In ubiquitous computing, user's location is one of the most important information. We have proposed ALTAIR, a new location system for indoors, using image processing in IR(InfraRed) region and wireless network. The system can automatically detect and track the locations of the mobile PC users so that each user can derive the information based on the place where he/she is in a building. In this paper, we introduce location logging system based on ALTAIR. The system automatically makes log of users' location, and helps reviewing work.