Driggers Ronald, Furxhi Orges, Vaca Gonzalo, Reumers Veerle, Vazimali Milad, Short Robert, Agrawal Prashant, Lambrechts Andy, Charle Wouter, Vunckx Kathleen, Arvidson Carl
Appl Opt. 2019 May 1;58(13):D98-D104. doi: 10.1364/AO.58.000D98.
The Florida Everglades is infested with Burmese pythons caused by the release of exotic pets in the 1980s. The current estimates are between 30,000 and 300,000 pythons, where the result is a severe decline in Everglade mammals: 90% reductions in raccoon, opossum, bobcats, and foxes. The marsh rabbits are completely gone. The population of the pythons is rapidly increasing exponentially with 20-50 eggs per snake with a life span of up to 20 years. Pythons have been captured in the Everglades with lengths of nearly 6 m. Researchers in the state of Florida are concerned that these pythons are (1) permanently damaging the Everglades, (2) migrating further north into populated areas of Florida, and (3) endangering wildlife, pets, and eventually, people. There have been a number of sensing efforts attempted in the large-area detection of pythons, where limited success has been achieved. For example, infrared sensors have been applied to the problem, but the pythons are cold-blooded, so the infrared bands do not work well. Imec has leveraged its expertise and infrastructure in semiconductor processing to produce highly compact, higher performance, and relatively cheaper hyperspectral image sensors and camera systems. In this work, Imec teamed with the University of Florida and Extended Reality Systems to obtain hyperspectral reflectivity measurements of Burmese pythons along with natural Florida background foliage to determine bands or band combinations that may be exploited in the large-area detection of pythons. The bands investigated are the visible-near infrared (or VisNIR) and the shortwave infrared (SWIR) bands. The results show that there are enough differences in the data collection such that a single band, inexpensive VisNIR band camera may provide reasonable results and a two-band, VisNIR/SWIR combination may provide higher performance results. In this paper, we provide the VisNIR results.
佛罗里达大沼泽地因20世纪80年代外来宠物被放生而遭到缅甸蟒的侵扰。目前估计有3万至30万条缅甸蟒，导致大沼泽地哺乳动物数量急剧下降：浣熊、负鼠、山猫和狐狸的数量减少了90%。沼泽兔已完全绝迹。缅甸蟒的数量正以指数级迅速增长，每条蛇可产20至50枚卵，寿命长达20年。在大沼泽地捕获的缅甸蟒长度近6米。佛罗里达州的研究人员担心这些蟒蛇会：（1）对大沼泽地造成永久性破坏；（2）向北进一步迁徙至佛罗里达州人口密集地区；（3）危及野生动物、宠物，最终还会危及人类。在大面积检测蟒蛇方面已经进行了多次传感尝试，但取得的成功有限。例如，红外传感器已被用于解决这个问题，但蟒蛇是冷血动物，所以红外波段效果不佳。imec利用其在半导体加工方面的专业知识和基础设施，生产出高度紧凑、性能更高且相对便宜的高光谱图像传感器和相机系统。在这项工作中，imec与佛罗里达大学和扩展现实系统公司合作，获取缅甸蟒以及佛罗里达州自然背景植被的高光谱反射率测量数据，以确定可用于大面积检测蟒蛇的波段或波段组合。所研究的波段是可见近红外（VisNIR）和短波红外（SWIR）波段。结果表明，数据采集存在足够的差异，使得单波段、价格低廉的VisNIR波段相机可能会提供合理的结果，而双波段、VisNIR/SWIR组合可能会提供更高性能的结果。在本文中，我们给出了VisNIR的结果。
