Stand alone multiple unit tracking system

• US 5,243,530 A
• Filed: 07/26/1991
• Issued: 09/07/1993
• Est. Priority Date: 07/26/1991
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Woodard, Marcus W., Stanifer, Samuel D.
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): ZANELLI, MICHAEL J
• Application Number:
  US07/736,560
• Time in Patent Office: 774 Days
• Field of Search: 364/452, 364/449, 364/514, 364/516, 340/990, 340/991, 340/992, 340/993, 340/995, 342/389, 342/457, 73/178 R, 370/94.1
• US Class Current: 701/219
• CPC Class Codes: G01S 5/0009 Transmission of position information to remote stations involving assistance data G01S5/0236
• CPC Class Codes: G08G 9/00 Traffic control systems for craft where the kind of craft is irrelevant or unspecified

Abstract

A stand alone multiple unit tracking system which utilizes a packet radio link to periodically transmit information identifying the geographic position of ships, aircraft and other land mobile vehicles. The stand alone multiple unit tracking system comprises a base station, relay stations and a plurality of remote stations placed on board ships, aircraft or the like. The remote stations transmit latitude and longitude position information to the base station through relay stations, if required, using packet radio techniques.

Claims

1. A stand alone multiple unit tracking system for tracking, reporting and recording the latitude and longitude position of a plurality of vessels, said tracking system comprising:

a base station;

a plurality of remote stations, each of said remote stations communicating with said base station and each of said remote stations being located on different ones of said vessels;

each of said remote stations having a Loran-C receiver means for generating longitude and latitude Geodetic coordinate positional data, first computer means for assembling said longitude and latitude Geodetic coordinate positional data into up-direction data packets for transmission to said base station, first receiver means for transmitting said up-direction data packets over a single channel to said base station, and first terminal node controller means for controlling said first transceiver means so that each of said remote stations are linked to said base station to allow for the transmission of said up-direction data packets to said base station;

said base station having a second transceiver means for receiving said up-direction data packets from each of said remote stations, second terminal node controller means for controlling said second transceiver means so that said base station receives the up-direction data packets from each of said remote stations, monitor means for electronically displaying a range map which shows the location of said base station and each of said remote stations with respect to said base station and second computer means for storing therein x coordinate and y coordinate digital map data and for providing said x and y coordinate digital map data to said monitor means allowing said monitor means to visually display said range map;

said second computer means being adapted to disassemble said up-direction data packets, to convert said longitude and latitude Geodetic coordinate positional data from said dissembled data packets into x and y coordinate digital position data for plotting on said range map and then provide said x and y coordinate positional data to said monitor means so as to allow said monitor means to visually display the present position of each of said remote stations on said range map; and

each of said remote stations being adapted to monitor said single channel such that when said single channel is clear for transmission to said base station each of said remote stations with longitude and latitude positional data to transmit to said base station can link and then transmit said positional data to said base station;

each of said remote stations requesting an acknowledge message after transmitting at least ten up-direction data packets;

said base station being adapted to provide said acknowledge message to each of said remote stations requesting said acknowledge message; and

a plurality of relay stations, each of said relay stations having a transceiver and a terminal node controller connected to said transceiver, said terminal node controller and said transceiver at each of said relay stations being adapted to link and then transmit said up-direction data packets from one or more of said remote stations to said base station and transmit said acknowledge message to each of said remote stations requesting said acknowledge message.

2. The stand alone multiple unit tracking system of claim 1 wherein each of said up-direction data packets comprises:

a pair of eight bit flags located at the beginning and end of each up-direction data packet;

an address field following the first of said eight bit flags, said address field identifying each of said remote stations providing said up-direction data packet and said base station;

an eight bit control field following said address field indicating whether each of said up-direction data packets includes position information or a status message; and

an information field following said control field, said information field including the longitude and latitude positional data provided by each of said remote stations.

3. A stand alone multiple unit tracking system for tracking, reporting and recording the latitude and longitude position of a plurality of vessels, said tracking system comprising:

a base station;

a plurality of remote stations, each of said remote stations communicating with said base station and each of said remote stations being located on different ones of said vessels;

each of said remote stations having a Loran-C receiver means for generating longitude and latitude Geodetic coordinate positional data, first computer means for assembling said longitude and latitude Geodetic coordinate positional data into up-direction data packets for transmission to said base station, first receiver means for transmitting said up-direction data packets over a single channel to said base station, and first terminal node controller means for controlling said first transceiver means so that each of said remote stations are linked to said base station to allow for the transmission of said up-direction data packets to said base station;

said base station having a second transceiver means for receiving said up-direction data packets from each of said remote stations, second terminal node controller means for controlling said second transceiver means so that said base station receives the up-direction data packets from each of said remote stations, monitor means for electronically displaying a range map which shows the location of said base station and each of said remote stations with respect to said base station and second computer means for storing therein x coordinate and y coordinate digital map data and for providing said x and y coordinate digital map data to said monitor means allowing said monitor means to visually display said range map;

said second computer means being adapted to disassemble said up-direction data packets, to convert said longitude and latitude Geodetic coordinate positional data from said dissembled data packets into x and y coordinate digital position data for plotting on said range map and then provide said x and y coordinate positional data to said monitor means so as to allow said monitor means to visually display the present position of each of said remote stations on said range map;

each of said remote stations being adapted to monitor said single channel such that when said single channel is clear for transmission to said base station, each of said remote stations with longitude and latitude positional data to transmit to said base station can link and then transmit said positional data to said base station;

each of said remote stations requesting an acknowledge message after transmitting at least ten up-direction data packets;

said base station being adapted to provide said acknowledge message to each of said remote stations requesting said acknowledge message;

a plurality of relay stations, each of said relay stations having a transceiver and a terminal node controller connected to said transceiver, said terminal node controller and said transceiver at each of said relay stations being adapted to link and then transmit said up-direction data packets from one or more of said remote stations to said base station and transmit said acknowledge message to each of said remote stations requesting said acknowledge message; and

said base station having timer means for informing an operator at said base station that said base station has not received an up-direction data packet from one of said remote stations within a predetermined time period;

the operator at said base station being informed that one of said remote stations has not provided an up-direction data packet;

said base station transmitting to said one remote station an initiate message to reactivate said one remote station such that said one remote station will transmit said up-direction data packets.

4. The stand alone multiple unit tracking system of claim 3 wherein each of said up-direction data packets comprises:

a pair of eight bit flags located at the beginning and end of each up-direction data packet;

an address field following the first of said eight bit flags, said address field identifying each of said remote stations providing said up-direction data packet and said base station;

an eight bit control field following said address field indicating whether each of said up-direction data packets includes position information or a status message; and

an information field following said control field, said information field including the longitude and latitude positional data provided by each of said remote stations.

5. A stand alone multiple unit tracking system for tracking, reporting and recording the latitude and longitude position of a plurality of vessels, said tracking system comprising:

a base station;

a plurality of remote stations, each of said remote stations communicating with said base station and each of said remote stations being located on different ones of said vessels;

each of said remote stations having a Loran-C receiver means for generating longitude and latitude Geodetic coordinate positional data, first computer means for assembling said longitude and latitude Geodetic coordinate positional data into up-direction data packets for transmission to said base station, first transceiver means for transmitting said up-direction data packets over a single channel to said base station, and first terminal node controller means for controlling said first transceiver means so that each of said remote stations are linked to said base station to allow for the transmission of said up-direction data packets to said base station;

said base station having a second transceiver means for receiving said up-direction data packets from each of said remote stations, second terminal node controller means for controlling said second transceiver means so that said base station receives the up-direction data packets from each of said remote stations, monitor means for electronically displaying a range map which shows the location of said base station and each of said remote stations with respect to said base station and second computer means for storing therein x coordinate and y coordinate digital map data and for providing said x and y coordinate digital map data to said monitor means allowing said monitor means to visually display said range map;

said second computer means being adapted to disassemble said up-direction data packets, to convert said longitude and latitude Geodetic coordinate positional data from said dissembled data packets into x and y coordinate digital position data for plotting on said range map and then provide said x and y coordinate positional data to said monitor means so as to allow said monitor means to visually display the present position of each of said remote stations on said range map;

each of said remote stations being adapted to monitor said single channel such that when said single channel is clear for transmission to said base station, each of said remote stations with longitude and latitude positional data to transmit to said base station can link and then transmit said positional data to said base station;

each of said remote stations being adapted to request an acknowledge message after transmitting ten up-direction data packets having longitude and latitude Geodetic coordinate positional data therein;

said base station being adapted to provide said acknowledge message to each of said remote stations requesting said acknowledge message;

a plurality of relay stations, each of said relay stations having a transceiver and a terminal node controller connected to said transceiver and a terminal node controller connected to said transceiver, said terminal node controller and said transceiver at each of said relay stations being adapted to link and then transmit said up-direction data packets from one or more of said remote stations to said base station and transmit said acknowledge message to each of said remote stations requesting said acknowledge message;

said base station having first timer means for informing an operator at said base station that said base station has not received an up-direction data packet from one of said remote stations within a predetermined time period;

the operator at said base station being informed that one of said remote stations has not provided an up-direction data packet;

said base station transmitting to said one remote station an initiate message to reactive said one remote station such that said one remote station will transmit said up-direction data packets; and

each of said remote stations being adapted to enter into a quiescent state after transmitting twenty up-direction packets to said base stations without receiving said acknowledge message from said base station, each of said remote stations when in said quiescent state not transmitting up-direction data packets to said base station.

6. The stand alone multiple unit tracking system of claim 5 wherein each of said up-direction data packets comprises:

a pair of eight bit flags located at the beginning and end of each up-direction data packet;

an address field following the first of said eight bit flags, said address field identifying each of said remote stations providing said up-direction data packet and said base station;

an eight bit control field following said address field indicating whether each of said up-direction data packets includes position information or a status message; and

an information field following said control field, said information field including the longitude and latitude positional data provided by each of aid remote stations.