Fuzzy recognition of missile borne multi-line array infrared detection based on size calculating

In order to improve the infrared detection and discrimination ability of the smart munition to the dynamic armor target under the complex background,the multi-line array infrared detection system is established based on the combination of the single unit infrared detector.The surface dimension features of ground armored targets are identified by size calculating solution algorithm.The signal response value and the value of size calculating are identified by the method of fuzzy recognition to make the fuzzy classification judgment for armored target.According to the characteristics of the target signal,a custom threshold de-noising function is proposed to solve the problem of signal preprocessing.The multi-line array infrared detection can complete the scanning detection in a large area in a short time with the characteristics of smart munition in the steady-state scanning stage.The method solves the disadvantages of wide scanning interval and low detection probability of single unit infrared detection.By reducing the scanning interval,the number of random rendezvous in the infrared feature area of the upper surface is increased,the accuracy of the size calculating is guaranteed.The experiments results show that in the fuzzy recognition method,the size calculating is introduced as the feature operator,which can improve the recognition ability of the ground armor target with different shape size.

Multifunctional MXene/Carbon Nanotube Janus Film for Electromagnetic Shielding and Infrared Shielding/Detection in Harsh Environments

Multifunctional,flexible,and robust thin films capable of operating in demanding harsh temperature environments are crucial for various cutting-edge applications.This study presents a multifunctional Janus film integrating highly-crystalline Ti_(3)C_(2)T_(x) MXene and mechanically-robust carbon nanotube(CNT)film through strong hydrogen bonding.The hybrid film not only exhibits high electrical conductivity(4250 S cm^(-1)),but also demonstrates robust mechanical strength and durability in both extremely low and high temperature environments,showing exceptional resistance to thermal shock.This hybrid Janus film of 15μm thickness reveals remarkable multifunctionality,including efficient electromagnetic shielding effectiveness of 72 dB in X band frequency range,excellent infrared(IR)shielding capability with an average emissivity of 0.09(a minimal value of 0.02),superior thermal camouflage performance over a wide temperature range(−1 to 300℃)achieving a notable reduction in the radiated temperature by 243℃ against a background temperature of 300℃,and outstanding IR detection capability characterized by a 44%increase in resistance when exposed to 250 W IR radiation.This multifunctional MXene/CNT Janus film offers a feasible solution for electromagnetic shielding and IR shielding/detection under challenging conditions.

State-of-the-art development about cryogenic technologies to support space-based infrared detection

As a key technology for space-based Earth observation and astronomical exploration,cooled mid-wavelength and long-wavelength Infrared(IR)detection is widely used in national defense,astronomy exploration,medical imaging,environmental monitoring,agricultural and other areas.The performances of IR detectors,including cut-off wavelength,detectivity,sensitivity and temperature resolution,plays a significant role in efficiently observing and tracking the low-temperature far-distance moving targets.Achieving optimal detection performance requires the IR detectors to operate at cryogenic temperatures.The future development of space-based applications relies heavily on the mid-wavelength and long-wavelength IR detection technologies,which should be enabled by the long-life cryogenic refrigeration and high-efficiency energy transportation system operating below 40 K,to support the Earth observation and astronomical detection.However,the efficiency degradation caused by the super low temperature brings tremendous challenges to the life time of cryogenic refrigeration and energy transportation systems.This paper evaluates the influence of cryogenic temperature on the infrared detector performances,reviews the features,development and space applications of cryogenic cooling technologies,as well as the cryogenic energy transportation approaches.Additionally,it analyzes the future development trends and challenges in supporting the space-based IR detection.

Infrared Small Target Detection Algorithm Based on ISTD-CenterNet

This paper proposes a real-time detection method to improve the Infrared small target detection CenterNet(ISTD-CenterNet)network for detecting small infrared targets in complex environments.The method eliminates the need for an anchor frame,addressing the issues of low accuracy and slow speed.HRNet is used as the framework for feature extraction,and an ECBAM attention module is added to each stage branch for intelligent identification of the positions of small targets and significant objects.A scale enhancement module is also added to obtain a high-level semantic representation and fine-resolution prediction map for the entire infrared image.Besides,an improved sensory field enhancement module is designed to leverage semantic information in low-resolution feature maps,and a convolutional attention mechanism module is used to increase network stability and convergence speed.Comparison experiments conducted on the infrared small target data set ESIRST.The experiments show that compared to the benchmark network CenterNet-HRNet,the proposed ISTD-CenterNet improves the recall by 22.85%and the detection accuracy by 13.36%.Compared to the state-of-the-art YOLOv5small,the ISTD-CenterNet recall is improved by 5.88%,the detection precision is improved by 2.33%,and the detection frame rate is 48.94 frames/sec,which realizes the accurate real-time detection of small infrared targets.

PF-YOLOv4-Tiny: Towards Infrared Target Detection on Embedded Platform

Infrared target detection models are more required than ever before to be deployed on embedded platforms,which requires models with less memory consumption and better real-time performance while considering accuracy.To address the above challenges,we propose a modified You Only Look Once(YOLO)algorithm PF-YOLOv4-Tiny.The algorithm incorpo-rates spatial pyramidal pooling(SPP)and squeeze-and-excitation(SE)visual attention modules to enhance the target localization capability.The PANet-based-feature pyramid networks(P-FPN)are proposed to transfer semantic information and location information simultaneously to ameliorate detection accuracy.To lighten the network,the standard convolutions other than the backbone network are replaced with depthwise separable convolutions.In post-processing the images,the soft-non-maximum suppression(soft-NMS)algorithm is employed to subside the missed and false detection problems caused by the occlusion between targets.The accuracy of our model can finally reach 61.75%,while the total Params is only 9.3 M and GFLOPs is 11.At the same time,the inference speed reaches 87 FPS on NVIDIA GeForce GTX 1650 Ti,which can meet the requirements of the infrared target detection algorithm for the embedded deployments.

CAFUNeT:A small infrared target detection method in complex backgrounds

Small infrared target detection has widespread applications in various fields including military,aviation,and medicine.However,detecting small infrared targets in complex backgrounds remains challenging.To detect small infrared targets,we propose a variable-structure U-shaped network referred as CAFUNet.A central differential convolution-based encoder,ASPP,an Attention Fusion module,and a decoder module are the critical components of the CAFUNet.The encoder module based on central difference convolution effectively extracts shallow detail information from infrared images,complemented by rich contextual information obtained from the deep features in the decoder module.However,the direct fusion of the shallow detail features with semantic features may lead to feature mismatch.To address this,we incorporate an Attention Fusion(AF)module to enhance the network performance further.We performed ablation studies on each module to evaluate its effectiveness.The results show that our proposed algorithm outperforms the state-of-the-art methods on publicly available datasets.

Novel detection method for infrared small targets using weighted information entropy

This paper presents a method for detecting the small infrared target under complex background. An algorithm, named local mutation weighted information entropy （LMWIE）, is proposed to suppress background. Then, the grey value of targets is enhanced by calculating the local energy. Image segmentation based on the adaptive threshold is used to solve the problems that the grey value of noise is enhanced with the grey value improvement of targets. Experimental results show that compared with the adaptive Butterworth high-pass filter method, the proposed algorithm is more effective and faster for the infrared small target detection.

A review on the developments and space applications of mid- and long-wavelength infrared detection technologies

Mid-wavelength infrared(MWIR)detection and long-wavelength infrared(LWIR)detection constitute the key technologies for space-based Earth observation and astronomical detection.The advanced ability of infrared(IR)detection technology to penetrate the atmosphere and identify the camouflaged targets makes it excellent for space-based remote sensing.Thus,such detectors play an essential role in detecting and tracking low-temperature and far-distance moving targets.However,due to the diverse scenarios in which space-based IR detection systems are built,the key parameters of IR technologies are subject to unique demands.We review the developments and features of MWIR and LWIR detectors with a particular focus on their applications in space-based detection.We conduct a comprehensive analysis of key performance indicators for IR detection systems,including the ground sampling distance(GSD),operation range,and noise equivalent temperature difference(NETD)among others,and their interconnections with IR detector parameters.Additionally,the influences of pixel distance,focal plane array size,and operation temperature of space-based IR remote sensing are evaluated.The development requirements and technical challenges of MWIR and LWIR detection systems are also identified to achieve high-quality space-based observation platforms.

A proposal for detecting weak electromagnetic waves around 2.6μm wavelength with Sr optical clock

Infrared signal detection is widely used in many fields.Due to the detection principle,however,the accuracy and range of detection are limited.Thanks to the ultra stability of the^(87)Sr optical lattice clock,external infrared electromagnetic wave disturbances can be responded to.Utilizing the ac Stark shift of the clock transition,we propose a new method to detect infrared signals.According to our calculations,the theoretical detection accuracy in the vicinity of its resonance band of 2.6μm can reach the order of 10-14W,while the minimum detectable signal of common detectors is on the order of 10^(-10)W.

Using deep learning to detect small targets in infrared oversampling images

According to the oversampling imaging characteristics, an infrared small target detection method based on deep learning is proposed. A 7-layer deep convolutional neural network(CNN) is designed to automatically extract small target features and suppress clutters in an end-to-end manner. The input of CNN is an original oversampling image while the output is a cluttersuppressed feature map. The CNN contains only convolution and non-linear operations, and the resolution of the output feature map is the same as that of the input image. The L1-norm loss function is used, and a mass of training data is generated to train the network effectively. Results show that compared with several baseline methods, the proposed method improves the signal clutter ratio gain and background suppression factor by 3–4 orders of magnitude, and has more powerful target detection performance.

Two-dimensional heterostructure promoted infrared photodetection devices

It is a rapidly developed subject in expanding the fundamental properties and application of two-dimensional(2D)materials.The weak van der Waals interaction in 2D materials inspired researchers to explore 2D heterostructures(2DHs)based broadband photodetectors in the far-infrared(IR)and middle-IR regions with high response and high detectivity.This review focuses on the strategy and motivation of designing 2DHs based high-performance IR photodetectors,which provides a wide view of this field and new expectation for advanced photodetectors.First,the photocarriers'generation mechanism and frequently employed device structures are presented.Then,the 2DHs are divided into semimetal/semiconductor 2DHs,semiconductor/semiconductor 2DHs,and multidimensional semi-2DHs;the advantages,motivation,mechanism,recent progress,and outlook are discussed.Finally,the challenges for next-generation photodetectors are described for this rapidly developing field.

Sensitive detection of infrared photons using a high-Q microcantilever

A new approach based on microcantilevers is presented to detect infrared photons with high sensitivity. Infrared photons are measured by monitoring the amplitude change of a vibrating microcantilever under light pressure force.The irradiating light is modulated into sinusoidal and pulsed waves,and to be in-phase and anti-phase with the cantilever driving signal.A linear relationship between the amplitude change of the cantilever and the light power distributing on the cantilever was observed.Under a vacuum of 10^（-4） Pa,an infrared light power of 7.4 nW was detected with the cantilever.The in-phase and anti-phase modulation to the cantilever vibration using a pulsed light results in an enhanced response of the cantilever.

An automated water dispensing system for controlling fires in coal yards

In spite of recent moves to wean the world of fossil fuels,coal remains the main source of power in many countries.Coal yards are prone to spontaneous ignition,a problem faced in every country that stores or transports coal.Depending on the environment-temperature,ventilation,and the rank of the coal-heating and self-ignition can be a longer or shorter process,but the possibility can never be entirely dismissed.A plethora of studies have modelled this oxidation behavior and proposed countermeasures.Most often,human intervention is necessary,which is both slow and dangerous for the frefghters involved.In this study,we propose to build a complete frefghting solution which is mounted on a number of towers sufcient to cover the area of an open coal yard,complete with redundancy.Each tower includes an inexpensive infrared detector,a water dispenser and a controller programmed to identify areas of elevated temperature,and actuate the dispenser.The heat direction algorithm calculates the parameters to position the water dispenser so that it covers the area.A prototype has been built from inexpensive components to demonstrate the efectiveness at detecting and extinguishing arising fres,and a solution has been costed for the coal yard in the case study.This work has been conducted in collaboration with the managers of the coal yard of a power plant.

An Effective Method of Threshold Selection for Small Object Image

The image segmentation difficulties of small objects which are much smaller than their background often occur in target detection and recognition. The existing threshold segmentation methods almost fail under the circumstances. Thus, a threshold selection method is proposed on the basis of area difference between background and object and intra-class variance. The threshold selection formulae based on one-dimensional (1-D) histogram, two-dimensional (2-D) histogram vertical segmentation and 2-D histogram oblique segmentation are given. A fast recursive algorithm of threshold selection in 2-D histogram oblique segmentation is derived. The segmented images and processing time of the proposed method are given in experiments. It is compared with some fast algorithms, such as Otsu, maximum entropy and Fisher threshold selection methods. The experimental results show that the proposed method can effectively segment the small object images and has better anti-noise property.

Detection of near infrared light illumination with the aid of none-metal plasmonic nanocrystals

With the support by the National Natural Science Foundation of China,the research team led by Prof.Luo LinBao(罗林保)at the College of Electronic Sciences and Applied Physics,Hefei University of Technology,developed a simple and highly efficient near infrared light photodetector,which was published in Laser&Photonics Reviews(2016,10:595—602).

基于磁控溅射法制备的大面积高质量硒化铂薄膜及其在红外探测中的应用

PtSe_(2)因其可调的带隙、高载流子迁移率和较高的光吸收率在红外探测领域受到广泛的研究和关注.然而,传统的制备方法存在生长条件复杂、生长时间长、铂源和硒源的选择性较低、晶体质量不高、成本昂贵以及大规模制造困难等缺点,限制了其实际应用.在此,我们采用了一种便捷、低成本的磁控共溅射法来制备大面积、高质量的PtSe_(2)薄膜.在不同温度下生长的薄膜的表面形貌和微观结构表征结果表明,我们制备的PtSe_(2)薄膜具有良好的结晶性、可控性、均匀性、较窄带隙和优异的红外波段吸收特性,同时我们还研究了最合适的衬底和生长温度.基于PtSe_(2)的光电探测器展示出良好的红外探测能力和较快的响应速度.尤其值得注意的是,相比于传统制备方法,本研究提出的制备方法的制备时间非常短,为PtSe_(2)大规模应用于下一代红外探测,并与现有的硅技术兼容提供了有益的指导.

Progress and challenges in blocked impurity band infrared detectors for space-based astronomy

Astronomical detection at infrared wavelengths is crucial in astrophysics due to the critical information in this wavelength range.Blocked impurity band(BIB) infrared detectors are desirable for space-based astronomical observation due to their broad response range, low dark currents, high quantum efficiencies, and excellent radiation resistance. In this review, typical BIB device structures and device physics development are first introduced. Subsequently, we discuss progress in Si-based BIB detectors with different doping types and emphasize their applications in space-based infrared detection. Additionally, we discuss recent efforts on pixel performance optimization, response extension, and higher operating temperature devices. Finally,we conclude by proposing the challenges and perspectives of BIB detectors with improved detection performances.

Realization of an integrated seeding and compensating potato planter based on one-way clutch

The yield reduction caused by miss-seeding in potato mechanized sowing is astonishing.The existing research always needs to install a spare compensator on the original seed-metering device.Therefore,problems of complex planter structure and compensated potato seed poor landing accuracy need to be solved urgently.Consequently,a scheme of integrated seeding and compensating potato planter based on one-way clutch is proposed in this paper.Based on a basic‘improved one raw potato planter’and the working principle of one-way clutch,power of seed-metering system is provided through main power transmission one-way clutch by land wheels when the system works properly.However,when miss-seeding detection system with infrared radiation deciding that a miss-seeding incident has happened,the seed-metering power will be replaced by a compensatory motor through compensating one-way clutch at a higher speed.Thus,the idea of catching-up compensation can be realized.After compensation is completed,the system controller disconnects the compensatory motor,and the seed-metering power will naturally switch to the land wheels again.A prototype based on this idea was built.Field tests showed that the accuracy of seed monitoring system is more than 99.9%;the adoption of catching-up compensation scheme does not bring about empty spoon rate rise significantly.Within the range of 0.2-0.8 m/s of the seed-metering chain speed,although the average success compensation rate decreases evidently with the increase of the chain speed,the success compensation rate is still near 70%even at 0.8 m/s,the vast majority of missed seeds can be compensated effectively.