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3D-localization of gamma sources has the potential to improve the outcome of radio-guided surgery. The goal of this paper is to analyze the localization accuracy for point-like sources with a single coded aperture camera. We both simulated…

Medical Physics · Physics 2024-06-24 Tobias Meißner , Laura Antonia Cerbone , Paolo Russo , Werner Nahm , Jürgen Hesser

We present a robust and fast algorithm for performing astrometry and source cross-identification on two dimensional point lists, such as between a catalogue and an astronomical image, or between two images. The method is based on minimal…

Astrophysics · Physics 2009-11-11 Andras Pal , Gaspar Bakos

In sequel to Moradi et al. [2009, ApJ, 690, L72], we employ two established numerical forward models (a 3D ideal MHD solver and MHD ray theory) in conjunction with time-distance helioseismology to probe the lateral extent of wave-speed…

Solar and Stellar Astrophysics · Physics 2011-01-04 H. Moradi , S. M. Hanasoge

Images taken with modern detectors require calibration via flat fielding to obtain the same flux scale across the whole image. One method for obtaining the best possible flat fielding accuracy is to derive a photometric model from dithered…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Lodovico Coccato , Daniel M. Bramich , Wolfram Freudling , Sabine Moehler

In this paper we present follow-up optical observations of Ultra Steep Spectrum sources that were found by matching 150 MHz GMRT sources with either the 74 MHz VLSS or the 1400 MHz NVSS. These sources are possibly high-redshift radio…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-12 Samuel J. George , Ian R. Stevens

Flight height is a fundamental parameter for correcting the gamma signal produced by terrestrial radionuclides measured during airborne surveys. The frontiers of radiometric measurements with UAV require light and accurate altimeters flying…

Astronomical imaging using aperture synthesis telescopes requires deconvolution of the point spread function as well as calibration of instrumental and atmospheric effects. In general, such effects are time-variable and vary across the…

Astrophysics · Physics 2009-11-13 S. Bhatnagar , T. J. Cornwell , K. Golap , Juan M. Uson

The Hard X-ray Modulation Telescope (HXMT) will perform an all-sky survey in hard X-ray band as well as deep imaging of a series of small sky regions. We expect various compact objects to be detected in these imaging observations. Point…

Instrumentation and Methods for Astrophysics · Physics 2015-11-11 Zhuoxi Huo , Yiming Li , Xiaobo Li , Jianfeng Zhou

A novel algorithm for uncalibrated stereo image-pair rectification under the constraint of geometric distortion, called USR-CGD, is presented in this work. Although it is straightforward to define a rectifying transformation (or homography)…

Computer Vision and Pattern Recognition · Computer Science 2020-04-20 Hyunsuk Ko , Han Suk Shim , Ouk Choi , C. -C. Jay Kuo

Object cross-identification in multiple observations is often complicated by the uncertainties in their astrometric calibration. Due to the lack of standard reference objects, an image with a small field of view can have significantly…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Tamas Budavari , Stephen H. Lubow

All 543 pointed observations of the ROSAT High Resolution Imager (HRI) with exposure times higher than 50 sec in a field of 10 deg x 10 deg covering the Large Magellanic Cloud (LMC) were analyzed. A catalogue was produced containing 397…

Astrophysics · Physics 2009-10-31 Manami Sasaki , Frank Haberl , Wolfgang Pietsch

A Faraday rotation measure (RM) catalogue, or RM Grid, is a valuable resource for the study of cosmic magnetism. Using the second data release (DR2) from the LOFAR Two-metre Sky Survey (LoTSS), we have produced a catalogue of 2461…

The Siberian Solar Radio Telescope (SSRT) is a solar-dedicated directly-imaging interferometer observing the Sun at 5.7 GHz. The SSRT operates in the two-dimensional mode since 1996. The imaging principle of the SSRT restricts its…

Solar and Stellar Astrophysics · Physics 2014-10-20 Alexey Kochanov , Sergey Anfinogentov , Dmitry Prosovetsky , George Rudenko , Victor Grechnev

Tree height estimation serves as an important proxy for biomass estimation in ecological and forestry applications. While traditional methods such as photogrammetry and Light Detection and Ranging (LiDAR) offer accurate height measurements,…

Computer Vision and Pattern Recognition · Computer Science 2024-12-04 Grace Colverd , Jumpei Takami , Laura Schade , Karol Bot , Joseph A. Gallego-Mejia

Images of near-field SAR contains spatial-variant sidelobes and clutter, subduing the image quality. Current image restoration methods are only suitable for small observation angle, due to their assumption of 2D spatial-invariant…

Signal Processing · Electrical Eng. & Systems 2022-10-06 Wensi Zhang , Xiaoling Zhang , Xu Zhan , Yuetonghui Xu , Jun Shi , Shunjun Wei

Image correction aims to adjust an input image into a visually pleasing one. Existing approaches are proposed mainly from the perspective of image pixel manipulation. They are not effective to recover the details in the under/over exposed…

Computer Vision and Pattern Recognition · Computer Science 2018-04-13 Xin Yang , Ke Xu , Yibing Song , Qiang Zhang , Xiaopeng Wei , Rynson Lau

Understanding dark energy requires precision measurements of the expansion history of the universe and the growth of large-scale structure. The 21 cm intensity mapping (21 cm IM) technique enables rapid large-area surveys that can deliver…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-25 Jun-Da Pan , Yichao Li , Guo-Hong Du , Tian-Nuo Li , Xin Zhang

Radio tomographic imaging (RTI) enables device free localisation of people and objects in many challenging environments and situations. Its basic principle is to detect the changes in the statistics of some radio quality measurements in…

Other Computer Science · Computer Science 2014-02-13 Bo Wei , Ambuj Varshney , Wen Hu , Neal Patwari , Thiemo Voigt , Chun Tung Chou

Spectropolarimetric reconstructions of the photospheric vector magnetic field are intrinsically limited by the so-called 180$^\circ$ ambiguity in the orientation of the transverse component. The successful launch and operation of Solar…

Solar and Stellar Astrophysics · Physics 2022-02-02 Gherardo Valori , Philipp Löschel , David Stansby , Etienne Pariat , Johann Hirzberger , Feng Chen

Motion during image acquisition can cause image degradation in all medical imaging modalities. This is particularly relevant in 2-D ultrasound imaging, since out-of-plane motion can only be compensated for movements smaller than elevational…

Medical Physics · Physics 2019-02-07 S. Harput , K. Christensen-Jeffries , J. Brown , J. Zhu , G. Zhang , R. J. Eckersley , C. Dunsby , M-X. Tang
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