1966年至1967年，在乌拉圭进行了最后一次完整的航空摄影收集工作，以1：50,000的比例生产国家数据集。从那时起，只有该国的部分地区被捕获。2015年，认识到更新的制图信息的多重好处，以支持未来的发展，乌拉圭政府通过IDEUy（Infraestructura deatos espaciales de Uruguay）发起了一个绘制国家的项目。基于对替代方案的彻底评估，包括航空摄影，激光雷达和卫星图像，Ideuy选择了航空数码相机作为更新乌拉圭地理数据集的最佳技术。
(this article is brought to you by Vexcel)
项目一个ttracted International Interest
这个数百万美元的映射项目吸引了来自欧洲，北美和南美各地的空中公司的兴趣。188asia备用网址许多公司访188asia备用网址问了乌拉圭，并提出了解决招标规格的解决方案。
Ten foreign companies eventually submitted bids, and in early 2017Topocart, an experienced Brazilian company, was announced the winner. Topocart presented the most attractive proposal incorporating the leading equipment at that time – theVexcelImagingUltracam Eagle Mark 2，在整个飞行带和可交换镜头系统上提供了23,000像素的锅框架图像足迹。
“The excellence of the UltraCam Eagle M2 technology was fundamental for the success of the Uruguay project,” says Givanildo Silva, Technical Director, Topocart. “Not only the hardware components, but also the UltraMap processing software suite, which delivers a highly automated workflow with the capacity of generating true orthophotos, one of the most important requirements for the project. We worked closely with GeoToolBox Ibérica, Vexcel Imaging’s Latin American representative, to configure the most effective photogrammetric solution.”
Topocarthad already successfully completed a similar project flying the entire state of Sao Paulo in Brazil, an area almost the same size as Uruguay. The company’s experience, proximity and the state-of-the-art equipment it offered for the project contributed to Topocart’s selection as the winner of the tender.
Meeting the Strict Specifications
The project was divided into two subprojects: the first to capture the whole country at 32cm GSD and the second to acquire 10cm resolution imagery of the main population centers throughout Uruguay.
To meet the specifications, Topocart proposed the following:
- 国家飞行(178,000km2)
- GSD of 32cm
- Accuracy in XY, better than 1m
- Accuracy in Z, better than 1.5m
- 城市航班（1,298公里2)
- GSD of 10cm
- 在XY,精度比0.2米
- Z的精度高于0.3m
使用Ultracam Eagle Mark 2，有必要在24,000英尺左右飞行以捕获32厘米GSD和7,500英尺以达到10厘米。Topocart主要使用了卡拉雅飞机，并安装了带陀螺仪稳定架的相机。
与摄像头一起，Topocart将Applanix GNSS系统与接地控制点（GCP）相结合以达到所需的准确性。整个国家只需要大约600个GCP，这证明了将优质的IMU系统与高性能摄影摄像机相结合的优势。
除图像外，还产生了以下可交付成果：
- 国家飞行
- DTM为2.5x2.5m
- 基于RGB和NIR中DTM的Ortho图像
- 城市飞行(80 population centers)
- DTM为1.0x1.0m
- 基于RGB和NIR中DTM的Ortho图像
- True Ortho Images based on DSM in RGB and NIR
The project began in January 2017 and the last orthoimages were finished in June 2019 – it took approximately 2.5 years to acquire imagery and deliver all the products.
主要项目挑战
As with most aerial photography projects, a major challenge was the weather. Some areas of Uruguay were constantly cloudy, so it was necessary to wait for weeks, or even months, for clear skies to capture cloud-free images.
数据量也会影响该项目。总共为32厘米GSD收集了大约30,000张图像，这意味着许多飞行时间以及许多处理时间。至关重要的是，拥有能够有效处理大量数据的软件。Vexcel Imaging的Ultramap软件已选择为这项工作。
同样，建立一个基于DSM创建真实的Ortho映像的经济高效的过程需要预先计划以收集必要的数据。在这种情况下，该项目是在城市地区使用高重叠的，并使用Ultramap软件处理数据。结果超出了Ideuy的期望，并为乌拉圭提供了10厘米处的城市地区的真实正常流程，该地区其他大城市尚不可用。
For the IDEUy, a major challenge was quality control and how to ensure all the specifications were being met. Several experts from different external organizations were hired for the project. They focused on several aspects, such as accuracy of the flights and identification of well-defined ground control points. Additionally, the True orthophotos were checked for shadows and hotspots. Overall, the resulting deliverables were very high quality.
A Dataset for Many Applications
更新的全国数字数据集包括1：2,000比例的制图图 - 比1960年代生产的1：50,000比例地图的重大改进。其他可交付成果提供了有关人口中心，轮廓，水文和边界的有用信息，以及道路，学校，警察局，旅游景点和医院的位置。
正在开发一个地形，以使公众和政府机构在线访问此信息。政府的许多领域，例如城市规划，林业，国防，农业，环境保护，基础设施，灾难响应，农业等。乌拉圭政府致力于整个国家的可持续发展，改进的地理信息支持其努力。
Ideuy董事会主席Diego Pastorin博士说：“这个全国性的数字数据集对计划和完成所有类型的基础设施项目的乌拉圭政府机构非常有价值。”“我们认为该项目是我国未来发展的重要一步。”
关于Topocart
Topocart总部位于巴西，巴西，提供基础设施工程，城市规划，环境研究，映射，空中摄影测量，地理上处理以及测量和地理测地的全球服务。自2008年以来，该公司一直在操作Vexcel Imaging Ultracam数字摄影测量空中系统。它目前拥有Ultracamlp和Ultracam Eagle Mark 2。
关于GeoToolBox Iberica (GTBi)
GTBi has been providing photogrammetry solutions to clients throughout Spain, Portugal and Latin America for more than 25 years. The company seeks out the best and the latest technology to create custom hardware and software packages to meet specific needs.
