The researchers used satellite data that provided continuous high-resolution images of the busiest 15% of the world’s oceans from 2017 to 2021, and cross-checked this vast dataset with 53bn historical ship locations available through AIS.
研究人员使用了卫星数据,这些数据提供了2017年至2021年世界上15%活动最多的海洋的连续高分辨率图像,并通过AIS系统将这个庞大的数据集与530亿个历史船只位置进行了交叉核对。
They then trained neural networks to recognise ships, based on their characteristic glare of reflected light, and used data such as distance from port, daily speed and nearby signs of marine life to classify their activity.
然后,他们根据反射光特征训练神经网络来识别船只,并使用离港距离、每日速度和附近海洋生物迹象等数据来对船只的活动进行分类。
While noting that most vessels shorter than 15m probably escaped their view, they estimated a false positive rate of less than 2% for those they did identify.
虽然他们注意到大多数小于15米的船只可能逃脱了他们的视线,但他们估计,那些被他们识别出来的船只误报率不到2%。
Though legitimate reasons exist for sailing incognito, the researchers point to a number of suspicious sites of activity.
尽管隐身航行有正当的理由,但研究人员指出了一些可疑的活动地点。
These include a region in North Korean waters that the authors suggest corresponds to illegal fishing, having briefly boasted the world’s highest density of fishing vessels between 2017 and 2019.
其中包括朝鲜水域的一个地区,作者认为该地区与非法捕鱼有关,在2017年至2019年期间,该地区曾一度号称是世界上渔船密度最高的地区。
Meanwhile the Great Barrier Reef Marine Park, off the eastern coast of Australia, was visited by an average of three fishing vessels a day, suggesting possible unobserved environmental damage.
与此同时,澳大利亚东海岸的大堡礁海洋公园平均每天有三艘渔船到访,这表明可能存在未被察觉的环境破坏。
The researchers were also able to monitor the growth in stationary ocean-based infrastructure, an area where no comprehensive data is publicly available.
研究人员还能够监测固定的海洋基础设施的增长,这是一个没有公开全面数据的领域。
On the positive side, they found that the number of wind turbines in China increased by 900% between 2017 and 2021; Britain and Germany led growth in Europe with more modest figures of 49% and 28%, respectively.
在积极的方面,他们发现2017年至2021年间,中国的风力涡轮机数量增加了900%;英国和德国分别以49%和28%的适中数字引领欧洲经济增长。
However, the number of offshore oil structures also increased by 16% during that same period.
然而,同期海上石油结构的数量也增加了16%。
With improved satellite data, and yet more sophisticated algorithms, an even clearer picture of ocean traffic will soon emerge.
随着卫星数据改进,以及算法变得更复杂,一幅更清晰的海洋交通图景将很快出现。
The Flying Dutchmans of the world, wherever they may be, will be mysterious no longer.
世界上那些幽冥飞船,无论它们身在何处,都将不再神秘。