Abstract: A target identification device in a user object includes: a user information obtaining part and a target information obtaining part obtaining a position, a speed over ground and a course over ground of the user object and a target object; a processor that calculates a CPA distance and a TCPA with respect to the target object relative and the user object, based on the positions, the speeds over ground and the courses over ground of the user object and the target object. The processor replaces the course over ground of the user object with a direction toward the target object and calculates the CPA and the TCPA when the speed over ground of the user object is a low speed determination value or less.

Abstract: At least two or more wireless communication apparatuses of the present invention are located adjacent or separately in a relatively confined area. The output portion of any one currently used wireless communication apparatus of the wireless communication apparatuses is connected to the input portion of each of the other standby wireless communication apparatus. While a radio signal is transmitted from the transmitter of the currently used wireless communication apparatus, a reception limit signal is transmitted from the output portion of the currently used apparatus to the respective input portion of each of the nearby standby apparatuses so that the reception ability of the receiver of the standby apparatus is effectively limited.

Abstract: A target identification device in a user object includes: a user information obtaining part and a target information obtaining part obtaining a position, a speed over ground and a course over ground of the user object and a target object; a processor that calculates a CPA distance and a TCPA with respect to the target object relative and the user object, based on the positions, the speeds over ground and the courses over ground of the user object and the target object. The processor replaces the course over ground of the user object with a direction toward the target object and calculates the CPA and the TCPA when the speed over ground of the user object is a low speed determination value or less.

Abstract: At least two or more wireless communication apparatuses (10) of the present invention are located adjacently or separately in a relatively confined area, wherein the output portion (4) of any one of currently used wireless communication apparatus of the wireless communication apparatuses (10) is connected to each input portions (3) of the other standby wireless communication apparatuses (10), while a radio signal being transmitted from the transmitter (2) of the currently used wireless communication apparatus (10), a reception limit signal is transmitted from the output portion (4) of said currently used apparatus to the respective input portions of the nearby standby apparatuses (10) so that the reception ability of the receiver (1) of said standby apparatus (10) is effectively limited.