The aim of this project is to develop portable measurement tools with in-situ visualization for the construction industry. A future measurement tool will provide a direct augmented reality view of measured properties over the real environment and provide instructions as to where and how a certain task can be completed. For example, a metal detection tool should be able to provide direct visual feedback on the location of hidden metallic structures over a live video view of the inspected wall area. Furthermore it can guide a construction engineer to the optimal position for drilling a hole, avoiding any damage to existing structures. Thus the tools should combine information from several sources to provide interactive and contextaware guidance: Measurements from built-in sensors; location-aware through online tracking and registration; spatial, semantic information retrieved from a building information system (BIM). At the same time, future tools need to be simple to be used by non-expert users; therefore the system needs to be intelligent to guide the user in the correct operation to fulfil their tasks. Tools used at construction sites are per se mobile. With the advent of powerful mobile computing devices, it is obvious to combine both and make the tools smarter. We need to address a number of challenges to enable such smart tools:

• Tracking for mobile devices in changing and unknown environments for correct visual overlays. We will investigate the combination of visual online reconstruction methods with range finders and coarse models for absolute registration.

• X-Ray visualization of hidden and abstract information in unknown environments. Here we will investigate automatic approaches that take the environment’s appearance and the virtual information into account to select the best visualization method.

• User guidance based on measured and plan information requires automatic analysis of the spatial arrangements and automatic visualization.