The present invention relates to a portable garment rack that allows for storage of grooming items, other small items, and accessories, and clothes at a temporary location. The subscriber voice may then be compared to the to the background noise. A waveguide tube for guiding microwave is installed on the cavity wall. Via markers in the vehicle interior, the position of a view is defined, and at the position of the view, a detail of a virtual vehicle external environment is overlaid in the display device as a function of the position and viewing direction of the crew member.