Abstract
The authors developed a system to improve the performance of construction supervisors. The system provides an image which shows the situation of currently working top-floor to computer monitor of supervisor. Cameras are attached on the tower- crane, and the raw-images from cameras are transformed and assembled by the program. The system was used in actual site and evaluated in term of practical utility. According to the result, the authors confirmed that the system describes images of working top-floor which supervisors can recognize the situation without physical observation.