Restoration of German Forests Ravaged by Tornado

Immediately after the tornado, state agency Sachsenforst began the aerial survey and orthoimage production process for 600 square kilometres of forest. The raw data consisted of 326 tiles with each tile displaying 2 square kilometres at 20 centimetre resolution, in colour infrared as well as true colour RGB. To make the data more manageable, it was mosaicked and compressed using ERDAS' Enhanced Compression Wavelet (ECW) technology, which allows a considerable reduction of the data volume without losing visual quality. The ECW data format also enables highly efficient data transfer using the ECWP streaming protocol.

To optimise access speed and data security, a separate server was set up to distribute the disaster data independently of the existing ERDAS APOLLO-based raster data management system.  Sachsenforst used ERDAS APOLLO Essentials - Image Web Server, a low-cost solution providing high-speed access to large volumes of imagery on a minimum hardware set. Image Web Server requires very little server administration, and leverages the unmatched power of ECWP and Optimized Tile Delivery to ensure images are delivered very quickly.

Shortly after the tornado, various forestry agencies responsible for restoring the damaged forests were able to access the actual orthoimages of the storm damage. This was done via the Sachsenforst data portal. These organisations could use the precise geoinformation for damage assessment and coordination of the clean-up operations.

"The forestry agencies that obtained imagery from Sachsenforst using our data portal responded positively to the experience," said Karina Hoffman, Remote Sensing Consultant, Sachsenforst. "We were able to successfully manage our orthoimages and safely deliver them online with very good performance.  This approach serves as a model for future disaster response endeavors."