Results 41 to 50 of about 43,204 (241)

On-orbit geometric calibration of satellite laser altimeters using infrared detectors and corner-cube retroreflectors

International Journal of Digital Earth, 2023
After being launched into orbit, the geometric calibration of a satellite laser altimeter will reduce errors in laser pointing and ranging caused by satellite vibrations during launch, environmental changes, and thermal effects during long-term operation,
Junfeng Xie, Ren Liu, Xiaomeng Yang, Fan Mo, Fangxu Zhang, Lirong Liu   +5 more
doaj   +1 more source

Geometrical camera calibration with diffractive optical elements

Optics Express, 2008
Traditional methods for geometrical camera calibration are based on calibration grids or single pixel illumination by collimated light. A new method for geometrical sensor calibration by means of diffractive optical elements (DOE) in connection with a laser beam equipment is presented.
Grießbach, Denis, Bauer, Martin, Hermerschmidt, Andreas, Krüger, Sven, Scheele, Martin, Schischmanow, Adrian   +5 more
openaire   +2 more sources

Hip Morphology–Based Osteoarthritis Risk Prediction Models: Development and External Validation Using Individual Participant Data From the World COACH Consortium

Arthritis Care &Research, EarlyView.
Objective This study aims to develop hip morphology‐based radiographic hip osteoarthritis (RHOA) risk prediction models and investigates the added predictive value of hip morphology measurements and the generalizability to different populations. Methods We combined data from nine prospective cohort studies participating in the Worldwide Collaboration ...
Myrthe A. van den Berg, Fleur Boel, Michiel M. A. van Buuren, Noortje S. Riedstra, Jinchi Tang, Harbeer Ahedi, Nigel K. Arden, Sita M. A. Bierma‐Zeinstra, Cindy G. Boer, Flavia M. Cicuttini, Timothy F. Cootes, David T. Felson, Willem Paul Gielis, Joshua Heerey, Graeme Jones, Stefan Kluzek, Nancy E. Lane, Claudia Lindner, Joyce B. J. van Meurs, Andrea Mosler, Amanda E. Nelson, Michael C. Nevitt, Edwin H. Oei, Jos Runhaar, Harrie Weinans, Jesse H. Krijthe, Rintje Agricola   +26 more
wiley   +1 more source

Evaluation of the Potential of Laser Shock Peening Compared with Cold Expansion for Improving Fatigue Resistance of Riveted Lap Joints of Aerospace Grade 7175 Al Alloy

Advanced Engineering Materials, EarlyView.
This study investigates laser shock peening for enhancing fatigue performance of riveted aerospace aluminum joints. A comparative approach with cold expansion combines fatigue testing and synchrotron X‐ray methods. Integrating mechanical testing with residual stress and strain characterization provides insights into how different treatments affect the ...
Ogün Baris Tapar, David Osman Busse, Maximilian Sprengel, Domenico Furfari, Marc‐André Nielsen, Guilherme Abreu Faria, Jérémy Epp   +6 more
wiley   +1 more source

Numerical Investigation of a Dual‐Mode Shape Memory Alloy Stent Enabling Secondary Expansion via Focused Ultrasound: A Potential Strategy for Correcting In‐Stent Restenosis

Advanced Engineering Materials, EarlyView.
This study demonstrates a novel noninvasive strategy to treat in‐stent restenosis using focused ultrasound. A shape memory alloy stent initially expands at body temperature. If restenosis occurs, targeted ultrasound heating thermally actuates the stent, enabling a secondary expansion to reopen the blocked vessel, offering a potential alternative to ...
Stephen Asare, Lucinda Duncan, Josiah Owusu‐Danquah, Brian L. Davis   +3 more
wiley   +1 more source

A Novel Geometric Calibration Method of Spaceborne SAR for Rugged Terrain: A Case Study of LuTan-1 Images

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
The geometric positioning accuracy of synthetic aperture radar (SAR) images is affected by the radar system measurement and processing parameters, platform ephemeris data and auxiliary DEM data. Geometric calibration can compensate for the SAR systematic
Ke Shi, Qingsong Wang, Zhiming Liu, Wenlong Hu, Haisong Weng, Yuanhui Mo, Tao Lai, Haifeng Huang   +7 more
doaj   +1 more source

Microstructural Evolution and Vacancy Defect Formation in Mn–Mo–Ni RPV Steel Under Low Cycle Fatigue: Insights From EBSD and PALS

Advanced Engineering Materials, EarlyView.
Low‐cycle fatigue damage in Mn–Mo–Ni reactor pressure vessel steel is examined using a combined electron backscatter diffraction and positron annihilation lifetime spectroscopy approach. The study correlates texture evolution, dislocation substructure development, and vacancy‐type defect formation across uniform, necked, and fracture regions, providing
Apu Sarkar, Dhanadeep Dutta, G. Bharat Reddy   +2 more
wiley   +1 more source

3D CATENARY CURVE FITTING FOR GEOMETRIC CALIBRATION [PDF]

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2012
In modern road surveys, hanging power cables are among the most commonly-found geometric features. These cables are catenary curves that are conventionally modelled with three parameters in 2D Cartesian space. With the advent and popularity of the mobile
T.-O. Chan, D. D. Lichti
doaj   +1 more source

Landsat 9 Geometric Commissioning Calibration Updates and System Performance Assessment

Remote Sensing, 2023
Starting with launch of Landsat 7 (L7) on 15 April 1999, the USGS Landsat Image Assessment System (IAS) has been performing calibration and characterization operations for over 20 years on the Landsat spacecrafts and their associated payloads.
Michael J. Choate, Rajagopalan Rengarajan, James C. Storey, Mark Lubke   +3 more
doaj   +1 more source

Simulation‐Based Assessment of Second‐Order Residual Stress Fields on the Fatigue Performance of Silicon‐Strengthened Ferritic Ductile Irons

Advanced Engineering Materials, EarlyView.
This work presents a simulation‐based framework based on representative volume elements (RVEs) that explicitly incorporates process‐induced second‐order residual stresses into the fatigue strength assessment of ductile cast iron (DCI). For the first time, this approach enables a direct evaluation of the influence of second‐order residual stress fields ...
Lutz Horbach, Xuemei Lyu, Jiali Zhang, Felix Weber, Christoph Broeckmann   +4 more
wiley   +1 more source