Multichannel imaging for monitoring chemical composition and germination capacity of cowpea(Vigna unguiculata) seeds during development and maturation

This study aimed to set a computer-integrated multichannel spectral imaging system as a high-throughput phenotyping tool for the analysis of individual cowpea seeds harvested at different developmental stages. The changes in germination capacity and variations in moisture, protein and different sugars during twelve stages of seed development from 10 to 32 days after anthesis were nondestructively monitored. Multispectral data at 20 discrete wavelengths in the ultraviolet, visible and near infrared regions were extracted from individual seeds and then modelled using partial least squares regression and linear discriminant analysis(LDA) models. The developed multivariate models were accurate enough for monitoring all possible changes occurred in moisture, protein and sugar contents with coefficients of determination in prediction R^(2) of 0.93, 0.80 and 0.78 and root mean square errors in prediction(RMSEP) of 6.045%, 2.236% and 0.890%, respectively. The accuracy of PLS models in predicting individual sugars such as verbascose and stachyose was reasonable with R~2 of 0.87 and 0.87 and RMSEP of 0.071%and 0.485%, respectively;but for the prediction of sucrose and raffinose the accuracy was relatively limited with R^(2) of 0.24 and 0.66 and RMSEP of 0.567% and 0.045%, respectively. The developed LDA model was robust in classifying the seeds based on their germination capacity with overall correct classification of96.33% and 95.67% in the training and validation datasets, respectively. With these levels of accuracy,the proposed multichannel spectral imaging system designed for single seeds could be an effective choice as a rapid screening and non-destructive technique for identifying the ideal harvesting time of cowpea seeds based on their chemical composition and germination capacity. Moreover, the development of chemical images of the major constituents along with classification images confirmed the usefulness of the proposed technique as a non-destructive tool for estimating the concentrations and spatial distributions of moisture, protein and sugars during different developmental stages of cowpea seeds.

一种轻小型遥感相机多通道高速图像传输方案

遥感相机图像传输接口性能是影响相机整体性能的重要指标,为解决多通道相机图像数据传输速率高且同时满足轻小型化需求的问题,文章提出一种高吞吐率、低误码率的轻小型相机多通道高速图像数据传输方案,该方案基于CoaXPress接口采用Aurora 8B/10B通信协议,通过FPGA吉比特发送器(Gigabit Transceiver,GTX)实现4套焦面组件下行的高速图像传输,测试数据率达到13 Gbit/s,同时实现上行21 Mbit/s的相机控制数据率。仿真及测试结果表明:该方案极大地提高了相机的图像数据传输速率,接口电缆数量较传统减少近50%,可满足轻小型遥感相机多通道高速图像传输需求,为各类遥感相机高速小型化提供新的解决方案。

Geophysical Investigation of a Solid Waste Disposal Site Using Integrated Electrical Resistivity Tomography and Multichannel Analyses of Surface Waves Methods

Electrical resistivity tomography survey was deployed at a solid waste landfill in southwest Missouri USA with the intent to map variations in moisture content through the solid waste and underlying subsurface, and to map the top of bedrock. Multichannel analyses of surface waves survey was also deployed to map variations in engineering properties of the solid waste and underlying subsurface, and to constrain the interpretations of top of bedrock. The 2-D resistivity images through the waste suggest rainwater seeps through the cap cover system of the solid waste landfill, and moisture content within the solid waste increases with solid waste burial depth. The resistivity anomalies displayed by the soil and bedrock directly underneath the solid waste suggests a lateral component to moisture infiltrating at the toe of the landfill, which is flowing inward to the base of solid waste structural low. The 1-D shear wave velocity profiles obtained from the multichannel analyses of surface waves survey helped interpret the top of bedrock underneath the solid waste, where top of bedrock is difficult to map using electrical resistivity tomography, as shallow fractured bedrock is moist and displays comparable resistivity values to that of overlying soil. Not surprisingly, the top of bedrock is readily identified on the electrical resistivity tomography profiles in places where subsurface is relatively dry. The deployment of the combined non- invasive, cost and time effective geophysical surveys, along with engineering judgement on available site history data, has reasonably identified potential landfill seepage pathways. The methodology presented could be used in similar site investigation settings.

A non-local vectorial total variational model for multichannel SAR image speckle suppression

Abstract This paper aims at the multichannel synthetic aperture radar （SAR） image speckle reduc- tion. This paper proposes a novel energy minimized regularization model for multichannel image denoising, which is an extension of the non-local total variational model for gray-scale image. It contains two terms, namely the vectorial data fidelity term and the non-local vectorial total variation term. The latter is constructed by high-dimensional non-local gradient that contains the structure information of the multichannel image. The existence and the uniqueness of the solution of the model are proved. A fixed point iterative algorithm is designed to acquire the solution of this model. The convergence property of this algorithm is proved as well. This model is applied to the multipolarimetric and multi-temporal RAI）ARSAT-2 images despeckling. The result shows that this model performs better than the original vectorial total variational model on texture preserving.

基于仿生曲面复眼相机的目标定位技术

开展了基于仿生曲面复眼相机的空间目标定位实验研究。采用CALibration Tag标定板结合MATLAB标定工具箱对自研仿生复眼相机进行内外参数的标定。针对目标的三维定位,从曲面复眼相机成像原理出发并利用相机定标参数,确定目标点在复眼相机中各子眼坐标系下坐标的线性关系并建立线性方程组,通过最小二乘法进行求解以获得目标点的准确空间定位。设计了光斑定位实验,实验结果表明,在至少4 m的工作距离内,仿生曲面复眼相机的定位误差可以控制在2%以内,该目标定位方法应用于仿生曲面复眼相机能实现较高精度的目标定位。在此基础上,采用尺度不变特征转变算法实现了两个子眼所拍摄子图像的特征点粗匹配,结合随机抽取一致算法去除错误匹配点,进而由特征点在子眼像素坐标系中的二维坐标反演出其在空间坐标系中的三维坐标,最后通过对所有点进行点云拼接获得完整的重构点云。实验结果表明,对距离相机约0.6 m处的边长为5.5 cm的正方体可以实现较好的三维立体重构。

星载方位多通道斜视SAR对运动目标成像方法

由于受到斜视角和运动速度的影响,方位多通道合成孔径雷达(SAR)的方位模糊和速度模糊问题更加严重,从而影响斜视模式下运动目标的多通道重建与成像。为了解决该问题,文章提出了一种星载方位多通道斜视SAR运动目标成像方法。首先,分析并建立斜视模式下运动目标精确回波模型,然后,基于谱估计及改进Radon变换实现运动目标无模糊径向速度估计,对目标二维频谱进行匹配滤波实现运动目标成像。最后,点目标仿真实验验证了该方法的有效性。

基于FY-4A资料的20210430强对流天气过程分析

受东北冷涡影响,2021年4月30日傍晚起淮安市中北部地区出现最大直径为5 cm左右冰雹、12级雷雨大风等强对流天气。利用MICAPS观测资料、FY-4A卫星多通道扫描成像辐射计AGRI资料分析此次强对流天气的初生及发展过程,结果表明:(1)此次强对流天气过程整层天气系统呈现前倾结构和“上干下湿”的不稳定层结,利于强对流的触发;(2)淮安站上空云顶亮温下降—短暂上升—迅速下降的特征反映了淮安强对流天气是由不同对流云团造成的;(3)在较强对流天气发生前的0~1 h内,FY-4A AGRI卫星资料对云团的初生及发展有一定的短临预警指示作用。

Design of a new kind of chemical experiment container with virtual reality fusion

Background At present,the teaching of experiments in primary and secondary schools is affected by cost and security factors.Existing research on virtual experiment platforms has alleviated these problems.However,the lack of real experimental equipment and use of a single channel to understand user intentions weaken these platforms operationally and degrade the naturalness of interactions.Methods To solve these problems,we propose an intelligent experimental container structure and a situational awareness algorithm,both of which are verified and applied to a chemical experiment involving virtual-real fusion.First,the acquired images are denoised in the visual channel using the maximum diffuse reflection chroma to remove overexposure.Second,container situational awareness is realized by segmenting the image liquid level and establishing a relation-fitting model.Then,strategies for constructing complete behaviors and making priority comparisons among behaviors are adopted for information complementarity and independence,respectively.A multichannel intentional understanding model and an inter-active paradigm that integrates vision,hearing,and touch are proposed.Results The experimental results show that the accuracy of the intelligent container situation awareness proposed in this paper reaches 99%,and the accuracy of the proposed intention understanding algorithm reaches 94.7%.The test shows that the intelligent experimental system based on the new interaction paradigm also has better performance and a more realistic sense of operation experience in terms of experimental efficiency.Conclusion The results indicate that the proposed experimental container and algorithm can achieve a natural level of human-computer interaction in a virtual chemical experiment platform,enhance the user′s sense of operation,and achieve high levels of user satisfaction.

多通道ScanSAR成像算法研究

针对传统星载SAR系统分辨率和测绘带宽之间的矛盾,文章采用方位向偏置相位中心结合距离向波束扫描的多通道ScanSAR系统进行了成像算法研究.该算法采用方位向频域重构结合全孔径算法实现了多通道ScanSAR成像,使高分辨率和宽测绘带成像可以同时实现,通过7×7点阵成像仿真验证了该算法的有效性,为高分辨率宽测绘带SAR工程的实现奠定了基础.

高光谱技术的羊肉品种多波段识别研究

利用可见/近红外（400-1000 nm）及近红外（900-1700 nm）高光谱成像技术对宁夏地区滩寒杂交、盐池滩羊、小尾寒羊三个品种羊肉进行识别研究。针对不同波段光谱特点,分别优选出 Baseline 及 SG卷积平滑光谱预处理方法,并运用连续投影算法（SPA）提取特征波长,结合线性判别分析（LDA）及径向基核函数支持向量机（RBFSVM）模型进行全波段及特征波长识别分析。结果表明不同波段高光谱对羊肉品种识别均获得较好效果,其中400-1000 nm波段采用Baseline-Fullwave-RBFSVM及12个特征波长下准确率为100%与98.75%,900-1700 nm 波段采用 Baseline-Fullwave-RBFSVM 及7个特征波长下准确率为96.25%与87.80%；RBFSVM非线性分类准确率高于 LDA线性判别结果,400-1000 nm波段识别准确率优于900-1700 nm波段,说明三种羊肉在色泽纹理上差异比成分含量显著,利用高光谱成像技术结合RBFSVM方法能够获得较优的羊肉品种识别效果。

基于模糊C均值聚类和邻域分析的无监督多通道遥感图像变化检测

提出一种基于模糊C均值聚类(Fuzzy C-means,FCM)和邻域分析的多通道遥感图像变化检测方法。通常的多通道遥感图像变化检测方法将变化信息从多个波段压缩到一个波段,损失了遥感图像的波段信息。本文将多波段变化信息用FCM方法来实现多通道遥感图像的变化检测。但由于FCM有对孤立点敏感的特点,该方法容易受噪声的影响。本文在FCM的基础上,又提出了一种结合图像空间邻域信息的多通道遥感图像变化检测方法,改进了FCM对孤立点敏感的问题。实验结果表明,相对于其他变化检测方法及FCM方法,所提出的基于FCM和邻域分析的多通道遥感图像变化检测方法能较好地消除遥感图像中变化检测中噪声的影响,具有很好的变化检测性能。

多光谱阴道镜的微型化多通道滤光片设计

设计了一种可与阴道镜中的图像传感器集成的微型化多通道滤光片,以使阴道镜具有光谱成像能力。采用微光刻技术及真空多层镀膜技术制成微滤光片,内部微滤光单元的通光波长与病灶标志物反射光谱或荧光光谱的特征峰相对应,与图像传感器集成后,能够获取几幅与光谱特征峰对应的特征波长图像,这些图像凸显了病变组织与正常组织的差异,提供了宫颈组织上皮表面形态变化及上皮组织内病灶标志物含量变化的信息。已加工出通光波长为λ1=630nm、λ2=460nm、λ3=515nm、λ4=577nm的微滤光片,微滤光单元面积为10μm×10μm,各通道带宽约为40nm,透射率为30%～40%。实验显示微滤光片的光学性能已达到光谱成像的基本要求,与阴道镜集成后,能有效提高其诊断的灵敏度与特异性,减少活检频率。

基于空间可分辨光谱的番茄成熟度判别方法研究

对基于空间可分辨光谱的番茄成熟度分类判别方法进行了试验研究。首先根据番茄的内部颜色,将600个番茄分为6个不同成熟度(green,breaker,turning,pink,light red and red),然后用自行开发的多通道高光谱成像探头采集番茄的空间可分辨(SR)光谱,建立基于空间可分辨光谱的番茄成熟度偏最小二乘判别(PLSDA)模型和支持向量机判别(SVMDA)模型。结果显示,对于PLSDA模型,SR光谱15为最佳分类光谱,分类正确率达到81.3%;对于SVMDA模型,SR光谱10为最佳预测分类光谱,分类正确率为86.3%。对六个成熟度等级番茄的判别分类,SVMDA模型要明显优于PLSDA模型。此外,相对于较小的光源-检测器距离SR光谱,较大的光源-检测器距离SR光谱可以获得更好的判别效果,显示出空间可分辨光谱在果蔬品质检测方面的应用潜力。

±100kV气体轨道开关击穿特性

研制了一种用于快Marx发生器的三电极场畸变结构的气体轨道开关,针对3种不同的绝缘介质N2、干燥空气和SF6/Ar混合气体开展了轨道开关的自击穿特性和触发特性研究。结果表明:轨道开关的自击穿电压与气压基本呈现线性关系,并且在相同实验条件下,相对于N2和干燥空气,当绝缘介质为SF6/Ar混合气体时,轨道开关具有工作电压范围宽、工作系数低、触发击穿延时短、抖动小的优点。采用数码相机拍摄了开关导通过程中形成的放电通道积分图像,初步研究了绝缘介质、电流大小等因素对开关形成多通道的影响。结果表明:提高触发电压、充电电压和放电电流及采用SF6/Ar混合气体均能够有效增加放电通道数目。

可见光+1.54μm激光/长波红外分色片的设计和制备

可见+1.54μm激光/长波红外分色片分离可见光、激光和长波红外光,在多通道成像光学系统中起着重要的作用.分析了分色片基板和薄膜材料的选择,优化设计并用电子束蒸发法制备了该分色片,其反射率和透射率都达到了94%以上,已成功应用于实际光学系统.

一种简化的虚拟3D声方法

提出了一种简化的在耳机重发中虚拟出3D（三维空间）声像的方法。理论和实验结果表明，借鉴多通路声产生空间声像的原理，用HRTF卷积的方法在耳机重发中虚拟出空间8个不同方向的虚拟扬声器，通过调节馈给虚拟扬声器的信号，即可产生不同方位的空间声像。这种虚拟空间声像的方法在产生运动声像和需要同时虚拟空间不同方位的多个声像时较现有的方法要简单。

基于傅立叶和小波域的多通道图像恢复方法

提出了一种新的多通道图像恢复方法。该方法在傅立叶和小波域利用同态滤波进行模糊辨识,在迭代过程中采用基于小波变换的图像融合技术来增强图像的细节。在小波和傅立叶域进行正则化因子的估计,从而减少参数的输入和增强抗噪能力。试验表明所提出的算法能够有效地解决实际问题,效果很好。

闪光灯光谱的自动采集

本文描述了采用多道探测、平场色散及快速数据采集技术实现的瞬态光谱的自动采集方法，并给出仪器用闪光灯光谱的实测结果。

基于多通道Gabor滤波的指纹图像二值化方法

为解决传统的直接利用图像全局或局部灰度特性的指纹图像二值化方法的不足,提出一种多通道Gabor滤波的指纹图像二值化方法。首先构造多通道Gabor滤波器组对规格化后的指纹图像提取不同方向纹线对应的主要频率成分。将获得的多通道的滤波响应图线性叠加形成单幅Gabor滤波叠加响应图。然后对其再次采用以上滤波器组滤波,分别求取各位置的最大Gabor响应构成最终的指纹滤波能量响应图。最后分块并求取块内阈值实现二值化。实验结果表明,该方法较基于灰度特性的方法鲁棒性更好,特别对存在粘连、噪声和断纹、孔洞等现象的指纹图像有较好的处理效果。

300～1100nm多波段成像光学系统设计及杂光分析

设计了一套300～1100nm多波段光学系统,该系统能对目标的近紫外、可见光和近红外3个波段同时成像,可满足目标多波段信息探测的要求。由于在光学系统中镜筒内壁反射和棱镜表面反射会产生杂光和鬼像,因此,利用Light-Tools软件对此系统的杂光和鬼像进行了模拟分析。模拟结果表明,视场之外11.7～18.3°和-11.7～-18.3°的入射光线被胶合棱镜上下表面反射后,会聚焦到3个探测器靶面范围内,形成鬼像;6.2°～9.8°和-6.2°～-9.8°的入射光线被镜筒反射后会在3个探测器上形成杂光。利用设计的多波段光学系统进行了相关实验,结果证明了模拟分析的正确性,表明此分析能用于指导多波段光学系统的设计和研制。提出了减少杂光和鬼像的相应措施,实验结果验证了提出的措施能够减少杂光及消除鬼像,提高系统成像质量。