GB2379570A

GB2379570A - Maritime ship safety system

Info

Publication number: GB2379570A
Application number: GB0121388A
Authority: GB
Inventors: Robert Leighton Harding
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-09-05
Filing date: 2001-09-05
Publication date: 2003-03-12
Also published as: GB0121388D0

Abstract

The Maritime Ship Safety System utilises digital VHF radio signals, transmitted using short burst technology, to indicate on a receiving vessel's screen the relative position and type of vessel transmitting. Transmitters coupled to or with built-in GPSs, transmit a code identifying the type of vessel and its Latitude and Longitude. The Receiver plots the position of the transmitting vessel relative to its own position on a computer type screen. The receiver having a microprocessor and memory retains the plotted position for 5 or more minutes. The type identifier is replaced each transmission to the right of the latest plot. The Transmitter has an emergency button to transmit three flashing asterisks (*) before and after the signal. There is a LED to show it is transmitting, flashing if power drops. Transmitters can be programmed with the GMIDSS "call sign", which can be identified by special receivers.

Description

MARITIME SHIP SAFETY SYSTEM (MSSS) DESCRIPTION OF SYSTEM The Maritime Ship Safety System is a Radio based system of identifying the position of vessels relative to each other. By coupling a special transmitter to a GPS (Global Positioning System) receiver it will be possible to transmit the Latitude and Longitude of a vessel together with an identifying code letter. The radio signal is received by a special receiver, which coupled with a GPS receiver, indicates on a flat screen the position of each transmitting vessel relative to the receiving vessel.

Background The need for a system to prevent collisions at sea has for long been agreed by virtually all Maritime Agencies. Radar has been a great help, but the fact remains that smaller vessels and those built of plastic are often not registered by ships radar.

To provide a good"reflection"the radar reflector has to be of too great a weight and size to be practical. A Radar reflector, to operate well, should be at 900 to the transmitted radar signal. It is obvious in any type of swell that this is virtually impossible. Responders, which receive and retransmit an amplified signal, would need to have too large and heavy an aerial to be practical. Such a system would also be too expensive for most boat owners. What is needed therefore is a cheap and user friendly system that would work under all conditions. The Maritime Ship Safety System overcomes these problems. The system based on radio signals rather than radar signals is unaffected by the state of the sea or weather. It would be a system, whose transmitters would be affordable by all, and the receivers by most boats of 8 metres or more.

NOTE This system does not replace good watch-keeping practice or radar! It is another tool in aiding safety at sea.

THE SYSTEM The System employs two different parts, The Transmitter and the Receiver.

The Transmission The Transmission is a digital signal (see Note 3) which provides a code letter identifying the type of vessel-Example"W"for Warship, followed by its Latitude and Longitude. (See Notes 4 & 6).

The Reception The Receiver translates the incoming signal and interpolates the position on a screen.

The centre of the screen is the receiving vessel. The Signal is plotted automatically on the screen indicating the position (Latitude & Longitude) of the transmitting vessel relative to the GPS position of the receiving vessel. See diagram 1. The Computer chip in the receiver diagnosing the position, would be aligned with memory, which would repeatedly plot the position of the incoming signal for the last 5 minutes, or as required. The result would be that a"trail"is shown on the screen. If required the estimated future route, of the transmitting vessel, in the form of a dotted line, could be called up. See diagram 2. The Code letter for the type of vessel is always replaced at the right side of the last position on the screen, so showing the direction of the transmitting vessel. See Note 6. In an emergency the Code letter of the Transmitting Vessel would flash, preceded by and followed by asterisks, so drawing the attention of the watch-keeper on the receiving vessel.

The Transmitter The transmitter is a small self-contained unit which reads GPS signals using NMEA code. It transmits a code letter for the type of vessel followed by the Latitude and Longitude of the vessel on which it is fitted. This signal is sent out digitally within a 30-second period at random. See Note 2. The Transmitter operates on a VHF frequency (see Note 1).

Transmitters would be of two types.

Type A A Radio which when attached to a GPS (handheld or fixed) transmits the position of the vessel (see Note 2).

Type B A Radio transmitter with its own built in GPS receiver.

Both types of transmitter would be fitted with an emergency button, which when operated sends out an emergency signal which is shown on the receptor's screen. See Note 3. The transmitter would have a LED to indicate that it is transmitting. There would also be an on/off switch (protected against accidentally being turned off).

The Receiver This is a Radio receiver unit, capable of receiving only on the VHF channel or channels used by the system see Note 7. which would either be built into a complete display unit, or as a small separate unit which can be attached to a Computer, which is already connected to a GPS.

Strength of Signal The strength of the signal is exactly the same as a maritime handheld VHF signal. It is only necessary to be received clearly within a line of sight radius. It would not be affected by wave height or rain interference.

Power The Transmitters and Receivers would be capable of operating on 12 volts DC, or off batteries. A small buzzer would sound if the power of either was dropping too low for use. (similar to the smoke alarm).

Aerials The Aerials of both the Transmitter and Receiver need to be no different from the small compact aerials already fitted to VHF units. The Transmitters aerial would need to be a separate one, but the receiver's signals could be taken from the vessel's existing VHF aerial. NOTE There is no need for heavy weights aloft which could affect a vessels stability Programme The Integrated Programme of the receiver allows for various radiuses of view to be shown. These are indicated by rings, clearly marked on screen. There is an optional Danger zone area overlay that may be brought up to remind the Watch-keeper when it is necessary to take avoiding action. Diagram 3. The projected course and speed option only predicts what will happen if the vessel indicated continues on the same course at the same speed.

If the programme is supplied as a CD-ROM for use on a Laptop, it is hoped that the various Programme makers of Windows based and other Navigational Charting Systems will allow for the programme to overlay their charting systems. See diagram 4. In this case the overlay would not always show the ships head as the top of the screen. The positions and trails would be shown relative to the vessels heading.

Notes 1. The exact frequency for transmission would have to be decided by International Convention.

2. The time of each transmitter would be pre-programmed to provide as many different timed-short burst-transmissions within the 30 seconds period, to prevent jamming of the system.

3. When the Transmitter is connected to a GMDSS radio, it could also transmit the unique telephonic code of the transmitting vessel. A commercial type receiver could then read this when a cursor is placed over the position on the receptor screen. This could then be used to identify a vessel; especially useful to Coast Guard and similar type Agencies.

4. The Signal need only be received in a line of sight, similar to the VHF transmissions used by vessels. This means that it should give good response up to a radius of about 12 miles, depending on the height of the transmitting and receiving aerials. A small hydrogen balloon supported aerial could be made available for use on smaller vessels that do not have masts.

5. Since the signal is only being received within line of sight it automatically reduces the demands on the receiver.

6. Suggested Prefixes :- W = Warship S = Sailing Boat M = Motor Boat C = Container or Bulk Carrier 0 = Oil Tanker GO = Giant Oil Tanker F = Ferry FF = Fast Ferry ie Catamaran D = Dredger/Cable Layer P = Fishing PT = Trawler PD= Drifter T = Tug (A tug towing would be easy to locate because the letter T would appear immediately above the letter for the type of vessel under tow.

B = Navigation Mark Buoy BCN = Buoy Cardinal North BCS = Buoy Cardinal South BR = Buoy Red BG = Buoy Green BI = Buoy, Isolated Danger L = Light House/Lan-buoy Emergency Signals-Flashing on receiving screen *** (letter type) *** = SOS [Mayday type distress ### (letter type) ### = SOS [Pan Pan type distress Note: Only with type B transmitter.

?? ? (letter type)? ?? = Not Under Command, Commercial and larger vessels only can transmit this type of signal.

Claims

CLAIMS MARITIME SHIP SAFETY SYSTEM Claim 1 The Maritime Ship Safety System utilises"short burst"digital radio technology together with a GPS input to transmit by VHF on special transmitters a vessel type identifier code followed by the transmitting vessels Latitude and Longitude, to vessels within VHF range, the signal being received on special radio receivers incorporating a programmed microprocessor and memory to indicate on a screen the position of the transmitting vessel relative to the position of the receiving vessel.

Claim 2 The System as claimed in Claim 1 provides in the Receiver for the microprocessor and associated memory to maintain on the screen the signal of a transmitting vessel's position for a period of 5 minutes together with the latest signal and type indicator, so leaving a trail on the screen.

Claim 3 The System's Receiver as claimed in Claims I & 2 provides for a symbol to always be present on the centre of the receiver's screen indicating the position of the receiving vessel relative to the transmitting vessels.

Claim 4 The System's Receiver as claimed in Claim 1,2 & 3 shows the code identifying the type of the transmitting vessel to the right of the last transmission plotted position on the receiver's screen.

Claim 5 The System's Transmitters as claimed in Claims 1,2, 3 & 4 transmit at random intervals their signal within a period of 5 seconds, to avoid two vessels transmissions continuously overlapping, even though the signal is very short due to the"short burst" technology employed.

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Claim 6 The System's Transmitters as claimed in Claims 1,2, 3,4 & 5 are capable of being programmed with the vessel's GMDSS"call sign"which can be received on receivers equipped to do so by such Agencies as the Coast Guard, Lifeboats and other Emergency Services.

Claim 7 The System's Transmitters as claimed in Claims 1,2, 3,4, 5 & 6 are fitted with an emergency button that when activated adds three * before and after the Type Identifier and Latitude and Longitude of the transmitting vessel's signal, which flashes on the screen of the receiving vessel indicating the vessel transmitting requires assistance.

Claim 8 The System's Receiver as claimed in Claims 1, 2, 3, 4, 5, 6, & 7 is programmed so that when a button is depressed the estimated future course and speed of the transmitting vessels are shown on the screen, such estimates only being an indicator so long as the vessel transmitting does not change course or speed.

Claim 9 The System's Receiver as claimed in Claims 1,2, 3,4, 5,6, 7 & 8 is programmed to be able to provide an overlay indicating the area in which transmitting vessels are likely to have right of way as per the sea's Rule of the Road.

Claim 10 The System's Receiver as claimed in Claims 1,2, 3,4, 5,6, 7,8 & 9 is fitted with a LED to indicate that it is operating, this LED flashes if battery power drops near to a non transmittable amount.

Claim 11 The System's Transmitters as claimed in Claims 1,2, 3,4, 5,6, 7,8, 9 & 10 are normally run off the vessels 12-volt supply system or on batteries, which are supported by an emergency NICAD battery.

Claim 12 The System's Transmitters as claimed in Claims 1,2, 3,4, 5,6, 7,8, 9,10 & 11 are fitted with standard VHF type aerial connectors, so that the most suitable aerial for the type of vessel carrying the system transmitter can be fitted.

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Claim 13 The System's Transmitters as claimed in Claims 1,2, 3,4, 5,6, 7,8, 9,10, 11 & 12 can be fitted with various types of mounting as suitable for the vessel carrying it.

Claim 14 The System's Transmitters as claimed in Claims 1,2, 3,4, 5,6, 7,8, 9,10, 11,12 & 13 are constructed in such a way as to ensure that the transmitter is capable of withstanding all types of weather condition.

Claim 15 The System's Transmitters as claimed in Claims 1,2, 3,4, 5,6, 7,8, 9,10, 11,12, 13 & 14 are divided into two types-Type A & Type B, Type A has to be attached to a separate GPS receiver via an interconnecting lead, and Type B has it's own built-in GPS receiver ; when a G as in Type AG is shown it indicates that the transmitter is capable of being programmed with the Vessel's unique GMDSS"call sign".

Claim 16 The System's Receivers as claimed in Claims 1,2, 3,4, 5,6, 7,8, 9, 10, 11, 12,13, 14 & 15 are capable of outputting direct to a computer type monitor or to a computer so that the information can be overlaid on a proprietary Chart Plotting programme.

Claim 17 The System's Receivers as claimed in Claims 1,2, 3,4, 5,6, 7,8, 9,10, 11,12, 13,14, 15 & 16 are capable of being built into an integrated unit incorporating the receiver and a screen.

Claim 18 The System's Receiver as claimed in Claims 1,2, 3,4, 5,6, 7,8, 9,10, 11,12, 13,14, 15, 16 & 17 is connected by a standard connector cord to any fixed or handheld GPS receiver with a suitable NMEA output.