【技術文章】水下高光譜成像揭示了海洋的秘密

A new technology for mapping the seabed

一種用于繪制海底地圖的新技術

There is an increasing need for improved mapping in the marine environment and industry for effective marine management. Traditional methods of seabed mapping and inspection are very time demanding as they are performed by reviewing countless hours of video, and results have a tendency to vary from person to person. How can this information be gathered and analyzed in a systematic, reliable way within reasonable man-hours?
為了有效的海洋管理，越來越需要改進海洋環(huán)境和工業(yè)的測繪工作。傳統(tǒng)的海底測繪和檢查方法非常耗時，因為它們是通過查看無數(shù)小時的視頻來執(zhí)行的，并且結(jié)果往往因人而異。如何在合理的工時內(nèi)以系統(tǒng)、可靠的方式收集和分析這些信息？

A Norwegian company, Ecotone AS, delivers modern solutions for identification, monitoring and mapping of seabed features and marine installations.  Some years ago, the founders of Ecotone saw great potential in adapting remote sensing technology into underwater applications. Their prior knowledge with bio-optics and light in the arctic served as a springboard for testing new underwater sensors for improved mapping and detection techniques. Once the early prototype showed promise, Ecotone started to commercialize and patent the technology for Underwater Hyperspectral Imaging (UHI).
挪威公司 Ecotone AS 為海底特征和海洋設施的識別、監(jiān)測和測繪提供現(xiàn)代解決方案。幾年前，Ecotone的創(chuàng)始人看到了將遙感技術應用于水下應用的巨大潛力。他們在北極的生物光學和光方面的先驗知識是測試新的水下傳感器以改進測繪和探測技術的跳板。一旦早期的原型顯示出前景，Ecotone就開始將水下高光譜成像（UHI）技術商業(yè)化并申請專利。

UHI provides an autonomous mapping tool that can provide detailed, accurate and unbiased map products from the seabed. With hyperspectral imaging technology, UHI reveals detail that have never before been achievable in the subsea sector. It is possible to not only identify objects but also to monitor their health and condition.
UHI提供了一種自主測繪工具，可以提供詳細、準確和公正的海底地圖產(chǎn)品。借助高光譜成像技術，UHI揭示了海底領域以前從未實現(xiàn)的細節(jié)。不僅可以識別物體，還可以監(jiān)測它們的健康狀況和狀況。

Typical UHI use cases include environmental mapping, pipeline inspection, mapping of drill cuttings, mineral mapping and subsea structure inspection. There are also other experimental use cases currently being developed, such as an in-situ detector of salmon lice.
典型的 UHI 用例包括環(huán)境測繪、管道檢查、鉆屑測繪、礦物測繪和海底結(jié)構(gòu)檢查。目前正在開發(fā)其他實驗用例，例如鮭魚虱子的原位檢測器。

Technology development and design in collaboration with Specim
與Specim合作進行技術開發(fā)和設計

UHI design has been done closely with Specim, exploiting Specim’s hyperspectral imaging technology.
UHI的設計與Specim密切合作，利用了Specim的高光譜成像技術。

“Specim was the preferred provider for several of our founder’s colleagues in the scientific community and, as such, was the first choice to develop the UHI. It was very important for us to work with a provider who could think outside the box and see our obstacles not as limitations but as challenges to overcome.
“Specim 是我們創(chuàng)始人在科學界的幾位同事的首選供應商，因此是開發(fā) UHI 的首選。對我們來說，與能夠跳出框框思考的供應商合作非常重要，并且不會將我們的障礙視為限制，而是需要克服的挑戰(zhàn)。

The main issue we overcame together was our requirement for a very light-sensitive imaging unit to counter the effects of the water. The imager was also required to be fitted into our underwater housing (without considerable work/dismantling). On several occasions, Specim stepped up, and we found a solution together,” says Jorgen Tegdan, Ecotone’s CTO.
我們共同克服的主要問題是我們需要一個非常感光的成像單元來抵消水的影響。成像儀還需要安裝在我們的水下外殼中（無需大量工作/拆卸）。有幾次，Specim 挺身而出，我們一起找到了解決方案，“Ecotone 的首席技術官 Jorgen Tegdan 說。

How does Underwater Hyperspectral Imaging work?
水下高光譜成像是如何工作的？

UHI is an underwater push-broom scanner pointed towards the seabed and towed by a remotely operated underwater vehicle (ROV) along with a rig of external lights. Reflectance data are recorded in lines perpendicular to the ROV’s direction of movement as the light bounces back from the seabed and hits the scanner. Reflectance data are further processed to produce hyperspectral maps with location data. Using these hyperspectral maps, spectral libraries of different types of Objects of Interest can be produced. When used as an input to classification algorithms, large seabed areas can be automatically classified and Objects of Interest be identified.
UHI是一種水下推掃帚掃描儀，指向海床，由遙控水下航行器（ROV）和外部燈裝置拖曳。當光線從海底反射回來并照射到掃描儀時，反射率數(shù)據(jù)記錄在垂直于 ROV 運動方向的線上。反射率數(shù)據(jù)經(jīng)過進一步處理，以生成帶有位置數(shù)據(jù)的高光譜圖。使用這些高光譜圖，可以生成不同類型的感興趣物體的光譜庫。當用作分類算法的輸入時，可以自動對大型海底區(qū)域進行分類并識別感興趣的物體。

Principle of UHI UHI原理

The UHI works in concert with any other mapping tool, whether a straight line or a detailed mapping transect is required. Based on feedback from an initial transect, certain areas of interest can be revisited and examined in greater detail.
UHI 可與任何其他測繪工具協(xié)同工作，無論需要直線還是詳細的測繪樣帶。根據(jù)初始樣帶的反饋，可以更詳細地重新訪問和檢查某些感興趣的區(qū)域。

A 2D reconstruction of the seabed requires position and attitude data with accurate timing information
海床的二維重建需要位置和姿態(tài)數(shù)據(jù)以及準確的時間信息

Positive ID of drifting algae attached to a manmade object at 600m depth. The object itself is covered with a mixture of biological growth and detritus, as well as a few living organisms (sponges)
附著在600米深處的人造物體上的漂流藻類的陽性ID。物體本身覆蓋著生物生長和碎屑的混合物，以及一些生物體（海綿）

Example: Salmon lice detection
示例：鮭魚虱檢測

Salmon lice is a parasite living on salmon. In salmon farms, where numbers of salmon live together in a net-cage, salmon lice population can grow so high that it causes severe threat both to farmed and wild salmon population. Counting salmon lice by traditional, invasive methods causes serious stress on the salmon. Also, small lice are often not detected. Having tools to automatically detect and count the number of salmon lice at any stage would offer the fish farming industry a possibility to take preventive actions against the damage caused by the lice.
鮭魚虱是一種寄生在鮭魚身上的寄生蟲。在鮭魚養(yǎng)殖場，許多鮭魚生活在網(wǎng)箱中，鮭魚虱子種群數(shù)量可能增長得如此之高，以至于對養(yǎng)殖和野生鮭魚種群造成嚴重威脅。通過傳統(tǒng)的侵入性方法計算鮭魚虱子會對鮭魚造成嚴重壓力。此外，通常沒有檢測到小虱子。擁有在任何階段自動檢測和計算鮭魚虱數(shù)量的工具將為養(yǎng)魚業(yè)提供采取預防措施來防止虱子造成的損害的可能性。

Ecotone has invented a method that is able to detect salmon lice both in dead fish and on salmon swimming freely. They also found that lice of different stage have different spectral signature that can be identified with UHI. Further development is still required to be able to accurately tell the exact amount of lice in salmon swimming freely, but already now UHI can be used to detect trends in sea lice infestation. This method offers a notable opportunity to learn more about the trends of salmon lice population and infestation and plan preventive methods to protect the salmon population.
Ecotone發(fā)明了一種方法，能夠檢測死魚和自由游動的鮭魚身上的鮭魚虱子。他們還發(fā)現(xiàn)，不同階段的虱子具有不同的光譜特征，可以用UHI來識別。仍然需要進一步的開發(fā)才能準確地分辨出自由游動的鮭魚中虱子的確切數(shù)量，但現(xiàn)在UHI已經(jīng)可以用來檢測海虱侵擾的趨勢。這種方法提供了一個重要的機會，可以更多地了解鮭魚虱子種群和侵擾的趨勢，并計劃保護鮭魚種群的預防方法。

Example below shows four lice detected correctly.
下面的示例顯示了正確檢測到的四種虱子。

Four lice detected on a dead salmon.
在死鮭魚上檢測到四只虱子。

Endless number of applications
無數(shù)的應用程序

“Working with Ecotone has been a great chance for Specim to deepen our knowledge of both the requirements and possibilities in underwater hyperspectral imaging. Underwater deployment is again a fascinating example of the practically unlimited scientific and commercial potential of hyperspectral imaging. We are excited to have this opportunity and look forward to continued collaboration with Ecotone”, says Timo Hyv?rinen, Founder at Specim.
“與Ecotone的合作對Specim來說是一個很好的機會，可以加深我們對水下高光譜成像的要求和可能性的了解。水下部署再次成為高光譜成像幾乎無限的科學和商業(yè)潛力的一個引人入勝的例子。我們很高興有這個機會，并期待與Ecotone繼續(xù)合作“，Specim創(chuàng)始人Timo Hyv?rinen說。

Ecotone has taken great steps towards an automated mapping method to improve how we collect information about the seabed. They successfully use the spectral information in the seabed data to distinguish and characterize cold-water coral reefs and sponge habitats, as well as a range of its associated organisms such as lobsters, anemones and sea cucumbers. Ecotone has done this both as part of industry-standard visual surveys surrounding drill sites, but also in more experimental scenarios such as vertical walls covered with algae, corals and sponges.
Ecotone在自動測繪方法方面邁出了一大步，以改善我們收集海底信息的方式。他們成功地利用海底數(shù)據(jù)中的光譜信息來區(qū)分和表征冷水珊瑚礁和海綿棲息地，以及一系列相關生物，如龍蝦、?？秃ⅰcotone既是鉆井現(xiàn)場周圍行業(yè)標準目視調(diào)查的一部分，也是在更多的實驗場景中這樣做的，例如覆蓋著藻類、珊瑚和海綿的垂直墻。

Ecotone has also made great strides towards a method for mapping drill cuttings deposition following a drilling event. By using the spectral information from the top layer sediment, they can determine the extent of the deposition and yield information about the impact the drilling has had.
Ecotone在鉆探事件后測繪鉆屑沉積物的方法方面也取得了長足的進步。通過使用來自頂層沉積物的光譜信息，他們可以確定沉積的程度，并產(chǎn)生有關鉆探影響的信息。

“We came to Specim with a somewhat unique challenge, and we feel that Specim has taken every step to provide the necessary work on the product they deliver to us, no matter how custom and challenging. In addition to delivering the imaging unit, Specim has been a valuable contact during the technology’s development phase. We feel that the team at Specim was excited about our ideas and gladly assisted us in our development.
“我們帶著一個獨特的挑戰(zhàn)來到 Specim，我們認為 Specim 已經(jīng)采取了一切措施，為他們交付給我們的產(chǎn)品提供必要的工作，無論多么定制和具有挑戰(zhàn)性。除了提供成像單元外，Specim 在技術開發(fā)階段一直是寶貴的聯(lián)系人。我們覺得 Specim 的團隊對我們的想法感到興奮，并很樂意幫助我們進行開發(fā)。

We are exploring the ways to use hyperspectral data and what underwater objects are becoming visible to us that previously would have been very hard to detect using normal cameras. Based on our experiences, we are adapting and inventing new methods for image processing. We are still learning every day!” says Jorgen Tegdan.
我們正在探索使用高光譜數(shù)據(jù)的方法，以及哪些水下物體正在變得可見，而這些物體以前很難用普通相機檢測到。根據(jù)我們的經(jīng)驗，我們正在調(diào)整和發(fā)明新的圖像處理方法。我們每天都在學習！“Jorgen Tegdan說。