GB2593121A

GB2593121A - Deployable location system

Info

Publication number: GB2593121A
Application number: GB1907366.7A
Authority: GB
Inventors: Sebastian Innocente Mauro; Statheros Thomas
Original assignee: Coventry University
Current assignee: Coventry University
Priority date: 2019-05-24
Filing date: 2019-05-24
Publication date: 2021-09-22
Also published as: GB201907366D0

Abstract

A deployable location system 100 includes base units 20-29 provided around a perimeter of a monitored space 2, such as a building perimeter. Each base unit 20-29 comprises a wide area receiver 42 to receive wide area location signals 41 from a wide area location system 40. A base unit processor (19, Fig.2) determines the location of base unit 20-29 from the wide area location signals 41. A local transmitter (50, Fig.2) transmits local location system signals 51. The local location system signals 51 are received by location units (10, Fig.1b) and used to determine the location of the units (10, Fig1b) within the space. The location units (10, Fig.1b) may be adapted to be worn by a person by incorporation into garments. The base units 20-29 may be mounted on autonomous unmanned aerial (UAV) 36-39 or ground vehicles (UAG) at different heights. The location signals 41, 51 may be ultra-wideband (UWB) radio signals that at least partially penetrate walls or other structures.

Description

DEPLOYABLE LOCATION SYSTEM

Technical Field of the Invention

The present invention relates to a deployable location system and in particular to a deployable location system suitable for use without the use of pre-installed infrastructure. In particular, the deployable location system may be a system utilising one or more location units operable to detect signals that can at least partially penetrate walls or other structures, whether natural or man-made.

Background to the Invention

It is often beneficial to utilise a location system in an emergency or unplanned situation, for example an emergency service response to a fire. In such a situation, one or more firefighters may enter a building for the purpose of controlling, if not extinguishing a fire and rescuing any people trapped within the building. It is desirable to track the location of individual firefighters during this activity. This enables greater coordination of activity and facilitates recuse of individual firefighters that find themselves in difficulty. In general, location systems are useful in a number of emergency, police and defence operations, as well as in a number of civil services or emergencies (e.g. location of a child within a large shopping centre by the parents).

There are many location systems that are useable in open-air situations, such as the Global Positioning System (GPS). These systems are operable to transmit RF signals from satellites which are received by suitable location units. By comparing the time signatures of RF signals received from multiple different satellites, the receiving device can calculate its location. Such systems are not reliable within buildings as walls, roofs and the like block, delay or reflect the RF signals.

Within buildings, location can be determined by specifically adapted location systems. Such systems typically comprise multiple base units provided at predetermined fixed positions within a building. The base units are operable to broadcast RF signals including time signatures and/or different type of modulation techniques e.g. Pulse Position Modulation (PPM). Suitable mobile locations units may be provided operable to detect signals output from multiple base units and by comparing the time signatures of received signals thereby determine the location of the receiving device relative to the base units. Such systems can enable the location of receiving devices (and hence items to which the tags are attached) to an accuracy of few centimetres In order to operate effectively, such systems need to be carefully installed and calibrated. The installation and calibration process ensures that the base unit locations are very accurately defined within a known indoor environment or layout (known environment) If such locations are not accurately defined on installation, accurate location information is not generated. As this the case, it is only possible to rely on such systems in buildings where they have been pre-installed.

It is therefore an object of the present invention to provide a deployable location system that at least partially overcomes or alleviates the above problems.

Summary of the Invention

According to a first aspect of the present invention there is provided a deployable location system comprising: a plurality of base units provided around a monitored space, each base unit comprising a wide area receiver operable to receive wide area location signals from a wide area location system, a base unit processor operable to determine the location of base unit from the received wide area location signals, and a local transmitter operable to transmit local location system signals; one or more location units within the monitored space, each location unit comprising a local receiver operable to receive local location signals from said base units and a location unit processor operable to determine the location of location unit from the received local location signals; wherein at least a set of the base units are vehicle mounted base units.

According to a second aspect of the present invention there is provided a method of determining the location of one or more location units within a monitored space, said location units comprising a local receiver operable to receive local location signals, and a location unit processor operable to determine the location of location unit from the received local location signals, said method utilising a deployable location system comprising a plurality of base units provided around the monitored space, each base unit comprising a wide area receiver operable to receive wide area location signals from a wide area location system, a base unit processor operable to determine the location of base unit from the received wide area location signals, and a local transmitter operable to transmit local location system signals, the method comprising the steps of deploying base units around the monitored space, wherein at least a set of the base units are vehicle mounted base units; using received wide area location signals from a wide area location system to determine the location of each base unit; and using received local location signals to determine the position of each location unit relative to the base units.

The present invention thus provides for a readily deployable location system suitable for use in ad hoc deployments. By providing base units on vehicles it is possible to deploy sufficient base unit at sufficiently varied locations around the monitored space to locate location units within the monitored space to a useful accuracy, say of the order of +/-2m. For example, this is adequate for monitoring the location of emergency services personnel in a rescue situation, as well as police, civilian and defence operations in an unknown environment.

In some embodiments, the local transmitter of the base unit may be a transceiver. This may enable the utilisation of location technologies that require two-way signal transmission. In some embodiments, the local receiver of the location unit may be a transceiver. Similarly, this may enable the utilisation of location technologies that require two-way signal transmission.

In some embodiments, all of the base units are provided outside the monitored space. In other embodiments, some of the base units may be provided within the monitored space.

The monitored space may include one or more buildings or other structures The base units may be provided at different heights above a reference base level.

This can improve the vertical resolution and/or coverage of the deployable location system. This can also improve the horizontal resolution as signals from base units at different heights may not be blocked by obstacles within the monitored space In one possible embodiment, base units are provided at least four different heights The vehicles for vehicle mounted base units may be ground based vehicles. This can include wheeled or tracked vehicles and/or legged robots. In particular, these may comprise unaccompanied ground vehicle (UGVs). In a further embodiment, some or all of the vehicles may be aerial vehicles. In particular the aerial vehicles may comprise unmanned aerial vehicles (UAVs). Such UAVs are commonly referred to as drones. Beneficially use of UAVs allows a greater vertical separation between different base units to be achieved, improving vertical resolution and/or coverage. In some embodiments, the vehicle mounted base units may be provided on a mixture of UAVs and UGVs The vehicle mounted base units may be provided in fixed locations around the monitored space. In other embodiments, some or all of the vehicle mounted base units may vary in location. The variation may be a regular variation, for instance orbiting or oscillating around a particular location. This variation in location can enable local location signals transmitted from vehicle mounted base units to avoid blockage by obstacles within the monitored space and/or improve location capabilities based on past, current and future relative locations among the location units, base units, as well as the surrounding environment.

In some embodiments, all of the base units may be vehicle mounted base units. In other embodiments a first set of the mounted base units are vehicle mounted base units and a second set of base units are platform mounted base units. The platforms of the platform mounted base units may be adjustable. The adjustment can enable stable mounting of the base unit. Additionally or alternatively, the adjustment may allow variation of the height of the base unit relative to the local ground level. The platforms may be adapted to enable deployment by a single person. Additionally or alternatively, the platforms may be adapted to be mounted to one or more persons.

In a possible implementation, there may be six or more platform mounted base units and six or more vehicle mounted base units The wide area location system may be a satellite-based location system such as GPS or the like. In one embodiment, the base unit processors may be operable to apply real time kinematics (RTK) or Differential GPS to the received wide area signal. This provides for enhanced accuracy in calculating location of the base unit.

The local location signals may be radio frequency (RE) signals. In one embodiment, the local location systems may be based on ultra-wideband (UWB) RE signals. The local location signals may have the capability to go through a variety of building walls, structures or physical obstacles of different materials. The location unit processors and/or the base unit processors may be operable to process received signals and determine location by use of any suitable signal processing techniques. Such techniques may include, but are not limited to, analysis of any one or more of: signal transmission time; signal time of arrival; signal strength; signal angle of arrival; triangulation, trilateration, multilateration, time of transmission, two ways ranging, time of flight or the like. In some embodiments, the system may be operable to use different location signal timing or different location signal transmission sequences timings. This can improve the accuracy of location determination.

In some embodiments, the system may be operable to implement any suitable compensation algorithm (or other technique) to compensate for location signals deflection, reflection, multi-paths, location signals propagation delay, attenuation or the like of location signals by structures within the monitored space The location units and/or the base units may be adapted to be worn. This may be achieved by provision of a suitable strap, harness or the like. Additionally or alternatively, the location units may be incorporated into garments. The garments may comprise safety garments such as jackets or the like.

The location units and/or the base units may comprise an integral power unit. The power unit may comprise a battery. The battery may be a rechargeable battery. The power unit may be charged periodically via an external power connection. Additionally or alternately, the power unit may be charged by energy scavenging means. Such energy scavenging means may include but are not limited to: photoelectric devices, piezoelectric devices, thermoelectric devices, inductive devices, RE energy harvesting and the like.

The base units and/or location units may additionally be provided with communication units. The communication units may be operable to communicate data over a suitable wireless data connection. Examples of suitable wireless data connections include, but are not limited to WiFi, Bluetooth or the like. Additionally or alternatively, the base units and/or location units may be operable to utilise the local location system signals for communication. In such embodiments the local receivers of the location units and the local transmitters of the base units may be replaced with transceivers.

In some embodiments, the base units and/or location units may be provided with one or more sensors. The sensors may include any one or more of: movement sensors such as accelerometers, gyroscopes and inertial measurement units; local condition sensors such as temperature sensors pressure sensors moisture sensors or magnetic sensors; or imaging sensors such as cameras (visual, thermal or other waveband), radar, lidar or sonar/ultrasonic sensors; or the like. Sensor outputs may be processed locally and/or communicated to other devices for processing.

The system may additionally comprise a control module. The control module may comprise a communication unit operable to enable communication with the communication units of the base units and/or location units; a control module processor operable in response to the communication unit to determine the position of each base unit and/or each location unit; and a display unit operable to display information related to location and/or status of each base unit and or location unit. In many embodiments, the control module will additionally comprise user input means. The user input means may enable a user to input control commands and/or to interrogate the control module and/or individual base units or location units. In some implementations, the control module may be embodied by a computing device or more particularly a mobile computing device. Suitable examples of mobile computing devices include laptop or tablet computers, smartphones or the like.

In some implementations, the control module may be operable to issue /5 command signals to the vehicle mounted base units. The command signals may control variation of the location of vehicle mounted base units. The command signals may be generated automatically, semi-automatically or in direct response to user input. This can enable such locations to be varied periodically or on an ad hoc basis as necessary to improve system performance.

Where available, the control module may be provided with a map or plan of the monitored space. In some embodiments, the control module may be operable to generate or update a map of the monitored space in response to one or sensors provided on one or more base units and/or one or more location units. In some embodiments, the control module may be provided with one or more sensors. The sensors may include any one or more of movement sensors such as accelerometers, gyroscopes and inertial measurement units; local condition sensors such as temperature sensors pressure sensors moisture sensors or magnetic sensors; or imaging sensors such as cameras (visual, thermal or other waveband), radar, li dar or sonar/ultrasonic sensors; or the like.

In such embodiments, in response to the mapping tools the control module may be operable to build up a map of the monitored space.

The control module may be mounted on a suitable platform.

In some embodiments, the system may comprise multiple control modules. In such embodiments, each control module may have an equal rank. Alternatively, one control module may be designated as a master control module and the remaining control modules may be designated as slave control modules This can allow the master control module to be used to manage communications from all control modules According to a third aspect of the present invention there is provided a vehicle mounted base unit for use in a deployable location systems, the base unit comprising: a receiver operable to receive wide area location signals from a wide area location system, a processor operable to determine the location of base unit from the received wide area location signals, and a transmitter operable to transmit local location system signals; and a vehicle to which the receiver, processor and transmitter are mounted.

The vehicle mounted base unit of the third aspect of the present invention may comprise any or all features of the first two aspects of the present invention as desired or as appropriate.

Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 a is a schematic illustration of a deployable location system according to the present invention; Figure lb is a schematic illustration of the relative locations of base units and location units of the deployable location system of the present invention upon a floor of a building with a space monitored by use of the system; Figure 2 is a schematic block diagram of a base unit for use in the deployable location system according to the present invention; Figure 3 is a schematic block diagram of a location unit for use in the deployable location system according to the present invention, and Figure 4 is a schematic block diagram of a control module for use in the deployable location system according to the present invention; and Figure 5 is a schematic block diagram of a base unit for use in the deployable location system integrated into an autonomous vehicle.

Turning now to figure I a, there is provided a deployable location system 100 operable for detecting the location of one or more items 1 tagged by a location unit 10 (not visible in figure la) within a monitored space 1. In the example shown, the monitored space 1 comprises a multi-level building 21 and the immediate surrounds of building 21. The tagged item 3 is an item of protective equipment such as a jacket or helmet worn by a firefighter. The location system can thus be used to track the location of the tagged item 3 (and hence the firefighter) through building 21. This is illustrated in figure lb wherein the relative positions of a plurality of location units 10 and base units 20 are shown with respect to a single floor 21a of building 2L This can be used, in one example, to coordinate search and rescue activities or the like. Whilst in the example of figure 1, the location system 100 is used to monitor the location of a firefighter within a building 2, the skilled man will appreciate that the location system 100 can equally be used to monitor the location of other emergency service personnel in other spaces. Additionally or alternatively, the location system may be applied to the monitoring of the location of other personnel, including but not limited to military personnel, or other items including but not limited to autonomous vehicles.

The system 100 comprises a plurality of base units 20-29. A first set of base units 20-25 are deployed on platforms 30-35 provided around the monitored space 1. A second set of base units 26-29 are deployed on autonomous aerial vehicles (UAVs) 3639 which are positioned around the monitored space 1. The base units 21-29 can be rapidly deployed in suitable locations on an ad-hoc basis. This therefore enables the location system 100 to be used to monitor a space 1 that has not been previously prepared, surveyed or calibrated.

Each base unit 20-29 is operable to determine its location by receiving and processing signals 41 from a wide area location system 40. In this instance, the wide area location system 40 is a satellite-based location system such as UPS. In turn, each base unit 20-29 is operable to transmit local location signals 51 which can be received by the location unit 10. The location unit can process the received local location signals 51 to determine the location of the location unit 10 relative to the base units 20-29. Since the location of the base units 20-29 is already known from the wide area location system 40, the location of the location unit 10 and hence tagged item 3 can be determined.

Optionally, locations for base units 20-29 and location units 10 can be shared with a control module 70 via data signals 61. This can enable the control module 70 to display information relating to the location of tagged items 3 to a user and/or the status of base units 20-29 or location units 10. The control module 70 may optionally carry out some location determination calculations and/or be operable to issue commands to said base units 20-29 and location units 10. This can enable the control module 70 to control the UAVs 36-39 so as to position the base units 26-29 in optimum locations. Alternatively, the control module 70 may be operable to control the UAVs 36-39 so as to vary their position for optimum performance.

Whilst any location determined for the location unit 10 will incur some inaccuracies due to interference from stnictural features of building 2, providing sufficient base units 20-29 at a sufficiently varied set of locations around the monitored space 1, in particular at different vertical heights (by varying platform 30-35 height and UAV 36-39 height) can enable location determination to an accuracy of the order of say lm. This is sufficient for emergency deployment purposes. I 0

As is shown more dearly in figure 2, each base unit 20-29 comprises a wide area receiver 42 operable to receive wide area location signals 41 from the wide area location system 40 via antenna 41a. The received wide area location signals 41 are processed by a base unit processor 19. The base unit processor 19 is thus operable to determine the location of base unit 20-29 from the received signals 41. The base unit processor 19 can process the signals 41 or parameters of the signals 41 in any suitable manner to determine location. For example, the base unit processor 19 may be operable to analyse any one or more of signal transmission time, signal time of arrival; signal strength; signal angle of arrival; triangulation or the like. Typically, in the example of use of UPS wide area location system 40, the base unit processor 19 may apply real time kinematics (RTK) or differential UPS in determining location. This provides both an enhanced level of accuracy in determining location and allows for fast determination of location. Alternative technologies such as ground control points (GCPs) or post processed kinematic (PPK) are not suitable as GCP does not enable fast deployment of the base units 20-29 and PPK does not allow for real-time location determination.

Optionally, the base units 20-29 additionally comprise a communication unit 62 operable to enable the transmission and receipt of data signals 61 via an antenna 62a. The data signals 61 typically conform to a standard data network protocol such as WiFi, Bluetooth or the like. This can allow the exchange of commands or status data between the control units 20-29 and other components of system 100 In addition to the above, the base units 21-29 each comprise a local transmitter 50 operable to transmit local location system signals 51. Typically, the local location signals 51 are ultra wideband (UWB) Radio Frequency (RE) signals. Such UWB signals 51 provide for relatively reliable transmission and reception over short ranges.

In some embodiments, the transmitter 50 may be a transceiver. This allows the base unit 21-29 to utilise signals 51 for communicating data with other base units 21-29, location units 10 and control module 70 and/or to utilise signals 51 for locating base unit 21-29 relative to other base units 21-29.

In further embodiments, the base unit 21-29 may comprise one or more additional sensors 81. The sensors 81 may comprise any suitable sensors including but not limited to: movement sensors such as accelerometers, gyroscopes and inertial Ii measurement units; local condition sensors such as temperature sensors pressure sensors moisture sensors or magnetic sensors; or imaging sensors such as cameras (visual, thermal or other waveband), radar, lidar or sonar/ultrasonic sensors; or the like.

The base unit 21-29 shown in figure 2 further comprises a power source 85.

Typically, the power source 85 may be an internal battery (rechargeable or otherwise) or a socket for receiving an external power supply cable.

Turning now to figure 3, a location unit 10 comprises a local receiver 52 operable to receive local location signals 51 from said base units 20-29 via antenna 52a. The received local location signals 51 are processed by a location unit processor 11.

The location unit processor 11 is thus operable to determine the location of location unit 10 from the received local location signals 51. The location unit processor 11 can process the signals 51 or parameters of the signals Si in any suitable manner to determine location. For example, the location unit processor 11 may be operable to analyse any one or more of signal transmission time, signal time of arrival; signal strength; signal angle of arrival; triangulation or the like.

Optionally, as with the base units 20-29, the location unit 10 additionally comprises a communication unit 63 operable to enable the transmission and receipt of data signals 61 via antenna 63a.

In some embodiments, the receiver 52 may be a transceiver. This allows the location unit 10 to utilise signals 51 for communicating data with base units 21-29, other location units 10 and control module 70 and/or to utilise signals 51 for locating location unit 10 relative to other location units 10.

In further embodiments, the location unit 10 may comprise one or more additional sensors 82. The sensors 82 may comprise any suitable sensors including but not limited to: movement sensors such as accelerometers, gyroscopes and inertial measurement units; local condition sensors such as temperature sensors pressure sensors moisture sensors or magnetic sensors; or imaging sensors such as cameras (visual, thermal or other waveband), radar, lidar or sonar/ultrasonic sensors or the like.

The location unit 10 shown in figure 3 further comprises a power source 86. Typically, the power source 86 may be an internal battery (rechargeable or otherwise) or a socket for receiving an external power supply cable.

Turning now to figure 4, control module 70, which might typically be embodied by a tablet computer or the like, comprises a communication unit 60 operable to transmit/receive data signals 61 via antenna 60a. Additionally, the control, module 70 comprises a control module processor 71 operable in response to the data signals 61 received via communication unit 60 to determine the position of each base unit 20-29 and/or each location unit 10.

The control module 70 further comprises a display unit 72 operable to display information related to location and/or status of each base unit 20-29 and or location unit 10. Typically, the control module 70 additionally comprise user input means 73. The user input means 73 may comprise a keypad, touch-sensitive screen, pointing device or the like. This therefore enables a user to input control commands and/or to interrogate the control module 70 and/or individual base units 20-29 or location units 10.

Optionally, as is shown in figure 4, the control module 70 comprises a wide area receiver 43 operable to receive wide area location signals 41 from the wide area location system 40 via antenna 43a. The received wide area location signals 41 are processed by a processor 71 to determine the location of control module 70 from the received signals 41, as discussed above in relation to base units 21-29.

Optionally, as is shown in figure 4, the control module 70 comprises a local receiver (or transceiver) 53 operable to receive local location signals 51 from said base units 20-29 via antenna 53a. The received local location signals 51 are processed by a processor 71 to determine the location of control module 70 from the received local location signals 51, as discussed above in relation location units 10. In embodiments wherein the receiver 53 is a transceiver this allows the control module 70 to utilise signals 51 for communicating data with base units 21-29 and location units 10.

In further embodiments, the control module 70 may comprise one or more additional sensors 83 The sensors 83 may comprise any suitable sensors including but not limited to: movement sensors such as accelerometers, gyroscopes and inertial measurement units; local condition sensors such as temperature sensors pressure sensors moisture sensors or magnetic sensors; or imaging sensors such as cameras (visual, thermal or other waveband), radar, lidar or sonar/ultrasonic sensors; or the like.

The control module 70 shown in figure 3 further comprises a power source 87.

Typically, the power source 87 may be an internal battery (rechargeable or otherwise) or a socket for receiving an external power supply cable.

In some instances, the control module 70 may be operable to receive mapping information related to the monitored space 1. The mapping information may comprise previously prepared maps or plans of the space, such as planning blueprints where available. Alternatively, the mapping information may be generated by the output of sensors 81, 82, 83 provided on base units 21-29, location units 10 or on control module 70 itself Turning now to figure 5, it is possible that vehicle mounted base units 26-29 are integrated with vehicles 36-39. In such instances, the base unit 26-29 may have common features with the base unit 21-29 shown in figure 2. In order to integrate operation of the base unit 26-29 with vehicle 36-39, there is provided a connection between base unit processor 19 and vehicle processor 91 of the vehicle 36-39 and a connection between any optional sensors 81 and vehicle autopilot module 92. The vehicle processor 91 and autopilot module 92 can optionally be in communication with control module 70 via data signals 61 which may be received/transmitted via dedicated antennas 91a, 92a. connected to processor 91 and autopilot module 92 is one or more vehicle actuators operable to power or control vehicle motion. In this manner, the vehicle 36-39 can maintain a desired position or pattern of positions either in response to data preloaded into autopilot module 92 or in response to data received from control module 70.

The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims

Claims

CLAIMSA deployable location system comprising: a plurality of base units provided around a monitored space, each base unit comprising a wide area receiver operable to receive wide area location signals from a wide area location system, a base unit processor operable to determine the location of base unit from the received wide area location signals, and a local transmitter operable to transmit local location system signals; one or more location units within the monitored space, each location unit comprising a local receiver operable to receive local location signals from said base units and a location unit processor operable to determine the location of location unit from the received local location signals; wherein at least a set of the base units are vehicle mounted base units.
A deployable location system as claimed in claim t wherein all of the base units are provided outside the monitored space.
3. A deployable location system as claimed in any preceding claim wherein the base units are provided at different heights above a reference base level A deployable location system as claimed in any preceding claim wherein the vehicles for vehicle mounted base units comprise unmanned aerial vehicles (UAVs) or unmanned ground vehicles (UGVs).A deployable location system as claimed in any preceding claim wherein the vehicle mounted base units are provided in fixed locations around the monitored space A deployable location system as claimed in any one of claims 1 to 4 wherein some or all of the vehicle mounted base units vary in location 7. A deployable location system as claimed in any preceding claims wherein a first set of the base units are vehicle mounted base units and a second set of the base units are platform mounted base units.A deployable location system as claimed in any preceding claim wherein the base unit processors are operable to apply real time kinematics (RIK) to the received wide area signal.ISA deployable location system as claimed in any preceding claim wherein the local location systems are ultra-wideband (UWB) radio frequency signals O. A deployable location system as claimed in any preceding claim wherein the location unit processors and/or the base unit processors are operable to process received signals and determine location by use of any one or more of: signal transmission time; signal time of arrival; signal strength; signal angle of arrival; triangulation; trilateration; multilateration; time of transmission; two ways ranging; or time of flight.A deployable location system as claimed in any preceding claim wherein the location units or base units are adapted to be worn or incorporated into garments.A deployable location system as claimed in any preceding claim wherein the base units and/or location units are provided with one or more sensors.A deployable location system as claimed in any preceding claim wherein the base units and/or location units are provided with communication units operable to communicate data over a wireless data connection A deployable location system as claimed in any preceding claim wherein the base units and/or location units are operable to utilise the local location system signals for communication.A deployable location system as claimed in claim 13 or claim 14 wherein the system additionally comprises a control module, the control module comprising a communication unit operable to enable communication with the communication units of the base units and/or location units, a control module processor operable in response to the communication unit to determine the position of each base unit and/or each location unit; and a display unit operable to display information related to location and/or status of each base unit and or location unit. 12. 13. 1 5.16 A deployable location system as claimed in claim 15 wherein the control module additionally comprises user input means 17. 18. 19. 20. 21.A deployable location system as claimed in claim 15 or claim 16 wherein the control module is operable to issue command signals to the vehicle mounted base units.A deployable location system as claimed in claim 17 wherein the command signals control variation of the location of vehicle mounted base units.A deployable location system as claimed in any one of claims 15 to 18 wherein the control module is provided with a map or plan of the monitored space.A deployable location system as claimed in claim 19 wherein one or more of the base units and/or location units comprises one or more sensors and, in response to the sensor output, the control module is operable to build up a map of the monitored space.A method of determining the location of one or more location units within a monitored space, said location units comprising a local receiver operable to receive local location signals and a location unit processor operable to determine the location of location unit from the received local location signals, said method utilising a using a deployable location system comprising a plurality of base units provided around the monitored space, each base unit comprising a wide area receiver operable to receive wide area location signals from a wide area location system, a base unit processor operable to determine the location of base unit from the received wide area location signals, and a local transmitter operable to transmit local location system signals, the method comprising the steps of: deploying base units around the monitored space, wherein at least a set of the base units are vehicle mounted base units; using received wide area location signals from a wide area location system to determine the location of each base unit; and using received local location signals to determine the position of each location unit relative to the base units.22. A method as claimed in claim 21 wherein the base unit processors are operable to apply real time kinematics (RTK) to the received wide area signal.23. A method as claimed in claim 20 or claim 21 wherein the local location systems are ultra wideband (UWB) radio frequency signals.24. A method as claimed in any one of claims 21 to 23 wherein the location unit processors and/or the base unit processors are operable to process received signals and determine location by use of any one or more of signal transmission time; signal time of arrival; signal strength; signal angle of arrival; triangulation; tril aterati on; multilateration; time of transmission; two ways ranging; or time of flight.25. A vehicle mounted base unit for use in a deployable location system, the base unit comprising: a receiver operable to receive wide area location signals from a wide area location system, a processor operable to determine the location of base unit from the received wide area location signals, and a transmitter operable to transmit local location system signals and a vehicle to which the receiver, processor and transmitter are mounted.