The present invention relates to surveillance sensors, and particularly relates to rapidly deployable autonomous sensor carrier (“sonde”) for human or other surveillance, a method for deploying such sondes, and a surveillance system employing such sondes.
In many situations, it is desirable to monitor environmental conditions and/or human or animal activity at a position remote from the observer. This may be because the surveyed region is extensive, so that direct observation of the entire region is impractical. It may be because direct observation would disturb the phenomenon to be observed, for example in the case of observing human or animal behaviour. It may be because the surveyed region is dangerous for direct observation for reasons such as chemical or radiological pollution, seismic or water activity, or the threat of violence from other interested people.
For whatever reason, in these situations, it is required that a sonde may be deployed rapidly and accurately, so that personnel employed in the deployment of the sondes spend as little time as possible in the surveyed location. It is further required that the sonde be autonomous, sensitive to the events of interest and robust enough to require no maintenance after deployment, and have a useful lifetime.
U.S. Pat. No. 6,380,889 describes a reconnaissance sonde carrying sensors and communication equipment. The described sonde is deployed from a rocket, which breaks up to reveal a sonde on a parachute, which descends into the surveyed region. German patent applications DE 4104800 and DE3313648 and U.S. Pat. No. 3,962,537 all describe surveillance sensors and communication devices, which are launched from a gun, or deployed from a missile.
While such deployment methods may be suitable for the battlefield, they are unsuitable for the purposes of the present invention. The deployment methods described are very long-range. Typically, the sensor will be deployed several kilometres from the launch site. This means that the position of deployment can only approximately be determined before launch. The launch and arrival of the sensor will be very prominent events: the launch being accompanied by the sight and sound of a gun firing or a missile or rocket launching. The arrival of the sensor will be accompanied by the sight of an incoming artillery shell, missile or rocket, breaking up to deploy a parachute carrying the sensor to ground. Such methods are accordingly most unsuitable for situations in which the deployment of sensors is desired to pass relatively unnoticed. Such situations include the monitoring of animal behaviour, or the monitoring of human activity.
The present invention aims to provide a sonde and a method for deploying a sonde, suitable for rapid and accurate short-range ground placement of the sondes. The sonde and the method are suitable for applications such as detection and monitoring of human or animal activity, detection of ground or airborne vehicles, and environmental monitoring. The deployment method and the sonde itself should not be intimidating, to avoid the sonde and the deployment from influencing any activity which is to be monitored. Examples of situations in which human activity may be required to be detected or monitored include crowd control at sports events, political rallies and demonstrations, in disaster relief to detect the presence of survivors, or in monitoring hostile situations.
GB 2386673 describes a target immobilisation device or bolas, which is launched by imparting a spin and a directional velocity to the device or bolas, sufficient to carry it to a target. The device or bolas may carry a radio receiver and loudspeaker. The device or bolas may carry a proximity sensor, imaging sensor or radar device. Images may be formed at a remote location.
FR2518733 describes a fixed lookout post with vertically ejectable observation platform carrying an infra red detector.
U.S. Pat. No. 6,155,155 discloses a disk shaped anti-mine munition and launcher.
U.S. Pat. No. 6,761,117 discloses a combined reconnaissance sonde and ordnance system in the form of a hand grenade.
GB 1 213 389 discloses a system for launching disk shaped projectiles in a pattern surrounding the launcher.
The present invention accordingly provides apparatus and methods as set out in the appended claims.
The above, and further, objects, characteristics and advantages of the present invention will become more apparent by reference to the following description of certain embodiments, given by way of examples only, together with the accompanying drawings, wherein:
In another embodiment of the invention, the sondes may be thrown by hand, from a vehicle or by a pedestrian. In another embodiment of the invention, an automatic or remote controlled launcher may be provided, carried by a manned or unmanned vehicle, to project the sondes into the region of interest.
As will be discussed in more detail below, the sondes may be equipped with sensors such as microphones, video cameras and so on. The sondes may be provided with presence or movement detectors such as radar or CELLDAR™. CELLDAR™ is a presence or movement sensor system, which emits no signals, but detects reflections of signals such as mobile telephone signals from antennas 26. It is described in more detail in International patent application WO 03/012473. In an urban environment, it is useful for detecting the presence and velocity of vehicles.
The sondes are preferably also equipped with a location determining means, such as a GPS receiver or the like. The sondes are equipped with means for telecommunication, such as a radio transmitter. The transmitters may transmit information, typically including GPS position and data provided by the sensors to a central receiving location 24. This may, for example, be a police station. The sondes may be arranged to communicate according to WLAN and/or GPRS radio communications standards. Alternatively, the sondes may be provided with transmitters suitable for communication 5 over a mobile telephone network. This latter option is particularly suitable for urban deployment, where coverage by mobile telephone antennas 26, for example atop buildings 28, is good, but direct transmission to receiving station 24 may be blocked by the presence of such buildings. Once communicated to the mobile telephone network, the data may of course be carried anywhere in the world by the standard telephone network. Other means of wireless communication, such as WAP Internet access, may be provided to allow the sondes to transmit their data.
The son des 14 may also be equipped to communicate amongst themselves, for example to provide relay stations to convey data from distant sondes to the central receiving location 24; or to confer among peers to detect the direction of travel of any detected activity. Such calculations may alternatively be performed at the central receiving station 24 or other remote location.
The embodiment described above relates to monitoring the activity of a group of people in an urban environment. Such applications could relate to monitoring the activities of demonstrators, football crowds and so on. Other applications of the present invention include detecting the presence and/or movement of vehicles in a certain areas, for example for security purposes; the monitoring of the presence and activity of animals, environmental monitoring, pollution control, monitoring of seismic activity; monitoring human activity in situations such as a siege or hostage holding, where it is desirable to monitor activity and possibly also provide a communication link without physically approaching the area of interest. In all of these applications, it is advantageous that the method of deployment should be as rapid as possible, so that the deploying personnel and/or equipment spend as little time as possible in or adjacent to the region of interest as possible. It is also advantageous that the deployment of sensors and the sensors themselves, are unobtrusive and non-threatening to the persons, animals etc. under surveillance. Deployment and/or sondes which are not unobtrusive, or which are threatening, are to be avoided since they would likely modify the behaviour which is to be observed, and/or may provoke an aggressive response from the persons, animals etc. under surveillance.
Preferably, the sonde is of a suitably inconspicuous colour: a concrete grey, grass green, sandy brown or mud brown colour, for example. The object of such camouflage is firstly to reduce the likelihood of persons or animals under surveillance from noticing the presence of the sonde, and secondly to make the sonde appear unattractive to such persons or animals if the sonde is noticed. Sondes may be produced in different colours, and/or with differing combinations of sensors for deployment in different environments.
A number of sensors are provided in the sonde. As shown in
According to an embodiment of the invention, the sondes may be provided with a presence and/or motion sensor, for example, antennas and circuitry able to operate to measure the presence and/or speed of an approaching or receding ground or airborne vehicle. Such systems include radar and CELLDAR™ as described above. Any radar, CELLDAR™ 38 or similar device must be provided with a number of antennas 38a. This option will be discussed in more detail below.
The sonde may also be equipped with a radio detector or receiver, for detecting the presence of radio signals emitted by other systems, such as radar or communications systems. The radio detector or receiver may be arranged to detect the content and direction and/or distance of the source of the radio signals. A number of antennas, such as antennas 38a may be required to enable the operation of such a radio detector or receiver.
Any other type of sensor may be included within the sonde, together with appropriate control circuitry. It is envisaged that only a subset of the possible sensors would be included in any one sonde. The combination of sensors provided in a particular sonde should be chosen according to the required functions of the sonde, which in turn depends on the activity to be monitored using the sonde and the environment in which it is to be placed. The various sensors which may be employed will hereafter be referred to as environmental sensors, where “environmental” takes its broadest meaning, relating to any aspect of the environment in which the sonde is located.
The sonde will typically include a GPS receiver 39 or the like, enabling the sonde to determine its location.
A communications antenna 39a, for example a planar patch antenna, is provided to enable the communications and control circuitry 40 to transmit, and optionally also to receive, data to/from the central receiving location 24 and/or peer sondes 14.
All of the above-mentioned sensors are conventional in construction and operation. They are connected to control and communication circuitry 40, conventional in itself, to interpret the sensors' readings and to transmit the corresponding data to the central receiving location 24. The present invention does not relate to the sensors themselves, nor to the control and communication circuitry itself.
The sonde according to an aspect of the invention, and as illustrated in
The sensors provided within the sonde will need to communicate with the external environment. The fisheye lens 32a (or other optical receiving means) protrudes through and above the upper part 46 of the casing. A pattern of holes 49 may be provided to provide a path from the atmosphere to any of: gas or biological sensor 34; microphone 33; humidity sensor 37; air pressure sensor 37a or other sensors requiring access to the atmosphere, as appropriate. It may be unnecessary to provide such holes for microphone 33, if it is sufficiently sensitive. Care should be taken to ensure that the sonde as a whole is at least sufficiently watertight to resist significant water ingress. If a planar patch antenna 39a is employed, a flat region of the casing may need to be provided above the patch antenna to provide a region of constant dielectric thickness above the antenna. This flat region may conveniently be employed for affixing an 5 information or warning label. In an embodiment of the invention, the casing 43 has a diameter of approximately 15 cm and a thickness of approximately 3 cm.
Some sensors such as radar or CELLDAR® presence and motion detectors may require the deployment of antennas 38a of a required length and/or orientation which renders their incorporation within the casing 43 impractical. In such instances, retractable antennas may be provided. In
A rugged casing 43 encloses a cavity 44, which contains circuitry 30 such as shown in
The material chosen for any ring 45 should be resilient, with a relatively high coefficient of friction. The material chosen for the remainder of the casing 43 should also be resilient, not brittle. The casing, at least in the region of the rim 41, should be of resilient material, such as synthetic rubber, polyethylene, PVC or similar materials. It should maintain its shape under impact forces, and be strong enough to withstand a certain degree of abuse. A material used for casing 43 in an embodiment of the invention was NORYL®, a modified polyphenylene oxide resin which may be glass-filled for added strength. Other materials may be found suitable, such as polyethylene, PVC, synthetic rubber compounds. The casing 43 may be produced by injection moulding in two parts. Alternatively, the circuitry and sensors shown within the cavity 2044 in
The sonde 14 is launched as described above, and will typically hit the ground rim-first. It is therefore preferable that the material of the rim should absorb a significant amount of the shock of the impact by deforming, at least temporarily. The material of the casing 43 should, however, not be so flexible that damage to the circuit 30 could occur due to flexing of the whole sonde. Rim 41 and any ring 45 may be designed to encourage the sonde to roll on its edge along the ground away from its point of impact. The shape of the casing 43 and the distribution of weight within the sonde should be arranged such that the sonde will tend to come to rest the right way up, that is, in the orientation shown in
Some deployed sondes may come to rest on their edge, in vegetation, behind an obstacle, or in an inverted state. The sondes may be equipped to detect this condition and to transmit an “ERROR” or “HELP” signal to the central receiving location 24. A replacement sonde may be deployed, or manual intervention may be employed to correct the orientation of the sonde. Similarly, the GPS receiver in the sonde may detect motion of the sonde after deployment, typically indicating that the sonde has been stolen or carried away by an animal, or by water, or by other agents. The sonde may transmit a “HELP” signal in this case to the central receiving location, prompting deployment of a replacement sonde and/or recovery of the original sonde.
According to an aspect of the present invention, when the sonde is launched, a spin about axis A (
In certain preferred embodiments of the invention, the sonde may be shaped similarly to a clay pigeon or skeet. The sondes may be launched by a device 16 resembling a clay pigeon launcher. Sondes of an appropriate size and weight may in fact be launched by a clay pigeon launcher.
Number | Date | Country | Kind |
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0416204.6 | Jul 2004 | GB | national |