Creating a new ski jump complex

Author:Beate Wesenigk

无论是在世界滑雪锦标赛，四个山丘锦标赛还是高山世界滑雪杯中，在德国巴伐利亚州奥伯斯特多夫的Schattenberg滑雪跳跃都是每年国际滑雪跳跃比赛的主要场所。计划在2021年在奥伯斯特多夫举行的第53届北欧世界滑雪锦标赛计划进行翻新和新的构建工作。这将包括一个新的“ Einkehr”跳跃综合体，以“ Einkehr-schwung”命名，这是面临体育馆的现有烹饪机构。Ing-Geovision创建了一个数字地形模型（DTM），作为计划过程的一部分。

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滑雪跳上沙顿堡

In 1909, the first ski jump stage was built near Oberstdorf in Germany’s Allgäu Alps. Beautifully situated on a sunny hillside, after some initial scepticism, the sport was received with great enthusiasm. During the very first year, Bruno Biehler set the record jump at 22 metres pushing the limits of the facility. Plans for a new jump were devised at the start of the 1920s.

1925年12月27日，新的Schattenberg滑雪跳跃首次使用 - 现在已经93岁了。多年来，跳跃和周围的地形经过了重复的修改和反复扩展。为了改善2021年第53届北欧世界滑雪锦标赛的滑雪跳跃轨道，该设施将进行翻新。

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Challenges: area size, accessibility and self-imposed targets

德国调查公司Ing-Geovision收到了任务create a DTMrequired as a reliable basis for the ski jump complex plans. The firm faced several challenges:

1. The size of the area to be recorded - approximately 270,000 square metres.
2. 此外，丘陵，林区的某些区域非常困难，无法使用陆地测量设备到达。
3. The self-imposed target of capturing all data within just one day.

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Surveying 38 Alpine football fields in one day

三人的测量团队从Traunreut到德国的Oberstdorf提早出发，并为不同的测量设备做好了准备。

Step 1: The control point field

The foundation for the survey of the terrain was measured with the Leica GS16 Smart Antenna formed from an existing six-point control field.The GS16 Smart Antenna minimised the problem of mountainous areas with valleys and woods，为GNSS调查遮蔽了卫星接收。

Step 2: Measure the control points, the profile and the riverbanks

在确定控制点场时，扫描和飞行的控制点的目标是用Leica TS16总站设定的。TS16还用于测量木材的轮廓。总共产生了此方法900 individual points measured almost entirely on steep terrain。

Step 3: Laser scanning and panoramic photos

Leica Scanstation P40用36个角度来扫描该区域。全面扫描resolution of 3x3 milimetres记录10 m时。

“The P40 ScanStation took just3.5 minutesper standpointand has the added advantage that the black/white target points are available in the office. The result was a very dense point cloud made up of a total of 2,036,358,871 individual points. Full-HDR 360° spherical images were also recorded at each scan in a matter of seconds. The pictures can be read by the Leica Cyclone laser scanning software without any further processing and used for registering and processing the data,”Ing-Geovision测量主管Richard Steiglechner说。

Step 4: Fly over

To better survey the vast area and to be able to record the sections that cannot be reached using other methods, a fly over was done with a Leica Geosystems Unmanned Aerial Vehicle (UAV). A flight plan was generated with the software supported by the UAV before the自动GNSS支持飞行took place, covering all the sloping terrain as well as any obstacles, such as the jump towers. The software calculated the waypoints of the desired flight path based on the flight altitude, the obstacles, and the required accuracy using Bing maps. A series of643航空照片使用无人机中的附加摄像头拍摄。

也是受过训练的登山者的三个ggovision“白羊座”抓获了data of 270,000 m² at more than 4,000 of altitude in one dayand store their instruments before dawn.

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Prepare the measurement data from the sensors

GS16和TS16的调查控制和各个点由专家通过ASCII文件加载到国家坐标系统中。P40和MS50的扫描数据随后输入到左撇子旋风扫描软件中进行注册。选择了其他选项进行导入，例如将点云过滤为eliminate unwanted erroneous points。

“The combination of the Cyclone's sophisticated filter technology and the ScanStation's pulse measurement technique makes it possible to eliminate so-called mixed pixels, the hazy points that occur when the laser beam is split over an edge and an underlying surface,” said Steiglechner.

Ing-Geovision experts could automatically align the spherical 360° panoramic images with the point cloud and the true colours assigned at each scan point using the "fixed" option in Cyclone totransform the point clouds from each position into an overall coordinates systemusing target marks, cloud constraints (point clouds with identical geometry in the overlapping sections between two scans) and point standards.

“目标标记直接收集在旋风中。3D点云处理软件会自动找到相同的云约束或部分。如果有疑问，我们可以使用观众来协助我们。”Ing-Geovision工程测量主管Stefan Nawrat说。

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The result: a digital terrain model that perfectly fits

Once the data from the individual sensors was edited, all the individual points and the point clouds from the fly over were imported into Cyclone to join the already registered point clouds from the P40 and MS50 scans. All the points from five different surveying instruments were now combined in one software. Then, a visual check was made of the positional accuracy of the point clouds by cutting through the point clouds.

由21.5亿点组成的收集点云出口作为雷卡射击项目，因此可以在任何地方进一步使用并访问点云。

“这种方法减少了处理时间和错误的风险，因为数据不需要不断地向后复制，并且可以确保在不同程序中的所有进一步处理阶段都可以使用完全相同的准确信息3D Reshaper或Autodesk Revit，” said Bernd Hafensteiner, managing director of ing-Geovision.

To draw the ski jump complex in the CAD programme, the open JetStream point cloud was shared, assisted by the Leica CloudWorx point cloud plug-ins, simplifying the drawing of flaws based on the point cloud.

The DTM was created with 3D Reshaper, a software systemfor creating terrain contours and extracting ground and break lines。

“3D Reshaper purges the point cloud and creates a point cloud group that contains only the ground points, all in barely 30 seconds. Its comprehensive settings guaranteed our team precise results,”Markus Prechtl，Ing-Geovision的测量航班负责人。

The DTM created in 3D Reshaper was transferred to the contractor as a DXF file. To give contractors access to the point clouds in a browser, an additional password protected area on the company's Leica TruView Enterprise server was set up.

To plan the new "Einkehr” jump in the Audi Arena in Oberstdorf, only a precise point cloud and a comprehensive DTM would do. Using Leica Geosystems’ technology, the ing-Geovision team provided the best foundation for the next 93 years and beyond of ski jumping on the Schattenberg ski jump arena.