A new era of airborne city mapping

作者：Penny Boviatsou

Using a professional workflow solution as part of airborne mapping applications is as important as high-end sensor technology. In urban environments, this becomes even more apparent. They are subject to rapid changes and thus have a higher need for up-to-date data for:

1. Navigation
2. 计划目的和
3. Visualisation.

In addition, 3D mapping projects over metropolitan areas generate large amounts of data that need to be processed within reasonable timelines.

In order to meet the demand of mapping professionals’ efficient data collection and fast throughput without the loss of quality, Leica Geosystems has introduced莉卡实体, a tightly integrated solution combining efficient imaging and LiDAR data collection with theLeica CityMapperwith the post-processing workflow for high volume production,Leica HxMap.

Acquiring and processing LiDAR data across the US

Leica Geosystems与国际资产完整性和地理智能解决方案提供商Fugro合作开始acquiring and processing data over multiple cities and coastal regions across the US.

Using CityMapper, Fugro conductedaerial surveys over some of North America’s most densely populated urban centres,以支持他们的geospatial mapping services. As the world’s first hybrid airborne sensor combining oblique and nadir imaging as well as a LiDAR system into one instrument, the CityMapper enables significant time and cost savings by flying once to collect both imagery and LiDAR data. All collected LiDAR and imaging data can be processed in the one unified workflow solution, Leica HxMap.

“We have a long history working with Leica Geosystems sensors, because they are so reliable. CityMapper has proven no different,”Fugro计划经理Mike Wernau说。“该平台的出色设计，再加上Leica Geosystems的最新版本的HXMAP，它扩大了我们创建高度准确，功能丰富的地理空间内容的能力。”

The results of the airborne surveys were post-processed using the latest version of Leica HxMap, the unified high-performance multi-sensor workflow. Within a single and familiar interface common to processing other Leica Geosystems airborne sensors, all typical data products, from orthophotos and oblique images to point clouds, 3D meshes and models, can be quickly and efficiently produced.

最新更新的通用传感器post-processing software sees the addition of LiDAR point cloud generation, calibration, strip matching and viewing to the current image processing capability. Leica HxMap version 2.2 also incorporates enhanced noise filtering for both CityMapper and Leica SPL100 single-photon LiDAR sensors.

“HxMap v2.2 is extremely powerful, as it establishes a single environment to process our CityMapper oblique and nadir imagery, point cloud and terrain data all at once,”沃尔瑙说。“The products derived from the Leica RealCity workflow serve as the foundation for our land and property solutions, delivering real value to our customers in state and local government, insurance, and land-use management.”

Exciting CityMapper results in Bordeaux

The city of Bordeaux is among France's most exciting, vibrant and dynamic cities. It is a port city on the Garonne River in the Gironde department in southwestern France. Together with its suburbs, Bordeaux is the centre of the Bordeaux Métropole with about 760,000 inhabitants.

波尔多是世界上主要的葡萄酒产业资本。它是全球主要葡萄酒博览会，Vinexpo和都会区的葡萄酒经济体的所在地，每年需要145亿欧元。在2007年，经过将近十年的基础设施升级，波尔多被联合国教科文组织视为其巨大的启蒙时代城市核心的世界遗产。巴黎之后，波尔多拥有法国任何城市的保存历史建筑数量最多。

In 2017, APEI (Aéro Photo Europe Investigation), a well-recognised French aerial survey company specialising in the airborne acquisition of geospatial data using innovative techniques and equipment, worked together with the Direction de l'Information Géographique (D.I.G.) de Bordeaux Métropole for Bordeaux’s city mapping project. APEI deliveredAero三角式斜图像与Leica Citymapper和Bordeaux一起捕获的将使用这些图像创建3D城市模型。

挖。de BordeauxMétropole负责管理波尔多大都市中使用的地理信息系统的参考层。该项目被飞行only 2 days(10th and 11th March 2017) with a twin piston-engine Partenavia P68C, registered F-HPEI.

“该系统使用Leica Pav100和Leica Flightpro，这是Leica Airborn Common Platform的一部分。这使我们的员工非常容易操作，并且仅在2个小时内就进行了培训。我们使用了专门设计的Leica Podlifter将相机降低到PAV100中，以获取倾斜捕获的全视图。这是一个非常有用的功能，”APEI首席执行官兼技术经理Bruno Callabat说。

Airborne reality capture

查看特定的用例，并将图像生成点云的结果与融合成像和激光雷达数据产生的点云进行比较，好处是明显的。在许多国家 /地区，城市地区的35％都被树木覆盖。因此，图像点云在建筑物上非常密集，但是树下街道和表面的数字高程模型受到干扰。相比之下，CityMapper的LiDAR穿过树木，并产生具有扁平的地面地面的准确地面模型。在建筑物上有阴影或表面不规则的区域，图像点云中的建筑边缘可能是蓬松的。借助融合成像和激光雷达工作流程，这些边缘更加清晰，模型更准确。

It is a natural next step to improve image based point clouds with LiDAR-based point clouds, adding accuracy and additional information to help create the best 3D model possible. As urban environments change so rapidly, it is desired that image data and LiDAR data are collected at the same time, a requirement that gave birth to the Leica CityMapper, the world’s first hybrid airborne sensor specifically designed for urban planning application. The simultaneous acquisition of nadir and oblique image data as well as LiDAR data offers the most cost-effective way to generate a comprehensive geospatial base map for city planners and those who are engaged in urban mapping.