical Results

Abstract In radio astronomy, radio frequency interference (RFI) becomes more and more serious for radio observational facilities. The RFI always influences the search and study of the interesting astronomical objects. Mitigating the RFI becomes an essential procedure in any survey data processing. Five-hundred-meter Aperture Spherical radio Telescope (FAST) is an extremely sensitive radio telescope. It is necessary to find out an effective and precise RFI mitigation method for FAST data processing. In this work, we introduce a method to mitigate the RFI in FAST spectral observation and make a statistics for the RFI using ∼300 hours FAST data. The details are as follows. Firstly, according to the characteristics of FAST spectra, we propose to use the ArPLS algorithm for baseline fitting. Our test results show that it has a good performance. Secondly, we flag the RFI with four strategies, which are to flag extremely strong RFI, flag long-lasting RFI, flag polarized RFI, and flag beam-combined RFI, respectively. The test results show that all the RFI above a preset threshold could be flagged. Thirdly, we make a statistics for the probabilities of polarized XX and YY RFI in FAST observations. The statistical results could tell us which frequencies are relatively quiescent. With such statistical data, we are able to avoid using such frequencies in our spectral observations. Finally, based on the ∼300 hours FAST data, we got an RFI table, which is the most complete database currently for FAST.

scholarly journals Inverse Source Data-Processing Strategies for Radio-Frequency Localization in Indoor Environments

Sensors ◽  
2017 ◽  
Vol 17 (11) ◽  
pp. 2469 ◽  
Author(s):  
Gianluca Gennarelli ◽  
Obada Al Khatib ◽  
Francesco Soldovieri
Keyword(s):  
Data Processing ◽  
Radio Frequency ◽  
Indoor Environments ◽  
Processing Strategies ◽  
Source Data

Use of RFID in Supply Chain Data Processing

2008 ◽  
pp. 1184-1191
Author(s):  
Jan Owens ◽  
Suresh Chalasani ◽  
Jayavel Sounderpandian
Keyword(s):  
Supply Chain ◽  
Data Processing ◽  
Radio Frequency ◽  
Supply Chains ◽  
Radio Frequency Identification ◽  
Department Of Defense ◽  
Frequency Identification ◽  
Processing And Storage ◽  
And Storage ◽  
Existing Data

The use of Radio Frequency Identification (RFID) is becoming prevalent in supply chains, with large corporations such as Wal-Mart, Tesco, and the Department of Defense phasing in RFID requirements on their suppliers. The implementation of RFID can necessitate changes in the existing data models and will add to the demand for processing and storage capacities. This article discusses the implications of the RFID technology on data processing in supply chains.

scholarly journals Stochastic calibration of radio interferometers

2020 ◽  
Vol 493 (4) ◽  
pp. 6071-6078 ◽  
Author(s):  
Sarod Yatawatta
Keyword(s):  
Data Processing ◽  
Radio Frequency ◽  
Computational Cost ◽  
Spatial Localization ◽  
Radio Frequency Interference ◽  
Radio Telescopes ◽  
Data Rates ◽  
Data Volume ◽  
Radio Transients ◽  
Processing Steps

ABSTRACT With ever-increasing data rates produced by modern radio telescopes like LOFAR and future telescopes like the SKA, many data-processing steps are overwhelmed by the amount of data that needs to be handled using limited compute resources. Calibration is one such operation that dominates the overall data processing computational cost; none the less, it is an essential operation to reach many science goals. Calibration algorithms do exist that scale well with the number of stations of an array and the number of directions being calibrated. However, the remaining bottleneck is the raw data volume, which scales with the number of baselines, and which is proportional to the square of the number of stations. We propose a ‘stochastic’ calibration strategy where we read only in a mini-batch of data for obtaining calibration solutions, as opposed to reading the full batch of data being calibrated. None the less, we obtain solutions that are valid for the full batch of data. Normally, data need to be averaged before calibration is performed to accommodate the data in size-limited compute memory. Stochastic calibration overcomes the need for data averaging before any calibration can be performed, and offers many advantages, including: enabling the mitigation of faint radio frequency interference; better removal of strong celestial sources from the data; and better detection and spatial localization of fast radio transients.

scholarly journals A Simple Method to Analyze Radio Frequency Outbursts of Quasars

1996 ◽  
Vol 175 ◽  
pp. 101-102
Author(s):  
H. Teräsranta ◽  
E. Valtaoja ◽  
M. Lainela
Keyword(s):  
Fine Structure ◽  
Radio Frequency ◽  
Radio Telescope ◽  
Simple Method

Quasars have been monitored with the Metsähovi Radio Telescope since 1980 at 22 GHz and 37 GHz. During these years we have recorded numerous outbursts in our sample. Some of the outbursts are simple in nature, while others also seem to have fine structure. Can the outbursts be modelled in a simple way?

Use of RFID in Supply Chain Data Processing

2011 ◽  
pp. 1160-1165 ◽  
Author(s):  
Jan Owens ◽  
Suresh Chalasani ◽  
Jayavel Sounderpandian
Keyword(s):  
Supply Chain ◽  
Data Processing ◽  
Radio Frequency ◽  
Supply Chains ◽  
Radio Frequency Identification ◽  
Department Of Defense ◽  
Frequency Identification ◽  
Processing And Storage ◽  
And Storage ◽  
Existing Data

The use of Radio Frequency Identification (RFID) is becoming prevalent in supply chains, with large corporations such as Wal-Mart, Tesco, and the Department of Defense phasing in RFID requirements on their suppliers. The implementation of RFID can necessitate changes in the existing data models and will add to the demand for processing and storage capacities. This article discusses the implications of the RFID technology on data processing in supply chains.

scholarly journals Low radio frequency spectrum of Sgr-A*

2016 ◽  
Vol 11 (S322) ◽  
pp. 54-55
Author(s):  
Subhashis Roy
Keyword(s):  
Radio Frequency ◽  
Flux Density ◽  
Frequency Spectrum ◽  
Spectral Index ◽  
Radio Telescope ◽  
Major Axis ◽  
Galactic Centre ◽  
Preliminary Results ◽  
Radio Frequency Spectrum ◽  
Sgr A

AbstractWe observed the Galactic centre (GC) region with the partially upgraded Giant Metrewave Radio Telescope (GMRT) using a wideband system in frequency ranges of 300– 500 MHz with 16 antennas. Preliminary results are presented here. Sgr-A* is clearly detected down to 450 MHz. Sgr-A West slowly disappears at lower frequencies across the band. By taking cross-cuts across the known major-axis of Sgr-A*, we measure its total flux density across the band to be 0.4 Jy consistent with what is expected from earlier results. It clearly indicates lack of absorption from Sgr-A West. Its spectral index is consistent with its higher frequency value of +0.3.

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