Modelling Sea Surface Wind Vectors with Coherent Dual Polarization Synthetic Aperture Radar

使用相干双偏振合成孔径雷达模拟海面风矢量

• 批准号: RGPIN-2018-04221
• 负责人: Collins, Michael
• 金额: $ 3.13万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=647941
• 关键词: Modelling; Sea; Surface; Wind; Vectors

Canada is a maritime nation, whose economy and general well-being is closely tied to the sea. The sea ice in Canada's Arctic continues to reach annual minima that exceed historical levels, increasing ship traffic and resource exploitation, as well as extending the iceberg season in eastern Canada. Massive cruise ships are starting to ply the waters of the Northwest Passage and Baffin Bay exposing northern communities to new economic opportunities. Yet, global warming, which has created these ice-free conditions, has also led to extreme weather, which increases the risks of maritime operations in the North.******The overall objective of this research is to improve Canada's capability of monitoring the wind field in Canada's north, including the channels between the Arctic islands, and the waters between Greenland and Newfoundland.******An imaging radar is the perfect instrument for gathering information over Canada's northern waters as it is capable of imaging night or day and in all weather, including thick clouds. Imaging radar can transmit and receive microwaves at certain polarizations, like polarizing sunglasses can block out light reflected from the water that has a certain polarization. The Canadian Space Agency is preparing to launch a new generation of imaging radar satellites, called the Radarsat Constellation Mission or RCM. These new satellites will be able to transmit one polarization, and create one image, at the same polarization that was transmitted, plus a second image at the exact opposite polarization. This is called dual-polarization.******In this research I will explore the use of dual-polarized radar images of the sea to create maps of wind speed and direction. To do this I will look at the intensity of the energy in each image, and I will combine this with the Doppler frequency in each image. The Doppler effect is the change in frequency of a wave that is received by a moving receiver. You hear this effect when a fire engine drives past you - it is a high pitched sound as it approaches, and a lower pitched sound as it drives away. As the radar approaches a patch of sea surface it is at a higher frequency, and as it flies past the frequency gets lower. This situation gets more complicated as the receiver moves, e.g. if the fire engine is driving towards you as you are riding your bike. The frequency on approach is even higher and gets even lower as the radar passes by. This effect is predictable (and different for each polarization), and is related to the movement of the sea surface, and in turn to both the wind speed and direction, which is what I will estimate.

加拿大是一个海洋国家，其经济和一般福祉与大海紧密相关。 加拿大北极的海冰继续达到超过历史水平的年度最小值，增加了船舶交通和资源开发，并延长了加拿大东部的冰山季节。大型巡航船开始在西北通道的水域和巴芬湾的水域中占据，使北部社区接触了新的经济机会。 然而，创造了这些无冰条件的全球变暖也导致了极端天气，这增加了北部海上行动的风险。******这项研究的总体目标是提高加拿大的能力监视加拿大北部的风场，包括北极群岛之间的渠道以及格陵兰和纽芬兰之间的水域。白天或白天以及在所有天气中，包括厚云。 成像雷达可以在某些极化上传输和接收微波，例如偏振太阳镜可以阻止从具有一定极化的水反射的光。 加拿大航天局正在准备发射新一代的成像雷达卫星，称为Radarsat Constellation Mission或RCM。 这些新的卫星将能够在传播的相同极化下以及在完全相反的极化下的第二个图像上传输一个极化，并创建一个图像。 这被称为双极化。******在这项研究中，我将探索使用海洋双极化雷达图像来创建风速和方向的地图。 为此，我将查看每个图像中能量的强度，并将其与每个图像中的多普勒频率结合在一起。 多普勒效应是移动接收器接收的波的频率的变化。 当消防车驶过您时，您会听到这种效果 - 当它接近时，它是一种高音调的声音，并且在驱动器驱动时发出了较低的声音。 当雷达接近海面的斑块时，它处于较高的频率，并且飞越频率时，频率较低。 随着接收器的移动，这种情况变得更加复杂，例如如果消防车在骑自行车时向您开车。 接近的频率更高，随着雷达的流逝，频率甚至更低。 这种效果是可以预测的（对于每个极化而言是不同的），并且与海面的运动有关，进而与风速和方向相关，这是我将估计的。