Implementation of CILCO (Compact Instrument for Longwave Cirrus Observations)

该项目的目的是建立一种能够精确测量卷云的新型仪器。卷云是高海拔（8- 12公里）的冰粒子云，对地球的能量平衡有重大影响。这种新型仪器的测量结果表明，它们将提高我们对气候变化和天气预测的理解。为了对全球的长期和短期气候做出准确的预测，需要通过使用新的技术和方法来改进目前对卷云特性的认识。远红外和亚毫米波长的光非常适合测量卷云，因为该波长与发现的冰粒直径相似。这些测量提供了关于冰粒大小、粒子密度和粒子形状的信息。卷云参数是通过将仪器飞到卷云上方并使其面向地球来测量的。一些从低层大气发出的远红外线被云内的冰粒散射。相对于晴空条件，这种散射被仪器观察为减弱的信号。在多个波长处测量该信号减少的量，然后可以将其与模型进行比较以确定云的特性。拟议中的仪器在不同的波长上不同于目前的仪器，因为这种技术直接测量了一些重要的卷云特性，这是使用其他方法无法实现的。这项新技术已经通过使用一种名为FIRSC（远红外线卷云传感器）的类似仪器的模型和数据得到了证明。新仪器将不会像FIRSC那样测量连续光谱，而是测量光谱的离散部分，这些部分由光谱区域之间的“窗口”确定，这些光谱区域由于存在大气水蒸气而严重吸收光。因此，它的独特之处在于，它将准确地测量卷云属性，不使用移动部件，使用固定的频率通道，与机械驱动的光谱仪相对。这使得该仪器成本低、重量轻、体积小、操作简单并且非常可靠，从而形成易于安装在一系列飞行器上的封装。将来，这种仪器可以用这种机载辐射计作为原型安装在卫星上。

The purpose of this project is to build a novel instrument capable of making accurate measurements of cirrus clouds. Cirrus are high altitude (8-12km) ice particle clouds that have a significant effect on the Earth's energy balance. Measurements from this new type of instrument have been shown that they will improve our understanding of climate change and weather predictions. In order to make accurate global predictions of long and short term climate, current knowledge of cirrus properties need to be improved by using new technology and techniques. Light at far infrared and submillimeter wavelengths is ideally suited to measuring cirrus since this wavelength is similar to diameters of ice particle found. These measurements provide information about ice particle size, particle density and particle shape. Cirrus parameters are measured by flying the instrument above the cirrus and facing it towards the Earth. Some of the far-infrared light emitted from the lower atmosphere is scattered by ice particles within the cloud. Relative to clear sky conditions, this scattering is observed by the instrument as a reduced signal. The amount by which this signal is reduced is measured at a number of wavelengths which can then be compared to a model to determine cloud properties. The proposed instrument differs from current instruments at different wavelengths, as this technique directly measures some of the important cirrus properties, which is not possible using the other methods. The new technique has been proven using models and data from a similar instrument called FIRSC (Far InfraRed Sensor for Cirrus). The new instrument will not measure a continual spectrum like FIRSC, but instead discrete parts of the spectrum that are determined by 'windows' between spectral areas that heavily absorb light due to ever present atmospheric water vapour. It will therefore be unique in that it will accurately measure cirrus properties using no moving parts, using fixed frequency channels as apposed to a mechanically driven spectrometer. This makes the instrument low cost, light, small, simple to operate and extremely reliable which results in a package that is easily mountable on a range of aircraft. In the future, this kind of instrument could be satellite mounted using this airborne radiometer as a prototype.