Initial situation
The aerial images for the entire Austrian federal territory are updated in a three-year cycle, with around one third of the national territory being reflown each year. These aerial surveys are commissioned as part of a federal-state cooperation and are primarily used to create two-dimensional orthophotos (rectified, true-to-scale aerial images) for a variety of applications. The original aerial images are recorded with a transverse and longitudinal overlap, which makes it possible to generate high-resolution, three-dimensional data (point clouds, meshes, surface models) of the earth's surface using the image matching method, from the results of which central spatial information - such as vegetation heights, vegetation structures, terrain changes and building heights - can be derived, which provides a valuable basis for numerous application and research projects. At the moment, the calculation of one third of the national territory takes about one year of computing time and is currently being carried out at the Federal Office of Metrology and Surveying (BEV) - optimized for urban areas - and at the Federal Research Centre for Forests (BFW) - optimized for forest areas (forest inventory). The image matching products created to date are carried out on stand-alone computers and are only available after a long delay. The contracted flight companies supply aerial image data on hard disks, generating around 150 terabytes of data per year.
Objective
The main objective of this project is to accelerate the process of creating high-resolution digital surface models (DOM) using image matching. This acceleration is to be achieved with the help of a server architecture based on graphics processors in cluster operation. While it takes about a year to calculate using current methods, the aim is to shorten this to a few months so that calculated surface models can be used in the year following the flight.A further aim is to identify potential savings in the development of the processing infrastructure (hardware and software).In addition to accelerating the process, the optimization of the process parameters and results for use in agriculture and forestry (determining the usability of the results for agricultural funding as well as other applications and research projects) is also central.In 2022, the Federal Ministry of Agriculture, Forestry, Environment and Water Management (BML) issued an order to ensure easy access to the aerial images and to ensure the long-term usability of the raw data - to this end, the aerial images will be archived in their original format and resolution using LTO-8 magnetic tapes for future calculations and research.In addition, it was requested that the test infrastructure created in the course of the project be left in operation for the time being and maintained. In line with the recommendations of the BMNT's digitization report (2018), the methodological competence for the use of new geodata sources is to be expanded.It is not the aim of the project to provide a regular operation or service from the developed or tested products and procedures.Based on the valuable data basis and the infrastructure and methodology created, calculation tests will also be carried out to create and evaluate follow-up products with great future potential (3D mesh models and point clouds).The know-how built up will be made available to the entire department, the GIS coordination department of the BML and cooperating agencies and communicated to interested parties in the form of presentations and a final report.The objective was slightly adapted during the course of the project and in the course of the findings in consultation with the BML.
Status of the work
Work 2024
The cooperation and exchange of experience with the BEV should be continued and, if possible, the BFW should also be involved. The aim is to optimise the workflow and processing parameters in order to be able to provide results more quickly with aFollowing the successful optimization of the surface models, calculation tests of mesh models and point clouds will be carried out in 2024. The cooperation with the Federal Office of Metrology and Surveying (BEV) and the Federal Forest Research Center (BFW) to exchange experiences and further develop the methods will be continued.The results and findings of the project will be published in a final report and presented at the GIS-Jour-Fixe.The long-term backup of the raw aerial image data on LTO tapes will be continued, whereby the effort will increase towards the past, as a larger number of data carriers were used per flight block and older hard disks have already partially lost their functionality.The management of the data carriers will be transferred to the library system.
Schedule
Project start: 01/2021
Project end: 12/2024
