Connecting continents

Bosphorus上方的第三座桥，其高塔超过300米，是工程学的巨大杰作。它将有助于减少欧洲和亚洲大陆之间的交通，同样是伊斯坦布尔繁荣和经济增长的象征。Yavuz-Sultan-Selim桥是由土耳其公司ICA Construction建造的，不仅创建了铁路线的高速公路，而且还为两大洲之间的洲际大都市提供了额外的联系。在建造悬架桥期间，Leica Nova MS50展示了其许多多元化的应用可能性。

ICA与Leica Viva GS15 GNSS接收器和其他其他Leica Geosystems传感器一起利用了Leica Nova MS50多稳态，以进行大量的测量，控制和变形测量。有了新的扫描功能，可以将塔架的最新构造进度与建筑计划进行比较。

The highest bridge pylons in bridge construction
Four huge pylons connect the substructure of this bridge. With a height of 309 metres (approx. 1014 feet), they are the highest found on any suspension bridge worldwide. The two obliquely designed pylon pairs complete the top of the bridge and are hollow inside. Every day, these pylons grow approximately 2,5 metres (8,2 feet) – a challenge for the engineers, who must constantly check for deviations from the design of the ever-growing outer concrete shells of the pylons. Due to stringent demands of the construction requirements, there is only a short period of time available to check the pylons, nevertheless, these controls are absolutely imperative. Because any small deviation from the design would have an enormous impact on the subsequent stages of the bridge construction.

The laser scanning function and long range measurement of the Leica Nova MS50 was used to determine the concrete surface deviations against the design and was processed with Leica Cyclone point cloud software. To achieve the highest accuracy of the scanned data, the MS50 was set up over control points established using Leica Viva GS15 GNSS static observations and processed in Leica GeoOffice.

An additional challenge was the harsh environment in which this work was carried out. The Bosphorus Strait connects the Black Sea to the Marmara Sea and workers have to contend with a cold northernly wind, together with haze and humidity, which can persist throughout the winter months. All Leica equipment that was used for this project could easily cope with these challenging conditions. The Leica Nova MS50 has a working temperature range of –20°C to + 50°C and IP65 dust and water protection.

高质量的测量
Most of the work was carried out from three ground control points. Two were located on nearby hills to offer a clear line of sight to the pylons and construction site and the displacement control was carried out on a weekly basis to check if the coordinates were stable and to compare with the architectural designs for deviations.

另外，使用几个Leica TS30总站检查塔架的垂直比对。bob apple在施工期间从不同位置进行测量，以便在实时计划的实时验证准确性。

在控制点上设置了Nova MS50，定义了一个扫描窗口，并在150 m的距离内每100 m每100 m的密度为1 cm测量点云。在从塔的各个侧面收集扫描数据后，根据设计（CAD）数据检查了Leica Multiworx中创建的垂直切片。

快速准确的扫描
测量经理Yasar Hacieyupoglu评论说：“我们对Leica Nova MS50和Viva GS15 GNSS接收器完全有信心，以提供该项目所需的准确远程测量。Nova MS50是唯一可以在所需范围内准确扫描并以速度扫描的仪器。”

“Leica Geosystems has been a collaborative partner on this project – the construction company ICA, the main contractor, HYUNDAI Eng. and the surveying team, ENDEM Cons all use Leica Geosystems’ products and know they can count on the support, training and service they receive from the manufacturer and market leader.”

露丝·巴德利（Ruth Badley）撰写