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With their wide fields of view and often relatively long coverage of any position in the sky in imaging survey mode, modern radio telescopes provide a data stream that is naturally suited to searching for rare transients. However, Radio…

In this paper, we present a framework for assessing the effect of non-stationary Gaussian noise and radio frequency interference (RFI) on the signal to noise ratio, the number of false positives detected per true positive and the…

Instrumentation and Methods for Astrophysics · Physics 2017-04-19 E. van Heerden , A. Karastergiou , S. J. Roberts

The main challenge of 21 cm cosmology experiments is astrophysical foregrounds which are difficult to separate from the signal due to telescope systematics. An earlier study has shown that foreground residuals induced by antenna gain errors…

Raster images can have a range of various distortions connected to their raster structure. Upsampling them might in effect substantially yield the raster structure of the original image, known as aliasing. The upsampling itself may…

Computer Vision and Pattern Recognition · Computer Science 2007-05-23 Artur Rataj

Data reduction techniques published so far for the CoRoT N2 data product were targeted primarily on the detection of extrasolar planets. Since the whole dataset has been released, specific algorithms are required to process the lightcurves…

Instrumentation and Methods for Astrophysics · Physics 2015-03-20 Joerg Weingrill

The use of integral field units is now commonplace at all major observatories offering efficient means of obtaining spectral as well as imaging information at the same time. IFU instrument designs are complex and spectral images have…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Carina Lagerholm , Harald Kuntschner , Michele Cappellari , Davor Krajnovic , Richard McDermid , Marina Rejkuba

The sensitivity of radio telescopes is becoming increasingly limited by the presence of radio frequency interference (RFI), which will worsen as the radio spectrum becomes more crowded. One context where this poses a challenge is the field…

We present the intensity foreground algorithms and model employed within the BeyondPlanck analysis framework. The BeyondPlanck analysis is aimed at integrating component separation and instrumental parameter sampling within a global…

The problem of recovering a signal from its low frequency components occurs often in practical applications due to the lowpass behavior of many physical systems. Here we study in detail conditions under which a signal can be determined from…

Information Theory · Computer Science 2013-02-20 Yonina C. Eldar , Volker Pohl

We have developed a new method that uses wavelet analysis to remove interference fringe patterns from images. This method is particularly useful for flat fields in the common case where fringes vary between the calibration and object data.…

Astrophysics · Physics 2008-11-26 Patricio Rojo , Joseph Harrington

Transient radio frequency interference (RFI) is detrimental to radio astronomy. It is particularly difficult to identify the sources of transient RFI, which is broadband and intermittent. Such RFI is often generated by devices like…

Signal Processing · Electrical Eng. & Systems 2018-03-08 Daniel Czech , Amit Mishra , Michael Inggs

This paper presents an overview of methods for mitigating radio frequency interference (RFI) in radio science data. The primary purpose of mitigation is to assist observatories to take useful data outside frequency bands allocated to the…

Instrumentation and Methods for Astrophysics · Physics 2023-03-01 Willem A. Baan

Contemporary real-time RFI mitigation is carried out at different stages primarily using regulatory and technical approaches. Regulatory approaches include spectrum management, radio quiet zones, and ensuring protection from self-generated…

Instrumentation and Methods for Astrophysics · Physics 2025-01-08 Kaushal D. Buch , Ruta Kale , Kishor D. Naik , Ajithkumar B. , Thushara Gunaratne , N. Habana , Gregory Hellbourg , Jane Kaczmarek , L. Petrov , Cedric Viou , Benjamin Winkel

Partially-overlapping tones (POT) are known to help mitigate co-channel interference in uncoordinated multi-carrier networks by introducing intentional frequency offsets (FOs) to the transmitted signals. In this paper, we explore the use of…

Signal Processing · Electrical Eng. & Systems 2020-04-28 Mrugen Deshmukh , Md Moin Uddin Chowdhury , Sung Joon Maeng , Alphan Sahin , Ismail Guvenc

Active Radio Frequency Interference (RFI) mitigation becomes a necessity for radio astronomy. The solution commonly applied by the community consists in monitoring the statistics of the received signal, and flag out the detected corrupted…

Signal Processing · Electrical Eng. & Systems 2018-09-12 Gregory Hellbourg

Two iterative techniques are described for decomposing a long-slit spectrum into the individual spectra of the point sources along the slit and the spectrum of the underlying background. One technique imposes the strong constraint that the…

Astrophysics · Physics 2009-11-07 L. B. Lucy , J. R. Walsh

In addition to ever-present thermal noise, communication and sensor systems can contain significant amounts of interference with outlier (e.g. impulsive) characteristics. Such outlier interference (including that caused by nonlinear signal…

Signal Processing · Electrical Eng. & Systems 2019-07-10 Alexei V. Nikitin , Ruslan L. Davidchack

Radio frequency interference (RFI) mitigation remains a major challenge in the search for radio technosignatures. Typical mitigation strategies include a direction-of-origin (DoO) filter, where a signal is classified as RFI if it is…

Instrumentation and Methods for Astrophysics · Physics 2022-02-02 Pavlo Pinchuk , Jean-Luc Margot

Optical interferometric imaging enables astronomical observation at extremely high angular resolution. The necessary optical information for imaging, such as the optical path differences and visibilities, is easy to extract from fringes…

Ultrasound imaging often suffers from image degradation stemming from phase aberration, which represents a significant contributing factor to the overall image degradation in ultrasound imaging. Frequency-space prediction filtering or FXPF…

Image and Video Processing · Electrical Eng. & Systems 2023-08-24 Mostafa Sharifzadeh , Habib Benali , Hassan Rivaz