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Model calibration consists of using experimental or field data to estimate the unknown parameters of a mathematical model. The presence of model discrepancy and measurement bias in the data complicates this task. Satellite interferograms,…

Methodology · Statistics 2023-02-28 Mengyang Gu , Kyle Anderson , Erika McPhillips

LiDAR-camera extrinsic calibration is essential for multi-modal data fusion in robotic perception systems. However, existing approaches typically rely on handcrafted calibration targets (e.g., checkerboards) or specific, static scene types,…

Robotics · Computer Science 2026-01-06 Zhiwei Huang , Yanwei Fu , Yi Zhou , Xieyuanli Chen , Qijun Chen , Rui Fan

Current traditional methods for LiDAR-camera extrinsics estimation depend on offline targets and human efforts, while learning-based approaches resort to iterative refinement for calibration results, posing constraints on their…

Computer Vision and Pattern Recognition · Computer Science 2023-12-05 Shuang Xu , Sifan Zhou , Zhi Tian , Jizhou Ma , Qiong Nie , Xiangxiang Chu

In order to cope with the increased data volumes generated by modern radio interferometers such as LOFAR (Low Frequency Array) or SKA (Square Kilometre Array), fast and efficient calibration algorithms are essential. Traditional radio…

Instrumentation and Methods for Astrophysics · Physics 2016-11-15 Sarod Yatawatta

This paper proposes a depth estimation method using radar-image fusion by addressing the uncertain vertical directions of sparse radar measurements. In prior radar-image fusion work, image features are merged with the uncertain sparse…

Computer Vision and Pattern Recognition · Computer Science 2024-03-26 Masaya Kotani , Takeru Oba , Norimichi Ukita

Next generation radio telescope arrays are being designed and commissioned to accurately measure polarized intensity and rotation measures across the entire sky through deep, wide-field radio interferometric surveys. Radio interferometer…

Instrumentation and Methods for Astrophysics · Physics 2017-08-02 P. Jagannathan , S. Bhatnagar , U. Rau , A. R. Taylor

With the increasing sensitivity of modern radio interferometers, it has become important to image objects larger than the field of view while optimising sensitivity and image fidelity. We present a coherent visibility plane…

Instrumentation and Methods for Astrophysics · Physics 2025-12-19 Keegan S. Trehaeven , Cyril Tasse , Oleg Smirnov , Tiziana Venturi

Since its formulation by Hamaker et al., the radio interferometer measurement equation (RIME) has provided a rigorous mathematical basis for the development of novel calibration methods and techniques, including various approaches to the…

Instrumentation and Methods for Astrophysics · Physics 2011-02-07 Oleg M. Smirnov

Position and frequency switching techniques used for the removal of the bandpass dependence of radio astronomical spectra are presented and discussed in detail. Both methods are widely used, although the frequency dependence of the system…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 B. Winkel , A. Kraus , U. Bach

Higher spatial resolution and larger imaging scene are always the goals pursued by advanced space-borne SAR system.High resolution and wide swath SAR imaging can provide more information about the illuminated scene of interest on one…

Signal Processing · Electrical Eng. & Systems 2024-02-27 Xinhua Mao

The new generation of radio synthesis arrays, such as LOFAR and SKA, have been designed to surpass existing arrays in terms of sensitivity, angular resolution and frequency coverage. This evolution has led to the development of advanced…

Instrumentation and Methods for Astrophysics · Physics 2013-07-19 Sanaz Kazemi , Sarod Yatawatta , Saleem Zaroubi

We present a novel deep learning framework that models the scene dependent image processing inside cameras. Often called as the radiometric calibration, the process of recovering RAW images from processed images (JPEG format in the sRGB…

Computer Vision and Pattern Recognition · Computer Science 2017-07-27 Seonghyeon Nam , Seon Joo Kim

We analyse the accuracy of radio interferometric gridding of visibilities with the aim to quantify the Epoch of Reionization (EoR) 21-cm power spectrum bias caused by gridding, ultimately to determine the suitability of different imaging…

Instrumentation and Methods for Astrophysics · Physics 2019-10-16 A. R. Offringa , F. Mertens , S. van der Tol , B. Veenboer , B. K. Gehlot , L. V. E. Koopmans , M. Mevius

We present a data-driven approach to compensate for optical aberration in calibration-free quantitative phase imaging (QPI). Unlike existing methods that require additional measurements or a background region to correct aberrations, we…

Image and Video Processing · Electrical Eng. & Systems 2020-12-02 Taean Chang , Youngju Jo , Gunho Choi , Donghun Ryu , Hyun-Seok Min , Yongkeun Park

The data reduction procedure for radio interferometers can be viewed as a combined calibration and imaging problem. We present an algorithm that unifies cross-calibration, self-calibration, and imaging. Being a Bayesian method, that…

Instrumentation and Methods for Astrophysics · Physics 2019-07-23 Philipp Arras , Philipp Frank , Reimar Leike , Rüdiger Westermann , Torsten Enßlin

Purpose: Field monitoring measures field perturbations, which can be accounted for during image reconstructions. In certain field monitoring environments, significant phase deviations can arise far from isocenter due to the finite extent of…

Medical Physics · Physics 2023-01-25 Paul I. Dubovan , Kyle M. Gilbert , Corey A. Baron

In this lecture, we describe a number of advanced gain calibration techniques. In particular, self-calibration is an important tool in interferometric imaging at all wavelengths. It allows the observer to determine and remove residual phase…

Instrumentation and Methods for Astrophysics · Physics 2018-05-15 Crystal L. Brogan , Todd R. Hunter , Ed B. Fomalont

The most prevalent routine for camera calibration is based on the detection of well-defined feature points on a purpose-made calibration artifact. These could be checkerboard saddle points, circles, rings or triangles, often printed on a…

Computer Vision and Pattern Recognition · Computer Science 2020-03-23 Morten Hannemose , Jakob Wilm , Jeppe Revall Frisvad

We propose a differentiable imaging framework to address uncertainty in measurement coordinates such as sensor locations and projection angles. We formulate the problem as measurement interpolation at unknown nodes supervised through the…

Image and Video Processing · Electrical Eng. & Systems 2023-12-21 Sidharth Gupta , Konik Kothari , Valentin Debarnot , Ivan Dokmanić

We present a new technique for calibrating the primary beam of a wide-field, drift-scanning antenna element. Drift-scan observing is not compatible with standard beam calibration routines, and the situation is further complicated by…