Paper Title
Visibility Measurement by Image Analysis from UAS

Abstract
Visibility is the visible distance between target and the observer. It refers to the maximum distance from the background to the contour of the target when observing the target. Air pollution has strong correlation to air visibility that is also one of the important meteorological observations. We all know that air is a necessity for human living. However, low visibility will cause dangerous to ferries, civil aviation, highways, and all the other transportation; furthermore, polluted air is hazarded to human’s health. Therefore, it has many negative effects on people’s lives and living safety. Nowadays, due to the increasing industrial development, air pollution causes this seemingly significant problem to us. In the past decades, terrible traffic accidents caused by low visibility occurred frequently. The observation of visibility and the development of its instruments have attracted attention in many countries around the world. However, most of the instruments for air visibility measure are very expensive. In recent years, UAS has been more and more popular due to its low cost and stable which made it a mature product could be used in daily usage. Our research developed a UAS system equipping with a high-resolution camera to take picture and using the wavelets transform for image analysis to determine the visibility of the air. We set up the UAS to fly and take picture in the same altitude and location periodically to training the basic visibility measurement model. In practical application, we just fly to the UAS or the smart phone to take pictures; the system will analyze and give you the visibility quality for you to refer. Besides, it can also show you the area of air quality in our system. Experimental results show that it is a useful system to protect your body health and safety for daily usage. Index Terms - UAS, visibility measurement, image analysis, wavelets