Finding and tracking radioactive sources have numerous security applications in civilian energy installations, military facilities, and ports of entry. The price of radiological sensors varies proportionally to size and imaging characteristics such as angular resolution, and the cheapest devices are nearly isotropic-i.e., they integrate radiation from a sphere of directions centered at the sensor. While many radiation sensors have high aspect ratios or odd shapes, the sensors used here are right cylinders, with a near identical directional efficiency such that for analysis purposes, other aspects, such as counting statistics, would make nonisotropy of the sensor negligible. In this article, we propose a simple and robust way to integrate measurements from both isotropic radiological sensors and depth sensors, whose reliability and resolution benefit from recent advances in computer vision and imaging. Our key idea is to convert all sensor measurements into proximity signals based on radial distance variations over time. Based on this sensor fusion model, we show that for moving radiological sources even a simple Kalman filter can trade-off the complementary strength of high-resolution depth sensors and isotropic radiological sensors. We show novel results with a LIDAR sensor and a thermal stereo pair, and demonstrate applications such as tracking and rendering non-line-of-sight imagery behind obstacles and detecting multiple radiological sources in the same scene.

中文翻译：

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深度相机和各向同性辐射探测器的基于接近传感器的融合


寻找和跟踪放射源在民用能源设施、军事设施和入境口岸中有许多安全应用。放射传感器的价格与尺寸和成像特性（例如角分辨率）成正比，最便宜的设备几乎是各向同性的，即它们集成了来自以传感器为中心的方向球体的辐射。虽然许多辐射传感器具有高纵横比或奇怪的形状，但这里使用的传感器是正圆柱体，具有几乎相同的方向效率，因此出于分析目的，其他方面（例如计数统计数据）将使传感器的非各向同性可以忽略不计。在本文中，我们提出了一种简单而强大的方法来集成各向同性放射传感器和深度传感器的测量，其可靠性和分辨率受益于计算机视觉和成像的最新进展。我们的关键思想是根据径向距离随时间的变化将所有传感器测量结果转换为接近信号。基于这种传感器融合模型，我们表明，对于移动放射源，即使是简单的卡尔曼滤波器也可以权衡高分辨率深度传感器和各向同性放射传感器的互补强度。我们展示了激光雷达传感器和热立体对的新颖结果，并演示了跟踪和渲染障碍物后面的非视距图像以及检测同一场景中的多个放射源等应用。