表演的两倍

Author:竹enny牛

More than 90 years ago, National Geospatial Information (NGI), a component of the Department of Rural Development and Land Reform (DRDLR), commenced with the establishment of an integrated survey system and provision of extensive mapping coverage of South Africa.

NGI也被称为南非国家地图机构，拥有可以追溯到1926年的最大，最广泛的航空摄影和图像档案库，并拥有众多国家报道。随着时间的流逝，图像已经显着发展，自2008年以来，所有图像均以颜色（RGB）和颜色Infra-Red（CIR）的高分辨率数字传感器（CIR）获取。

2008年，NGI决定购买自己的Leica DMC I空降相机系统，并任命服务提供商代表其操作该系统。Geospace International是非洲领先的航空摄影服务提供商，成功招标并已由NGI任命为直到2016年。captured for NGI’s national mapping programme.

The mapping program started in 2008 and the aim was to cover the whole country (1.2 million square kilometres) every three years at 50 centimetres Ground Sampling Distance (GSD) until the end of 2016. In 2017, NGI decided to start a new cycle of acquisition at 25 cm GSD covering the country. The demand for higher resolution imagery by the users of the data led to the change in resolution.

NGI uses the data to generate 1:10,000 orthophotos, covering South Africa every three to five years with the 25 cm GSD. The orthophotos are used to update the 1:50 000 topographical maps. The orthophotos are also made available at no cost to South African citizens and companies that need to use this data for their GIS or other applications.

用于广域映射的独特解决方案

从NGI到2017年以来的25厘米GSD图像覆盖南非的新方向，Geospace International决定购买新的Leica DMC III airborne digital camera,基于所有新的CMOS技术特别是engineered for airborne applications. As part of the Leica RealWorld large area airborne imagine bundle, this sensor combines the world’s largest single frame with the most efficient post-processing workflow, HxMap, crucial for a project as such. This solution delivers unprecedented image quality and the unsurpassed geometric accuracy of a monolithic sensor, which enables Geospace International to perform the new 25 cm GSD acquisitions with the latest technology.

“ Leica DMC III的完整安装仅花了三天。我们的目标是使用Leica DMC I以与50 cm GSD项目相同的飞行高度以大致相同的飞行高度获取25 cm GSD图像，从而与以前的每份工作成本大致相同。Leica DMC III允许我们这样做，”said Bernhard Jacobs, director at Geospace International.

一旦Geospace International收集了NGI的25 cm GSD RGB和CIR图像，将校准的图像以及后处理后的GPS/INS数据提供给NGI。然后，南非国家地图机构使用HEXAGON GEOPSOTIAL IMACETRATION IMACETRATION产品套件进行了进行空中三角剖分，高程捕获和最终正势创建的过程。亚搏彩票手机版下载亚搏苹果app该软件提供了大量的摄影测量和生产映射工具，包括来自空中和卫星图像的项目创建，方向和三角剖分。

Twice the performance

Geospace International is operating an Aero Commander 690B twin turbine aircraft. The team consists of two pilots and two camera operators.

“The light-weighted Leica DMC III allowed us to add additional 1.5 hours of flying time per day. Previously, we had to return to refuel, having an impact on cost and time,”said Jacobs.

The additional fuel allows Geospace International to cover more areas in a day than before. With an average 5.1 hour of flying time per day and high performance, processing of HxMap, the DMC IIIdoubled the performance.

“We can now fly the same job previously flown at 50 cm GSD with the Leica DMC I, at 25 cm GSD with the Leica DMC III, with 5 to 10 percent additional flight time. In mountainous areas, we fly the same amount of flight lines to cover the area at 25 cm GSD as we would with the DMC I at 50 cm GSD.

“新的DMC III在整个块上具有更好的总体辐射测定法和更均匀的质量。GPS/IMU结果给我们留下了深刻的印象。”said Jacobs.

Unprecedented productivity

Geospace has covered more than 240,000 km2 at 25 cm GSD from July to November 2017, close to 50,000 releases, and three months ahead of schedule. The company aims to continue procuring imagery for NGI covering South Africa every three to four years.

“我们会向空中调查行业中的任何人推荐Leica Geosystems产品和解决方案亚搏彩票手机版下载，因为使用该系统时的质量，出色的支持以及整体耐用性和长期使用而没有问题，”said Jacobs.