WO2008109929A1

WO2008109929A1 - Remote monitoring of underwater objects

Info

Publication number: WO2008109929A1
Application number: PCT/AU2008/000305
Authority: WO
Inventors: Cameron Tarbotton; Simon Allen; Matthew Dunbabin
Original assignee: Commonwealth Scientific And Industrial Research Organisation
Priority date: 2007-03-09
Filing date: 2008-03-07
Publication date: 2008-09-18

Abstract

A system for monitoring conditions in a remote environment. The system comprising a data transmission network including a plurality of data sensing nodes. Each data sensing node includes an environment sensing means for periodically sensing the environment around node, a transmission means for periodic wireless transmission of sensed data to adjacent data sensing nodes. These adjacent data sensing nodes combining their sensed data with the received data from other data sensing nodes and on transmit the combined data.

Description

REMOTE MONITORING OF UNDERWATER OBJECTS

FIELD OF THE INVENTION

[0001] The present invention relates to the field of remote monitoring, and, in particular, discloses a system allowing for remote monitoring of undersea pipelines or the like using localised power generation sources.

BACKGROUND OF THE INVENTION

[0002] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

[0003] Remote monitoring of equipment in inhospitable environments such as along undersea pipelines is becoming increasing important for the effective operation of such equipment.

[0004] Current methods of temperature monitoring consists of fixed temperature sensors (into or attached to the pipeline that are wired or wireless with finite energy storage and acoustic communication links. Another method is the use of fibre optic cable and Braggs gratings to determine temperature and approximate location along the fibre. Fibre optic has the advantage of not only getting temperature but it can also be used for communications. Installation of fibre and fixed nodes can be costly and not typically achievable in an existing field. Also pigs can be used to measure various parameters, but they must be deployed upstream and are costly to install and disrupt production.

[0005] Current sub-sea pipeline sensor networks pose a number of problems. Using acoustics or fibre optic cables as a primary communication mode is very expensive to install and maintain, and hence are used sparingly at critical locations. Using acoustic communications is also energy intensive, when compared to radio-frequency (RF) communications, and are typically plagued with problems such as multi-path interference and high background noise.

[0006] A number of remote monitoring systems are known. For example, Japanese patent JP2000321361-A considers a subterranean pipe monitoring system that uses thermo electric device to charge a battery and to provide power for a wireless communication and sensors.

[0007] Underwater RF communications are considered in WO2001195529-A, which considers through water communication between underwater bodies, by way of example between an autonomous underwater vehicle (AUV) and sensors. United

States patent application US 2004/0051649- Al considers sub-sea RF communications that use a cathodic protection anode as a transmitting antenna. US 2004/0051649 claims communications between other underwater bodies, such as AUVs. United States patent application US 2005/0001721-A1 considers a system of sensors and repeaters that effectively form a waveguide that can extract data from the sensors. This system is designed for very high sensor counts that are attached to a vessel's structure.

[0008] Radio -frequency identification (RFID) sensors are considered in Japanese patent

JP2003139271-A, where a passive RFID tag containing pipeline and valve-opening degree information is embedded within the valve itself. United States patent application US 2005/0176373-Al also considers an advanced capability RFID system in which a microcontroller is capable of reading external sensors in both a passive and active case.

[0009] Japanese patent JP20051811111-A also claims the use of RFID tags placed on buried pipes, wire or optic fibre cables. These RFID tags contain information about the element it is attached to.

[0010] United States Patent US 6,995,677 describes a remote sensing system. This system includes remote RF communications and attachment methods. They also claim the use of pigs to interrogate the sensor nodes. The arrangement of US 6,995,677 has a significant number of disadvantages when operating in a sub-sea environment as conventional RF transmissions may not properly operate in such environments.

[0011] There is a need in the art for remote monitoring of undersea pipelines or the like. SUMMARY OF THE INVENTION

[0012] It is an object of the present invention to provide an improved system for the monitoring of remote equipment such as pipelines or the like.

[0013] Ideally, the remote monitoring device is able to remotely and wirelessly monitor the remote equipment such as a sub-sea oil and gas pipeline and down-hole well for a set of parameters which include, but not limited to, temperature and pressure.

[0014] In accordance with a first aspect of the present invention, there is provided a system for monitoring conditions in a remote environment, the system comprising: a data transmission network including a plurality of data sensing nodes, wherein each data sensing node includes: an environment sensing means for periodically sensing the environment around the node; a transmission means for periodic wireless transmission of sensed data to adjacent data sensing nodes; the adjacent data sensing nodes combining their sensed data with the received data from other data sensing nodes and on transmitting the combined data.

[0015] Preferably, the system further comprises a mobile data reception apparatus intermittently coming into transmission range of the transmission means of a data sensing node and receiving a transmission of sensor data information from multiple data sensing nodes. The transmission means preferably transmits via one of radio frequency transmission or acoustic transmission.

[0016] The data sensing nodes are preferably placed on the seabed or on an underwater structure. For example, a pipeline to monitor the pipeline environment. The data sensing nodes are preferably placed along a pipeline and monitor the pipeline environment through electromagnetically exciting the pipeline with the sensing nodes. Alternatively, each of the data sensing nodes may also be implanted in marine life such as fish

[0017] The data sensing nodes are preferably driven by an electrical current supply derived from temperature differences surrounding the data sensing nodes. Preferably, the temperature characteristics of a structure to which a sensing device can be attached can be inferred from the amount of energy extracted from the electrical current supply.

[0018] The energy extraction mechanism can preferably further include one of: tidal, biological or solar energy extraction.

[0019] In accordance with a second aspect of the present invention, there is provided a system for monitoring conditions in a remote underwater environment, the system comprising: at least one data sensing node, the data sensing nodes including an environment sensing means for periodically sensing the environment around a node and a transmission means for underwater periodic wireless transmission of the sensed data to a mobile underwater data reception apparatus; and a mobile underwater data reception apparatus intermittently coming into the transmission range of the transmission means of at least one data sensing node and receiving a transmission of sensor data information from at least one data sensing node.

[0020] This system preferably further comprises: a data transmission network including a series of interconnected data sensing nodes, the interconnected data sensing nodes including: environment sensing means for periodically sensing the environment around a node; transmission means for periodically wireless transmission of the sensed data to adjacent data sensing nodes; the adjacent data sensing nodes combining their sensed data with the received data from other data sensing nodes and on transmitting the combined data.

[0021] In accordance with a third aspect of the present invention, there is provided a system for monitoring conditions in a remote underwater environment, the system comprising: a data transmission network including a plurality of interconnected data sensing nodes; a mobile underwater data reception apparatus intermittently coming into the transmission range of a first data sensing node and receiving a transmission of sensor data information from the plurality of data sensing nodes; wherein each interconnected data sensing nodes includes: an environment sensing means for periodically sensing a local environmental parameter; and a transmission means for periodical wireless transmission of the sensed data to adjacent data sensing nodes, the adjacent data sensing nodes combining their sensed data with the received data from other data sensing nodes and on transmitting the combined data; wherein the transmission means enables the system to transmits the data substantially along the pipeline such that the sensor data information from the plurality of data sensing nodes can be transmitted from the first data sensing node to the mobile underwater data reception apparatus.

[0022] The data sensing nodes are preferably placed on the exterior of an underwater structure, and the system monitors conditions within the structure. More preferably, the data sensing nodes are placed along a pipeline and monitor the pipeline environment through electromagnetically exciting the pipeline with the RF sensing nodes.

[0023] The transmission means preferably transmits via one of radio frequency transmission, electrical transmission or acoustic transmission.

[0024] Preferably, data sensing nodes are driven by an electrical current supply derived from any one of: tidal, biological or solar energy extraction. Alternatively the data sensing nodes are driven by an electrical current supply derived from temperature differences surrounding the data sensing nodes.

[0025] The temperature characteristics of a structure to which a sensing device is attached is preferably inferred from the amount of energy extracted from the electrical current supply.

[0026] In accordance with a further aspect of the present invention, there is provided a system for monitoring conditions in a remote environment, the system including: a data transmission network including a group of data sensing nodes, the group of data sensing nodes including: environment sensing means for periodically sensing the environment around a node; transmission means for periodically wireless transmission of the sensed data to adjacent data sensing nodes; the adjacent data sensing nodes combining their sensed data with the received data from other data sensing nodes and on transmitting the combined data.

[0027] In accordance with a further aspect of the present invention, there is provided a system for monitoring conditions in a remote underwater environment, the system comprising: at least one data sensing node, the interconnected data sensing nodes including an environment sensing means for periodically sensing the environment around a node and a transmission means for underwater periodic wireless transmission of the sensed data to a mobile underwater data reception apparatus; and a mobile underwater data reception apparatus intermittently coming into the transmission range of the transmission means of at least one data sensing node and receiving a transmission of sensor data information from at least one data sensing node.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Preferred forms of the present invention will now be described with reference to the accompanying drawings in which:

FIG. 1 illustrates a schematic view of a single sensor node;

FIG. 2 illustrates a side perspective view of a single sensor node; and

FIG. 3 illustrates a side perspective view of a series on sensor nodes forming a sensing network, attached to a pipeline.

DESCRIPTION OF THE PREFERRED AND OTHER EMBODIMENTS

[0029] In the preferred embodiments there is provided a remote monitoring and communications system having advantageous use properties.

[0030] Referring to FIG. 1 and FIG. 2, a sensor device 100 (or sensing device) is shown by way of example only. This sensor device 100 includes an antenna 110 for external in water communications, an energy storage device 120, a circuit unit 130, and an energy scavenging device 140. [0031] Referring to FIG. 2, there is illustrated a sensor device 100, by way of example only. The energy storage device 120 can comprise a battery or super-capacitor type device. The circuit unit 130 can include various electronic devices. These electronic devices 130 can include a very low power microcontroller interconnected to a variety of sensing equipment and to a radio frequency (RF) interface for driving the

Antenna 110. The microcontroller preferably implements standard RFID protocols. The energy scavenging device 140 is responsible for acquiring energy from an environment for powering the overall device 100, and can take various forms including a Peltier device and/or a solar panel.

[0032] By way of example only, the sensor device includes:

> An antenna 110.

> An energy storage device 120, for providing a system of energy storage.

> A circuit unit 130, which includes:

• an RF chip; • sensors or a sensor interface; and

• a microcontroller with enough memory to implement sensor reading, communications and power management.

> An energy-scavenging device 140, for providing a system of energy generation. > An attachment method.

[0033] In an embodiment, these items can be embedded within a single self-contained structure that can withstand extreme pressure of sub-sea operations (e.g. depths of 2km). FIG. 2 shows an embodiment of a sensor device 100 that can be attached (or adhered) to a pipeline.

[0034] Referring to FIG. 3, by way of example only, the sensor device 100 can be attached, either internally or externally, to a sub-sea structure 310. In this example embodiment, a series of sensor devices 100 are attached to a sub-sea structure in the form of a pipeline 310. This device draws power from the thermal differences between the pipeline and surrounding water. The sensor devices 100 are attached at regular intervals along the pipeline. A device 330 external (or internal) to the pipeline, such as an autonomous underwater vehicle (AUV) device or a remotely operated vehicle (ROV), can interrogate the sensor devices. It would be appreciated that other devices can interrogate externally mounted sensor devices.

[0035] The sensor devices can transmit data 340 in the form of a data packet, or packets, containing the collected sensor information as well as a unique ID for that sensor. The sender device can include an RF-tag configured with a unique ID and adapted to transmit the sensor information and unique ID. In an embodiment, a modem 320 (for example an acoustic modem) can be used for receiving, transmitting and forwarding data.

[0036] In the case of electrically conductive (for example metal) pipeline structures 310, externally attached RF tags sensor devices 100 can be attached at regular intervals along the pipeline for enabling communication with other nodes 350.

[0037] It would be appreciated that other devices can interrogate the sensor devices, for example an internal pig. Internally attached sensor devices can communicate with internal interrogation devices such as pigs. This is due to the inability of RF signals to travel through the metal substrate.

[0038] In the case of electrical non-conductive structures, a sensing device is capable of communicating with both internal and external interrogation devices.

[0039] When an interrogation signal is received by a sensing device antenna (for example the antenna 110 of FIG. 2), the microcontroller can briefly power the sensors using the on-board energy storage system. The microcontroller then waits for a pre- specified time for transient effects to become negligible to the sensor reading. The microcontroller then takes the sensor reading (either digital or via converting a voltage to a digital signal on the microcontroller) and incorporates the readings into an information packet of predefined protocol. The information packet contains the sensor readings and the sensor device's unique identifying number. The microcontroller then powers the RF transmitters and transmits the information packet using the on-board energy storage to increase the current through the antenna, and ultimately the maximum achievable propagation range.

[0040] The preferred energy scavenging system utilises the Seebeck effect, which uses the temperature difference between the fluid/gas within the pipe and that of the ^• surrounding structure to generate charge in a thermoelectric device. If necessary, multiple thermoelectric devices can be connected in series to increase the voltage generated. This generated voltage, once above a threshold, can then be stepped up to a fixed value using power electronics and the charge stored in a number of ways. Energy storage can be on a battery or on a capacitor(s), which can include super- capacitors. Some of this energy is diverted to the microcontroller to which maintains a low-power "sleep" mode for the receiver and is awoken when an interrogation signal is reached.

[0041] In an embodiment, by way of example only, communication is initiated by an RF signal sent by the interrogation device. An RF tag activates and sends the sensor readings as described above which are then received by the interrogation device and decoded based on a predetermined protocol.

[0042] In another embodiment, by way of example only, communication can be achieved by daisy chaining the sensor devices such that the information from one node can be communicated to another device in a single direction along the pipeline. The sensor devices are placed at distances where they can each communicate with at least one other sensor device. To activate the sensor devices, a unique signal is sent by an interrogation device and or another sensor device. The sensor device that receives this signal, reads its sensors, generates the information packet containing the unique ID and sensor values and transmits the signal along with the unique interrogation signal. As the sensing devices will typically expire its stored energy at the end of the transmission and recharge times are relatively long compared to the time of communication, the node is then rendered ineffective for retransmission. The sent signal is received by the next sensing device along the pipeline where it is activated, reading its sensors. The information is then concatenated to the received signal and resent to the next node in sequence where the process is repeated until the end of the chain is reached or the information is uploaded by another interrogation device.

[0043] In an embodiment, the determination of pipeline temperature is based on the pipe temperature. The measurement of temperature can be by a separate temperature sensor embedded within the sensing device, which is fed into the microcontroller. In another embodiment, sensing pipeline temperature is inferred by using the thermoelectric energy scavenging system, where the voltage generated is a function of temperature difference across the device V = f(dT) . By applying this voltage into an analog-to- digital converter ADC circuit, the microcontroller can read the voltage and utilise algorithms to convert it to a temperature difference.

[0044] In an embodiment, the determination of the pipeline pressure is based on a strain gauge attached at to surface of the sensing device that is adhered to the pipeline. The strain gauge measures the hoop strain around the pipeline. The strain gauge signal is converted by an ADC circuit and read by the microcontroller, which can apply an algorithm for converting the measured voltage to a differential pressure measurement. The measurement can be temperature compensated using the temperature measured by the method above. As the pipeline is generally at a fixed depth, the hydrostatic pressure remains effectively constant.

[0045] In-situ calibration of the pressure measurement is achievable in another embodiment where the sensing devices are capable of receiving data from the interrogation system. If an interrogation device has a reference pressure (for example hydrostatic in the case of an AUV, or internal pipe pressure in the case of a pig), then this value can be sent by the interrogator and can be superimposed (in the microcontroller) to the differential pressure value obtained by the strain gauge to give an estimate of the absolute pressure.

[0046] It would be appreciated by a person skilled in the art that a system could be attached either internally or externally to the sub-sea structure.

[0047] In an embodiment, as illustrated in FIG. 3, a series of sensor devices 100 are attached to a pipeline 310 and draw power from the thermal differences between the pipeline and surrounding water. The sensor devices 100 are attached at regular intervals along the pipeline. The sensor devices 100 can be interrogated by a device 330 external to the pipeline, such as an AUV via communication path 340. The tag returns a packet, or packets, containing the collected sensor information as well as a unique ID for that sensor. Alternatively, it would also be appreciated that sensor devices can be interrogated by a device internal to the pipeline, such as an internal pig. [0048] In an alternative embodiment, the sensor devices are placed along the pipeline at inter-node distances in which one sensor device is within communication range with at least one other sensor device. With either an external interrogation or some predetermined (timed) trigger, one sensor device sends its data to the next sensor device and its data is concatenated with the next sensors data and sent on in set a sequential chain of sensor device reads and transmissions which propagates along the pipeline to a collector (or another interrogator).

[0049] It would be appreciated by a person skilled in the art that a number of alternative arrangements are possible for the acquisition of driving energy. By way of example only, referring to FIG. 3, the device can use RF energy from the interrogation device that impinges the RF antenna of the sensor device 100 to power the device, and thereby enable data to the transmitted back to interrogation device. It would be appreciated that, after a device has sent its information, the device can use this RF energy to charge up its onboard energy storage system, for example until the next interrogation commences. The stored energy can be used to increase the range of data transmission of the device. Further energy for charging can come from thermo- electrical devices e.g. via energy scavenging embedded with the tag with one surface on the pipeline (hot side) and the other with the surrounds (cold side). Other forms of energy scavenging can include biological, solar, chemical or mechanical.

[0050] The devices can be initially attached to the pipeline at known locations. When an external device interrogates a device, the returned data includes a unique ID. Therefore, the external device can know its position with respect to the pipeline. This can aid AUV and pig localization and the localizing of faults or areas of interest along the pipeline.

[0051] In a further alternative embodiment, the pipeline itself can be used to propagate inter-node communication by means of daisy chain electrical excitation of the pipeline itself. In this arrangement, the signal transmitted by an RF device propagates in the material of the pipeline (if it is metal) rather than the seawater itself. Specifically, the RF signal emitted from a transmitting RF device induces an electric current along the length of the pipe. This current produces its own RF signal around the pipeline, which in turn induces a signal in a receiving RF device further down the pipeline. In this manner daisy chaining of communication can be achieved. It would be appreciated that, this arrangement will be dependant on the conductive properties of the pipeline conduit, which can be previously measured and analysed before in situ placement. The signal propagation by pipeline excitation greatly increases the communications range that can be achieved between devices and helps to make daisy-chain communications more robust and reliable.

[0052] By way of example only, an embodiment of system for monitoring conditions in a remote underwater environment, the system comprising a data transmission network and a mobile underwater data reception apparatus. This data transmission network including a plurality of interconnected data sensing nodes. The mobile underwater data reception apparatus intermittently comes into the transmission range of a first data sensing node and receiving a transmission of sensor data information from the plurality of data sensing nodes.

[0053] Each interconnected data sensing node includes an environment sensing means for periodically sensing a local environmental parameter; and a transmission means for periodical wireless transmission of the sensed data to adjacent data sensing nodes. The adjacent data sensing nodes combines their sensed data with the received data from other data sensing nodes and on transmitting the combined data. The transmission means enables the system to transmit the data substantially along the pipeline such that the sensor data information from the plurality of data sensing nodes can be transmitted from the first data sensing node to the mobile underwater data reception apparatus.

[0054] The preferred embodiment of a sensor device enables or provides a number of capabilities including, any one or more of the following:

> The device is a self-contained integrated wireless device attached to a sub-sea structure (pipeline) for measuring various properties such as (but not limited to) temperature and pressure without through pipe connectors.

> The device can receive an RF trigger signal from either an external source through an antenna or from an internal clock, and transmits the sensor data one-way via an RF antenna. > The device comprises an energy scavenging system, energy storage system, antenna, receiver, CPU (microprocessor), transmitter, sensor interface, sensors, communication software and power electronics.

> This device is intended to transmit its sensor data over relatively short ranges (<100m), due in part to limited on-board energy storage.

> This devise can be installed during manufacture and laying of a structure (pipeline), or alternatively attached in situ by adhesive or other forms of coupling such as magnetic. The system can be buried up to a predefined depth.

> The device allows in situ power generation. > The device has an energy scavenging system that generates electrical energy from the environment by extracting thermal energy (from the pipeline), tidal energy, biological energy or solar energy. The device could also be powered from a battery.

> The energy system can be a hybrid system that can combine RF energy extracted from the second device (like a passive RFID tag) and that of the onboard storage to increase the range of transmitted signal or recharge the device (like an active RFID tag).

> The device preferably operates in a sleep mode (for power saving) and is awakened by an external or internal trigger to transmit the sensor information in a message packet via the RF antenna.

> A second device can remotely interrogate and upload information from the first device through electromagnetic radiation (RF). This device could be an AUV, ROV, diver, pig that is within communication range.

> If the individual devices are within communication range on the structure(s), they can form a daisy-chain network operation that sends information from one to another without the need for the AUV, ROV or pig to "mule" the data using their on-board power.

> By interrogating the sensor for an ID, an AUV, ROV, diver, or pig can relate this information back to a known position along the pipeline for localisation. ^ The device can be read from inside or outside the pipeline if the pipeline is electrically non-conductive.

> The recorded sensor data can be used to locate a fault or area of interest in the pipeline that can be located by the ID number of the device. > The temperature of the structure can be inferred from the energy scavenging system in the case of a thermo-electrical device as dT = /{output - voltage).

> The pressure within the structure can be monitored from a strain gauge or similar device attached to the inside or outside pipeline. > The system can use an AUV or pig to calibrate the pressure sensor (strain measurement), if two-way communications is enabled.

> A system allows temperature and pressure profiles to be obtained at device locations along pipeline and other sub-sea infrastructure.

> A system allows location of second device (AUV, ROV, pig) with respect to device location with respect to the pipeline.

> A system allows inter-node communication to pass information in one- direction at a time along the pipeline (as long as they are within range of each other) to a cluster point or to shore.

[0055] The sensor devices are preferably packaged together into a self contained node and installed during the laying of the pipeline, well or other sub-sea structures. The nodes would be pre-programmed with their ID and operating software to operate and communication with on- board or attached sensors.

[0056] The attached structure will preferably be electrically non-conductive to allow RF to penetrate into as well as out from the structure. Improved communication range is also achieved using an electrically non-conductive substrate. If the structure is conductive, (e.g. current steel pipelines) then RF propagation is reduced and will not penetrate into or out of the pipe, and choice of appropriate antenna is also required.

[0057] It would be appreciated by a person skilled in the art that, for thermal energy to be used in power generation, the nodes need to be placed at locations where sufficient temperature differential exists between the structure or fluid and its surrounds, such that sufficient voltage can be generated to charge an energy storage system.

[0058] It would be appreciated that, for inter node data transfer (daisy-chain) to be used, then node spacing should be such that at least one node can communicate to its neighbour along the chain. [0059] In an alternative embodiment, the data sensing nodes may also be implanted in marine life such as fish. These marine life are then able to swim about sensing external conditions.

[0060] Attachment of nodes can be via adhesive, magnetic, mechanical or other coupling either during field development, or via AUV, ROV, divers, or pigs.

[0061] A number of modified embodiments are possible. By way of example only, these modification can include:

> The use of small acoustic transducers to form the communication link. These transducers would replace the antenna and RF transmitter and receiver. > The use of alternate power scavenging methods such as converting vibration

(mechanical) energy, biological energy, solar energy (when just below or above the surface), or electro-magnetic waves into electrical energy to power the nodes.

> The sensing devices also actuating a device, instead of just sensing parameters.

[0062] It would be appreciated by a person skilled in the art that the above embodiments disclosed can provide a number of advantages over the prior art. By way of example only, advantages of the proposed system can include any one or more of the following:

> Remotely obtain temperature and possibly pressure at greater spatial distribution than currently available. > Using relatively inexpensive system (of RFID tags) enables more sensors to be deployed.

> Using relatively inexpensive system (of RFID tags) eliminates the need for external communication wires.

> Allows an AUV to localize itself on the pipeline by using unique identification number of a sensor device, and enables a potential fault to be localized.

> Allows devices travelling within the pipeline to localise.

> Removes the need for pigs for pipeline inspection.

> Can be made conformal to structures and encapsulated into a single piece without need for pressure housing and connectors. > Can be formed into structure during manufacture (in case of composite pipelines). ^ Less bulky and power hungry compared to acoustic nodes.

> Significantly fewer part counts compared to acoustics.

> Non-destructive sensors and communications (does not need through hole sensors). > Can operate with the pipeline buried (compared with acoustics) up to certain depths. ^ Can be made conformal to structures and encapsulated into a single piece without need for pressure housing and connectors. ^ Can allow multiple antenna types for different RF propagation patterns.

[0063] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

[0064] As used herein, unless otherwise specified the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[0065] Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as "processing", "computing", calculating", "determining", "applying", "deriving" or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulate and/or transform data represented as physical, such as electronic, quantities into other data similarly represented as physical quantities.

[0066] In a similar manner, the term "processor" may refer to any device or portion of a device that processes electronic data, e.g., from registers and/or memory to transform that electronic data into other electronic data that, e.g., may be stored in registers and/or memory. A "computer" or a "computer system" or a "computing machine" or a "computing platform" may include one or more processors. [0067] It will be understood that the steps of methods discussed are performed in one embodiment by an appropriate processor (or processors) of a processing (Le., computer) system executing instructions (computer-readable code) stored in storage. It will also be understood that the invention is not limited to any particular implementation or programming technique and that the invention may be implemented using any appropriate techniques for implementing the functionality described herein. The invention is not limited to any particular programming language or operating system.

[0068] Thus, one embodiment of each of the methods described herein is in the form of a computer-readable carrier medium carrying a set of instructions, e.g., a computer program that are for execution on one or more processors.

[0069] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may refer to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0070] Similarly it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention. [0071] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0072] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0073] Although the invention has been described with reference to specific examples it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. Modification, obvious to those skilled in the art can be made thereto without departing from the scope of the invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:-

1. A system for monitoring conditions in a remote environment, the system comprising: a data transmission network including a plurality of data sensing nodes, wherein each said data sensing node includes: an environment sensing means for periodically sensing the environment around said node; a transmission means for periodic wireless transmission of sensed data to adjacent data sensing nodes; said adjacent data sensing nodes combining their sensed data with the received data from other data sensing nodes and on transmitting the combined data.

2. A system as claimed in claim 1 further comprising: a mobile data reception apparatus intermittently coming into transmission range of said transmission means of a data sensing node and receiving a transmission of sensor data information from multiple data sensing nodes.

3. A system as claimed in any one of the previous claims wherein said data sensing nodes are placed on the seabed or on an underwater structure.

4. A system claimed in any one of the previous claims wherein each of the data sensing nodes are implanted in marine life such as fish.

5. A system as claimed in any one of claims 1 to 3 wherein said data sensing nodes are placed along a pipeline and monitor the pipeline environment through electromagnetically exciting the pipeline with the sensing nodes.

6. A system as claimed in claim 5 wherein said transmission means transmits information substantially along said pipeline.

7. A system as claimed in any one of the previous claims wherein said transmission means transmits via one of radio frequency transmission, electrical transmission or acoustic transmission.

8. A system as claimed in any one of the previous claims wherein said data sensing nodes are driven by an electrical current supply derived from temperature differences surrounding said data sensing nodes.

9. A system as claimed in claim 8 wherein the temperature characteristics of a structure to which a sensing device is attached is inferred from the amount of energy extracted from the electrical current supply.

10. A system as claimed in any one of the previous claims wherein said energy extraction mechanism further includes one of: tidal, biological or solar energy extraction.

11. A system for monitoring conditions in a remote underwater environment, the system comprising: at least one data sensing node, said data sensing nodes including an environment sensing means for periodically sensing the environment around a node and a transmission means for underwater periodic wireless transmission of the sensed data to a mobile underwater data reception apparatus; and a mobile underwater data reception apparatus intermittently coming into the transmission range of the transmission means of at least one data sensing node and receiving a transmission of sensor data information from at least one data sensing node.

12. A system as claimed in claim 11 further comprising: a data transmission network including a series of interconnected data sensing nodes, said interconnected data sensing nodes including: environment sensing means for periodically sensing the environment around a node; transmission means for periodically wireless transmission of the sensed data to adjacent data sensing nodes; said adjacent data sensing nodes combining their sensed data with the received data from other data sensing nodes and on transmitting the combined data.

13. A system for monitoring conditions in a remote underwater environment, the system comprising: a data transmission network including a plurality of interconnected data sensing nodes, a mobile underwater data reception apparatus intermittently coming into the transmission range of a first data sensing node and receiving a transmission of sensor data information from said plurality of data sensing nodes; wherein each said interconnected data sensing node includes: an environment sensing means for periodically sensing a local environmental parameter; and a transmission means for periodical wireless transmission of the sensed data to adjacent data sensing nodes, said adjacent data sensing nodes combining their sensed data with the received data from other data sensing nodes and on transmitting the combined data; wherein said transmission means enables said system to transmits said data substantially along said pipeline such that said sensor data information from said plurality of data sensing nodes can be transmitted from said first data sensing node to said mobile underwater data reception apparatus.

14. A system as claimed in claim 13 wherein said data sensing nodes are placed on the exterior of an underwater structure, and said system monitors conditions within said structure.

15. A system as claimed in claim 14 wherein said data sensing nodes are placed along a pipeline and monitor the pipeline environment through electromagnetically exciting the pipeline with the RF sensing nodes.

16. A system as claimed in claim 14 wherein said transmission means transmits via one of radio frequency transmission, electrical transmission or acoustic transmission.

17. A system as claimed in any one of claims 13 to 16 wherein said data sensing nodes are driven by an electrical current supply derived from temperature differences surrounding said data sensing nodes.

18. A system as claimed in claim 17 wherein the temperature characteristics of a structure to which a sensing device is attached is inferred from the amount of energy extracted from the electrical current supply.

19. A system as claimed in any one of claims 13 to 16 wherein said data sensing nodes are driven by an electrical current supply derived from any one of: tidal, biological or solar energy extraction.

20. A system for monitoring conditions in a remote underwater environment, substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.