GECOV develops a system that supports semi- automatic classification and validation of geospatial information, with the focus on highest resolution laser scan point clouds and aerial pictures.
The GeCov Project focuses on highest resolution laser scan point clouds and aerial pictures which are used as a basis for the virtual track routes and, if necessary, additional terrestrially recorded inventory data. The main project activities are research and development of innovative visualization techniques and methods to stream extremely large point clouds of Austrian rail tracks from a database in real-time.
Highest resolution laser scans and high quality aerial images build the optimal basis for the development of data structures which are visualised using 3D viewers – developed in this project. Due to the low flight speed required in order to get high scan density, the production of the highest resolution laser scans is best achieved from helicopters: Flight height: 200 m; flight speed: 45 kt; corridor width: 200 m; point density: approx. 20 points per m2. The laser scans for this project have been recorded by BEWAG Geoservice GmbH, which has the ALS (air-borne laserscan) equipment and know-how developed in the field of high-voltage cable surveying. The ALS system consists of a RIEGL LMS-Q560 full waveform-processing airborne laser scanner, an IMAR INAV_FJR-001 inertial measurement unit, a Topcon Legacy-E GPS/Glonass receiver and a CCD camera (22 MPixel) with calibrated lens for taking synchronised pictures. In addition to these images, further photographic data was produced using aerial orthophotography. Using a Vexcel UltraCamX from MEIXNER VERMESSUNG, Dipl.-Ing. Dr. Harald Meixner, and corresponding photogrammetric evaluation geo-referenced aerial images with a ground level resolution of few centimetres were obtained, processed and merged with the laser scan images.
The digital elevation and object surface models used for further processing had a minimal resolution of 50 cm, and additional orthophotography at 5 cm resolution was also available. However, the 3D visualisation also incorporates further information that are collected in vector data formats, e.g. such as from GI systems. It is possible to overlay important data about access routes, bridges, the environment, property boundaries, cables and other additional information about the environment usable for different kinds of tasks.
A main objective of the project is the research on methods to stream pointclouds directly from a database. With state of the art techniques it should be possible to explore huge areas around rail tracks in real-time. Additionally the streaming will lead to user-oriented exploration of the whole railway network in Austria.
IQSoft GmbH prepares the database and prepares the enormous data amounts for streaming into the 3D Viewer developed by VRVis GmbH. With a highly extended Level of Detail technique it is possible to load parts of the pointcloud shortly and reach high responsivness.