冒险的纪事

Author:Penny Boviatsou

On October 19, 2014 Matteo Miceli, a famous Italian oceanic sailor, left the Port of Riva di Traiano located close to Rome, Italy, with the Italian sailboat ECO40 for the Roma Ocean World Project. His goal was to sail around the world alone, without the help of any fossil fuel or additional supplies, other than what he brought with him for the entire 27,000 nautical miles (50,000 kilometres) journey.

ECO40类40海洋船(总长度of 12,0 metres) that was equipped with a data acquisition system for both the met-ocean parameters recorded on-board (i.e. apparent and real wind speed and wind direction, atmospheric pressure, current velocity, air and sea temperature, etc.) and the kinematic characteristics of the boat itself (i.e. speed and course over ground). A team of professors from the University of Rome and the Polytechnic Turin recorded the boat’s movements by using three Leica GR25 GNSS reference receivers. With these they were able to:

• 通过使用船作为浮标来计算沿Eco40路线的波高，并验证英国基于英国的MET（气象）办公室的数值模型；
• 通过计算旅行期间的动态压力和船材耐用性，改善40级帆船的结构设计；
• Record the wave characteristics taken from the ECO40’s movements to produce a polar diagram of the boat’s speed, which would be useful for future Class 40 racing boats.

Miceli通过卫星传输了数据，以分析罗马拉萨皮安萨大学的Paolo de Girolamo和Mattia Crespi教授，并向Polytechnic都灵的Alessandro Pezzoli分析。

在回到意大利的途中，将三个斗篷和航行25,000海里航行后，Eco40在赤道上盖了。马特奥（Matteo）在巴西海岸附近约600英里。他被一艘货船救了。当他回到意大利时，他组织了一次探险，试图恢复Eco40，这是没有成功的。一个月后，探险队再次尝试，并在巴西海岸发现了Eco40 300英里。现在，该船回到了意大利。

Fortunately, the data were saved together with the boat and the researchers were able to do the final analysis of the journey.

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The sailor’s journey

The planned route was the classic clipper route that runs from west to east through the Southern Ocean, taking advantage of the strong westerly winds. Namely the route consists in passing the Gibraltar Strait, then in descending the Atlantic Ocean and sailing around the Antarctic, at an average latitude of 50° S, from west to east rounding the most famous capes of the world: Cape of Good Hope, Cape Leeuwin and Cape Horn. Finally, sailing the Atlantic Ocean back to the Strait of Gibraltar and come back to the homeport.

米切利说：“莱卡GR25 GNSS接收器和左侧的天线收集的数据涉及该船的运动，报告说，在第一次暴风雨中，Eco40的波浪高度约为6米，最大波达到10,0 m。”“旅行结束后，我们现在能够计算确切的测量结果。”

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Gathering the data

卫星调制解调器每天将一部分测量数据发送给土地团队。这些数据是由船只衡量并几乎实时传输的，它极大地帮助了负责Eco40安全的团队；船在航行过程中真正面对的实际天气条件的知识可以改善路线策略并提高船只安全性。

“The measurements of the boat movements, obtained from the three GPS receivers, if properly analysed, can provide a measure of the waves that the ECO40 encountered during the navigation,” said Miceli.

将三个高精度的Leica Geosystems GPS接收器放在船尾沿船尾横轴的左侧和右侧，而其余的则沿着船只的主纵轴靠近船入口。数据是在ECO40导航期间被系统获取的，并将每个接收器存储在灰烬卡上。数据分析是在回收灰信卡后进行后处理的。

Two different strategies were adopted in the post-processing:

1. The “Variometric Approach for Displacements Analysis Standalone Engine” (VADASE)
2. The moving base kinematic approach.

The two methods were used complementary in order to obtain the boat motion, and the boat motion has been applied to estimate the waves’ properties faced by the sailboat during its navigation around the world.

Indeed, the first (i.e. variometric approach) was used to calculate the boat heave, surge and sway motions, while the second one (i.e. moving base kinematic approach) was used to calculate the roll, pitch and yaw motions. The wave characteristics (i.e. directional wave spectrum) were derived by using the heave, pitch and roll motions.

When fast movements have to be detected and their effects suddenly evaluated, Leica VADASE can help researchers make the most informed decisions immediately. The solution adds additional value to traditional GNSS monitoring, providing accurate velocity information based on a stand-alone GNSS receiver that is continually available in real time for precise and reliable analysis of fast movements.

船舶性能数据（即地面的速度和路线）可以在需要一定的时间后获得统计意义的数据库，以估算船的真正极性速度曲线。实际上，这些曲线用于预测土地团队通过使用路线优化软件制定的最佳路线，该路线优化软件每天发送到梅克利。

实际的极地速度曲线的差异r from the theoretical ones estimated by the designer of the boat. This is due to several causes, among which plays an important role the ability of the crew to “push” the boat to the maximum of its performance and the presence of waves that normally is not taken into account when calculating the curves themselves.

These data are used mainly for two technical and scientific purposes:

1. The first purpose is the calibration and/ or verification of the numerical models output that are commonly used for the wind and wave forecast and/or analysis into the oceans, and the calibration of the remote sensing data (e.g. satellite wind and wave measurements).
2. 第二目的与容器设计直接相关。实际上，这种容器可以处理的运动和载荷以及材料对疲劳应力的响应的知识可以显着改善设计方法。

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分析测量值

这项事业是有史以来第一次通过GNSS准确地测量了帆船运动在全球旅程中，并且每隔几个小时通过卫星传输数据。就大洋的条件和船尾而言，ECO40在航行过程中经历的第一次暴风雨发生在2014年10月21日至22日的狮子湾。使用移动基础运动学方法分析的信号。该分析允许在整个风暴事件中估计脚跟角α。

De Girolamo说：“关于大洋的条件，我们根据船只几乎实时测量和传输的风数据分析了风暴。”

Wind data were measured on board of the ECO40 by means of an anemometer placed on the top of the mast. The first comparison was carried out with the European Centre for Medium-Range Weather Forecasts (ECMWF) and the second one was carried out by using the forecasted data, provided by the numerical model GFS (Global Forecast System).

This comparison, along with the results of the heeling analysis, showed that the wind measurement height plays an important role. The corrected measurements of the wind are comparable with the results obtained from the numerical models: a good agreement is noticeable within the first 60 hours. Nevertheless, a sensible discrepancy between the measured wind data and the numerical one is noticeable as the storm peak occurs.

The direct comparison between the forecast and the measured wind speed showed, in the present case, as expected, relevant discrepancies. These discrepancies are such to underestimate the forecast wind condition in the order of 50 per cent of the forecast wind for severe storm conditions.

研究人员和教授能够根据测量和数值风数据之间的比较来汇总研究论文。

“Still, despite the unexpected end of the journey, the data collected from the Leica GR25 GNSS receiver and the Leica AS10 antenna were enough to provide ocean scientific information for the development of new ocean knowledge and technologies for the benefit of society,” said Frank Pache Senior Product Manager, GNSS Networks and Reference Stations at Leica Geosystems.