A multinational treaty signed in March 1992 and entered into force January 1, 2002, which establishes an aerial observation regime for the purpose of building confidence and increasing military openness. States Parties may fly over the territory of other States Parties using unarmed aircraft equipped with treaty-approved sensors to collect data. These imaging sensors include optical panoramic and framing cameras, video cameras, infrared line-scanning devices, and sideways-looking synthetic aperture radar.