Detecting small moving objects using temporal hypothesis testing

This paper addresses the problem of detecting small, moving, low amplitude objects in image sequences that also contain moving nuisance objects and background noise. We formulate this problem in the context of a hypothesis testing procedure on individual pixel temporal profiles, leading to a computationally efficient statistical test. The technique assumes we have reasonable deterministic and statistical models for the temporal behavior of the background noise, target, and clutter, on a single pixel basis. Based on these models we develop a generalized likelihood ratio test (GLRT) and perfect measurement performance analysis, and present the resulting decision rule. We also propose a parameter estimation technique and compare its performance to the Cramer Rao bound (CRB). We demonstrate the effectiveness of the technique by applying the resulting algorithm to real world infrared (IR) image sequences containing targets of opportunity. The approach could also be applicable to other image sequence processing scenarios, using acquisition systems besides IR imaging, such as detection of small moving objects or structures in a biomedical or biological imaging scenario, or the detection of satellites, meteors or other celestial bodies in night sky imagery acquired using a telescope     

A target cueing and tracking system (TCATS) for smart videoprocessing

A smart system that uses state-of-the-art image processing techniques to detect and track targets moving in video or infrared imagery is presented. It is a general-purpose system that was developed to be independent of the application and the user interface. TCATS has successfully demonstrated a high detection capability and the ability to ignore exterior environmental conditions, such as cloud shadows moving through the scene, snow, blowing dust, rain and moderate camera motion. TCATS can handle many targets and retain the identity of each object from one frame to the next. Special rugged hardware has been developed to reduce the size, cost, and power consumption and to increase the processing rate, reliability, and environmental operating capability of the system. TCATS can be incorporated into an existing video assessment system without a major cost outlay intruder. The TCATS algorithms, custom-developed hardware, and preliminary field test results are described     

Spatial-temporal detection of electro-optic moving targets

A maximum likelihood algorithm to detect moving targets in space-time electro-optic data is derived using a model of temporally stationary and spatially nonstationary clutter statistics. Performance is evaluated in term of the probabilities of false alarm and detection. This algorithm is applied to a variety of image sequences: visible band and infrared (IR) sensors, with terrestrial and celestial clutter backgrounds. Comparison of theoretically predicted and experimentally derived statistics shows excellent agreement, validating the model and theoretical predictions     

Effectiveness of MMW aerosols in defeating a battlefieldsurveillance radar: field demonstration preliminary results

The US Army ERDEC is developing advanced aerosol systems to combat threat surveillance, fire control, and seeker systems operating in the visible, infrared, and millimeter wave portions of the electromagnetic spectrum. One such system is the M56 multispectral smoke generator, which presently operates in the visible and infrared portions of the spectrum; a millimeter wave (MMW) Module is in development to extend the M56 spectral range. This paper documents preliminary results of a field demonstration test of the M56 MMW Module. An MMW instrumentation radar was modified to simulate the scan pattern and radar parameters of a tactical battlefield surveillance radar system. A test grid was populated with both stationary and moving tactical targets, and the radar scanned the grid to simulate a surveillance radar in operation. Once a realistic tactical engagement scenario was developed, MMW aerosols were deployed to demonstrate the impact such aerosols could have on radar detection and classification performance     

Performance Analysis of a Target Detection System Using Infrared Imagery

The automatic detection of targets in cluttered infrared imagery is considered. The environment for the problem is that of a "fire-and-forget" weapon, and the mission philosophy for such a weapon dictates that the weapon has to find one and only one target in the automatic detection phase. A detection system that meets this requirement is presented. The system uses techniques of image processing and pattern recognition, with the extension that ranking methods are used instead of thresholds to accommodate the requirement of finding one and only one target. A probability model of the system is developed to determine the system performance as a function of throughput and expressions derived for the probability that the object chosen by the system as the target is actually a target. In order to validate the theoretical results, the actual performance of the detection system on a database of 68 infrared images is determined and compared with the predicted performance of the system. It is shown that there is good correspondence between the empirical results and the theoretical performance.     

结合核相关滤波器和深度学习的运动相机中无人机目标检测

针对无人机与相机快速相对运动造成的运动模糊问题，以及小型无人机外观信息缺失和背景复杂造成漏警和虚警问题，提出了一种新的无人机检测-跟踪方法。针对成像尺寸小于32像素×32像素的无人机目标，提出改进的多层特征金字塔的分类和目标框回归器作为目标检测器，克服漏警。利用检测结果初始化基于核相关滤波的目标跟踪器，并持续修正跟踪结果，跟踪结果为剔除检测器虚警提供依据。在跟踪过程中，引入对观测场景纹理自适应的相机运动补偿策略实现目标重定位。多场景下的实验结果表明：提出的方法在对高速运动小目标的检测和跟踪指标上显著优于传统方法，且运动补偿机制的引入进一步增强了方法在极端复杂场景下的鲁棒性。     

基于红外视觉/激光雷达融合的目标识别与定位方法

近年来,基于可见光图像的目标识别在无人车感知领域得到了广泛应用.然而,可见光图像目标识别无法应用于弱光和黑暗环境.针对于此,提出了一种基于红外视觉/激光雷达融合的目标识别与定位算法.首先,通过基于颜色迁移的数据增强训练方法,提高了红外目标识别算法的泛化性能.继而,提出了一种基于激光雷达修正的单目深度估计方法,通过视觉图...     

红外航空图像自动目标识别的形态滤波神经网络算法

 提出了一种有实用意义的形态滤波神经网络模型及其自适应 BP学习算法。形态滤波网络的优化设计过程实际上是网络参数 (结构元素 )不断调整、逐步适应图像环境的优化学习过程,从而将目标客体的特征规律反映到网络结构上来,以实现对复杂变化的图像具有良好的滤波性能和稳健的适应能力。为结合运动图像目标的检测需要,采用了渐进收缩误差、适时校正网络权值的动态跟踪学习算法。通过实验结果可以看出,该算法不仅能适应复杂多样的背景环境,而且对运动目标的连续检测能力具有位移不变、伸缩不变和旋转不变的特性。     

Optimal polarimetric processing for enhanced target detection

The results of a study of several polarimetric target detection algorithms are summarized. The algorithms were tested using real target-in-clutter data collected by the Lincoln Laboratory 35 GHz synthetic aperture radar (SAR) sensor. Fully polarimetric measurements (HH, HV, VV) are processed into intensity imagery using adaptive and nonadaptive polarimetric whitening filters (PWFs). Then a two-parameter constant false alarm rate (CFAR) detector is run over the imagery to detect the targets. Nonadaptive PWF processed imagery is shown to provide better protection performance than either adaptive PWF processed imagery or single-polarimetric-channel HH imagery. In addition, nonadaptive PWF processed imagery is shown to be visually clearer than adaptive processed imagery     

基于红外视频的火灾探测算法

视频火灾探测技术成为火灾探测的主要研究方向之一,该技术的难点是保证对火灾准确快速地探测。针对目前视频火灾探测识别率较低、报警时间较长的问题,为了提高火灾识别率,增强算法实时性,本文提出一种红外视频的火灾火焰探测方法,采用带有截止可见光透红外滤波片的摄像头采集现场红外影像,结合火焰的静态和动态特征,对火灾进行准确快速探测,同时,综合运用火焰圆形度和尖角个数变化判据对稳定火焰和非稳定火焰进行区别,实现对火灾的分级报警。实验结果表明,改进算法对火焰识别的准确性高,抗干扰能力较强,并且具有显著的快速性,其处理速度达到20ms/帧,并且系统平均报警时间小于200ms。     

Doppler and direction-of-arrival (DDOA) radar for multiple-mover sensing

A low-cost two-element receiving array concept is investigated for detecting multiple moving targets in indoor surveillance applications. Conventional direction-of-arrival (DOA) detection requires the use of an antenna array with multiple elements. Here we investigate the use of only two elements in the receiver array. The concept entails resolving the Doppler frequencies of the returned signals from the moving targets, and then measuring the phase difference at each Doppler frequency component to calculate the DOA of the targets. Simulations are performed to demonstrate the concept and to asses the DOA errors for multiple movers. An experimental system is designed and constructed to test the concept. The system consists of a two-element receiver array operating at 2.4 GHz. Measurement results of human subjects in indoor environments are presented, including through-wall scenarios.     

Ralph: A Visible/Infrared Imager for the New Horizons Pluto/Kuiper Belt Mission

The New Horizons instrument named Ralph is a visible/near infrared multi-spectral imager and a short wavelength infrared spectral imager. It is one of the core instruments on New Horizons, NASA’s first mission to the Pluto/Charon system and the Kuiper Belt. Ralph combines panchromatic and color imaging capabilities with SWIR imaging spectroscopy. Its primary purpose is to map the surface geology and composition of these objects, but it will also be used for atmospheric studies and to map the surface temperature. It is a compact, low-mass (10.5 kg) power efficient (7.1 W peak), and robust instrument with good sensitivity and excellent imaging characteristics. Other than a door opened once in flight, it has no moving parts. These characteristics and its high degree of redundancy make Ralph ideally suited to this long-duration flyby reconnaissance mission.     

红外极小目标检测算法研究

低信噪比检测技术是实现红外自动目标识别的基本前提,其性能指标将直接决定系统探测距离的远近,是反映红外低可观测目标识别能力至关重要的一项核心技术。自适应背景估计方法是实现这一目标的有效途径。本文在重点论述几种背景估计常用技术的基础上,提出了红外极小目标的形态滤波优化改进算法,通过理论分析和实验检测表明：该算法简化了形态变...     

多弧离子镀Cr/Cr2O3薄膜红外及可见光谱特性

采用多弧离子镀制备了具有不同色彩的Cr/Cr2O3薄膜,利用紫外-可见光分光光度计研究了薄膜在可见和红外波段的光谱特性,利用SEM进行薄膜表面结构和形貌的分析,利用四探针测阻仪测试了样品的方块电阻,利用红外发射率测量仪测试了样品的红外发射率。结果表明:Cr/Cr2O3薄膜具有丰富的色彩,在可见光区有明显的反射峰,可见光区光谱特性主要受膜厚的影响,方块电阻随膜厚增加而有变大,样品的红外发射率主要取决于金属层,平均红外发射率最小降至0.371。     

曲面红外测温方向性误差分析与修正方法研究

通过实验验证与理论分析,探讨了曲面特征的红外辐射测温特性。研究结果表明：曲面红外辐射测温在本质上与平面辐射测温相同,满足同一数学表达式;出现曲面红外测温失真的根本原因是被测表面等效面出现了不满足表面漫射条件假设的状况,这主要是由被测表面法向与测量方向夹角过大导致的;通过测量当地表面发射率可以校正因等效面不满足漫射条件假设造成的红外测温结果失真。     

曲面红外测温方向性误差分析与修正方法

通过实验验证与理论分析,探讨了曲面特征的红外辐射测温特性.研究结果表明:曲面红外辐射测温在本质上与平面辐射测温相同,满足同一数学表达式;出现曲面红外测温失真的根本原因是被测表面等效面出现了不满足表面漫射条件假设的状况,这主要是由被测表面法向与测量方向夹角过大导致的;通过测量当地表面发射率可以校正因等效面不满足漫射条件假设造成的红外测温结果失真.      

弹道导弹中段目标/背景红外图像建模与仿真

提出了一种针对弹道导弹中段目标和背景的动态红外辐射特性仿真方法。首先,建立了弹头目标^秀饵的三维模型,并结合其运动位置分析了影响弹头目标／诱饵红外辐射的因素,建立了较为完善的弹头目标/诱饵红外物理模型;其次,基于红外星表数据对恒星大气层外的辐照度进行了计算,根据红外传感器视轴指向和红外传感器视场,确定了红外传感器视场中的可见恒星,并根据拟生成背景图像的空间分辨率计算出这些恒星在背景图像中的相对位置分布,对星空背景直接进行了动态图像生成;然后,对成像过程中红外探测系统的噪声效应进行了建模与分析,同时给出了噪声的计算机模拟方法;最后,将生成的弹头目标,诱饵的红外图像与星空背景红外图像在灰度和空间2个层次上进行合成形成完整的弹头目标赝饵／星空背景的红外仿真图像,可为弹道导弹中段红外电子对抗突防提供较为准确的数据支持。     

基于自适应混合高斯模型的运动目标检测

随着智能视频监控应用领域的不断拓展,为了在各种复杂场景下都能快速稳定地检测出运动目标,众多研究者提出了很多解决方法。鉴于背景减除法自身在算法理论的复杂度小,且对不同场景适应性强的优点,成为运动目标检测研究领域的基础方法。而在背景减除法的各种背景建模方法中,混合高斯模型方法以其适应性强、灵活高效的优点成为该领域的经典方法。详细介绍了背景更新机制中常用的混合高斯模型,并据此研究了基于自适应更新率的高斯背景建模方法,经过对比试验,论证了改进方法在建模速度上的大幅度提升。     

光电稳定平台红外光轴对准方法

光电稳定平台中,红外光学器件以其特有的优势越来越多地被采用。精确、快速地对红外光轴进行校准和标定是红外器件应用的一个重要课题。本文介绍了一种基于红外准直仪原理设计的红外光轴校准系统,对靶标位置偏差造成的光轴偏差进行了分析计算,并提出了确定抛物面镜光轴的具体方法。研制了红外光/可见光靶标模拟器,解决了无人机光电稳定平台中红外热像仪与其他可见光光学器件的光轴平行度校准、红外光轴相对系统零位基准标定等问题。所述方法经试验证明,在目前不具备红外准直仪的条件下同样实现了较高精度的红外光轴校准和标定,有着重要的实际工程意义。     

可见光迷彩低红外发射率薄膜制备及其特性

采用多弧离子镀技术,在Al基底上制备了TiO2/TiN多层膜。通过控制基底材料的粗糙度使制备出的薄膜在可见波段具有非镜面反射效果。采用扫描电镜、红外辐射率测量仪、紫外-可见-近红外光光度计等测试手段对薄膜样品进行了表征。结果表明,采用多弧离子镀法在Al基底上制备了结合力良好、具有迷彩效果的低红外发射率薄膜。研究发现,随氧化层厚度增加,薄膜发射率趋向稳定(0.2左右)。薄膜电阻随氧化层厚度的变化无明显变化。