3D information from 2D images recorded in the European Modular Cultivation System on the ISS

The European Modular Cultivation System (EMCS) on the ISS allows long-term biological experiments, e.g. on plants. Video cameras provide near real-time 2D images from these experiments. A method to obtain 3D coordinates and stereoscopic images from these 2D images has been developed and is described in this paper. The procedure was developed to enhance the data output of the MULTIGEN-1 experiment in 2007. One of the main objectives of the experiment was to study growth movements of the Arabidopsis plants and the effect of gravity on these. 3D data were important during parts of the experiment and the paper presents the method developed to acquire 3D data, the accuracy of the data, limitations to the technique and ways to improve the accuracy. Sequences of 3D data obtained from the MULTIGEN-1 experiment are used to illustrate the potential of this newfound capability of the EMCS. In the experiment setup, a positional depth accuracy of about ±0.4 mm for relative object distances and an absolute depth accuracy of about ±1.4 mm for time dependent phenomena was reached. The ability to both view biological specimens in 3D as well as obtaining quantitative 3D data added greatly to the scientific output of the MULTIGEN-1 experiment. The uses of the technique to other researchers and their experiments are discussed.     

Effects of lighting and air movement on temperatures in reproductive organs of plants in a closed plant growth facility

Temperature increases in plant reproductive organs such as anthers and stigmas could cause fertility impediments and thus produce sterile seeds under artificial lighting conditions without adequately controlled environments in closed plant growth facilities. There is a possibility such a situation could occur in Bioregenerative Life Support Systems under microgravity conditions in space because there will be little natural convective or thermal mixing. This study was conducted to determine the temperature of the plant reproductive organs as affected by illumination and air movement under normal gravitational forces on the earth and to make an estimation of the temperature increase in reproductive organs in closed plant growth facilities under microgravity in space. Thermal images of reproductive organs of rice and strawberry were captured using infrared thermography at air temperatures of 10–11 °C. Compared to the air temperature, temperatures of petals, stigmas and anthers of strawberry increased by 24, 22 and 14 °C, respectively, after 5 min of lighting at an irradiance of 160 W m⁻² from incandescent lamps. Temperatures of reproductive organs and leaves of strawberry were significantly higher than those of rice. The temperatures of petals, stigmas, anthers and leaves of strawberry decreased by 13, 12, 13 and 14 °C, respectively, when the air velocity was increased from 0.1 to 1.0 ms⁻¹. These results show that air movement is necessary to reduce the temperatures of plant reproductive organs in plant growth facilities.     

一种航空图像道路中心线快速提取算法

经典的航空图像道路中心线提取算法针对非实时应用,计算耗时长,难以满足视觉辅助导航、实时地物识别等应用的要求。在研究了图像中道路法向和等效道路宽度的基础上,建立了近似道路法向和等效道路宽度模型来代替经典道路模型,提出了基于道路中心线的快速提取方法。对比实验的结果说明：快速提取方法和经典方法取得了相近的道路提取效果,计算耗时大大下降,可以满足实时性要求。     

基于衍射图像的大型光学镜面在位检测

介绍了相位恢复测量系统的软硬件实现原理。构建了由CCD移动平台等硬件装置和基于GS迭代算法的软件程序组成的实验平台。并对一面口径500mm的球面反射镜进行了在位加工环境下的测量实验。测试结果与干涉测量相比较表明测量数据准确,精度满足光学镜面研抛加工要求。     

Scalable Preparation of SrTiO3 Submicro-wires from Layered Titanate Nanowires

SrTiO3 submicro-wires were prepared by the reaction of layered titanate nanowires with Sr(OH)2 powder in an autoclave. The wires were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Ultra-violet visible (UV-vis), photoluminescence (PL) and Raman spectroscopy. The XRD measurement shows that the prepared SrTiO3 submicro-wires hardly have impurity phases. The SEM and TEM images demonstrate that the scalable wires, which need to be proc- essed at the reaction temperature of 180 ℃ for about 48 hours, are not composed of single crystals. The PL shows that the wire-like SrTiO3 has emission peaks at the wavelengths of 568 and 585 nm. Further, the Raman spectroscopy reveals structural changes in the products through different reaction time.     

高帧频数字相机在高速流动显示中的应用

根据高速流动显示实验研究对高帧频图像采集设备的需要,基于分幅式光路设计原理,结合快响应像增强器和低照度CCD相机,研制了一套兆赫兹采样的高帧频数字相机。利用高帧频数字相机,开展了高速流动显不实验研究：基于高帧频数字相机,结合纹影技术,在激波管上针对方块、凹槽模型,开展了高速流动显示实验,获取了运动激波与模型边界相互作用的序列图像,观察到湍流涡随时间演化发展的过程。结合一台输出功率为8W的连续激光光源和高帧频数字相机,建立了一套高速片光散射流动显示系统,获取了喷流的米氏散射序列图像。实验证明,基于高帧频数字相机的纹影及片光散射技术具备开展高速流动显示实验研究的能力。     

细缝裁减和非均匀映射结合的图像自适应方法

采用将细缝裁减和非均匀映射相结合的图像尺寸自适应框架,提出了一种基于内容的图像重要信息变形的度量方法.首先提取原始图像的重要性像素点,利用细缝裁减去掉一条像素细缝后,相应的重要性像素点会被更新.对于图像中保留的重要性像素点,计算它们的子图像平均偏差(ADSI,Average Difference of Sub Images);对于被移除的重要性像素点,计算它们的平均丢失能量(ALE,Average Lost Energy).通过ADSI和ALE可计算出重要信息变形的度量函数(IIDF,Important Information Deformation Function)的值,通过分析IIDF的趋势得到细缝裁减的终止条件,然后改用非均匀映射方法(non-homogeneous warping)将图像自适应到目标尺寸.实验结果证明,新方法处理的结果图像重要区域变形较小,并且计算效率比较高.     

Spiral eddies in the Baltic,Black and Caspian seas as seen by satellite radar data

Despite spiral eddies were first seen on the sea surface more than 40 years ago, there is still a lot of uncertainty concerning these eddies. The present paper is aimed to provide the comprehensive results on the occurrence and statistics of small-scale eddies in the three inner seas (the Baltic, Black and Caspian) using satellite synthetic aperture radar (SAR) images. The dataset used includes over 2000 medium resolution Envisat ASAR and ERS-2 SAR images obtained in 2009–2010 in the different parts of the seas mentioned. As a result of the analysis performed ∼14,000 vortical structures were detected. 71% of them were visualized due to surfactant films (“black” eddies), while 29% due to wave/current interactions (“white” eddies). Practically all the eddies detected were cyclonically rotating. Their diameter was within 1–20 km. Characteristic size of the “black” eddies in all the basins was discovered to be less than that of the “white” eddies. Characteristic eddy size for the Baltic, Black and Caspian seas proved to be strictly proportional to the values of the baroclinic Rossby radius of deformation typical for these basins. The “black” eddies did not demonstrate a significant connection with the basin- and meso-scale surface circulation of the seas. Most of the “white” eddies detected were attributed to the zones with the most intense drift currents, i.e. those along the western boundaries and (in the Baltic Sea only) in the elongated parts of the basin.     

Relationships between soil properties of the abandoned fields and spectral data derived from the advanced spaceborne thermal emission and reflection radiometer (ASTER)

The structural transformation of Polish agriculture after 1989 has been leading to significant changes in land use. As a result a large part of formerly ploughed fields lies abandoned and they occur across considerable variability in soil typological units. Accurate information about soil conditions within the abandoned fields facilitates proper management in the new socio-economic situation. Such information can be collected using satellite images since the structure and condition of the vegetation growing on the abandoned fields reflects soil properties. The objective of this study is to evaluate the relationships between physical and chemical attributes of soil within the abandoned fields and spectral reflectance patterns recorded by ASTER sensors onboard Terra Satellite. Soil samples were collected at five abandoned fields which have not been ploughed since 2000 and analyzed in the laboratory to determine their physical and chemical properties. Nine ASTER nearly cloud-free pictures were used for this study in order to derive the remote-sensing attributes of the abandoned fields. In order to evaluate the relationships between soil fertility and remotely sensed data, partial least-squares (PLS) and a multiple linear regression (MLR) analysis between these two datasets were carried out. In the regression analysis, only soil TEB (total exchangeable bases) stock in the whole profile displayed the highest correlation with remotely sensed data acquired in April and May and the best predictors were NDVI and LSWI vegetation indices.     

进动锥体目标散射特性仿真及实验分析

目标微动及结构参数的获取有助于弹道目标的识别。准确获得进动锥体目标散射特性的时频分布(TFD)、一维距离像及二维逆合成孔径雷达(ISAR)像分布是获取锥体目标微动及结构参数的关键。分析了进动锥体在窄带及宽带条件下的目标散射特性,总结了锥体目标强散射源在时频分布、距离像序列和ISAR像序列中的理论表现形式,并分析了存在锥面镜面散射时锥体目标散射特性,构建了进动锥体目标电磁回波仿真方法及微波暗室动态测试系统,通过仿真及测试数据得到了典型条件下锥体目标的散射特性,对比表明仿真及测试结果均与本文散射特性理论分布相一致,说明了本文所提散射特性理论分布与散射特性分析方法的正确性,可为分析弹道目标散射特性研究提供参考。