초록 ▼

A navigation-monitoring apparatus comprises a fixed ground station sending forth an interrogation signal to a ship and a transponder carried on the ship and transmitting a reply signal to the fixed ground station in response to the interrogation signal. A microwave sensor carried on the ship measure

A navigation-monitoring apparatus comprises a fixed ground station sending forth an interrogation signal to a ship and a transponder carried on the ship and transmitting a reply signal to the fixed ground station in response to the interrogation signal. A microwave sensor carried on the ship measures the distance between the ship and the nearest bank. Data on the measured distance is added to a reply signal sent forth from the ship to the fixed ground station. The fixed ground station measures an interval between a point of time at which the interrogation signal was issued and a point of time at which a reply signal from the ship was received, thereby defining the position of the ship from said time interval and data on the ship-to-bank distance.

대표청구항 ▼

A navigation-monitoring system for detecting the position of ships relative to a nearest bank and a ground station which comprises: a transmitting and receiving device installed in a ground station to transmit an interrogation signal including a specified address code for each ship; a transmitting a

A navigation-monitoring system for detecting the position of ships relative to a nearest bank and a ground station which comprises: a transmitting and receiving device installed in a ground station to transmit an interrogation signal including a specified address code for each ship; a transmitting and receiving device carried on each ship to receive said interrogation signal and issue a reply signal; said ship transmitting and receiving device including means for detecting said specified address code, and a ship-to-bank distance measuring device for measuring ship-to-bank distance, after detecting said specified address code, and providing data indicative thereof; said ship-to-bank distance data being added to said reply signal in response to said interrogation signal; means installed in said ground station for calculating a ground station-to-ship distance from a time interval between the time at which said interrogation signal is issued and the time at which said reply signal from the ship is received; and means installed in said ground station for obtaining said ship-to-bank distance data from said reply signal.