据外媒报道，几十年前，Arthur C. Clarke设想了一种“水下望远镜”，它可以让使用者从海洋表面向下看并进入它漆黑的深处。现在，利用现有技术，这样的能力离现实又更近了一步。通常情况下，当科学家们想要监测诸如海藻大量繁殖等生态上重要的现象时，他们会利用卫星拍摄的照片。然而根据缅因州毕格罗海洋科学实验室的研究人员，卫星摄像机通常只能“看到”5到10米深的海洋。 Pc7 : hu c P1jw%3P
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o W[,EW+u 为了寻找更好的替代方案，由Barney Balch博士领导的毕格罗团队转向了舰载激光雷达(LiDAR)装置。这种技术在机器人和自动驾驶汽车上更为常见，激光雷达设备通过发射激光束来工作，然后测量光线从任何物体反射回来所需要的确切时间。这种方法不仅可以检测到障碍物的存在，还可以检测到它们跟用户的距离以及它们的轮廓。 8Vn6* Xn (*RybKoaA Balch的团队跟弗吉尼亚奥多明尼昂大学的同事一起将这项技术用于2018年在缅因湾的一次巡航研究。通过这种方式他们成功地收集到了关于颗石藻爆发的信息。 -!0LIr:" z~ H Gc"~ 这些生物用碳酸钙板保护自己，其以一种独特的方式散射反射光。因此，科学家们能通过分析反射的激光确定海藻的存在以及数量。 Wj:QC<5
v nB5[]x' 事实上，该地区正经历着过去30年来最大的颗石藻爆发。通过使用激光雷达，其可以比使用卫星照片看到的深度多三倍。 UW*aSZ/? %RN -J *s] 该技术已经在其他地区成功测试，如马尾藻海和纽约市海岸。研究人员希望，激光雷达最终能让科学家们快速、以更低成本、容易地收集到海洋数据，而不需要停下船去收集深海样本。 /pU6trIM \uk #pL Balch说道：“对一种工具的利用让我们可以更深入地观察海洋，就像拥有了一双新的眼睛。”
Researchers have advanced a new way to see into the ocean's depths, establishing an approach to detect algae and measure key properties using light. A paper published in Applied Optics reports using a laser-based tool, lidar, to collect these measurements far deeper than has been typically possible using satellites. ;J(,F:N "Traditional satellite remote sensing approaches can collect a wide range of information about the upper ocean, but satellites typically can't 'see' deeper than the top five or 10 meters of the sea," said Barney Balch, a senior research scientist at Bigelow Laboratory for Ocean Sciences and an author of the paper. "Harnessing a tool that lets us look so much deeper into the ocean is like having a new set of eyes." QYgN39 gp Lidar uses light emitted by lasers to gain information about particles in seawater, much as animals like bats and dolphins use sound to echolocate targets. By sending out pulses of light and timing how long it takes the beams to hit something and bounce back, lidar senses reflective particles like algae in the water. 9|?Lz Lead study author Brian Collister used a shipboard lidar system to detect algae and learn about conditions deeper in the ocean than satellites can measure. The research team on this 2018 cruise was composed of scientists from Old Dominion University and Bigelow Laboratory for Ocean Sciences. ^\&g^T% "The lidar approach has the potential to fill some important gaps in our ability to measure ocean biology from space," said Collister, a PhD student at Old Dominion University. "This technique will shed new light on the distribution of biology in the upper oceans, and allow us to better understand their role in Earth's climate." Yp]G)}'R In the Gulf of Maine, the team used lidar to detect and measure particles of the mineral calcium carbonate, gathering information about a bloom of coccolithophores. These algae surround themselves with calcium carbonate plates, which are white in color and highly reflective. The plates scatter light in a unique way, fundamentally changing how the light waves are oriented - and creating an identifiable signature that the lidar system can recognize. (nD$%/uK' Balch's research team has studied the Gulf of Maine for over two decades through the Gulf of Maine North Atlantic Time Series. Their experience in finding and identifying algae in this ecosystem provided key background information for testing the lidar system in what turned out to be the largest coccolithophore bloom observed in the region in 30 years. R2a K5~ "This cruise allowed us an ideal opportunity to try the lidar system out with the ability to sample the water and know exactly what species were in it," Balch said. "Lidar has been used in the ocean for decades, but few, if any, studies have been done inside a confirmed coccolithophore bloom, which profoundly changes how light behaves in the environment." &f W=5' Coccolithophores thrive around the global ocean and exert a huge level of control on the biogeochemical cycles that shape the planet. Studying them is key to understanding global ocean dynamics, but field research is always costly. The team established that using lidar could potentially allow researchers to remotely estimate coccolithophore populations without stopping the ship to collect water samples - increasing their ability to collect valuable data, thus also conserving precious ship-time funds. ;q; C ^l The research team also tested this approach in ocean environments that included the clear depths of the Sargasso Sea and the turbid waters off the coast of New York City. They found it to be effective across these diverse environments. Lidar systems can probe the ocean up to three times deeper than passive satellite remote sensing techniques that rely on the sun. Further research may establish approaches that allow lidar measurements to be taken by satellites, as well. Tr0V6TS7 "It's a huge deal that we are learning to reliably identify particles in the ocean from a lidar system positioned above the water," said Richard Zimmerman, a study author and professor at Old Dominion University. "This is a significant advance, and it could revolutionize our ability to characterize and model marine ecosystems."
mang2004:Researchers have advanced a new way to see into the ocean's depths, establishing an approach to detect algae and measure key properties using light. A paper published in Applied Optics reports using a laser-based tool, lidar, to collect these measurements .. (2020-08-02 08:55) l-<3{!
Jh37 pI Hej, Mr. Mang! 8%;}LK Is it a paper? If yes, may I have the title for search. Thanks.
mang2004
2022-01-13 01:53
bairuizheng:Hej, Mr. Mang! j_!bT!8 Is it a paper? If yes, may I have the title for search. Thanks. (2022-01-03 01:29) F(d:t!
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