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Weak gravitational lensing is one of the most powerful tools for cosmology, while subject to challenges in quantifying subtle systematic biases. The Point Spread Function (PSF) can cause biases in weak lensing shear inference when the PSF…

Instrumentation and Methods for Astrophysics · Physics 2021-12-13 Tianqing Zhang , Rachel Mandelbaum , The LSST Dark Energy Science Collaboration

Investigations of the point spread functions (PSFs) and flux calibrations for stacking analysis have been performed with the far-infrared (wavelengths range of 60 to 140 um all-sky maps taken by the Far-Infrared Surveyor (FIS) onboard the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Ko Arimatsu , Yasuo Doi , Takehiko Wada , Satoshi Takita , Mitsunobu Kawada , Shuji Matsuura , Takafumi Ootsubo , Hirokazu Kataza

To determine the precise positions of stars in CCD frames, various centering algorithms have been proposed for astrometry. The effective point spread function (ePSF) and the Gaussian centering algorithms are two representative centering…

Instrumentation and Methods for Astrophysics · Physics 2021-12-28 F. R. Lin , Q. Y. Peng , Z. J. Zheng , B. F. Guo , Y. J. Shang

Self-calibrating and dual-slope measurements have been used in the field of diffuse optics for robust assessment of absolute values or temporal changes in the optical properties of highly scattering media and biological tissue. These…

Optics · Physics 2025-05-05 Giles Blaney , Angelo Sassaroli , Tapan Das , Sergio Fantini

One of the possible approaches to detecting optical counterparts of GRBs requires monitoring large parts of the sky. This idea has gained some instrumental support in recent years, such as with the "Pi of the Sky" project. The broad sky…

The wavelength dependence of atmospheric refraction causes elongation of finite-bandwidth images along the elevation vector, which produces spurious signals in weak gravitational lensing shear measurements unless this atmospheric dispersion…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Andrés A. Plazas , Gary M. Bernstein

Our aim is to estimate the perspective-effected geometric distortion of a scene from a video feed. In contrast to all previous work we wish to achieve this using from low-level, spatio-temporally local motion features used in commercial…

Computer Vision and Pattern Recognition · Computer Science 2015-04-22 Ognjen Arandjelovic , Duc-Son Pham , Svetha Venkatesh

We present a detailed analysis of the point spread function (PSF) of JWST NIRCam imaging in eight filters: F070W, F115W, F150W, F200W, F277W, F356W, F444W, and F480M, using publicly available data. Spatial variations in the PSF FWHM…

Astrophysics of Galaxies · Physics 2023-04-28 Ming-Yang Zhuang , Yue Shen

Precise centroid estimation plays a critical role in accurate astrometry using telescope images. Conventional centroid estimation fits a template point spread function (PSF) to the image data. Because the PSF is typically not known to high…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Chengxing Zhai , Mike Shao , Renaud Goullioud , Bijan Nemati

The use of wide-field multi-object fiber-input spectrographs for large redshift surveys introduces the possibility of variations in the observed signal-to-noise ratio across the survey area due to errors in positioning the fibers with…

Astrophysics · Physics 2011-12-16 Peter R. Newman

Telescope Point Spread Function (PSF) quality is critical for realising the potential of cosmic weak lensing observations to constrain dark energy and test General Relativity. In this paper we use quantitative weak gravitational lensing…

This paper proposes a method for estimating and detecting optical signals in practical photon-counting receivers. There are two important aspects of non-perfect photon-counting receivers, namely, (i) dead time which results in blocking…

Signal Processing · Electrical Eng. & Systems 2024-08-21 Chen Wang , Zhiyong Xu , Jingyuan Wang , Jianhua Li , Weifeng Mou , Huatao Zhu , Jiyong Zhao , Yang Su , Yimin Wang , Ailin Qi

The Vera C. Rubin Observatory's LSST Camera (LSSTCam) pixel response has been characterized using laboratory measurements with a grid of artificial stars. We quantify the contributions to photometry, centroid, point-spread function size,…

A novel method to estimate the pixels simultaneous detection probability and the spatial resolution of pixelized detectors is proposed, which is based on the determination of the statistical correlations between detector neighbor pixels.…

Medical Physics · Physics 2008-02-25 V. Grabski

We introduce Posterior Distillation Sampling (PDS), a novel optimization method for parametric image editing based on diffusion models. Existing optimization-based methods, which leverage the powerful 2D prior of diffusion models to handle…

Computer Vision and Pattern Recognition · Computer Science 2024-04-03 Juil Koo , Chanho Park , Minhyuk Sung

Coherence properties and wavelength of light sources are indispensable for optical coherence microscopy/tomography as they greatly influence the signal to noise ratio, axial resolution, and penetration depth of the system. In the present…

Rayleigh's criterion states that it becomes essentially difficult to resolve two incoherent optical point sources separated by a distance below the width of point spread functions (PSF), namely in the subdiffraction limit. Recently,…

Quantum Physics · Physics 2019-01-09 Sisi Zhou , Liang Jiang

Fitting spectral distributions of total fluxes or image intensities are two standard methods for estimating the masses of starless cores and protostellar envelopes. These mass estimates, which are the main source and basis of our knowledge…

Instrumentation and Methods for Astrophysics · Physics 2016-09-28 Alexander Men'shchikov

Change detection is one of the most challenging issues when analyzing remotely sensed images. Comparing several multi-date images acquired through the same kind of sensor is the most common scenario. Conversely, designing robust, flexible…

Computer Vision and Pattern Recognition · Computer Science 2016-09-21 Vinicius Ferraris , Nicolas Dobigeon , Qi Wei , Marie Chabert

Reconstruction of the point spread function (PSF) plays an important role in many areas of astronomy, including photometry, astrometry, galaxy morphology, and shear measurement. The atmospheric and instrumental effects are the two main…

Instrumentation and Methods for Astrophysics · Physics 2024-04-25 Pedro Alonso , Jun Zhang , Cong Liu