CA2202018A1 - Drifting datum marker buoy - Google Patents
Drifting datum marker buoyInfo
- Publication number
- CA2202018A1 CA2202018A1 CA 2202018 CA2202018A CA2202018A1 CA 2202018 A1 CA2202018 A1 CA 2202018A1 CA 2202018 CA2202018 CA 2202018 CA 2202018 A CA2202018 A CA 2202018A CA 2202018 A1 CA2202018 A1 CA 2202018A1
- Authority
- CA
- Canada
- Prior art keywords
- marker buoy
- compact
- water
- buoy
- flotation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B22/00—Buoys
- B63B22/003—Buoys adapted for being launched from an aircraft or water vehicle;, e.g. with brakes deployed in the water
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63C—LAUNCHING, HAULING-OUT, OR DRY-DOCKING OF VESSELS; LIFE-SAVING IN WATER; EQUIPMENT FOR DWELLING OR WORKING UNDER WATER; MEANS FOR SALVAGING OR SEARCHING FOR UNDERWATER OBJECTS
- B63C9/00—Life-saving in water
- B63C9/08—Life-buoys, e.g. rings; Life-belts, jackets, suits, or the like
- B63C9/20—Life-buoys, e.g. rings; Life-belts, jackets, suits, or the like characterised by signalling means, e.g. lights
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Aviation & Aerospace Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Position Fixing By Use Of Radio Waves (AREA)
Abstract
This invention relates to a drifting marker buoy that exhibits dual drift characteristics. These characteristics emulate the drift of a person in water, i.e. a minimum leeway object, as well as a larger object such as a life raft in water, i.e. a maximum leeway object. The marker buoy is capable of being packaged within a small housing and can be easily air deployed using, for example, a small military "A-size"
launch tube. The buoy can be monitored by a variety of means and adapted so that it is capable of acquiring geographical self-location data via satellite-based positioning systems. Incorporating a configurable drift object, in a sonobuoy air launch package, along with the capability of a wave crest sensor represents a significant advance in SAR
buoy technology.
launch tube. The buoy can be monitored by a variety of means and adapted so that it is capable of acquiring geographical self-location data via satellite-based positioning systems. Incorporating a configurable drift object, in a sonobuoy air launch package, along with the capability of a wave crest sensor represents a significant advance in SAR
buoy technology.
Description
The present invention relates to a drifting marker buoy. More specifically this invention relates to a drifting datum marker buoy capable of dual drift characteristics.
BACKGROUND OF THE INVENTION
A fundamental problem in marine search and rescue is the rapid growth of the search area. Marine search areas expand exponentially with time. From the instant of the last known position, the search area begins to expand and move in a highly variable manner dependent on environmental conditions, and the accuracy with which these conditions can be estimated. In a very short period of time, the search area can expand to such a large size that it will be impossible for available resources to cover the search area without leaving some gaps in coverage.
A recent example of how quickly the search area expands is the sinking of the Salvador Allende 900 kilometres south of St. John's Newfoundland in December 1994.
In this case, the search area expanded from a few square miles to the size of Prince Edward Island in only two days. Two of the thirty-one member crew were rescued in the search and rescue (SAR) operation. One of the survivors was found in the water 1 12 2 o kilometres southeast of where rescuers thought he should be.
The Coast Guards of Canada and the United States have conducted experiments which have shown that the use of Datum Marker Buoys (DMBs) can significantly reduce the errors associated with the estimation of sea surface ~;ullelll~7. Search and Rescue 2 5 coordinators at the Halifax RCC have recommended the use of air launched self locating DMBs in oceanic SAR operations. However, ~;ullelllly available DMBs are costly to produce and deploy, and require specialized handling for deployment resulting in limited flexibility for use under adverse conditions. Furthermore, existing DMBs have proved unreliable under rough water conditions.
A review of the techniques and results associated with the use of recently developed marker buoys including ADDAM (Air Deployable Datum Marker) and the Self LocatingDMB (SL-DMB) was presented at the Advanced Technologies in Search and Rescue Symposium, in September 1994 (Leger, G., Paterson, A., Datum Marker Buoys for SAR drift Measurements, Proceedings of the Advanced Technologies in Search and Rescue Symposium, 1994 C~n~ n Conference on Electrical and Computer Engineering, Transport Development Centre, September 1994). A variety of air launch packages, drift configurations and satellite navigation and telemetry techniques were evaluated within the existing DMB technology. Based on the limitations present within 0 these prototypes, the innovative new search and rescue-datum marker buoy (SAR-DMB) was developed that is the subject matter of this invention. This SAR-DMB design incorporates several unique features which enables it to meet the requirements and limitations identified in the previous development prototypes for a practical DMB.
The ADDAM buoy utilized the concept of a DMB with variable drift geometry. The Air Deployable Datum Marker (ADDAM) mimics the geometry of two representative search and rescue objects, an inflatable liferaft or a person in water. The ADDAM has to be pre-configured as either a minimum or maximum leeward object prior to its use. This drifter is equipped with satellite navigation (GPS) and satellite data telemetry (Inmarsat 2 o Standard C), to report hourly positions (Leger, G., Innovation: Using GPS-equipped drift buoys for Search and Rescue Operations, November 1992, GPS World, Vol 3, #10, pp 36-41). Field trials demonstrated that ADDAM's drift characteristic correctly modelled the desired search objects, and that the GPS-Inmarsat satellite technology combination provides timely drift data of suitable accuracy. However, ADDAM is large, 2 5 over 6 feet in length when emulating a maximum leeward object, and is deployed from water craft only. Efficient monitoring of drifting people or liferafts requires the deployment of any SAR-DMB as quickly as possible, requiring air launch capability.
Use of the ADDAM is limited due to the size and increased buoy weight arising from the Inmarsat transceiver and associated power requirements. These features result in high 3 o production and deployment costs making it impractical for a DMB. Other limitations were identified in the sail integrity, reliability (e.g. satellite communications errors in 2 ~ ~ ~
.
heavy seas were noted), and, due to its size, the lack of ease in its deployment and operation. Furthermore, this buoy could only operate as either a minimum leeway, or a maximum leeway object, emulating a person or liferaft, respectfully, at one time.
The Sampling Autonomous Buoy for Evidence Recovery (SABER) is a buoy dropped from an aircraft into an oil slick to collect pollution samples. The buoy is equipped with electronics to aid recovery and the sample is used as evidence against the polluter. The SABER is designed using mass produced sonobuoy technology, substituting a sample chamber for the hydrophone sensor in the sonobuoy and adding a 0 GPS sensor to the sonobuoy electronics package. However, this buoy was not adapted for use as a drifting marker buoy and did not emulate the drifting characteristics or either a minimum or maximum leeway object within water.
7 ~ 8 SUMMARY OF THE INVENTION
The present invention relates to a compact drifting marker buoy that emulates a minimum or maximum leeward object floating in water.
According to the present invention there is provided an air deployable compact marker buoy system capable of exhibiting minimum leeway flotation and drift characteristics emulating a person drifting in water comprising;
a) a body, comprising a flotation portion and a hull;
b) a means for deploying said marker buoy within the water;
c) a means for restricting minimum leeway drift; and d) a means for determininp the position of said marker buoy.
The hull lying below the water line, and the flotation portion lying above the water line when the marker buoy is in water.
This invention is also directed to compact marker buoys wherein the minimum leeway drift is restricted by a submersible drogue, by increasing the surface area of the 2 o hull of the marker buoy, or by using extensions from the body of the marker buoy such as planer extensions.
This invention also relates to compact marker buoys of a spar type, so that the increased surface area is obtained by increasing the diameter of the hull with respect to 2 5 the diameter of the flotation portion.
This invention is also directed to compact marker buoys wherein the flotation portion is comprised of a flotation bag.
3 o Other embodiments of this invention embrace determining the position of said marker buoy using visual means, or electronic means, or both. The electronic means i 8 may include a wave crest sensor such as an accelerometer based sensor, and an RFantenna and associated RF board, a GPS antenna and associated GPS engine, or both.
This invention also relates to an air deployable compact marker buoy system capable of exhibiting maximum leeway flotation and drift characteristics emulating a liferaft drifting in water comprising;
a) a body comprising a flotation portion and a hull;
b) a means for deploying said marker buoy within the water; and c) a means for deterrnining the position of said marker buoy, with the hull lying below the water line, and the flotation portion above the water line when placed in water. This marker buoy comprises a flotation portion being a flotation bag. Furthermore, an aspect of an embodiment of this invention includes a compact marker buoy as defined above wherein the means for determining the position of said marker buoy include visual means, or electronic means, or both. Wherein the electronic means may comprise a wave crest sensor such as an accelerometer based sensor, and an RF antenna and associated RF board, a GPS antenna and associated GPS engine, or both.
2 o This invention is also directed to an air deployable compact marker buoy system capable of exhibiting both minimum and maximum leeway flotation and drift characteristics emulating a person or liferaft drifting in water, respectively, comprising;
a) a body comprising a flotation portion and a hull;
2 5 b) a means for deploying said marker buoy within water;
c) a means for restricting minimum leeway drift; and c) a means for deterrnining the position of said marker buoy.
with the hull lying below the water line, and the flotation portion above the water line 3 o when placed in water. This marker buoy comprises a flotation portion being a flotation bag. Furthermore, an aspect of an embodiment of this invention includes a compact marker buoy as defined above wherein the means for determining the position of said marker buoy include visual means, or electronic means, or both. The electronic means may comprise a wave crest sensor such as an accelerometer based sensor, and an RF
antenna and associated RF board, a GPS antenna and associated GPS engine, or both.
This compact marker buoy also comprises a detachable means for restricting minimum leeway drift.
This invention also embraces an air deployable compact marker buoy system capable of exhibiting both minimum and maximum leeway flotation and drift o characteristics emulating a person or liferaft drifting in water, respectively, comprising:
a) a body comprising a flotation bag and a hull, comprising:
I) a means for detecting water comprising two water sensitive electrodes;
ii) a means for deploying said marker buoy when water is detected comprising infl~ting the floatation bag with a compressed gas;
iii) a means for detecting the temperature of the water;
iv) a means for determining the position of said marker buoy comprising m~rkin~s that enhance visual detection, and electronic means 2 o comprising a wave crest sensor, and an RF antenna and RF board, a GPS antenna and GPS engine or both, operatively associated with said digital board and motherboard; and v) a means for sinking said marker buoy comprising heating a resistor located in the tip of said flotation bag; and 2 5 b) a means for restricting minimum leeway drift comprising a detachable tethered drogue;
wherein said marker buoy is placed within a suitable air deployment package to be launched from a suitable air craft, said air deployment package comprising means to aid 3 o said marker buoy to the surface of a body of water.
All existing drifting marker buoy systems are large, costly to produce, non-air deployable, and non-reliable in rough waters. These limitations result in reduced use of such marker buoy systems. No DMB is available that is air deployable and that permits enhanced detection within rough seas. Thus there is a need within this art for a compact, cost effective, air deployed marker buoy that is capable of emulating both a person and a liferaft drifting in the water and that is adaptable to permit a variety of methods for detection and monitoring, even within rough seas.
2 ~
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein:
FIGURE 1 is a schematic overview of the drifting marker buoy of this invention.
FIGURE 2 is a diagrammatic overview of the principles of the search and rescue datum marker buoy (SAR-DMB) of this invention. The satellite tracked surface drifter is 0 packaged into a standard sonobuoy air launch package; Figure 2A. On reaching the water, the drifter inflates its air bag (sail) from a small carbon dioxide gas cartridge;
Figure 2B. This causes the launch sleeve to fall away allowing the surface drogue to deploy, configuring the DMB as a minimum leeway drifter; Figure 2C. To configure the SAR-DMB as a maximum leeway object, the drogue is disconnected prior to launch; Figure 2D. The drifters have distinctly different drift characteristics and report their GPS positions to Rescue Coordinations Centres over the Argos satellite network.
FIGURE 3 is a representation of ~;ullelllly available maximum leeway, wind driven, datum 2 o marker buoy: Air Deployable Datum Marker (ADDAM), and Sample Autonomous Buoy for Evidence Recovery (SABER) FIGURE 4 is a representation of the currently available minimum leeway datum marker buoy the Air Deployable Datum Marker (ADDAM).
FIGURE 5 is a representation of other embodiments of the DMB of this invention indicating alternate methods for emulating minimum leeward drift objects. Figure5A demonstrates the use of planer extensions; Figure 5B shows the use of increased hull diameter of a spar-type DMB.
FIGURE 6 shows a GPS receiver with an Argos satellite transmitter that is 10 cm in height.
FIGURE 7 shows the SAR-DMB with the flotation bag cont~ining a satellite antenna and hull cont~ining electronics, and drogue.
FIGURE 8 shows the marker buoy packaged within a "A" size sonobuoy launch package.
- ~ 2 ~ 8 DESCRIPTION OF PREFERRED EMBODIMENT
In order to reduce the area of growth of a marine search area which results in reduced time and resources spent by rescuers in locating survivors, measuring on-the-scene drift and using these measurements as input for search planning tools is required.
A schematic illustrating the deployment and use of the SAR-DMB is found in Figure 2. The search and Rescue-Datum Marker Buoy (SAR-DMB) of this invention provides such a tool as required within the field. This drifter can be configured to exhibit two 0 different drift characteristics. It is packaged into a standard air launch package (Figure 8). The SAR-DMB can mimic the drift of a person in the water or an unm~nned liferaft.
The SAR-DMB can be monitored using a variety of means including visual, camera or electronic monitoring. The SAR-DMB can be equipped with a mini~hlre satellite navigator (GPS) and a small satellite data transmitter (ARGOS).
The SAR-DMB can be m~nuf~ctured to allow use of parts used in mass produced air launched military underwater listening devices called sonobuoys. However, the casing for the SAR-DMB may include a variety of housings as are known to those of skillwithin the art. Similarly, as would be appreciated by one of skill in the art, the method of 2 o deployment would be in keeping with the type of casing used to house the SAR-DMB.
In order to demonstrate the ease associated with the use of the SAR-DMB of this invention, a SAR-DMB is exemplified that is housed so that it is identical in appearance and size, and that exhibits the weight and centre of gravity of a standard "A" size sonobuoy. Using sonobuoy technology the SAR-DMB of this invention results in a low 2 5 cost, manufacturable SAR-DMB that is compatible with existing military air launch technologies, an important economic and logistical benefit.
In order to overcome identified limitations with prior art drift buoys (see Figures 3 and 4), such as satellite communications errors in heavy seas, a wave crest sensor can 3 o optionally be incorporated into the design. The sensor causes the drifters to transmit when they are at the top of a wave with a clear view of the sky. This greatly increases - 2 ~ ~ 2 ~ 1 %
the probability of satellite detection and monitoring. Furthermore, the SAR-DMB of this invention can be easily modified to emulate either a person, or a liferaft drifting in water, at the time of launch based on the perceived need at the time. This capability does not exist within prior art DMBs.
Referring to Figure 1, there is shown the SAR-DMB of this invention (10). The SAR-DMB is comprised of a floatation bag/hull unit comprised of a flotation bag (100) and hull (1 10) cont~ining a self contained RF transmitter ( ) and GPS receiver (22), a flotation assembly (9) and a battery pack (12). The SAR-DMB can be configured to1 0 simulate either the drift of a man in the water in a survival suit or, by cutting the drogue line (35), the drift of a four man liferaft.
The main SAR-DMB function, other than permitting monitoring via data/communication, or visual methods, is related to its drift parameters. The floatation bag/hull unit provides air drag to simulate the drift of a four man liferaft or a man in a survival suit depending on the configuration. The flotation bag/hull unit floats the buoy to the surface after air deployment and operates a parachute release mechanism that jettisons the float unit upon its inflation. The air bag also supports an optional RF
antenna (11). The bag tip has a resistor (31) attached which can melt a hole in the bag 2 o for end of life scuttle. The flotation bag/hull unit encloses an optional GPS antenna for all-weather operation. The bag is m~nuf~ctured using coloured and reflective materials to ensure visual detection of the SAR-DMB. For example, the bag may be manufactured using International Orange and retro-reflective material patches.
2 5 The flotation bag/hull unit is pressurized to keep water out and ensure floating of the unit. The hull baseplate forms attachment point for the drogue/tether assembly The baseplate also forms base of battery assembly and is aluminum for light weight, strength, thermal conductivity and anti corrosion. The baseplate also locates an optional thermal measuring device (33) and an optional water sensing device (33) as well as locates a port 3 o for testing and evacuating the flotation bag. The bag and baseplate fit onto standard deployment housings available within the art, for example a Hermes UEU can (Hermes - - 2 ~ 'l 8 Electronics of Dartmouth, Nova Scotia, Canada) having the same diameter, crimping mechanism and o-ring groove to seal the system.
The buoy is packaged in any suitable housing system, such as a standard A-size sonobuoy housing, and is supplied to customer ready for air deployment (see Figure 8).
The SAR-DMB can be adapted to fit within existing housing systems with proven package launch capabilities. If the weight, and centre of gravity characteristics are kept the same as for existing launch purposes, further launch testing requirements are minimi7~d. Using available housings also ensures consistent launch characteristics. An 0 example, which is not to be considered limiting is the launch package of the Hermes 53D
sonobuoy (can, parachute, parachute release mech~ni~m, windflap and other supporting parts; available from Hermes Electronics of Dartmouth, Nova Scotia, Canada) which can be used to house the SAR-DMB of this invention so that the weight and centre of gravity are kept the same as other items typically launched within an "A" size launch tube. It is to be understood however, that other suitable deployment housings, as would recognized by one of skill in the art may also be used without departing from the spirit of this invention.
The buoy is sealed hermetically in an appropliate CAD launch tube to protect the2 o buoy environmentally before use.
The electronics are housed in an alllminllm cylinder with an inflatable flotation bag at one end. Inside, are found a gas cartridge (24), an optional Global Positioning System (GPS) receiver (22), an optional satellite transmitter, microprocessor and batteries (12).
The SAR-DMB may comprise a RF Antenna (l l) to transmit signal to an Argos satellite. Such an ~ntenn~ would be supplied with a Hermes float bag (9) with some modification.
--' 2 ~
In order to control housekeeping functions of the SAR-DMB, standard software, for example OOD PTT software, is used. Custom modules can be used perform any specific tasks within the SAR-DMB including detection of water, release of the squib, and/or bag.
All power for electronics and buoy functions are supplied by battery (12). The pack assembly (13) is designed to withstand air-deployment shocks and vibration. The pack assembly has mounting provision for the electronics (14) and inflation device (15).
It also mounts solidly on a bottom plate assembly which anti-rotates the inner buoy 0 components. The battery uses 21 standard alkaline C-cells. Tab welding may be used for interconnection reliability.
A GPS Antenna (16) is required for GPS operation.
A Standard RF board (17), such as that provided by SEIMAC (Seimac Limited, Halifax Nova Scotia, Canada) with a header allows it to be easily connected to a Digital Board and provides an outgoing data link to Argos satellite (not shown). The Digital Board (18), for example a Standard SEIMAC Digital board, comprises headers to allow it to be easily connected to a Motherboard (19) and RF board (17). Provides all logic, 2 o control, memory, communication, and data functions. The software is run on a micro controller (20) onboard the Digital board (18).
The motherboard (19) physically carries and supplies conditioned power to RF
(17), Digital (18) and GPS boards (21). The motherboard mates with Digital, RF and 2 5 GPS boards, providing a one piece electronics assembly which can be powered up and tested independently of the rest of the SAR-DMB and is easily removable for test/troubleshooting. The EPROM is easy to remove and replace and uses an easy to access socket.
3 o The motherboard enables the following functions to be performed:
water detection squib firing bag internal pressure (for testing) bag scuttle battery protection diodes temperature The motherboard mates, using connectors, to the Bottom plate board. The motherboard may use a DC to DC converter (optional) if the power budget requires one.
A multi-channel GPS Engine (22) receives GPS information (position and time).
This engine is characterized in that it preferably is an all-in view engine, having low power consumption and a footprint similar to the RF board.
The float bag (29) is inflated using compressed gas, a preferred gas is nitrogen, which is less permeable than C02. The inflation assembly (23) is composed of the gas cylinder (24), a piston (25) with sharp pin (26), a squib (27) and a housing (28). The squib drives the pin down the housing and through the end of the cylinder allowing the gas to escape and fill the float bag (29). The cylinder has the required amount of gas to 2 o inflate float bag. The entire bag inflation assembly fits into battery pack (30) and is securely clamped into place. The squib may be electrically fired, a function controlled by the motherboard.
The buoy may be sunk at the end of its use by heating a resistor (3 l ) in the bag 2 5 tip. This causes the bag to leak and the unit to flood and sink. This resistor is part of the Hermes bag assembly (9).
If desired the SAR-DMB may comprise a water detect function electronically carried out on the motherboard. Safety against accidental firing is provided by the use of 3 o two separate water sense testers. A pair of electrodes (32) coming in contact with the water will initiate firing of the inflation squib. Water contacting electrode one will wake ' 2 ~
up the electronics for an interval of time as deemed appropriate (e.g. one second). If water also contacts electrode two, for an appro~fiate period of time (e.g. one second), this will cause the squib (27) to fire. The circuit must be sensitive enough to fire in fresh and salt water. The squib is preferably fired so that the float bag is infl~te(l within about 20 seconds of water entry.
Surface water temperature is optionally measured with a thermistor (33) embedded in the aluminum bottom plate potted with heat sink compound. For easy of assembly, a small circuit board on the bottom plate is connected to the thermistor (33) l o and water sense electrodes (32) to the motherboard.
The drogue (34) provides drag to the SAR-DMB to simulate the drift of a man in the water in a survival suit. It is designed to float just under the surface of the water.
(approximately within the top 40 cm) All drogue materials and tether may pack into the space available below the float unit inside a suitable deployment package. The drogue may use a Hermes drogue hoop for support, however, other such support structure could be employed. Furthermore, the drogue may be manufactured from bright yellow, or other parachute cloth for extra visibility. The drogue is attached to the float unit with shock cord (35) to reduce jerk loading (figure 7). The drogue unit is designed to be 2 o easily disconnected of the surface unit before deployment to configure the unit for liferaft drift simulation. Drogues are built as a standard item and chained together as needed to provided the required drag (Figure 7).
Dual Drift Characteristics The SAR-DMB design provides for a drifter capable of two distinctly different drift characteristics to be packaged into available launch packages, for example, an "A-size" air launch package, allowing each SAR-DMB to mimic the drift of either a person in the water (minimum leeway object, Figure 2C) or an l]nm:mned liferaft (maximum 3 o leeway object, Figure 2D). The drifters are optionally equipped with a mini~tllre satellite - - ~ 2 ~
navigator (GPS), a small satellite data transmitter (e.g. Argos) or both. The concept is illustrated in Figure 2.
The critical design parameter for a minimum leeway drifter is that the above water area and the below water area should meet the following relationship:
[AU/AW]1/2<0.4 From a m~nllf~cturing point of view a drogued design is preferred. However, a drogue very near the surface may become tangled in high seas. Other alternate solutions include the small self locating-datum marker buoy (SL-DMB) type drifter comprising submerged wing-like projections as shown in Figure 5, or a mini~ture spar buoy also displayed in Figure 5. Each of these designs have the required area ratio identified above and are alternate solutions for the required characteristics.
Satellite Technology GPS positioning in a satellite tracked surface drifter was pioneered by the inventors and is now routinely used for drifter positioning (Leger, G. Surface Tracked 2 o Lagranian Drifters, Sea Technology, August l99l, Vol 32 #8, pp. 27-30). Other various oceanographic drifters have proven the accuracy and practicality of GPS
positioning systems floating at the ocean surface (Risley, W.C., Fraser, I.A., Leger, G.T.
Lagranian Ambient Noise Drifter, Proceedings of Oceans'94, Ocean Engineering Society of IEEE, September l 994, Col III, pp. 34-39), including the ADDAM buoy. For 2 5 example, the Smart CAT Certified Argos Transmitter, manufactured and available from Seimac Limited can be used for such a purpose. This satellite transmitter integrates a GPS receiver to encode drift data in the Service Argos specified GPS position message (Figure 6). This small and inexpensive device reports hourly GPS position measurements via the Argos satellite system by storing acquired positions in internal 3 o memory and continuously broadcasting a message cont~ining the six most recent hourly positions. This reporting scheme overcomes gaps in satellite orbits and provides a o~ ~
complete data set. Experiments using Argos have shown that the system can provide drift data within an acceptable time frame. Even though an Argos based system has proved useful for the monitoring of the SAR-DMB of this invention, other monitoring systems, as would be readily apparent to one of skill in the art to which this invention pertains, could be readily employed for use. For example, the Argos telemetry provides a migration path to potentially incorporate the emerging technology associated with the LEO satellite.
Wave Crest Sensor One of the key problems in any satellite tracked surface drifter is the degradation in buoy-satellite communications in heavy seas. Since these are precisely the times when marine SAR incidents tend to occur, an important optional component of our design is the ability to incorporate an accelerometer based sensor which triggers satellite data tr~n~mi~.~ions from the crests of waves when the antenna is "in the clear". This improves the success rate of buoy-satellite "hits". The wave crest sensor is based on a wave height sensor developed by the inventors for use in a Lagrangian Ambient Noise Drifter (Leger, G., Grant, J. A Wave Height Sensor for Drogued Argos Drifters, Proceedings of Oceans'95, Ocean Engineering Society of IEEE, September l 995).
Sonobuoy Air Launch P~ck~ging The air launch packaging of the maximum and minimum drift objects of the SAR-DMB is based on any available housing systems known to those of skill in the art.
2 5 An example of such a system is a high volume m~nuf~tured sonobuoy and associated parts developed by Hermes Electronics of Dartmouth Nova Scotia, Canada. In this example, the SAR-DMB can be packaged into the sonobuoy launch package to conformexactly to the military "A" size sonobuoy flight specifications (Figure 8). It can be safely launched from long range military surveillance and anti-submarine aircraft including 3 o helicopters as well as other aircraft employed in search and rescue operations.
Sonobuoy, or other launch chutes are a standard, mature aerospace technology which can ~ 18 be easily installed in aircraft used by non-military agencies. The use of this launch package makes the SAR-DMB economical and compatible with existing air launch technologies.
Air Drop Certification Testing C~n~ n DND air certification officials (DMAEM 442) coordinated air drop certification tests of ten SAR-DMB. The flight characteristics of SAR-DMB's was also verified in drop tests near Halifax harbour from a C~n~ n DND Aurora aircraft.
The drift characteristics of the SAR-DMB as a minimum and maximum leeway drifter have also been verified. A number of drift experiments have been conducted from the CCG Bickerton in the summer and fall of 1996. Open ocean trials of the development model using C~n~ n Forces Auxiliary vessel Quest in the North Atlantic in November 1996 verified the SAR-DMB drift characteristics.
All scientific publications and patent documents are incorporated herein by reference.
The present invention has been described with regard to preferred embodiments.
However, it will be obvious to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as described herein.
BACKGROUND OF THE INVENTION
A fundamental problem in marine search and rescue is the rapid growth of the search area. Marine search areas expand exponentially with time. From the instant of the last known position, the search area begins to expand and move in a highly variable manner dependent on environmental conditions, and the accuracy with which these conditions can be estimated. In a very short period of time, the search area can expand to such a large size that it will be impossible for available resources to cover the search area without leaving some gaps in coverage.
A recent example of how quickly the search area expands is the sinking of the Salvador Allende 900 kilometres south of St. John's Newfoundland in December 1994.
In this case, the search area expanded from a few square miles to the size of Prince Edward Island in only two days. Two of the thirty-one member crew were rescued in the search and rescue (SAR) operation. One of the survivors was found in the water 1 12 2 o kilometres southeast of where rescuers thought he should be.
The Coast Guards of Canada and the United States have conducted experiments which have shown that the use of Datum Marker Buoys (DMBs) can significantly reduce the errors associated with the estimation of sea surface ~;ullelll~7. Search and Rescue 2 5 coordinators at the Halifax RCC have recommended the use of air launched self locating DMBs in oceanic SAR operations. However, ~;ullelllly available DMBs are costly to produce and deploy, and require specialized handling for deployment resulting in limited flexibility for use under adverse conditions. Furthermore, existing DMBs have proved unreliable under rough water conditions.
A review of the techniques and results associated with the use of recently developed marker buoys including ADDAM (Air Deployable Datum Marker) and the Self LocatingDMB (SL-DMB) was presented at the Advanced Technologies in Search and Rescue Symposium, in September 1994 (Leger, G., Paterson, A., Datum Marker Buoys for SAR drift Measurements, Proceedings of the Advanced Technologies in Search and Rescue Symposium, 1994 C~n~ n Conference on Electrical and Computer Engineering, Transport Development Centre, September 1994). A variety of air launch packages, drift configurations and satellite navigation and telemetry techniques were evaluated within the existing DMB technology. Based on the limitations present within 0 these prototypes, the innovative new search and rescue-datum marker buoy (SAR-DMB) was developed that is the subject matter of this invention. This SAR-DMB design incorporates several unique features which enables it to meet the requirements and limitations identified in the previous development prototypes for a practical DMB.
The ADDAM buoy utilized the concept of a DMB with variable drift geometry. The Air Deployable Datum Marker (ADDAM) mimics the geometry of two representative search and rescue objects, an inflatable liferaft or a person in water. The ADDAM has to be pre-configured as either a minimum or maximum leeward object prior to its use. This drifter is equipped with satellite navigation (GPS) and satellite data telemetry (Inmarsat 2 o Standard C), to report hourly positions (Leger, G., Innovation: Using GPS-equipped drift buoys for Search and Rescue Operations, November 1992, GPS World, Vol 3, #10, pp 36-41). Field trials demonstrated that ADDAM's drift characteristic correctly modelled the desired search objects, and that the GPS-Inmarsat satellite technology combination provides timely drift data of suitable accuracy. However, ADDAM is large, 2 5 over 6 feet in length when emulating a maximum leeward object, and is deployed from water craft only. Efficient monitoring of drifting people or liferafts requires the deployment of any SAR-DMB as quickly as possible, requiring air launch capability.
Use of the ADDAM is limited due to the size and increased buoy weight arising from the Inmarsat transceiver and associated power requirements. These features result in high 3 o production and deployment costs making it impractical for a DMB. Other limitations were identified in the sail integrity, reliability (e.g. satellite communications errors in 2 ~ ~ ~
.
heavy seas were noted), and, due to its size, the lack of ease in its deployment and operation. Furthermore, this buoy could only operate as either a minimum leeway, or a maximum leeway object, emulating a person or liferaft, respectfully, at one time.
The Sampling Autonomous Buoy for Evidence Recovery (SABER) is a buoy dropped from an aircraft into an oil slick to collect pollution samples. The buoy is equipped with electronics to aid recovery and the sample is used as evidence against the polluter. The SABER is designed using mass produced sonobuoy technology, substituting a sample chamber for the hydrophone sensor in the sonobuoy and adding a 0 GPS sensor to the sonobuoy electronics package. However, this buoy was not adapted for use as a drifting marker buoy and did not emulate the drifting characteristics or either a minimum or maximum leeway object within water.
7 ~ 8 SUMMARY OF THE INVENTION
The present invention relates to a compact drifting marker buoy that emulates a minimum or maximum leeward object floating in water.
According to the present invention there is provided an air deployable compact marker buoy system capable of exhibiting minimum leeway flotation and drift characteristics emulating a person drifting in water comprising;
a) a body, comprising a flotation portion and a hull;
b) a means for deploying said marker buoy within the water;
c) a means for restricting minimum leeway drift; and d) a means for determininp the position of said marker buoy.
The hull lying below the water line, and the flotation portion lying above the water line when the marker buoy is in water.
This invention is also directed to compact marker buoys wherein the minimum leeway drift is restricted by a submersible drogue, by increasing the surface area of the 2 o hull of the marker buoy, or by using extensions from the body of the marker buoy such as planer extensions.
This invention also relates to compact marker buoys of a spar type, so that the increased surface area is obtained by increasing the diameter of the hull with respect to 2 5 the diameter of the flotation portion.
This invention is also directed to compact marker buoys wherein the flotation portion is comprised of a flotation bag.
3 o Other embodiments of this invention embrace determining the position of said marker buoy using visual means, or electronic means, or both. The electronic means i 8 may include a wave crest sensor such as an accelerometer based sensor, and an RFantenna and associated RF board, a GPS antenna and associated GPS engine, or both.
This invention also relates to an air deployable compact marker buoy system capable of exhibiting maximum leeway flotation and drift characteristics emulating a liferaft drifting in water comprising;
a) a body comprising a flotation portion and a hull;
b) a means for deploying said marker buoy within the water; and c) a means for deterrnining the position of said marker buoy, with the hull lying below the water line, and the flotation portion above the water line when placed in water. This marker buoy comprises a flotation portion being a flotation bag. Furthermore, an aspect of an embodiment of this invention includes a compact marker buoy as defined above wherein the means for determining the position of said marker buoy include visual means, or electronic means, or both. Wherein the electronic means may comprise a wave crest sensor such as an accelerometer based sensor, and an RF antenna and associated RF board, a GPS antenna and associated GPS engine, or both.
2 o This invention is also directed to an air deployable compact marker buoy system capable of exhibiting both minimum and maximum leeway flotation and drift characteristics emulating a person or liferaft drifting in water, respectively, comprising;
a) a body comprising a flotation portion and a hull;
2 5 b) a means for deploying said marker buoy within water;
c) a means for restricting minimum leeway drift; and c) a means for deterrnining the position of said marker buoy.
with the hull lying below the water line, and the flotation portion above the water line 3 o when placed in water. This marker buoy comprises a flotation portion being a flotation bag. Furthermore, an aspect of an embodiment of this invention includes a compact marker buoy as defined above wherein the means for determining the position of said marker buoy include visual means, or electronic means, or both. The electronic means may comprise a wave crest sensor such as an accelerometer based sensor, and an RF
antenna and associated RF board, a GPS antenna and associated GPS engine, or both.
This compact marker buoy also comprises a detachable means for restricting minimum leeway drift.
This invention also embraces an air deployable compact marker buoy system capable of exhibiting both minimum and maximum leeway flotation and drift o characteristics emulating a person or liferaft drifting in water, respectively, comprising:
a) a body comprising a flotation bag and a hull, comprising:
I) a means for detecting water comprising two water sensitive electrodes;
ii) a means for deploying said marker buoy when water is detected comprising infl~ting the floatation bag with a compressed gas;
iii) a means for detecting the temperature of the water;
iv) a means for determining the position of said marker buoy comprising m~rkin~s that enhance visual detection, and electronic means 2 o comprising a wave crest sensor, and an RF antenna and RF board, a GPS antenna and GPS engine or both, operatively associated with said digital board and motherboard; and v) a means for sinking said marker buoy comprising heating a resistor located in the tip of said flotation bag; and 2 5 b) a means for restricting minimum leeway drift comprising a detachable tethered drogue;
wherein said marker buoy is placed within a suitable air deployment package to be launched from a suitable air craft, said air deployment package comprising means to aid 3 o said marker buoy to the surface of a body of water.
All existing drifting marker buoy systems are large, costly to produce, non-air deployable, and non-reliable in rough waters. These limitations result in reduced use of such marker buoy systems. No DMB is available that is air deployable and that permits enhanced detection within rough seas. Thus there is a need within this art for a compact, cost effective, air deployed marker buoy that is capable of emulating both a person and a liferaft drifting in the water and that is adaptable to permit a variety of methods for detection and monitoring, even within rough seas.
2 ~
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein:
FIGURE 1 is a schematic overview of the drifting marker buoy of this invention.
FIGURE 2 is a diagrammatic overview of the principles of the search and rescue datum marker buoy (SAR-DMB) of this invention. The satellite tracked surface drifter is 0 packaged into a standard sonobuoy air launch package; Figure 2A. On reaching the water, the drifter inflates its air bag (sail) from a small carbon dioxide gas cartridge;
Figure 2B. This causes the launch sleeve to fall away allowing the surface drogue to deploy, configuring the DMB as a minimum leeway drifter; Figure 2C. To configure the SAR-DMB as a maximum leeway object, the drogue is disconnected prior to launch; Figure 2D. The drifters have distinctly different drift characteristics and report their GPS positions to Rescue Coordinations Centres over the Argos satellite network.
FIGURE 3 is a representation of ~;ullelllly available maximum leeway, wind driven, datum 2 o marker buoy: Air Deployable Datum Marker (ADDAM), and Sample Autonomous Buoy for Evidence Recovery (SABER) FIGURE 4 is a representation of the currently available minimum leeway datum marker buoy the Air Deployable Datum Marker (ADDAM).
FIGURE 5 is a representation of other embodiments of the DMB of this invention indicating alternate methods for emulating minimum leeward drift objects. Figure5A demonstrates the use of planer extensions; Figure 5B shows the use of increased hull diameter of a spar-type DMB.
FIGURE 6 shows a GPS receiver with an Argos satellite transmitter that is 10 cm in height.
FIGURE 7 shows the SAR-DMB with the flotation bag cont~ining a satellite antenna and hull cont~ining electronics, and drogue.
FIGURE 8 shows the marker buoy packaged within a "A" size sonobuoy launch package.
- ~ 2 ~ 8 DESCRIPTION OF PREFERRED EMBODIMENT
In order to reduce the area of growth of a marine search area which results in reduced time and resources spent by rescuers in locating survivors, measuring on-the-scene drift and using these measurements as input for search planning tools is required.
A schematic illustrating the deployment and use of the SAR-DMB is found in Figure 2. The search and Rescue-Datum Marker Buoy (SAR-DMB) of this invention provides such a tool as required within the field. This drifter can be configured to exhibit two 0 different drift characteristics. It is packaged into a standard air launch package (Figure 8). The SAR-DMB can mimic the drift of a person in the water or an unm~nned liferaft.
The SAR-DMB can be monitored using a variety of means including visual, camera or electronic monitoring. The SAR-DMB can be equipped with a mini~hlre satellite navigator (GPS) and a small satellite data transmitter (ARGOS).
The SAR-DMB can be m~nuf~ctured to allow use of parts used in mass produced air launched military underwater listening devices called sonobuoys. However, the casing for the SAR-DMB may include a variety of housings as are known to those of skillwithin the art. Similarly, as would be appreciated by one of skill in the art, the method of 2 o deployment would be in keeping with the type of casing used to house the SAR-DMB.
In order to demonstrate the ease associated with the use of the SAR-DMB of this invention, a SAR-DMB is exemplified that is housed so that it is identical in appearance and size, and that exhibits the weight and centre of gravity of a standard "A" size sonobuoy. Using sonobuoy technology the SAR-DMB of this invention results in a low 2 5 cost, manufacturable SAR-DMB that is compatible with existing military air launch technologies, an important economic and logistical benefit.
In order to overcome identified limitations with prior art drift buoys (see Figures 3 and 4), such as satellite communications errors in heavy seas, a wave crest sensor can 3 o optionally be incorporated into the design. The sensor causes the drifters to transmit when they are at the top of a wave with a clear view of the sky. This greatly increases - 2 ~ ~ 2 ~ 1 %
the probability of satellite detection and monitoring. Furthermore, the SAR-DMB of this invention can be easily modified to emulate either a person, or a liferaft drifting in water, at the time of launch based on the perceived need at the time. This capability does not exist within prior art DMBs.
Referring to Figure 1, there is shown the SAR-DMB of this invention (10). The SAR-DMB is comprised of a floatation bag/hull unit comprised of a flotation bag (100) and hull (1 10) cont~ining a self contained RF transmitter ( ) and GPS receiver (22), a flotation assembly (9) and a battery pack (12). The SAR-DMB can be configured to1 0 simulate either the drift of a man in the water in a survival suit or, by cutting the drogue line (35), the drift of a four man liferaft.
The main SAR-DMB function, other than permitting monitoring via data/communication, or visual methods, is related to its drift parameters. The floatation bag/hull unit provides air drag to simulate the drift of a four man liferaft or a man in a survival suit depending on the configuration. The flotation bag/hull unit floats the buoy to the surface after air deployment and operates a parachute release mechanism that jettisons the float unit upon its inflation. The air bag also supports an optional RF
antenna (11). The bag tip has a resistor (31) attached which can melt a hole in the bag 2 o for end of life scuttle. The flotation bag/hull unit encloses an optional GPS antenna for all-weather operation. The bag is m~nuf~ctured using coloured and reflective materials to ensure visual detection of the SAR-DMB. For example, the bag may be manufactured using International Orange and retro-reflective material patches.
2 5 The flotation bag/hull unit is pressurized to keep water out and ensure floating of the unit. The hull baseplate forms attachment point for the drogue/tether assembly The baseplate also forms base of battery assembly and is aluminum for light weight, strength, thermal conductivity and anti corrosion. The baseplate also locates an optional thermal measuring device (33) and an optional water sensing device (33) as well as locates a port 3 o for testing and evacuating the flotation bag. The bag and baseplate fit onto standard deployment housings available within the art, for example a Hermes UEU can (Hermes - - 2 ~ 'l 8 Electronics of Dartmouth, Nova Scotia, Canada) having the same diameter, crimping mechanism and o-ring groove to seal the system.
The buoy is packaged in any suitable housing system, such as a standard A-size sonobuoy housing, and is supplied to customer ready for air deployment (see Figure 8).
The SAR-DMB can be adapted to fit within existing housing systems with proven package launch capabilities. If the weight, and centre of gravity characteristics are kept the same as for existing launch purposes, further launch testing requirements are minimi7~d. Using available housings also ensures consistent launch characteristics. An 0 example, which is not to be considered limiting is the launch package of the Hermes 53D
sonobuoy (can, parachute, parachute release mech~ni~m, windflap and other supporting parts; available from Hermes Electronics of Dartmouth, Nova Scotia, Canada) which can be used to house the SAR-DMB of this invention so that the weight and centre of gravity are kept the same as other items typically launched within an "A" size launch tube. It is to be understood however, that other suitable deployment housings, as would recognized by one of skill in the art may also be used without departing from the spirit of this invention.
The buoy is sealed hermetically in an appropliate CAD launch tube to protect the2 o buoy environmentally before use.
The electronics are housed in an alllminllm cylinder with an inflatable flotation bag at one end. Inside, are found a gas cartridge (24), an optional Global Positioning System (GPS) receiver (22), an optional satellite transmitter, microprocessor and batteries (12).
The SAR-DMB may comprise a RF Antenna (l l) to transmit signal to an Argos satellite. Such an ~ntenn~ would be supplied with a Hermes float bag (9) with some modification.
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In order to control housekeeping functions of the SAR-DMB, standard software, for example OOD PTT software, is used. Custom modules can be used perform any specific tasks within the SAR-DMB including detection of water, release of the squib, and/or bag.
All power for electronics and buoy functions are supplied by battery (12). The pack assembly (13) is designed to withstand air-deployment shocks and vibration. The pack assembly has mounting provision for the electronics (14) and inflation device (15).
It also mounts solidly on a bottom plate assembly which anti-rotates the inner buoy 0 components. The battery uses 21 standard alkaline C-cells. Tab welding may be used for interconnection reliability.
A GPS Antenna (16) is required for GPS operation.
A Standard RF board (17), such as that provided by SEIMAC (Seimac Limited, Halifax Nova Scotia, Canada) with a header allows it to be easily connected to a Digital Board and provides an outgoing data link to Argos satellite (not shown). The Digital Board (18), for example a Standard SEIMAC Digital board, comprises headers to allow it to be easily connected to a Motherboard (19) and RF board (17). Provides all logic, 2 o control, memory, communication, and data functions. The software is run on a micro controller (20) onboard the Digital board (18).
The motherboard (19) physically carries and supplies conditioned power to RF
(17), Digital (18) and GPS boards (21). The motherboard mates with Digital, RF and 2 5 GPS boards, providing a one piece electronics assembly which can be powered up and tested independently of the rest of the SAR-DMB and is easily removable for test/troubleshooting. The EPROM is easy to remove and replace and uses an easy to access socket.
3 o The motherboard enables the following functions to be performed:
water detection squib firing bag internal pressure (for testing) bag scuttle battery protection diodes temperature The motherboard mates, using connectors, to the Bottom plate board. The motherboard may use a DC to DC converter (optional) if the power budget requires one.
A multi-channel GPS Engine (22) receives GPS information (position and time).
This engine is characterized in that it preferably is an all-in view engine, having low power consumption and a footprint similar to the RF board.
The float bag (29) is inflated using compressed gas, a preferred gas is nitrogen, which is less permeable than C02. The inflation assembly (23) is composed of the gas cylinder (24), a piston (25) with sharp pin (26), a squib (27) and a housing (28). The squib drives the pin down the housing and through the end of the cylinder allowing the gas to escape and fill the float bag (29). The cylinder has the required amount of gas to 2 o inflate float bag. The entire bag inflation assembly fits into battery pack (30) and is securely clamped into place. The squib may be electrically fired, a function controlled by the motherboard.
The buoy may be sunk at the end of its use by heating a resistor (3 l ) in the bag 2 5 tip. This causes the bag to leak and the unit to flood and sink. This resistor is part of the Hermes bag assembly (9).
If desired the SAR-DMB may comprise a water detect function electronically carried out on the motherboard. Safety against accidental firing is provided by the use of 3 o two separate water sense testers. A pair of electrodes (32) coming in contact with the water will initiate firing of the inflation squib. Water contacting electrode one will wake ' 2 ~
up the electronics for an interval of time as deemed appropriate (e.g. one second). If water also contacts electrode two, for an appro~fiate period of time (e.g. one second), this will cause the squib (27) to fire. The circuit must be sensitive enough to fire in fresh and salt water. The squib is preferably fired so that the float bag is infl~te(l within about 20 seconds of water entry.
Surface water temperature is optionally measured with a thermistor (33) embedded in the aluminum bottom plate potted with heat sink compound. For easy of assembly, a small circuit board on the bottom plate is connected to the thermistor (33) l o and water sense electrodes (32) to the motherboard.
The drogue (34) provides drag to the SAR-DMB to simulate the drift of a man in the water in a survival suit. It is designed to float just under the surface of the water.
(approximately within the top 40 cm) All drogue materials and tether may pack into the space available below the float unit inside a suitable deployment package. The drogue may use a Hermes drogue hoop for support, however, other such support structure could be employed. Furthermore, the drogue may be manufactured from bright yellow, or other parachute cloth for extra visibility. The drogue is attached to the float unit with shock cord (35) to reduce jerk loading (figure 7). The drogue unit is designed to be 2 o easily disconnected of the surface unit before deployment to configure the unit for liferaft drift simulation. Drogues are built as a standard item and chained together as needed to provided the required drag (Figure 7).
Dual Drift Characteristics The SAR-DMB design provides for a drifter capable of two distinctly different drift characteristics to be packaged into available launch packages, for example, an "A-size" air launch package, allowing each SAR-DMB to mimic the drift of either a person in the water (minimum leeway object, Figure 2C) or an l]nm:mned liferaft (maximum 3 o leeway object, Figure 2D). The drifters are optionally equipped with a mini~tllre satellite - - ~ 2 ~
navigator (GPS), a small satellite data transmitter (e.g. Argos) or both. The concept is illustrated in Figure 2.
The critical design parameter for a minimum leeway drifter is that the above water area and the below water area should meet the following relationship:
[AU/AW]1/2<0.4 From a m~nllf~cturing point of view a drogued design is preferred. However, a drogue very near the surface may become tangled in high seas. Other alternate solutions include the small self locating-datum marker buoy (SL-DMB) type drifter comprising submerged wing-like projections as shown in Figure 5, or a mini~ture spar buoy also displayed in Figure 5. Each of these designs have the required area ratio identified above and are alternate solutions for the required characteristics.
Satellite Technology GPS positioning in a satellite tracked surface drifter was pioneered by the inventors and is now routinely used for drifter positioning (Leger, G. Surface Tracked 2 o Lagranian Drifters, Sea Technology, August l99l, Vol 32 #8, pp. 27-30). Other various oceanographic drifters have proven the accuracy and practicality of GPS
positioning systems floating at the ocean surface (Risley, W.C., Fraser, I.A., Leger, G.T.
Lagranian Ambient Noise Drifter, Proceedings of Oceans'94, Ocean Engineering Society of IEEE, September l 994, Col III, pp. 34-39), including the ADDAM buoy. For 2 5 example, the Smart CAT Certified Argos Transmitter, manufactured and available from Seimac Limited can be used for such a purpose. This satellite transmitter integrates a GPS receiver to encode drift data in the Service Argos specified GPS position message (Figure 6). This small and inexpensive device reports hourly GPS position measurements via the Argos satellite system by storing acquired positions in internal 3 o memory and continuously broadcasting a message cont~ining the six most recent hourly positions. This reporting scheme overcomes gaps in satellite orbits and provides a o~ ~
complete data set. Experiments using Argos have shown that the system can provide drift data within an acceptable time frame. Even though an Argos based system has proved useful for the monitoring of the SAR-DMB of this invention, other monitoring systems, as would be readily apparent to one of skill in the art to which this invention pertains, could be readily employed for use. For example, the Argos telemetry provides a migration path to potentially incorporate the emerging technology associated with the LEO satellite.
Wave Crest Sensor One of the key problems in any satellite tracked surface drifter is the degradation in buoy-satellite communications in heavy seas. Since these are precisely the times when marine SAR incidents tend to occur, an important optional component of our design is the ability to incorporate an accelerometer based sensor which triggers satellite data tr~n~mi~.~ions from the crests of waves when the antenna is "in the clear". This improves the success rate of buoy-satellite "hits". The wave crest sensor is based on a wave height sensor developed by the inventors for use in a Lagrangian Ambient Noise Drifter (Leger, G., Grant, J. A Wave Height Sensor for Drogued Argos Drifters, Proceedings of Oceans'95, Ocean Engineering Society of IEEE, September l 995).
Sonobuoy Air Launch P~ck~ging The air launch packaging of the maximum and minimum drift objects of the SAR-DMB is based on any available housing systems known to those of skill in the art.
2 5 An example of such a system is a high volume m~nuf~tured sonobuoy and associated parts developed by Hermes Electronics of Dartmouth Nova Scotia, Canada. In this example, the SAR-DMB can be packaged into the sonobuoy launch package to conformexactly to the military "A" size sonobuoy flight specifications (Figure 8). It can be safely launched from long range military surveillance and anti-submarine aircraft including 3 o helicopters as well as other aircraft employed in search and rescue operations.
Sonobuoy, or other launch chutes are a standard, mature aerospace technology which can ~ 18 be easily installed in aircraft used by non-military agencies. The use of this launch package makes the SAR-DMB economical and compatible with existing air launch technologies.
Air Drop Certification Testing C~n~ n DND air certification officials (DMAEM 442) coordinated air drop certification tests of ten SAR-DMB. The flight characteristics of SAR-DMB's was also verified in drop tests near Halifax harbour from a C~n~ n DND Aurora aircraft.
The drift characteristics of the SAR-DMB as a minimum and maximum leeway drifter have also been verified. A number of drift experiments have been conducted from the CCG Bickerton in the summer and fall of 1996. Open ocean trials of the development model using C~n~ n Forces Auxiliary vessel Quest in the North Atlantic in November 1996 verified the SAR-DMB drift characteristics.
All scientific publications and patent documents are incorporated herein by reference.
The present invention has been described with regard to preferred embodiments.
However, it will be obvious to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as described herein.
Claims (4)
1. An air deployable, compact marker buoy system capable of exhibiting minimum leeway flotation and drift characteristics emulating a person drifting in water comprising;
a) a body, comprising a flotation portion and a hull;
b) a means for deploying said marker buoy within the water;
c) a means for restricting minimum leeway drift; and d) a means for determining the position of said marker buoy,
a) a body, comprising a flotation portion and a hull;
b) a means for deploying said marker buoy within the water;
c) a means for restricting minimum leeway drift; and d) a means for determining the position of said marker buoy,
2. The compact marker buoy of claim 1 wherein said hull lies below the water line, and said flotation portion lies above the water line when said marker buoy is in water.
3. The compact marker buoy of claims 1 or 2 wherein the means for restricting minimum leeway drift comprises a submersible drogue.
4. The compact marker buoy of claim 2 wherein the means for restricting minimum leeway drift is achieved by increasing the surface area of said hull of said marker buoy.
The compact marker buoy of claim 4, wherein the means for restricting minimum leeway drift comprises planer extensions radiating from the body of the marker buoy.
7. The compact marker buoy of claim 4 wherein said marker buoy is of a spar type, and said increased surface area is obtained by increasing the diameter of said hull with respect to the diameter of said flotation portion.
8. The compact marker buoy of claim 1 wherein the flotation portion is comprised of a flotation bag.
9. The compact marker buoy of claims 1 to 8 wherein the means for determining the position of said marker buoy include visual means.
10. The compact marker buoy of claim 1 to 9 wherein the means for determining the position of said marker buoy include electronic means.
11. The compact marker buoy of claim 10 wherein the electronic means includes a wave crest sensor.
12. The compact marker buoy of claim 11 wherein the wave crest sensor comprises an accelerometer based sensor.
13. The compact marker buoy of claims 10 to 12 wherein the electronic means comprises an RF antenna and associated RF board 14. The compact marker buoy of claims 10 to 13 wherein the electronic means comprises a GPS antenna and associated GPS engine.
15. An air deployable compact marker buoy system capable of exhibiting maximum leeway flotation and drift characteristics emulating a liferaft drifting in water comprising;
a) a body comprising a flotation portion and a hull;
b) a means for deploying said marker buoy within the water; and c) a means for determining the position of said marker buoy.
16. The compact marker buoy of claim 15 wherein said hull lies below the water line, and said flotation portion lies above the water line when said marker buoy is in water.
17. The compact marker buoy of claims 15 or 16, wherein the flotation portion is comprised of a flotation bag.
18. The compact marker buoy of claims 15 to 17 wherein the means for determining the position of said marker buoy include visual means.
19. The compact marker buoy of claims 15 to 18 wherein the means for detemining the position of said marker buoy include electronic means.
20. The compact marker buoy of claim 19 wherein the electronic means includes a wave crest sensor.
21. The compact marker buoy of claim 20 wherein the wave crest sensor comprises an accelerometer based sensor.
22. The compact marker buoy of claim 19 to 21 wherein the electronic means comprises an RF antenna and associated RF board.
23. The compact marker buoy of claims 19 to 22 wherein the electronic means comprises a GPS antenna and associated GPS engine.
24. An air deployable compact marker buoy system capable of exhibiting both minimum and maximum leeway flotation and drift characteristics emulating a person or liferaft drifting in water, respectively, comprising;
a) a body comprising a flotation portion and a hull;
b) a means for deploying said marker buoy within water;
c) a means for restricting minimum leeway drift; and c) a means for determining the position of said marker buoy, 25. The compact marker buoy of claim 24 wherein said hull lies below the water line, and said flotation portion lies above the water line when said marker buoy is in water.
26. The compact marker buoy of claims 24 or 25 wherein the means for restricting minimum leeway drift is detachable.
27. The compact marker buoy of claims 24 to 26 wherein the flotation portion is comprised of a flotation bag.
28. The compact marker buoy of claims 24 to 27 wherein the means for determining the position of said marker buoy include visual means.
29. The compact marker buoy of claims 24 to 28 wherein the means for determining the position of said marker buoy include electronic means.
30. The compact marker buoy of claim 29 wherein the electronic means includes a wave crest sensor.
31. The compact marker buoy of claim 30 wherein the wave crest sensor comprises an accelerometer based sensor.
32. The compact marker buoy of claims 30 to 31 wherein the electronic means comprises an RF antenna and associated RF board.
33. The compact marker buoy of claim 30 to 31 wherein the electronic means comprises a GPS antenna and associated GPS engine.
34. An air deployable compact marker buoy system capable of exhibiting both minimum and maximum leeway flotation and drift characteristics emulating a person or liferaft drifting in water, respectively, comprising:
a) a body comprising a flotation bag and a hull, comprising:
I) a means for detecting water comprising two water sensitive electrodes;
ii) a means for deploying said marker buoy when water is detected comprising inflating the floatation bag with a compressed gas;
iii) a means for detecting the temperature of the water;
iv) a means for determining the position of said marker buoy comprising markings that enhance visual detection, and electronic means comprising either an antenna and associated board operatively associated with a digital board and a motherboard, and a wave crest sensor; and v) a means for sinking said marker buoy comprising heating a resistor located in the tip of said flotation bag; and b) a means for restricting minimum leeway drift comprising a detachable tethered drogue;
wherein said marker buoy is placed within a suitable air deployment package to be launched from a suitable air craft, said air deployment package comprising means to aid said marker buoy to the surface of a body of water.
The compact marker buoy of claim 4, wherein the means for restricting minimum leeway drift comprises planer extensions radiating from the body of the marker buoy.
7. The compact marker buoy of claim 4 wherein said marker buoy is of a spar type, and said increased surface area is obtained by increasing the diameter of said hull with respect to the diameter of said flotation portion.
8. The compact marker buoy of claim 1 wherein the flotation portion is comprised of a flotation bag.
9. The compact marker buoy of claims 1 to 8 wherein the means for determining the position of said marker buoy include visual means.
10. The compact marker buoy of claim 1 to 9 wherein the means for determining the position of said marker buoy include electronic means.
11. The compact marker buoy of claim 10 wherein the electronic means includes a wave crest sensor.
12. The compact marker buoy of claim 11 wherein the wave crest sensor comprises an accelerometer based sensor.
13. The compact marker buoy of claims 10 to 12 wherein the electronic means comprises an RF antenna and associated RF board 14. The compact marker buoy of claims 10 to 13 wherein the electronic means comprises a GPS antenna and associated GPS engine.
15. An air deployable compact marker buoy system capable of exhibiting maximum leeway flotation and drift characteristics emulating a liferaft drifting in water comprising;
a) a body comprising a flotation portion and a hull;
b) a means for deploying said marker buoy within the water; and c) a means for determining the position of said marker buoy.
16. The compact marker buoy of claim 15 wherein said hull lies below the water line, and said flotation portion lies above the water line when said marker buoy is in water.
17. The compact marker buoy of claims 15 or 16, wherein the flotation portion is comprised of a flotation bag.
18. The compact marker buoy of claims 15 to 17 wherein the means for determining the position of said marker buoy include visual means.
19. The compact marker buoy of claims 15 to 18 wherein the means for detemining the position of said marker buoy include electronic means.
20. The compact marker buoy of claim 19 wherein the electronic means includes a wave crest sensor.
21. The compact marker buoy of claim 20 wherein the wave crest sensor comprises an accelerometer based sensor.
22. The compact marker buoy of claim 19 to 21 wherein the electronic means comprises an RF antenna and associated RF board.
23. The compact marker buoy of claims 19 to 22 wherein the electronic means comprises a GPS antenna and associated GPS engine.
24. An air deployable compact marker buoy system capable of exhibiting both minimum and maximum leeway flotation and drift characteristics emulating a person or liferaft drifting in water, respectively, comprising;
a) a body comprising a flotation portion and a hull;
b) a means for deploying said marker buoy within water;
c) a means for restricting minimum leeway drift; and c) a means for determining the position of said marker buoy, 25. The compact marker buoy of claim 24 wherein said hull lies below the water line, and said flotation portion lies above the water line when said marker buoy is in water.
26. The compact marker buoy of claims 24 or 25 wherein the means for restricting minimum leeway drift is detachable.
27. The compact marker buoy of claims 24 to 26 wherein the flotation portion is comprised of a flotation bag.
28. The compact marker buoy of claims 24 to 27 wherein the means for determining the position of said marker buoy include visual means.
29. The compact marker buoy of claims 24 to 28 wherein the means for determining the position of said marker buoy include electronic means.
30. The compact marker buoy of claim 29 wherein the electronic means includes a wave crest sensor.
31. The compact marker buoy of claim 30 wherein the wave crest sensor comprises an accelerometer based sensor.
32. The compact marker buoy of claims 30 to 31 wherein the electronic means comprises an RF antenna and associated RF board.
33. The compact marker buoy of claim 30 to 31 wherein the electronic means comprises a GPS antenna and associated GPS engine.
34. An air deployable compact marker buoy system capable of exhibiting both minimum and maximum leeway flotation and drift characteristics emulating a person or liferaft drifting in water, respectively, comprising:
a) a body comprising a flotation bag and a hull, comprising:
I) a means for detecting water comprising two water sensitive electrodes;
ii) a means for deploying said marker buoy when water is detected comprising inflating the floatation bag with a compressed gas;
iii) a means for detecting the temperature of the water;
iv) a means for determining the position of said marker buoy comprising markings that enhance visual detection, and electronic means comprising either an antenna and associated board operatively associated with a digital board and a motherboard, and a wave crest sensor; and v) a means for sinking said marker buoy comprising heating a resistor located in the tip of said flotation bag; and b) a means for restricting minimum leeway drift comprising a detachable tethered drogue;
wherein said marker buoy is placed within a suitable air deployment package to be launched from a suitable air craft, said air deployment package comprising means to aid said marker buoy to the surface of a body of water.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2202018 CA2202018A1 (en) | 1997-04-07 | 1997-04-07 | Drifting datum marker buoy |
| CA 2234285 CA2234285A1 (en) | 1997-04-07 | 1998-04-07 | Drifting datum marker buoy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2202018 CA2202018A1 (en) | 1997-04-07 | 1997-04-07 | Drifting datum marker buoy |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2202018A1 true CA2202018A1 (en) | 1998-10-07 |
Family
ID=4160360
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2202018 Abandoned CA2202018A1 (en) | 1997-04-07 | 1997-04-07 | Drifting datum marker buoy |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2202018A1 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017075876A1 (en) * | 2015-11-07 | 2017-05-11 | 深圳市易特科信息技术有限公司 | Maritime rescue catcher |
| FR3065197A1 (en) * | 2017-04-14 | 2018-10-19 | Thales | BUOY |
| CN109895949A (en) * | 2019-02-13 | 2019-06-18 | 重庆水利电力职业技术学院 | A kind of Buoys Release Device controlled for hydrologic monitoring |
| CN111976899A (en) * | 2020-08-18 | 2020-11-24 | 江苏航运职业技术学院 | Ship driving blind area guiding system and guiding method based on marine radio communication technology |
| CN112208715A (en) * | 2020-10-26 | 2021-01-12 | 卿云 | Unmanned navigation mark ship system based on cloud control and navigation mark ship moving method thereof |
| CN116691966A (en) * | 2023-07-07 | 2023-09-05 | 威海宇成杰舶游艇有限公司 | Automatic inflatable boat for air drop |
-
1997
- 1997-04-07 CA CA 2202018 patent/CA2202018A1/en not_active Abandoned
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017075876A1 (en) * | 2015-11-07 | 2017-05-11 | 深圳市易特科信息技术有限公司 | Maritime rescue catcher |
| FR3065197A1 (en) * | 2017-04-14 | 2018-10-19 | Thales | BUOY |
| CN109895949A (en) * | 2019-02-13 | 2019-06-18 | 重庆水利电力职业技术学院 | A kind of Buoys Release Device controlled for hydrologic monitoring |
| CN111976899A (en) * | 2020-08-18 | 2020-11-24 | 江苏航运职业技术学院 | Ship driving blind area guiding system and guiding method based on marine radio communication technology |
| CN112208715A (en) * | 2020-10-26 | 2021-01-12 | 卿云 | Unmanned navigation mark ship system based on cloud control and navigation mark ship moving method thereof |
| CN116691966A (en) * | 2023-07-07 | 2023-09-05 | 威海宇成杰舶游艇有限公司 | Automatic inflatable boat for air drop |
| CN116691966B (en) * | 2023-07-07 | 2023-11-14 | 威海宇成杰舶游艇有限公司 | Automatic inflatable boat for air drop |
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