Keeping Track (IMAGE) Fraunhofer-Gesellschaft Caption It is difficult for security officers to keep everything in view on the apron. Who is entitled to be there? Who is not authorized? Where is there a risk of accident? Credit Fraunhofer IIS Usage Restrictions The picture may be used for editorial purposes only. It is protected by copyright. The use is free of charge if the reference is mentioned. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.