Power line RF interference-sounds, patterns, and myths

Loftness, Marvin O.

doi:10.1109/61.584416

Cited by 9 publications

(5 citation statements)

References 1 publication

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“…The broadband nature of the emission suggests that whatever is producing the emission is a reflection of either natural or unintentional human‐made radio emissions, or combination of both. The two most likely sources include lightning (Proctor, 1981) or the burst‐like noise caused by arcing power‐lines and connected hardware such as transformers (Loftness, 1997; Pakala & Chartier, 1971). Both of these sources are well known to be bright and broadband.…”

Section: Discussionmentioning

confidence: 99%

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Using Broadband Radio Noise From Power‐Lines to Map and Track Dense E_s Structures

et al. 2021

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We present passive observations of midlatitude sporadic E (Es) structures in the 30–50 MHz range using the long wavelength array telescopes in New Mexico. Spectral and temporal analysis of the structures reveals that some of the emissions can be characterized by broadband, spark‐like radiation occurring at a repetition frequency of 60 Hz. The azimuthal distribution indicates that the brightest emissions come from the directions of several large metropolitan centers with distances ranging from 700 to 1,250 km from the telescopes. This implies that the source is unintended human‐made noise, originating from devices connected to 60 Hz alternating current power. The geometry of our observations rule out coherent scatter from field‐aligned irregularities, and indicate that the unintended noise must undergo a specular reflection off of over‐dense plasma distributed approximately parallel to Earth's surface. On certain occasions the reflections are seen at such high frequencies and high elevation angles that the local plasma frequency must be above 30 MHz. During both day and night Es conditions, the dense structures are observed to be arranged in propagating fronts, and travel at speeds of 70–100 m/s. We also present observations that reveal quasi‐periodic amplitude oscillations with frequencies consistent with atmospheric gravity waves and acoustic waves.

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Section: Discussionmentioning

confidence: 99%

“…However, on the five second time scales of LASI images, unintentional human‐made noise coming from power‐lines would appear to vary slowly. Power‐line noise is composed of many sources of broadband bursts repeating at 60 Hz, but the brightness averaged over 5 s changes little (Loftness, 1997; Pakala & Chartier, 1971).…”

Section: Discussionmentioning

confidence: 99%

Using Broadband Radio Noise From Power‐Lines to Map and Track Dense E_s Structures

et al. 2021

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“…As is seen in this plot, the strength of the RFI changes across uGMRT bands. The amplitude and distribution of impulsive events may vary between the bunches (Swarup, 2008;Loftness, 1997). The periodicity is typically 10ms or 20ms (due to 50 Hz powerline frequency) or less depending on the fault on the powerline (Swarup, 2008).…”

Section: Broadband Rfi At Gmrt and Real-time Rfi Filtering Systemmentioning

confidence: 99%

Performance Analysis Techniques for Real-Time Broadband RFI Filtering System of uGMRT

Buch

Kale

Naik

et al. 2022

J. Astron. Instrum.

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Electromagnetic radiation from human activities, known as man-made Radio Frequency Interference (RFI), adversely affects radio astronomy observations. In the vicinity of the Upgraded Giant Metrewave Radio Telescope (uGMRT) array, the sparking on power lines is the major cause of interference at observing frequencies less than 800[Formula: see text]MHz. A real-time broadband RFI detection and filtering system is implemented as part of the uGMRT wideband signal processing backend to mitigate the effect of broadband RFI. Performance analysis techniques used for testing and commissioning the system for observations in the beamformer and correlator modes of the uGMRT are presented. The concept and implementation of recording simultaneous unfiltered and filtered data along with data analysis and interpretation is illustrated using an example. For the beamformer mode, spectrogram, single spectral channel, and its Fourier transform is used for performance analysis whereas, in the correlator mode, the cross-correlation function, closure phase, and visibilities from the simultaneously recorded unfiltered and filtered is carried out. These techniques are used for testing the performance of the broadband RFI filter and releasing it for uGMRT users.

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“…It has long been observed that corona discharge pulses and micro-gap discharges occurring on high-voltage power transmission and distribution lines could disrupt radio and television reception [2,3,4]. This noise was frequently the result of a defect in the system, which, unchecked, sooner or later could result in an outage.…”

Section: Introductionmentioning

confidence: 98%

A novel approach to high voltage substation surveillance using radio frequency interference measurement

Nesbitt

Stewart

McMeekin

et al. 2009

2009 IEEE Electrical Insulation Conference

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The deployment of radio frequency interference (RFI) measurement has gained increasing acceptance as a front line, non-invasive technique to assess the condition of individual high-voltage (HV) electrical equipment items as part of a substation surveillance program. However, successful detection and discrimination of low-repetition rate discharges that typically accompany electrical deterioration is constrained by the capabilities and limitations of the field spectrum/RFI analysers used and the electro-magnetic interference (EMI) measurement techniques supported. This paper presents a novel approach to RFI measurement and assessment that is more sensitive to the RFI emissions that typically accompany electrical deterioration and provides more effective discrimination of the discharge phenomena from the ambient frequency spectrum and noise. Case studies from substation surveillance are presented to demonstrate the effectiveness of the approach. The technique is effective with a wide range of HV equipment and is less reliant on expert knowledge for a practicing engineer to confidently characterise and trace electrical deterioration with a high degree of confidence.

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Power line RF interference-sounds, patterns, and myths

Cited by 9 publications

References 1 publication

Using Broadband Radio Noise From Power‐Lines to Map and Track Dense E_s Structures

Using Broadband Radio Noise From Power‐Lines to Map and Track Dense E_s Structures

Performance Analysis Techniques for Real-Time Broadband RFI Filtering System of uGMRT

A novel approach to high voltage substation surveillance using radio frequency interference measurement

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Power line RF interference-sounds, patterns, and myths

Cited by 9 publications

References 1 publication

Using Broadband Radio Noise From Power‐Lines to Map and Track Dense Es Structures

Using Broadband Radio Noise From Power‐Lines to Map and Track Dense Es Structures

Performance Analysis Techniques for Real-Time Broadband RFI Filtering System of uGMRT

A novel approach to high voltage substation surveillance using radio frequency interference measurement

Contact Info

Product

Resources

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Using Broadband Radio Noise From Power‐Lines to Map and Track Dense E_s Structures

Using Broadband Radio Noise From Power‐Lines to Map and Track Dense E_s Structures