FlyTitle: Big wet data

Compared with the land, the seas are poorly monitored. That is about to change

相比陆地,人类对海洋的监测十分匮乏。这即将改变

经济学人双语版-浩如烟海 An ocean of things

THERE IS TWICE as much water on Earth as land. Oceanographers are nevertheless fond of saying that science knows less about the high seas than it does about the moon. If John Waterston gets his way, though, that could soon change.

地球上海洋的面积是陆地的两倍。然而海洋学家总爱吐槽说,科学对海洋的了解还不如对月球多。不过这可能很快就会改变,如果约翰·沃特斯顿(John Waterston)能够如愿以偿的话。

Mr Waterston is the head of the “Ocean of Things” project at the Defence Advanced Research Projects Agency (DARPA), an American military think-tank that has helped develop everything from the internet to stealthy fighter planes. The project’s name is a play on the “Internet of Things”, the awkward phrase which describes the trend for stuffing sensors and an internet connection into all manner of ordinary objects, from cars and toothbrushes to factory robots and doorbells. The Ocean of Things aims to likewise wire up the high seas with swarms of floating, connected sensors.

沃特斯顿是美国军事智库国防部高级研究计划局(DARPA)的“海基物联网”(Ocean of Things)项目的负责人。DARPA参与研发的事物从互联网到隐形战斗机无所不有。该项目的名称套用了“物联网”(Internet of Things)一词,这个有点别扭的词描述了一种趋势,即通过各种传感器将汽车、牙刷、工业机器人、门铃等形形色色的普通物品用互联网连接起来。同样,海基物联网的目标是用大量漂浮的、互联的传感器把海洋连接起来。

Such devices are not in themselves new. There are around 6,000 floating sensors deployed around the world’s oceans, run by navies and research institutes. What is unprecedented is the scale of Mr Waterston’s ambition. Over the next few years he hopes to deploy 50,000 sensors across 1m square kilometres of sea, an area considerably larger than Texas. The eventual goal—much more distant—is to enable the continuous monitoring and analysis of a significant fraction of the world’s oceans.

这样的装置本身并不新鲜。在世界各地的海洋中已经漂浮着大约6000个由各国海军和研究机构布设的传感器。但沃特斯顿的雄心之大前所未有。在接下来的几年里,他希望能在一百万平方公里(比得克萨斯州大很多)的海域内布设五万个传感器。而该项目的最终目标——尽管目前还遥不可及——就是能对全球相当一部分海域展开持续的监测和分析。

Peering into Neptune’s kingdom

探视海神的国度

The project’s main aim, mindful of the “D” in DARPA’s name, is tracking ships. But rather than building something that can do just one job, Mr Waterston wants the Ocean of Things to supply a wealth of other information, from water temperature to wave heights, weather conditions, nearby wildlife and more. All this would then be made freely available to scientific and commercial users.

DARPA的这个项目主要是为了跟踪船舶——毕竟它的名字中有个“D”(国防)。但沃特斯顿希望打造出的海基物联网不止于此,还能提供水温、浪高、天气状况、附近的野生生物等大量其他信息。所有这些信息届时都将无偿提供给科研和商业用户。

Existing “floating instrument packages”, known as floats or drifters, are often custom-built, and usually contain the highest-quality instruments available. They therefore tend to be expensive, and are bought only in small numbers. A typical existing float, designed for scientific research, is the Argo. It costs around $20,000, and can measure water temperature and salinity.

现有的“浮式仪器包”,也就是所谓的浮标或漂浮物,大多是定制的,配备的通常也都是当前质量最好的仪器。因此它们往往价格不菲,采购量也比较小。目前最常见的就是用于科研的Argo浮标。它的造价大约2万美元,可以测量水温和盐度。

The Ocean of Things takes the opposite approach. The aim is to cram as many cheap, off-the-shelf components as possible into a single low-cost package. Current float prototypes cost around $750, and Mr Waterston hopes that economies of scale could drive the cost down further. That would allow tens of thousands to be deployed without breaking the bank. Large numbers are crucial for coverage. They also help compensate for inaccuracies in individual instruments. “Can a $5 sensor do the same things as a $1,000 temperature gauge?” Mr Waterston asks rhetorically. “The answer is ‘yes’ if you have a lot of them, because you can cross-correlate. Maths solves the problem for you.”

海基物联网则反其道而行之。它尽可能多地使用便宜和现成的组件,打造低成本的仪器包。目前的浮标原型成本大概在750美元,沃特斯顿希望规模化生产还会进一步降低成本。这样即使布设几万个浮标,花费也不至于太大。能大量部署浮标对扩大监测范围至关重要,也有助于弥补个别仪器产生的误差。“一个5美元的传感器和一个1000美元的温度计量器效果能一样吗?”沃特斯顿设问,“如果有很多个传感器,那答案就是‘一样’。因为它们之间可以交叉关联。数学能让这个问题迎刃而解。”

The project’s researchers are evaluating three designs from different manufacturers, ranging in size from about six to 18 litres. One, proposed by Xerox’s Palo Alto Research Centre, is made of glass, like a traditional Japanese fishing float. A second, from a firm called Areté Associates, has an aluminium shell, and uses wood for buoyancy. Both models feature solar panels. The third, made by a company called Numurus, is made of lacquered cardboard, and relies entirely on its batteries. All three are designed to last for a year or so and are made to be as environmentally friendly as possible, with minimal use of plastics. That is important because, at the end of their mission, the floats are designed to scuttle themselves.

项目研究人员正在评估来自不同厂商的三种设计方案,大小从6升到18升不等。由施乐公司(Xerox)的帕洛奥多研究中心(Palo Alto Research Centre)提出的第一种设计用玻璃制作,像一个老式的日本鱼漂。来自Areté Associates公司的第二种设计,用铝制作外壳,使用木头产生浮力。这两者都采用太阳能板。第三种来自Numurus公司,由涂漆的硬纸板制成,完全依靠自带的电池。三种设计的使用寿命都在一年左右,而且都尽量少用塑料,尽可能地环保。这一点很重要,因为根据设计,这些浮标在完成任务后会自沉海底。

Some of the instruments on offer are common to any smartphone—GPS sensors, accelerometers to detect motion, a compass, a microphone, temperature sensors and a camera. Others are more directly tailored for the job, such as an underwater microphone, a gizmo to measure the water’s conductivity (and therefore its salinity), and detectors to pick up radar and radio signals, including transmissions from marine anti-collision beacons. Some data from these instruments will be crunched on board, but most will be sent back to land in bursts, for onshore analysis. For now, that connectivity is provided by the Iridium network of geosynchronous satellites. But the modems necessary to talk to those satellites, says Mr Waterston, are the most expensive and power-hungry devices on the floats. He hopes that new, lower-flying satellite networks, currently being built by firms such as SpaceX and OneWeb, will provide cheaper alternatives.

目前可使用的一些仪器在任何一部智能手机里都能见到,如GPS传感器、用于探测运动的加速度计、罗盘、麦克风、温度传感器和相机等。其他一些仪器则是为该项目定制的,如水下麦克风、用来测量水体导电性(进而可以测得盐度)的小装置,以及用来接收雷达和无线电信号(包括从海上防撞航标传输的信号)的探测仪。来自这些仪器的数据有一些会在船上被处理,大部分会被分批传回陆地供分析。目前,这种传输连接由地球同步卫星组成的铱星网络提供。但沃特斯顿表示,与这些卫星通信所需的调制解调器是浮标上最昂贵也最耗电的装置。他希望,目前SpaceX和OneWeb等公司正在建造的新型低空卫星网络能成为更加经济的替代方案。

Having lots of different sensors will help the floats build the best possible picture of what is going on around them. For example, if the microphone picks up a sound at the same time as the accelerometer shows movement, it could mean that a bird has landed on the float. Several birds landing on several floats could show how a flock is moving. Their presence, in turn, might be an indicator of shoals of fish or other biological activity.

拥有众多不同类型的传感器有助于浮标最大限度地了解周边情况。例如,如果在加速度计显示运动的同时,麦克风也接收到了声音,那可能是有只鸟停在了浮标上。停在多个浮标上的多只鸟可能显示一群鸟的运动轨迹。反过来,鸟的存在可能表示附近有鱼群或其他生物活动。

Similarly, a ship sailing through a float field will leave all sorts of traces. It might be detected by its radio beacon, or its radar. It might sail close enough for a float to take a picture, or hear it on the hydrophone, or be disturbed by its wake. Correlating data from several floats will reveal the ship’s speed and direction. By building a database of such encounters, the project’s scientists hope to learn quickly how to tell different sorts of craft apart. Fishing vessels might be using fish-finding sonar or noisy trawl nets. A giant supertanker will sound different from a naval frigate.

同样,驶经浮标布设区域的船只也会留下各种痕迹。或许可以通过船上的无线电信标或雷达探测到船只。如果船行驶得足够近,浮标可以对它拍照,通过水听器能听到船只的声响,或者浮标会受到船只尾流的干扰。将多个浮标提供的数据关联在一起,就能显示船只的速度和方向。通过建立这种船只与浮标相遇的数据库,该项目的科学家希望能很快学会辨识不同种类的船舶。渔船可能使用寻鱼声纳或嘈杂的拖网。巨型油轮发出的声响又与海军护卫舰不同。

The range of sensors on a float will also produce a mass of data of interest to oceanographers, meteorologists and biologists. The cameras and microphones on a field of floats could, for example, detect and track whales and dolphins. At the moment, whenever a marine mammal is spotted in the shipping lanes off Los Angeles harbour, one of the busiest in America, traffic is slowed down. Better tracking would allow traffic to be rerouted, benefiting both critters and commerce. Float fields could watch for illegal fishing, smuggling and icebergs. They could monitor and track oil spills and algal blooms.

浮标上配备的各类传感器还会产生令海洋学家、气象学家和生物学家感兴趣的大量数据。例如,一定区域内浮标上的摄像机和麦克风可以探测并跟踪鲸和海豚。目前,在美国最繁忙的港口之一洛杉矶附近的航道上,只要发现海洋哺乳动物,船只就会放慢速度。更强大的追踪能让船只改变航线,这对生物和商业都有好处。浮标布设区域可用于监控非法捕鱼、走私和冰山活动,也可以监测和跟踪石油泄漏和藻华现象。

That, at least, is the long-term goal. So far, DARPA has bought around 4,500 floats, and has tested them only in small numbers. The next stage, starting this spring, will see fields of 1,000 at a time deployed in the Gulf of Mexico and in the waters off California. The plan is to deploy one float for every three square kilometres of ocean. The hope is that, as the technology matures, useful data could be gleaned from densities as low as one float per 20 square kilometres. With 361m square kilometres of ocean on the planet, a true Ocean of Things, monitoring everything on and under the water, would require about 18m floats. That will not happen for a while yet. But Mr Waterston’s plans are a start. ■

这至少是长期目标。迄今DARPA购买了约4500个浮标,而且只完成了小规模测试。下一阶段,也就是从今年春天开始,它将在墨西哥湾和加州附近海域一次性布设1000个浮标。它计划的布设密度是每三平方公里一个浮标。DARPA希望,随着技术的成熟,在把布设密度降低到每20平方公里一个浮标的情况下,仍能收集到有用的数据。地球上海洋面积多达3.61亿平方公里,一个名副其实的、能监测海面和水下万事万物的海基物联网将需要约1800万个浮标。这在短期内还无法实现。但沃特斯顿的计划拉开了序幕。