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Calibration of a typical radio interferometric array yields thousands of parameters as solutions. These solutions contain valuable information about the systematic errors in the data (ionosphere and beam shape). This information could be…

Instrumentation and Methods for Astrophysics · Physics 2018-01-31 Sarod Yatawatta

Calibration is an essential prerequisite for the accurate data fusion of LiDAR and camera sensors. Traditional calibration techniques often require specific targets or suitable scenes to obtain reliable 2D-3D correspondences. To tackle the…

Computer Vision and Pattern Recognition · Computer Science 2025-01-29 Shujuan Huang , Chunyu Lin , Yao Zhao

In radio interferometry imaging, the gridding procedure of convolving visibilities with a chosen gridding function is necessary to transform visibility values into uniformly sampled grid points. We propose here a parameterised family of…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 Haoyang Ye , Stephen F. Gull , Sze M. Tan , Bojan Nikolic

Calibration precision is currently a limiting systematic in 21 cm cosmology experiments. While there are innumerable calibration approaches, most can be categorized as either `sky-based,' relying on an extremely accurate model of…

Instrumentation and Methods for Astrophysics · Physics 2021-03-17 Ruby Byrne , Miguel F. Morales , Bryna Hazelton , Michael Wilensky

In view of contemporary panoramic camera-laser scanner system, the traditional calibration method is not suitable for panoramic cameras whose imaging model is extremely nonlinear. The method based on statistical optimization has the…

Computer Vision and Pattern Recognition · Computer Science 2017-09-14 Mingwei Cao , Ming Yang , Chunxiang Wang , Yeqiang Qian , Bing Wang

The development of new phased array systems in radio astronomy, as the low frequency array (LOFAR) and the square kilometre array (SKA), formed of a large number of small and flexible elementary antennas, has led to significant challenges.…

We present a method to calibrate a high-resolution wavefront-correcting device with a single, static camera, located in the focal plane; no moving of any component is needed. The method is based on a localized diversity and differential…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Visa Korkiakoski , Niek Doelman , Johanan Codona , Matthew Kenworthy , Gilles Otten , Christoph U. Keller

Co-Registration of aerial imagery and Light Detection and Ranging (LiDAR) data is quilt challenging because the different imaging mechanism causes significant geometric and radiometric distortions between such data. To tackle the problem,…

Computer Vision and Pattern Recognition · Computer Science 2020-04-22 Bai Zhu , Yuanxin Ye , Chao Yang , Liang Zhou , Huiyu Liu , Yungang Cao

Context. The QUBIC collaboration is building a bolometric interferometer dedicated to the detection of B-mode polarization fluctuations in the Cosmic Microwave Background. Aims. We introduce a self-calibration procedure related to those…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 M. -A. Bigot-Sazy , R. Charlassier , J. -Ch. Hamilton , J. Kaplan , G. Zahariade

Radio interferometers must grapple with apparent fields of view that distort the true radio sky. These so-called 'A-term' distortions may be direction-, time- and baseline-dependent, and include effects like the primary beam and the…

Instrumentation and Methods for Astrophysics · Physics 2025-02-26 Torrance Hodgson

We present an algorithm to photometrically calibrate wide field optical imaging surveys, that simultaneously solves for the calibration parameters and relative stellar fluxes using overlapping observations. The algorithm decouples the…

Interferometers play an increasingly important role for spatially resolved observations. If employed at full potential, interferometry can probe an enormous dynamic range in spatial scale. Interpretation of the observed visibilities…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 C. Brinch , C. P. Dullemond

Fourier ptychography captures intensity images with varying source patterns (illumination angles) in order to computationally reconstruct large space-bandwidth-product images. Accurate knowledge of the illumination angles is necessary for…

Signal Processing · Electrical Eng. & Systems 2018-11-01 Regina Eckert , Zachary F. Phillips , Laura Waller

We present a prescription to correct large-scale intensity variations affecting imaging data taken with the Wide Field Imager (WFI) at the MPG/ESO 2.2 m telescope at the European Southern Observatory at La Silla in Chile. Such smoothly…

Astrophysics · Physics 2009-11-10 A. Koch , M. Odenkirchen , E. K. Grebel , J. A. R. Caldwell

Camera calibration is a process of paramount importance in computer vision applications that require accurate quantitative measurements. The popular method developed by Zhang relies on the use of a large number of images of a planar grid of…

Computer Vision and Pattern Recognition · Computer Science 2024-06-25 Katia Genovese

The sparse layouts of radio interferometers result in an incomplete sampling of the sky in Fourier space which leads to artifacts in the reconstructed images. Cleaning these systematic effects is essential for the scientific use of…

Instrumentation and Methods for Astrophysics · Physics 2023-07-27 Kevin Schmidt , Felix Geyer , Stefan Fröse , Paul-Simon Blomenkamp , Marcus Brüggen , Francesco de Gasperin , Dominik Elsässer , Wolfgang Rhode

This paper addresses the challenges of wideband signal beamforming in radar systems and proposes a new calibration method. Due to operating conditions, the frequency dependent characteristics of the system can be changed, and amplitude,…

Signal Processing · Electrical Eng. & Systems 2023-06-27 Hyung-Woo Kim , Jin-woo Kim , Jin-ha Kim , JaeYoung Choi , Sangpyo Hong , Byungkwan Kim

Despite the increasing prevalence of rotating-style capture (e.g., surveillance cameras), conventional stereo rectification techniques frequently fail due to the rotation-dominant motion and small baseline between views. In this paper, we…

Computer Vision and Pattern Recognition · Computer Science 2023-07-12 Yongcong Zhang , Yifei Xue , Ming Liao , Huiqing Zhang , Yizhen Lao

Precise sensor calibration is critical for autonomous vehicles as a prerequisite for perception algorithms to function properly. Rotation error of one degree can translate to position error of meters in target object detection at large…

Robotics · Computer Science 2025-06-24 Zhongyuan Li , Honggang Gou , Ping Li , Jiaotong Guo , Mao Ye

Cameras and LiDAR are essential sensors for autonomous vehicles. Camera-LiDAR data fusion compensate for deficiencies of stand-alone sensors but relies on precise extrinsic calibration. Many learning-based calibration methods predict…

Computer Vision and Pattern Recognition · Computer Science 2025-07-08 Ni Ou , Zhuo Chen , Xinru Zhang , Junzheng Wang