LIDAR在线：分析地震损害

在11th May 2011, two earthquakes with their epicentres in Lorca caused significant damaged in the region of Murcia, Spain. A new flight was carried out in the region three days after the earthquake to obtain more accurate Lidar data to supplement the data that was already available thanks to the PNOA project from 2009. The new Lidar data was also made available to anyone who needed it, allowing the damage to be assessed quickly and efficiently. In the case of a natural disaster, releasing data obtained both from flights beforehand and afterwards allows relevant users to create an inventory of the damage and detect any changes quickly and accurately using the appropriate tools.

Aware of the importance of high-level geospatial information for territorial knowledge, Spain's IGN (National Geographic Institute) collaborates in the PNOA project (Aerial Orthophoto National Plan) which produces complete coverage of Spain with submeter orthophotos every 2 years in collaboration with national and regional governments.

PNOA项目的创建是为了获得高临界性覆盖范围，以实现Inspire（附件II，第3小节），同时提供制图基础以创建库存（从INSPIRE中完成附件I，II和III）。同样，还需要具有双重功能的整个国家的数字高程模型：既有帮助支持矫正仪，又遵守Inspire附件II的第1款。PNOA的技术规范规定了5x5 m的DEM，但尽管足够准确，可以进行矫正，但这不足以生成SNCZI（国家洪水区域制图系统）所需的高度准确性。由于需要这种需求，LIDAR数据已成立以提高自2009年以来的准确性。了解可用的资源，PNOA认为每平方米密度0.5点将满足大多数激光雷达申请，以可持续的国家承保范围。

Assessing The Damage

在11^th2011年5月，在两个小时的空间中发生了两次地震，都以5.1兆瓦的幅度为中心，第二个地震围绕西班牙，西班牙和第二次地震。地震造成了7人死亡和穆尔西亚地区的重大破坏。由于它靠近欧亚和非洲盘子，这座有60,000名居民的城市位于西班牙最高风险的地区之一。

一旦知道了灾难的幅度，区域政府就领导了整个恢复计划，迅速有效地工作。在制图区域，认为有必要对损坏的建筑物及其随后在GIS进行的整合和处理。

知道PNOA项目的激光雷达数据已经可用，在地震发生后三天就在该地区进行了新飞行，以获取更准确的激光雷达数据，以评估地震造成的损害（2008年，Chen等。），并提供高度准确的数据，用于该地区的未来研究。得益于瓦伦西亚制图学院（ICV）和HeligràficsfotogrametríaS.L的“团结”，新飞行于14号进行^th2011年5月，获得LIDAR数据，密度为每平方米12点（2008； Anderson等人）。

可访问性

下一步是使这些信息可以le to anybody who would find it useful. In the modern-day information society, people are increasingly becoming aware of the benefits of, and hence demanding, geospatial data, from simple GPS locations or routes to specialised and complex information addressing various topics, including natural disasters. Making both pre-disaster and post-disaster information publicly available can help people - ranging from concerned citizens and journalists to insurance companies and governments - to learn about and evaluate the situation for themselves.

Original Lidar data is a data source which allows highly accurate information to be compiled about the area of interest. However, the problem is that most people do not know about Lidar or how to interpret the results obtained from this data source. By making coherent pre-disaster and post-disaster data and tools for interpreting it widely available online, any user will be able to obtain accurate and reliable information. This in turn makes future prevention, recovery and/or damage assessment easier, as well as helping to increase the general level of awareness throughout society as a whole.

在线的

The objective of releasing and managing Lidar data online presented two main problems: how to help visitors interpret the information, and how to make it available to all the potential users. To solve these problems, Dielmo 3D S.L. created a Lidar web service to manage Lorca's earthquake data, based on Dielmo Server Technology. The technology enables visualisation of the Lidar point cloud before and after the disaster through WMS protocols, and provides free tools for visualising the information in 3D or setting up profiles so that users can classify the data in different categories and/or take measurements (height, distance, slope, etc.). The capabilities of this technology contributed to Dielmo Server Technology being chosen by Spain's IGN to publish Lidar data about the entire country on the internet.

Data from the PNOA Project 2009 and from the post-disaster flight of 14^thMay will soon be available to any users who may be interested in using it, and more than one user can access the information simultaneously.

整个西班牙

As a result, the PNOA project is planning to fly the entire length and breadth of Spain with Lidar. Thanks to Dielmo Server Technology, all data will be made available on the internet. Notably, by the end of 2011, information about more than 137,000 square kilometres of Spain (approx. 28% of the country) will be published online. This is intended to promote the use of Lidar data among any users, whether they are ‘experts' or not, and for any projects needing accurate data about Spanish territory.

诸如PNOA之类的项目帮助各行各业的人们提高他们对领土的了解。同时，通过向专家和非专家用户开放新的可能性，改进了对此类信息的访问，可以增加此数据的总数。如果社会拥有探索和评估发生了什么的工具，自然危害和环境变化可能会更好地理解和管理。

Further Reading

- Andersen, H.-E., Reutebuch, S.E. and McGaughey, R.J., 2006b. A rigorous assessment of tree height measurements obtained using airborne Lidar and conventional field methods.Canadian Journal of Remote Sensing, 32(5): 355-366.

- Lohani, B. and Singh, R., 2008. Effect of data density, scan angle, and flying height on the accuracy of building extraction using Lidar data.Geocarto International，23（2）：81-94。Chen，L.-C.，Tee，T.-A.，Kuo，C.-Y.和Rau，J.-Y.，2008年。通过矢量图和激光点云的融合来塑造多面体建筑。Photogrammetric Engineering and Remote Sensing, 74(9): 1,147-1,157.

公共数据和工具

通过登录到www.iderm.es, users will gain online access to:

Lidar data from the 2009 PNOA project and from the flight of 14^thMay 2011, including the possibility to visualise the data through WMS services or manipulate the original point cloud by using the open source tools included in the web service.

从2009年PNOA项目获得的正势和14次飞行^th2011年5月，包括通过WMS服务可视化它们的可能性。

Vector layers containing information relating to changes in the damaged areas, provided through WMS services.

Users will be able to:

Visualise Lidar data and aerial images on the map of the Lorca area before and after the earthquake.

Analyse accurate information by using the tool of the temporary profiles. By doing so, when creating a profile of the information, users will obtain the required data within an intuitive environment which will allow them to compare temporary changes between two dates and also to conduct measurements and classify the information.

在三个维度上在线可视化要求的区域，包括更改可视化模式（强度，高度，分类，RGB等）的可能性

从地图上表示的每个点获取信息。

Obtain Lidar data by region or by profile, using HTTP requests with the region of interest and a coordinate system. Dielmo's web service is able to create a new file containing only the information relevant to the selected region.

Obtain accurate data from Lidar in other standard formats as shp, dfx, img, kml, etc., opening up new possibilities for experts in other subjects who are not yet familiar with Lidar.