Miniaturised Hyperspectral Imager for Remotely Piloted Aircraft Surveys

物体的颜色，例如一棵树或一片草地，是由光与物体的材料（树叶、树干、土壤）相互作用的方式来控制的。通过测量物体的颜色（它的反射光谱），我们可以计算出存在什么物质，有多少物质，有时我们甚至可以计算出它们是健康的还是垂死的。光谱相机用于使用不同颜色（波长）的光从远处拍摄物体的图像。通过在绕地球运行的卫星上安装光谱相机，我们可以监控地球的广大地区；整个海洋和大陆。然而，卫星上的光谱相机通常被设计为覆盖大面积（宽带），许多不能解决~1km以下的小特征。卫星相机也受限于不能透过云层看东西。这意味着我们需要一种不同的车辆来安装光谱相机，用于当地研究，例如河流，湖泊，河口或观看田地和森林的高分辨率图像。多年来，人们一直用飞机来做这件事，非常成功，但它们的运行成本很高，而且很难组织起来，让飞机与地面或船上的人同时到达偏远地区。最近，一种新型的遥控飞机（RPA——也被称为无人机）已经变得足够便宜和可靠，以至于个人或小型研究小组都有能力购买和操作它们。这些rpa很小，很容易发射和降落，如果我们能把光谱相机做得足够小，可以安装在上面，它们就可以成为一个非常有用的平台，用于高质量的环境调查。这个项目将尝试开发一种小型光谱相机，它足够轻，可以在RPA上使用。我们将构建相机，使其能够测量许多不同颜色的光（例如100种不同的颜色-高光谱）。我们将使用一种新型的光学滤光片来帮助减小尺寸和重量，我们将与爱丁堡的现场光谱学设施合作，以确保相机能够非常准确地读取每种颜色的光量。

The colour of an object, e.g. a tree or a field of grass, is controlled by the way in which light interacts with the material of the object (leaves, trunk, soil). By measuring the colour of an object (its reflectance spectrum), we can work out what materials are present, how much of them are there, and sometimes we can even work out whether they are healthy or dying. Spectral cameras are used to take images of objects from a distance using different colours (wavelengths) of light. By putting spectral cameras on satellites orbiting the Earth, we can monitor vast areas of the planet; whole oceans and continents. However spectral cameras on satellites are generally designed to cover big areas (wide swath) and many are not able to resolve small features below ~1km. Satellite cameras are also limited by being unable to see through clouds. This means we need a different vehicle to mount spectral cameras on for local studies of e.g. rivers, lakes, estuaries or for seeing high resolution images of fields and forests. Aircraft have been used to do this for many years, very successfully, but they are expensive to run and it is very hard to organise getting the aircraft out to a remote location at exactly the same time as people on the ground or on a boat. Recently a new type of remotely piloted aircraft (RPA - also known as a drone) has become cheap enough and reliable enough for it to be possible for individuals or small research groups to be able to afford to buy and operate them. These RPAs are small and easily launched and landed, and if we could make spectral cameras small enough to mount on them, they could be a really useful platform for high quality environmental surveys. This project will try to develop a small spectral camera that is light enough to be able to use it on an RPA. We will build the camera so that it is able to measure many different colours of light (e.g. 100 different colours - hyperspectral). We will use a new kind of optical filter to help keep the size and weight down and we will work with the Field Spectroscopy Facility in Edinburgh to make sure that the camera gives very accurate readings of the amount of light of each colour.