Mobile mapping at high speed

The Midland Mainline (MML) is an integral portion of the United Kingdom’s rail network. With 639 kilometres of track, 16 tunnels and 35 stations, the MML has been serving the UK since 1870.

Periodic maintenance and upgrades are needed to keep the rail line functioning at optimal speed. As part of the MML Enhancement project, significant alterations were planned for the Market Harborough Station in Leicestershire, England to remove a major kink in the through alignment. The project required 8 km of the mainline surveying, consisting of high accuracy track alignment, structure gauging, drainage tracing and topographic cess detail.

Severn Partnership是一家位于英国什鲁斯伯里（Shrewsbury）的特许地理测量师的测量公司，以提供所需的高精度测量。

Survey grade results from mobile mapping

Severn合作伙伴关系自2010年以来一直参与MML升级项目。该线路的改进计划是自1870年完成以来最广泛的，Severn Partnership提供了超过161公里的永久性调查控制和随后的永久性方式（P-方式）轨道调查。作为电气化计划的一部分，添加了70多个桥梁结构和三个主线火车站。Severn Partnership安装了与原始SnakeGrid控件有关的所有调查。

Combined with its knowledge and expertise in the rail industry, Severn Partnership, needed a safe and cost effective method of capturing topographical line side details of the 8 km site at Market Harborough. The firm used itsLeica Pegasus:Twosurvey grade, mobile mapping system to reduce track access requirements and to capture topographical detail.

移动映射将激光扫描技术与GNSS和运动传感器结合到一个单元中，该单元易于安装在任何车辆上。在铁路环境中，利卡（Leica Geosystems）认为强制使用第二GNSS天线。Leica Pegasus：两个系统始终需要GNSS覆盖范围，从而通过将其连续校准到零漂移来确保IMU的精确动态性能。

Mounted on a motorised personnel carrier, it captured a 3D laser scan point cloud and imagery. This was done on a rail mounted vehicle, at 16 km/hour for the length of the site in a single 3 hour shift. The resulting data could then be digitised at the office without the time and safety pressures inherent with working on the railway network.

To maintain high accuracy, the point cloud was linked to the site grid using the newly surveyed track alignment. The rails in the scan were automatically matched to the traditionally surveyed rail strings, resulting in sub-10 mm accuracy relative to the track alignment.

“Working with the Leica Pegasus:Two on the Midland Mainline Speed Enhancement project saved us significant time and cost,” said Rollo Rigby, Severn Partnership associate director.

移动映射更安全

The Pegasus:Two offered survey grade accuracy and high resolution images required for the project specification. Its versatility in being mounted on to any kind of vehicle enabled it to be mounted to a rail enabled vehicle as well as a road vehicle to capture all on and off track data. Using mobile mapping and the Pegasus:Two meant that the data was captured in one shift on one weekend as opposed to multiple weekends if more traditional methods were used.

在潜在危险的环境中工作，降低了人员的风险。所有细节均快速有效地捕获，包括CESS细节，压载剖面，结构和植被，而无需进行现场访问。网站图像也与项目团队共享了“街景”风格，可能会减少进一步的现场访问的需求。

“In this project, with mobile mapping, we were able to reduce man hours on the track as well as improve the overall safety for the rail team,” concluded Rigby.