One of the main criteria determining thermal comfort of occupants is the air temperature and the airflow velocity. To monitor these parameters, in-situ sensors are usually mounted in the indoor environment. One of the drawbacks of this conventional method is the measurement at a certain location instead of the distribution of the target parameters in the whole room including the occupant zone. Moreover, the placement of multiple sensors can be problematic due to their physical interference with the test environment. Acoustic travel-time tomography (ATOM) technique as a remote sensing method is a solution to overcome the mentioned shortcoming of traditional sensors. ATOM utilizes the dependency of the sound velocity on air temperature and flow velocity in the medium. The average sound velocity, along the propagation paths, can be determined by travel-time estimation of a defined acoustic signal between transducers. This detected sound velocity can be converted into spatially distributed air temperature and flow velocity by using a proper tomographic algorithm.

Over the course of studies conducted in the climate chamber of the BUW, a three-dimensional representation of the air temperature distribution was successfully measured by placing a transmitter and a receiver at optimal positions. The German Research Foundation (DFG) is funding the further development of this analysis method as a cooperation between the Bauhaus University Weimar and the TU Dresden. The extension of the method to include the air flow velocity measurement in parallel to the air temperature is one of the tasks of this project. Furthermore, the measuring system will be developed for an occupied room condition considering an actual workplace. With the aim of resolution enhancement, several tasks are defined in terms of numerical methods and practical measurements. To draw conclusions about the measurement accuracy, the required comparative measurements will be conducted under different climatic conditions.