초록 ▼

A system and method for determining the locations of freight containers in a freight yard is described. A remote unit that includes a GPS receiver is attached to the freight containers. The remote receivers have an independent power supply--a battery. Intermittently, either by a timer or by a motion

A system and method for determining the locations of freight containers in a freight yard is described. A remote unit that includes a GPS receiver is attached to the freight containers. The remote receivers have an independent power supply--a battery. Intermittently, either by a timer or by a motion detector, the remote receivers are operated. During operation, the remote receivers receive signals from the global positioning satellite system and at an allotted time, transmit the GPS data to a base station before shutting down to conserve power. The base station processes the GPS data to determine a position in the freight yard of each freight container. When a particular freight container or contents is desired, a data base in the base station can be consulted and the contents and location of a particular freight container located. The freight yard is typically outside with a view of the GPS constellation, such as a rail yard, airport baggage area, ship yard, truck park, etc. An alternative is described for use where the freight yard is a warehouse and the satellite view is obstructed. The alternative uses psuedolites or repeaters to track freight containers within the warehouse.

대표청구항 ▼

[ What is claimed is:] [1.]1. A method for determining locations of freight containers in a freight yard comprising:attaching a number of GPS receivers to a number of freight containers in said freight yard;operating each receiver to receive GPS signals indicative of receiver position;intermittently

[ What is claimed is:] [1.]1. A method for determining locations of freight containers in a freight yard comprising:attaching a number of GPS receivers to a number of freight containers in said freight yard;operating each receiver to receive GPS signals indicative of receiver position;intermittently operating each receiver to transmit data indicative of receiver identification and receiver position, including the substep of determining time and initiating said intermittent transmission based on said time;receiving said receiver identification and receiver position at a base station;correcting said receiver positions at the base station to determine corrected positions of said receivers; anddisplaying the identification and corrected position of said receivers in said freight yard.