Dr. Yingwei He Profile

Dr. Yingwei He

at National Institute of Metrology

SPIE Involvement:

Author

Publications (46)

Proceedings Article | 8 November 2024 Paper

Aircraft detection in high-resolution synthetic aperture radar images based on optical training dataset

Shaozhe Cui, Zhe Peng, Yuanrui Dong, Yingwei He, Guojin Feng, Haiyong Gan

Proceedings Volume 13247, 132470M (2024) https://doi.org/10.1117/12.3036454

KEYWORDS: Synthetic aperture radar, Object detection, Target detection, Image processing

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Synthetic Aperture Radar (SAR) emits microwave electromagnetic pulses and detects remote targets through the backscattered echo signals. With the continuous advancement of technology, high-resolution SAR imaging can accurately observe various targets with small sizes, dense connections, and diverse shapes. The steep terrain or tall objects in SAR images display prominent shadows due the obstruction of ground-facing electromagnetic waves resulting in weak echo signals in the shadowed areas. Small targets can generate discrete shadows with contours similar to optical contours in high-resolution SAR images when the radar observing angle is appropriate. This characteristic, which shares similarities with the target contour, can be utilized to build the correlation between SAR images and other modal images such as optical images. This study uses aircraft as an example to validate the feasibility of this approach. It trains the YOLOv5 object detection network on the Remote Sensing Object Detection (RSOD) dataset of optical airport images, which is then utilized to detect the shadows of aircraft in high-resolution SAR images, indirectly achieving aircraft detection.

Firstly, the shadows in SAR images have an inverse relationship with the signal of the aircraft body in optical images in terms of grayscale. Therefore, it is possible to simply invert the grayscale of one of them. In this study, SAR images were chosen for grayscale inversion. After a simple grayscale inversion, the network detected a significant number of aircraft in the image at a confidence level of 0.2, while only part of aircraft were detected in the image without inversion. Besides, a series of adjustments were made to the brightness and contrast of the grayscale inverted image in order to find the optimal setting for aircraft detection. After scanning and adjusting the brightness and contrast, the network detects a certain number of additional aircraft in the grayscale inverted images at a confidence level of 0.2. The maximum number of aircraft detections was achieved at a specific filtering spatial frequency after applying filtering with different spatial frequencies. The overall detection result achieved an accuracy of over 80%.The maximum number of aircraft detections was achieved at a specific filtering spatial frequency after applying filtering with different spatial frequencies. The overall detection result achieved an accuracy of over 80%.

Proceedings Article | 11 October 2024 Paper

Optical path design facing θ/θ reflectance measurement of test targets for autonomous vehicles

Tao Liang, Weijie Wang, Xikuai Xie, Shaozhe Cui, Qi Zang, Xiaolu Zhan, Guojin Feng, Yingwei He, Qiaoning Yang, Haiyong Gan

Proceedings Volume 13278, 132781D (2024) https://doi.org/10.1117/12.3032329

KEYWORDS: LIDAR, Reflectivity, Reflection, Spectrometers, Optical fibers, Calibration, Unmanned vehicles, Design, Incident light, Autonomous driving

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As a pair of "wise eyes" for autonomous vehicles to perceive the external environment, Lidar (Light detecting and Ranging) plays a crucial role in detecting target characteristics in driving scenarios. To ensure the accuracy and reliability of Lidar, precise measurement of target reflectance under θ/θ reflection conditions is an indispensable step. Determining the reflectance value of targets under θ/θ reflection conditions is a critical part of completing Lidar calibration and traceability. When designing the θ/θ optical path, a significant challenge lies in achieving almost perfect overlap between the lighting and detecting paths while ensuring system compactness and measurement accuracy. Fiber optic spectrometers, known for their fast and accurate measurement capabilities, can be directly applied to measure target reflectance. Therefore, combining a compact θ/θ reflection optical path with a fiber optic spectrometer is key to achieving small-angle reflectance measurements for Lidar, marking an important step towards improving the calibration and traceability chain. For Lidar under θ/θ reflection conditions, various "N+1" lighting/detecting combined optical paths based on fiber bundles have been designed. Simulation analysis of these designs has been conducted using ray-tracing methods, comparing the uniformity and optical flux efficiency of the tested samples. The results indicate that when N=6, the uniformity and incident flux efficiency are optimal. Based on the simulation results, a "6+1" lighting/detecting fiber optic spectrometer has been developed, and actual measurements have been performed on a standard diffuser. The measurement data shows that the angular accuracy under 0/0 and 45/45 conditions is better than 0.1°, and the optimal relative error of the reflection measurement results in the 905nm laser wavelength was less than 0.5%. This meets the requirements for on-site measurements and is significant for further improving the Lidar measurement traceability chain.

Proceedings Article | 30 April 2024 Paper

Investigation of spectral responsivity of imaging sensor and systems with a differential approach

Wende Liu, Haiyong Gan, Haifeng Meng, Nan Xu, Limin Xiong, Yingwei He

Proceedings Volume 13153, 131531K (2024) https://doi.org/10.1117/12.3020162

KEYWORDS: Sensors, Imaging systems, Image sensors, Cameras, Measurement uncertainty

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Proceedings Article | 30 April 2024 Paper

Illumination pattern and path control through laser beam steering using a calibrated two-dimensional galvo scanner

Qi Zang, Shaozhe Cui, Weijie Wang, Tao Liang, Xiaolu Zhan, Wende Liu, Yingwei He, Zhengang Lu, Haiyong Gan

Proceedings Volume 13153, 1315318 (2024) https://doi.org/10.1117/12.3018684

KEYWORDS: Laser scanners, Galvanometers, Calibration, Mirrors, Beam controllers, Servomechanisms, Light sources and illumination, Laser frequency, Beam steering, Scanners

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Proceedings Article | 27 March 2022 Paper

Evaluation of the detection ability of a multi-sensor system under weak light

Zhengxing Qiu, Yingce Wang, Changyu Shen, Xiangliang Liu, Yangting Fu, Yingwei He, Haiyong Gan

Proceedings Volume 12169, 121698U (2022) https://doi.org/10.1117/12.2625187

KEYWORDS: Sensors, Cameras, Target detection, LIDAR, Target recognition, Clouds, Signal detection

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Proceedings Article | 5 November 2020 Paper

Radiance uniformity measurement of a miniaturized integrating sphere light source for microscope radiance responsivity calibration

Yangting Fu, Xiangliang Liu, Yingwei He, Wende Liu, Nan Xu, Yandong Lin, Haiyong Gan

Proceedings Volume 11567, 115673R (2020) https://doi.org/10.1117/12.2580225

KEYWORDS: Calibration, Integrating spheres, Microscopes, Luminescence, Light sources, Microscopy, Sensors, Radiometry

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Proceedings Article | 5 November 2020 Paper

Time-multiplexed photon-number-resolving low-level light detection at 850 nm using a Si-APD single photon detector

Xiangliang Liu, Yangting Fu, Nan Xu, Haifeng Meng, Yingwei He, Wende Liu, Yandong Lin, Haiyong Gan

Proceedings Volume 11567, 115674E (2020) https://doi.org/10.1117/12.2580375

KEYWORDS: Optical fibers, Sensors, Photodetectors, Signal detection, Single photon detectors, Light sources, Multiplexers, Photon counting

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Proceedings Article | 10 October 2020 Poster + Paper

Comparison measurement of absolute power responsivity of silicon photodetector between He-Ne laser and supercontinuum white light source

Nan Xu, Haiyong Gan, Yangyang Wang, Yingwei He, Wende Liu, Ruoduan Sun, Yandong Lin

Proceedings Volume 11552, 115521A (2020) https://doi.org/10.1117/12.2573635

KEYWORDS: Supercontinuum sources, Silicon, Light sources, Radiometry, Polarization, Photodetectors, Cryogenics, Monochromators

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Proceedings Article | 10 October 2020 Poster + Paper

Research of relative spectral responsivity calibration of InGaAs photodetector based on supercontinuum light source

Yong-jie Lin, Nan Xu, Zhi-wei Liu, Ying-wei He, Wen-de Liu, Hua-ping Gong

Proceedings Volume 11552, 115521G (2020) https://doi.org/10.1117/12.2573856

KEYWORDS: Light sources, Calibration, Indium gallium arsenide, Spectral calibration, Photodetectors, Sensors, Quantum efficiency, Capacitance, Optical testing, Optical communications

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Proceedings Article | 10 October 2020 Presentation + Paper

Large-area, uniform light field generated using a galvo scanning system for bi-directional reflectance distribution function measurement

Yinuo Xu, Yingwei He, Xufeng Jing, Xiangliang Liu, Yangting Fu, Yingce Wang, Guojin Feng, Houping Wu, Chundi Zheng, Haiyong Gan

Proceedings Volume 11552, 115520K (2020) https://doi.org/10.1117/12.2575385

KEYWORDS: Reflection, Bidirectional reflectance transmission function, Femtosecond phenomena, Sensors, Laser systems engineering, Optical parametric oscillators, Harmonic generation, Mode locking, Pulsed laser operation, Silicon

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Proceedings Article | 10 October 2020 Poster + Paper

A new spectral responsivity calibration comparison of InGaAs photodiode based on cryogenic radiometer fundamentals at the National Institute of Metrology of China

Yingwei He, Haiyong Gan, Wende Liu, Yongjie Lin, Yangyang Wang, Ning Xu, Weiqiang Zhao, Zhiwei Liu, Limin Xiong, Nan Xu, Yandong Lin

Proceedings Volume 11552, 115521V (2020) https://doi.org/10.1117/12.2575380

KEYWORDS: Indium gallium arsenide, Calibration, Photodiodes, Cryogenics, Radiometry, Spectral calibration, Metrology, Monochromators, Light sources, Radio optics

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Proceedings Article | 10 October 2020 Poster + Paper

Recent advances in measurement of radiometric aperture area using optical method at NIM

Wende Liu, Nan Xu, Yingwei He, Yandong Lin, Haiyong Gan, Xiangliang Liu, Yangting Fu

Proceedings Volume 11552, 115521U (2020) https://doi.org/10.1117/12.2575376

KEYWORDS: Radio optics, Optical components, Laser metrology, Metrology, Optical spheres, Sensors

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