Correcting for the influence of frozen lakes in satellite microwave radiometer observations through application of a microwave emission model

The spatial resolution of passive microwave observations from space is of the order of tens of kilometers with currently available instruments, such as the Special Sensor Microwave/Imager (SSM/I) and Advanced Microwave Scanning Radiometer (AMSR-E). The large field of view of these instruments dictates that the observed brightness temperature can originate from heterogeneous land cover, with different vegetation and surface properties.In this study, we assess the influence of freshwater lakes on the observed brightness temperature of AMSR-E in winter conditions. The study focuses on the geographic region of Finland, where lakes account for 10% of the total terrestrial area. We present a method to mitigate for the influence of lakes through forward modeling of snow covered lakes, as a part of a microwave emission simulation scheme of space-borne observations. We apply a forward model to predict brightness temperatures of snow covered sceneries over several winter seasons, using available data on snow cover, vegetation and lake ice cover to set the forward model input parameters. Comparison of model estimates with space-borne observations shows that the modeling accuracy improves in the majority of examined cases when lakes are accounted for, with respect to the case where lakes are not included in the simulation. Moreover, we present a method for applying the correction to the retrieval of Snow Water Equivalent (SWE) in lake-rich areas, using a numerical inversion method of the forward model. In a comparison to available independent validation data on SWE, also the retrieval accuracy is seen to improve when applying the influence of snow covered lakes in the emission model.     

Mapping arctic landfast ice extent using L-band synthetic aperture radar interferometry

In recent years methods have been developed to extract the seaward landfast ice edge from series of remote sensing images, with most of them relying on incoherent change detection in optical, infrared, or radar amplitude imagery. While such approaches provide valuable results, some still lack the required level of robustness and all lack the ability to fully automate the detection and mapping of landfast ice over large areas and long time spans. This paper introduces an alternative approach to mapping landfast ice extent that is based on coherent processing of interferometric L-band Synthetic Aperture Radar (SAR) data. The approach is based on a combined interpretation of interferometric phase pattern and interferometric coherence images to extract the extent and stability of landfast ice. Due to the low complexity of the base imagery used for landfast ice extraction, significant improvements in automation and reduction of required manual interactions by operators can be achieved. A performance analysis shows that L-band interferometric SAR (InSAR) data enable the mapping of landfast ice with high robustness and accuracy for a wide range of environmental conditions.     

南水北调邢石段弧形闸门埋件融冰设计

针对南水北调总干渠四季输水的要求和弧门冬季运行的设计工况,采用了以超导液为传热介质、以电加热管和电加热器为加热源的新型电加热融冰装置。从融冰设备的工作原理、融冰设备的结构与布置、组装与试验及融冰设备的保温等方面分别进行了阐述,为有冬季运行需要融冰的工程提供了设计实例。     

微/纳米流体控制用冰阀器件执行过程的数值模拟

冰阀是一种利用微/纳米流道内流体自身的冻结/融化相变过程来实现关断或开启作用的新型流体元件.由于无运动部件、无泄漏、不会引起流体污染且易于实现电控等优点,该器件在微/纳米流体系统的控制中具有重要的应用前景.针对冰阀的工作原理,基于相应的流体力学及传热学数学模型,从数值计算角度对微流道冰阀器件的执行过程进行了模拟,并开展了相应的参数化研究,在此基础上可对冰阀的工作状态及控制过程更好地加以理解和剖析.     

微波除冰方法研究

为解决我国北方寒冷地区冬季道路积冰不易清除的问题,提出了应用微波加热清除道路积冰的设想.通过实验证实了冰不易吸收微波,而路面材料能够吸收大量微波.因此,微波能够透过冰层加热路面,使贴近路面的冰层融化,消除冰层与路面之间的结合力,然后就可以很容易地利用除冰机械对其清除,这样,就消除了纯机械除冰的弊病.     

人造滑冰场制冰技术及使用维护探讨

室内人造滑冰场是国内新兴的娱乐性体育活动场所，具有很大的开发潜力。介绍了冰场制冰原理、技术及冰面使用维护措施，并对两种不同的冰场制冰排管布置方式做了较为全面的比较分析。     

背光成像技术测量冷冻靶参数研究进展

建立了可见光背光成像装置,测量距离实现了4~30 cm可调,对应分辨率为0.7 ~4.6 μm,并可对样品仓内的冷冻靶进行有效的中心定位,定位精度达0.1 mm,获得了不同分辨率下的塑料靶球与玻璃靶球的背光影像。通过获得背光图像的能量密度图及靶球的光路追踪模型,建立了靶球内部DD/DT冰层厚度的精确测量及计算方法。研究发现,将背光成像技术与干涉条纹法相结合可获得一种无损测量透明聚变靶丸材料折射率的方法。结果表明,背光成像技术是透明冷冻靶有效的诊断方法。     

水电站零压起动和变频技术在线路融冰中的应用

通过理论计算和现场在用的设备相结合,利用小水电站零电压起动、变频,均压起励的方法融冰取得良好、效果。     

高分子吸水树脂作为蓄冷材料的性能研究

研究了不同吸水倍率的高分子吸水树脂的相变温度、相变潜热及作为蓄冷材料在35℃环境下的相变时间,并与冰做了对比。结果显示:吸收不同倍率水的高分子树脂,相变温度和相变潜热基本与水相似,随着吸水倍率的增加,相变潜热越接近于水的潜热;在相同条件下放置于隔冷袋中的高分子吸水树脂,在35℃的高温环境中,可以维持20℃以下低温5h,比冰多了将近1h,克服了渗漏的缺点,在蓄冷领域表现出了明显的优势。