WO1993002749A1

WO1993002749A1 - Method for detecting and combatting forest fires

Info

Publication number: WO1993002749A1
Application number: PCT/FR1992/000754
Authority: WO
Inventors: Jacques Julien Lang
Original assignee: Jacques Julien Lang
Priority date: 1991-07-31
Filing date: 1992-07-30
Publication date: 1993-02-18
Also published as: FR2679779A1; AU2435792A; FR2679779B1

Abstract

The method of the invention consists in flying over systematically and at high altitude the surface of the risk area under surveillance according to a predefined circuit and with a number of aircrafts varying as a function of the total surface to be covered and of the desired frequency of passes, said airplanes being equipped with very precise navigation means and with equipments for recording their position as well as thermosensing means and means for transmission to the ground command station; all spots of anomalies detected are transmitted in real time to said command station so that, according to the characteristics of the area concerned, the means actually available and the environmental conditions which can be controlled also in real time, the most necessary and appropriate fire combatting means can be sent to the region concerned in order to fight against the cause of said anomaly and against any disaster which may have been caused by said anomaly.

Description

METHOD FOR THE DETECTION AND CONTROL OF FOREST FIRES

DESCRIPTION The present invention relates to a method for the systematic detection and positioning of thermal anomalies on the ground surface.

The basic concept is based on the implementation of material means of dynamic geographic positioning and transmission of information in real time of images and temperature zones on the ground which, although each existing individually, have never been all combined and implemented specifically to achieve the object of the present invention.

One of the main applications of the invention, for which is developed as an important example, because using all the specificities and interests of the process, in the description below, is the detection and positioning of the start of forest fires, based on preventive surveillance of regions at risk.

Other applications are however and also possible such as in the field of pollution, night surveillance of pipelines transporting petroleum products, early detection of the risks of volcanic eruption, detection of aircraft crashes, positioning and evaluation of areas of forests affected by diseases etc ..., that is to say whenever the speed of detection and the accuracy of positioning are useful if not vital.

It is recognized in fact, in the application to the detection of starting fires in particular, that even in the conditions known as "with severe risks", frequently met, in particular the summer in the hot and dry regions such as in the South from FRANCE, a starting fire attacked within ten minutes can be controlled. Attacked within twenty minutes, it already requires the implementation of significant resources and requires several hours of struggle to control it. From forty minutes, especially by Fort Mistral, it became a serious fire, endangering the lives of rescuers and homes. Only then does the sagging or stopping of the wind make it possible to reverse the situation.

However, detection techniques, and especially positioning techniques fires currently in use hardly ever allow a rapid and effective intervention of the helpers, which explains the considerable damage caused each year by forest fires.

Control officials recognize that fire detection in mountainous areas is very uncertain. To date, "fixed land watch" systems are used, made up of lookouts: the observer who has visually detected suspicious smoke must then locate it and then give the alert to the Intervention Forces. Practiced from watchtowers, this starting position for fires is random: in most cases, the watchman does not have direct vision of the base of the fire. He sees only the smoke emerging from a mask at a point which can be very far from its source due to the combined effects of the relief and the wind. The "triangulation" then gives the most often aberrant results. At this stage of the process, there is no other solution than to go to see on the spot to realize directly what it returns. As the use of the helicopter is far from being generalized, and the use of a lookout plane being completely uncertain, it is most often by car that this reconnaissance is carried out. The addition of these different deadlines leads to delays in intervention and the poor positioning made on sight causes very detrimental route errors: thus if the surface concerned exceeds one hectare, there is every chance, on windy days , to see the affair degenerate into a catastrophic fire. In addition, visual detection is random, on the one hand because of possible human failures, and on the other hand because a fire may have started long before smoke is visible. To overcome these drawbacks, automatic detection equipment is increasingly used, such as thermal sensors, but even in this case, costly errors are still made by ignorance of the technical characteristics of certain materials, and the absence of '' a specific method of use of these materials which is suitable for this detection.

In fact, a thermal sensor only measures the emissivity level of the visible surface of an object or a tree, or the temperature of an open flame. Any volume of insulating material hiding the direct view of the flame prevents the detection of a rise in object or tree temperature, and view or analyze the hidden flame.

In the case of a forest, if a sensor is placed in a watchtower or at the top of a water tower, the sensor can only detect a fire if it is lit at the edge of the forest, in vision direct optics, without there being any tree trunk between the flames and the sensor, because wood is a thermal insulator. It would therefore be preferable for the sensor to be placed on a mobile vector: the lateral displacement relative to a wood edge would, however, randomly allow the flame to be seen for a few moments between the trees whose relative entanglement will be modified by the displacement of the point of view. On the other hand, a thickness of several kilometers of low atmosphere, makes any correct measurement of temperature illusory, the measurement being able to be distorted by a volume, even small, of an atmosphere locally overheated by radiation of a clear limestone surface returning for example the heat of the sun, and being on the trajectory.

Another handicap is that a tree 40 cm in diameter and 12 meters high represents a screen of 4.8 m ² : around twenty trees randomly planted and sufficiently tight represent a thermal screen of 100 m ² in average. A fire inside a forest, even just 50 meters from the edge will therefore not be detectable by a thermal sensor located at a horizontal distance of 1km, even if the sensor has a location located at an angle of 20 to 30 ° of inclination, as can be the case for a watchtower at the top of a hill.

On the other hand, in plains or hilly areas, the multiplication of lookout stations and therefore of lookouts provided with radio transmission stations, all being in principle on the same frequency, quickly leads to a blocking of this frequency as soon as a fire was perceived by one of them, thus preventing the transmission of urgent messages which would allow rapid organization of the rescue.

Furthermore, the "trace of water on the ground" made by a fight aircraft, such as for example a CANADAIR CL215, is limited to an ellipse whose axes are less than 55 * 20 meters for a drop height of 50 meters; and for a TRACKER type aircraft, the trace is 18 x 4 meters at full load, for a height of drop of 35 meters. If the wind is strong, the progression of the fire can then be much faster than the possibilities of extinguishing all the combined water bombers, depending on the distance from the scooping site, or of replenishing water and retarding by report to the place of fire, which lengthens the interval between the drops.

The problem is therefore to be able to quickly detect thermal anomalies on the ground surface, such as in this main application, the start of fires (within ten minutes at least) and with a minimum of interpretation error on the cause of this anomaly, and at the same time provide the Control and / or Command centers: the precise position of this anomaly by automatic recording on a computer screen of its clear geographic coordinates, allowing its progress and speed to be measured progression, and in the case of a fire, the temperature levels reached at its various points. These objectives and problems to be solved are the same in most causes of pollution, pipeline leaks, etc.

A solution to the problem posed is a method of systematic airborne detection and positioning of thermal anomalies on the surface of the ground, thanks to the use of various planes and terrestrial means, sensors adapted to the desired detection and communication systems and location, in which:

- We choose planes offering a high visibility on the ground and we equip them, on the one hand, with very precise navigation means such as by satellite reference, associated with equipment for recording their position, on the other hand with means thermal detection by scanner or laser scanning sensor, and finally means of transmission to a ground command post;

- the number of planes required is determined based on the total area to be covered and the desired frequency of passage, and we systematically fly at high altitude over the area of the risk zone that we want to monitor, according to a predefined circuit , determined as a function of the relief and of a selected maximum speed, compatible with the detection means; - any thermal anomaly is identified and interpreted according to its nature, using said detection means, either vertically, by means of a vertical viewfinder or a video camera in suitable position, either when passing through, the precise coordinates of the anomaly then being supplied by the computer of the installed thermal scanning scanner detector, refined by the attitude detector; - the said raised position is transmitted to the command post where its clear coordinates are displayed in real time on a digital vector map of the area concerned, centered around the point of the anomaly which appears visibly;

- for the region concerned centered on this anomaly, we consult all the useful information previously stored in memory at said command post, and relating to all the communication and access routes to the terrain, the relief of the site and its characteristics, the location of the habitat, any obstacles present in the region and all the rescue and intervention means available by area depending on the type of cause that caused the detected anomaly;

- one chooses, among these means, the availabilities, of which one is then informed, the best suited to combat the cause of the anomaly and the disaster which may have declared and spread, and one initiates the order of their mobilization towards the point and the zone identified of this anomaly.

The objective of the present invention is also achieved by means of a systematic airborne detection and positioning device for thermal anomalies making it possible to apply the above method, thanks to the use of various planes and land means, and comprising:

- on board said aircraft, very precise navigation means, such as by satellite reference, associated with a device for recording their position and means of thermal detection by scanning or laser scanning sensors and finally means of transmission to a ground command post,

- ashore, in said command post, any means of communication with said planes and any means of processing the information transmitted by them, with those stored in a memory of any suitable computer means corresponding to the region to be controlled, in order to to display on a screen the map thereof, centered around said points of the anomaly detected by said planes.

The object of the present invention is to allow both the detection and the precise localization of an anomaly within eight to ten minutes, and the immediate and automatic transmission of this information by coded radio to a control station and / or command or alert concerned.

The result is a new systematic airborne detection and positioning process for thermal anomalies.

This process makes it possible to provide immediately on a screen to the person on duty all information, by digital vector or scanned maps of the site, of synthetic images by mesh established from an altimetry database allowing him to visualize the site in relief, with all the obstacles and the possibilities of access, to know the current geographical situation of the various terrestrial means of fight, and for a fire, the water points, in canalization as in the open air, then from that the close surveillance aircraft is on the scene, the temperatures reached at the various stages of the fire as it evolves, in real time. The information must be sufficiently numerous and up-to-date to enable it to assess the importance of the means to be sent to the scene, being then certain that these means, if they are well used, will be sufficient.

The invention therefore essentially relates to a method for detecting and locating an anomaly, such as the start of a forest fire, with a precision and a speed making it possible to combat it with maximum efficiency, this method consisting in particular:

- on the one hand to visually observe the sensitive areas concerned by means of a fast airplane flying at a minimum altitude representing on average three and a half times the altitude of the highest peaks of the region being monitored. In the departments with accentuated reliefs as in FRANCE that of the Alpes Maritimes, the advantage of aerial observation at high altitude is obvious, especially if it is carried out with modern means of automatic positioning, by passing vertically or by its across. - on the other hand, to analyze the hot spots on the ground using a thermal scanning scanner, by measuring their exact position, using a sufficiently precise navigation system. The detection flight must be carried out at high altitude for five main reasons: a / the search for the minimum of turbulence in strong winds, in order to limit instability in pitching, roll, and yaw, the residual fluctuations being however smoothed electronically by the beam stabilizer of the thermal scanning scanner, and thus obtain a geometrically stable image allowing perfect reliability of location and vertical measurements. b / the search for the purest and clearest atmosphere possible, in order to increase the contrast of the image of the ground. c / the search for the highest point in relation to mountain peaks, especially when the slopes are very steep and surround deep gorges, requiring a line of sight with a pronounced oblique. d / the possibility of a high speed to reduce the number of planes in relation to the surface monitored, and limit the congestion of the radio frequencies used, while observing all the points of the region concerned every ten minutes. The high speed can only be obtained at high altitude with relatively low power and low consumption turbines. Furthermore, an overly rapid overflight at low altitude would not allow sufficient observation time, and the speed of angular displacement relative to a phenomenon seen on the ground must remain low and compatible with the time necessary for this analysis. The angular speed is linked to the speed of the scanning of the scanner for a determined speed. e / the higher the plane flies, the easier and more reliable the radio links and the data transmission from the scanner.

Detection takes place in two different modes, independent of each other, the first being able to operate alone and the second specifically adapted to fire detection:

- by means of thermal scanning sensors analyzing the ground surface in the 3.5u band and in the 8-12μ band. Unlike the use of sensors at ground level as indicated above, the same thermal infrared sensors used vertically on an aircraft are much more effective: thus, the same tree trunk 40 cm in diameter seen from above. above it only represents a surface of 0.123 m ² and is no longer a screen thermal, because the tree first ignites on its outer surface in contact with the oxygen in the air, and this rise in surface temperature will be directly detectable by the sensor vertically or obliquely very pronounced. - on sight, a smoke which can possibly be detected before the passage of the plane, by a human observer, who can generally within two minutes ensure that it is indeed a fire, if necessary by using a pair of binoculars with a gyroscope stabilized beam. In this case, a passage to the exact vertical controlled from a vertical viewfinder of the type used for aerophotogrammetry allows the precise pointing of the position of the light at the same time as it allows to raise the doubt on the reality of the departure of fire, and measurement of its coordinates, the coordinates being reported by copying information from a navigation / positioning receiver by satellites, for example of the "GPS" (Global Positioning System) type, equipping the aircraft. The attitude of the aircraft must be perfectly neutral at the time of aiming, which is not obvious, the pilot is often required to make small course corrections of last seconds to pass exactly vertical to the point, this which changes two of the parameters.

In the first case, systematic detection by thermal scanning sensors indicates the exact position of the anomaly thanks to an integrated computer, which avoids the slight diversion required by a "vertical" passage, as for optical sighting. The anomaly is then detected at the time of the "vertical" or "cross" passage of the aircraft by measuring the emissivity carried out by the scanner, above a threshold considered normal.

Depending on the high speed (more than 720 km / h) of the detection aircraft, voluntary random degradation of the positions, by coding the point information of the satellite navigation system such as the G.P.S. , requires its coupling with a computer providing an interpolation of the position every

0.05 seconds, i.e. a geographic accuracy in clear coordinates better than 10 meters- However, the aircraft's roll variations must be compensated for by the scanner computer in order to obtain the same accuracy if an anomaly is detected far from the pure vertical, by the simultaneous use of another means, such as example an inertial unit coupled to the satellite navigation system such as GPS, or other means such as the use of the Doppler effect for measuring the attitude of the aircraft by comparing the response times of the distance information from two antennas located at the ends of the wings, for roll, and at the ends of the fuselage for pitching: attitude errors are then taken care of by the computer.

The observer or pilot must be able to "freeze" information from. position by pressing a button, which activates the radio transmission of digitized information of this position. It is actually more reliable to automate the radio transmission of the anomaly position by sending a series of digitized data as soon as the scanner sensor has detected this temperature anomaly at a point on the ground not listed as normal, because such an anomaly can be caused by the operation of a thermal plant, municipal landfill, hydrocarbon transport pipe, etc. which are pre-identified and their normal emissivity level canceled electronically as a decoy such as shown in figure 1. reference. The elevation of the level on one or more pixels, compared to the normal level of emissivity previously spotted on the same site or an enlargement of the surface concerned by this anomaly triggers the emission of its coordinates.

The transmission of an alert by elevation of the temperature above the normal threshold or its widening to an abnormal surface will then be considered as the start of a disaster and displayed as such in clear geographic coordinates on the screen, for example at high definition, from a computer located at the command post. The detection plane continues its flight according to the established plan, the continuity of the surveillance having to be ensured.

At the control and / or command post, the computer activated automatically by the message it receives immediately displays the scanned map of the region concerned, centered exactly on the point of the anomaly, which appears highlighted and intermittently 35. at a fast pace, in the center of the screen. The coordinates of this anomaly or of the start of a disaster appear in clear in the margins of the image, or in a box in degrees minutes and thousandths of minute. The importance and the dangers presented by the type of anomaly considered in relation to its environment and to the disaster which it can then cause is displayed on the screen by means of codes.

According to the invention, the same information: clear coordinates of the anomaly, date, hour, minute, second, of its discovery, are transmitted in real time to the operational center concerned, to the operational centers which depend on it, and to similar organizations, depending on the country and the types of anomalies and the causes that caused them. Furthermore, and in a second step, the invention provides for the transmission of a take-off order within five minutes of the arrival of the alert message, from a twin-engine close observation aircraft, designed for this activity or having undergone the necessary adaptations certified by the administrations concerned, capable of large differences in flight speed, and with total visibility on the ground up to the vertical, equipped with the same means of precise positioning and hatches allowing vertical shooting and the use of a thermal scanner identical to that fitted to detection planes, thermal imaging cameras and photographic cameras; all these sensors allow the image of the anomaly to be transmitted in real time to the same units and organizations concerned as well as to emergency managers, who will also be equipped with the same autonomous geographic positioning means and reception equipment by radio of digitized images, and of a computer with map and color graphic screen, preferably of high resolution, providing them with the display of the information necessary for the good knowledge of the phenomenon that they are in charge of assisting or / and fight if it is harmful. This same aircraft can also provide in real time the elements allowing the automatic tracing of a three-dimensional image of the site taken on board the aircraft and at the ground control post from two images taken at two separate points of a distance adapted to the flight height and the dimension of the phenomenon.

As soon as it arrives at the site, the close-up surveillance plane uses the thermal scanner to record the different temperature ranges on the incident, by rectilinear passes, and will possibly carry out the processing which will be transmitted in time real by radio at the command post, or will transmit the raw data directly to a truck equipped for this treatment and transferred at a suitable distance from the disaster site, if it presents dangers of rapid extension. These analyzes carried out at regular intervals in order to inform the command post about the evolution of the incident, and to enter into computer memory as calculation data for an "EXPERT" system, the value of which is described below, are time-stamped from the electronic clock, the information of which is transmitted by the satellite positioning system, ie with extremely rigorous precision. This precise information marking the date and the exact time from a precise time base at 1 x 10 "8 is also recorded on all computer screens used for the fight engaged, and is at the same time recorded on a locked computer file.

In other words, the invention relates to a method for the detection and localization of anomalies, which can be the beginnings of claims with thermal incidence, with a precision and a speed making it possible to route the means of assistance and / or wrestling with maximum efficiency: this process consists, as already indicated above, of systematically flying over areas at risk, by specific fast planes, flying at high altitude, with high visibility on the ground equipped with navigation means displaying a position very precise geographic on the screen of a navigation and positioning system by satellites; this system, for more precision, is adjusted by a second system located on the ground and allowing differential operation, stabilized by a navigation system of a different principle, (for example an inertial unit), provided with a control of display and recording of positioning in clear geographic coordinates, the assembly making it possible to measure the position at a given instant of a thermal anomaly on the ground: this is positioned in real time either by an optical sighting system, or by the computer of a thermal scanning detector with a precision such that it can discover and measure the emissivity level of a point on the ground with a surface of a minimum of lm ² and determine if it '' is a decoy, a normal temperature spike listed (fig. 1, 45) or an anomaly, such that a loss start, such as a fire for example: the precise coordinates of this anomaly are calculated in real time by the trigonometric calculator of the scanning scanner and the transmission of these coordinates, the processing of the necessary data, then take place as described previously.

On the screen displaying the digitized map of the region affected by the anomaly, the operator then has the possibility of displaying, by using computer function keys, various computer layers from the overlay cartography, to the same scale, adding or subtracting, at will, useful information and related information, in particular if it is a fire:

- road communications,

- the possibilities of access to the land, by a three-dimensional mesh,

- the relief of the site by the quoted contour lines,

- vegetation by theme, with indication of the limit temperatures for spontaneous ignition, depending on the species,

- to the hydrographic network, - to various limits, in particular administrative,

- toponymy,

- the establishment of isolated houses,

- longitudinal profiles on any desired axis,

- at the possible points of water supply, - at the possible points of water supply in the open air (private swimming pools, ponds -), with their available cubic volumes and the dangers of approach for the helicopters,

- High Voltage energy transport networks,

- to the position of the existing firebreaks, - to the ground rescue services available with their current position,

- at the temperature ranges reached, in real time, by the different zones of the offending phenomenon, this list not being exhaustive but dependent on the activity undertaken.

This information is intended to enable specialized personnel to dispatch from the nearest barracks and other intervention centers the most appropriate means to assist and / or combat the phenomena detected; information provided by the real-time transmission of temperature ranges in the event of a disaster and the measurement of the rapidity of its evolution over time will, by their immediate use as variables in an expert system taking into account all the necessary parameters, the number and the type of emergency means necessary to overcome the detected anomaly and its consequences, and above all not to be overwhelmed by an evolution of the phenomenon faster than the possibilities of fight.

The invention also relates to such a method in which the most rational routing of ground control means is ensured by displaying on their on-board computer screens the best routes to reach the site, according to their current position, which is constantly provided by means of positioning by satellites, in real time, on the route displayed on the screen, also showing the position of the fire, the estimated time of arrival on the premises according to their average accomplished so far and their current speed of progression, also displayed by means of positioning and navigation by satellites and taken into account by the computer. The characteristics set out above alone make it possible to overcome the difficulties of such an operation while respecting a certain number of technical requirements. We will therefore set out succinctly these difficulties and these imperatives with reference to the appended drawings which illustrate by simple diagrams the conditions for implementing the method according to the invention.

Figure 1 is a diagram illustrating the need for a high observation altitude in dry high pressure weather, in order to increase the apparent contrast of the ground in medium oblique vision.

Figure 2 is a diagram similar to Figure 1, but illustrating the obligation of a high observation altitude depending on the terrain.

FIG. 3 is an example of application of the method for monitoring thermal incidents of a French department chosen as an example for this purpose, with an area of approximately six thousand km ² .

Figure 4 shows schematically the principle of optimum spacing between parallel aerial passes, determined in particular by the best position calculation accuracy at the edge of the scanning field of the high-definition thermal scanner, compared to the visual field of detection by good visibility.

FIG. 5 diagrams the architecture of the system of equipment on board mobile command posts.

FIG. 7 schematizes the architecture of the system of the computer equipment of the emergency vehicles, in the case of forest fires.

Firstly, if we refer to FIG. 1 which illustrates the conditions for detecting a ^" thermal ^" incident 4, the typical example of which is that of a forest fire in the presence of a layer of dry mist 5 with increasing density towards the ground, we see: that a lookout 6 located on the ground is in the worst conditions of observation of a phenomenon such as a fire or its manifestation as smoke 7. because the polluted layer and the constant oscillations of the air due to changes in the refractive index of the lower layers are the most important: it is therefore random to see under these conditions white smoke against a background of milky sky. From a height of 2,500 meters (point A), the thickness of mist to cross to observe a point located at a distance of 5-000 meters from the observer is 5-700 meters, while at a height of 5-000 meters (point B ), it is still 4,300 meters: but at a height of 10,000 meters (point C ), it is no more than 3-500 meters.

From point A, smoke 7 would be barely visible, the contrast being insufficient, while from point C, located very above the polluted layer, the resulting thickness of the polluted air layer becoming minimal, the apparent contrast of the terrain increases, and at the same time, the angular speed of travel decreases, which allows both a better readability of the site, and more time to observe it.

If an observer located in an airplane 1 positioned at A experiences observation difficulty due to the distance, he can use an optical approximation means of sufficient magnification, with a virtual image stabilized by a high-speed rotating mirror mounted as a gyrometer, (for example binoculars of magnification 8 to 10, with image gyro-stabilized). The vibrations, whether at high or low frequency, will thus be completely filtered, and the conditions of observation perfect.

Similarly, if we refer to Figure 2, which illustrates, diagrammatically to scale, the conditions for observing a massif for example of 1,147 meters above sea level such as the Sainte Beaume massif in the South of France, we see that at an altitude of 10,000 meters, the entire massif and its region is visible, while from a height of 3-000 meters, an entire slope can be hidden. From point D representing the situation of a plane which would fly at 5-000 meters, vision is possible on the two slopes of the same mountain, but from point E, located on the next pass at the same altitude, but offset by 10 km, vision becomes impossible on the entire northern slope of this mountain. From points F and G, the whole mountain is visible despite the distance and from point F the contrast remains identical to that offered by the vision obtained from point D. Second, the speed of the aircraft used is a determining factor : considering a region of surface equivalent to that of a department, like VAR, in the South of France is 6.023 km ² of air surface to leave no point without observation more than 10 minutes supposes parallel passes, as represented figure 3. separated by 10 km, i.e. a linear distance of 6,000 / 10 = 600 km.

In this figure 2 we note that the analysis angle of each scan of the scanner is 120 °: only half, or 60 ° is taken into account in a stabilized straight line, allowing full coverage of 10 km. wide ; in rapid standard turn, the airplane turning with an inclination of 30 °, the scanning remains ensured under the same conditions by the use of the extreme part of the scanning beam on the inside of the turn; the expected field width of

10 km. remains identical, and the entire area is thus really monitored without leaving any surface of uncertainty: the nadir reference, its precise geographic coordinates, and the calculation of the position of a thermal anomaly far from the vertical maintain the same precision; indeed, the angle of analysis on the inside side of the turn is 30 °, the used part of the opposite corner, outside side remains 30 ° - 16

Figure 3 shows in fact that with two planes 11 and 12 flying at the desired speed between 9-000 and 10,000 meters above sea level, each according to a route programmed according to the best situation in relation to the reliefs, the surveillance of a surface of 6,000 km ² would leave no point in such an area for more than 10 minutes without observation made at an angle of 30 ° obliquely on either side of the vertical, which is the goal. We note the joint interest in the use of "armed watch" planes 8ι and 82 which appear in Figure 3 e waiting and monitoring in this area, performing a circuit in the shape of a racetrack located in the wind of the department at 2,500 meters altitude, usual flight level of medium-capacity water bombers currently used as an air watch against fire so that they can intervene quickly, as they will then find themselves in downwind or 3/4 tail, in descent, therefore in optimal speed conditions for attacking a fire. In case of implementation of the two armed watch planes (another type of water bomber plane can also be used, the principle being that it is already in the air, upwind of the sensitive area, ready to drop on any point in 5 minutes), two other planes of the same formula come to take their place in watch at 2,500 meters, on the same zone, so that there is no rupture of potential of rapid fight all water transport by land being slower than two planes in flight between 400 and 500 km / hour (ground speed), tailwind, and less efficient, often due to the difficulties of penetration to the area of fire.

A rapid detection airplane 1 fulfilling the required conditions must have a high or at least median wing located very aft, preferably powered by two rear turbines equipped with pushing propellers with 5 or 6 blades, so as to offer the greatest visibility. possible towards the front, on the sides, and towards the rear, in particular when cornering, which practically excludes almost all of the classic twin-engine low wings, the time zones and the low wing obstructing visibility towards the ground, especially on the inside when cornering; the cabin of this type of aircraft flying at 10,000 meters must obviously be under pressurization, the analysis head of the thermal sensor being housed, either in a bell in the open air, outside pressurization, or in a luggage compartment, not pressurized. 17

The best option is to use the new 10-seat twin-turbo "duck" or "semi-duck" configuration, the wing located at the rear, the spindles and the propellers being at the level where the tail unit is generally located. back; the reduced-size stabilizer located at the front then does not hinder visibility in any way. There is in Europe a manufacturer of twin-engine pressurized airplanes of this type, whose cruising speed is 7 ^ 0 km / hour at 9-000 meters, and the payload conforms to the requirements of this detection process. FIG. 4 shows the standard spacing between the parallel passes of a detection plane 1 at an altitude of 10,000 meters, this spacing of the passes being determined by the best scanning angle of a high-definition thermal detector 2 compatible with the speed of flight of the proposed aircraft suitable for the surface to be monitored, and in relation to the surveillance rate recommended by French Civil Security. The angle of field of view αl represents a width of field on the ground of approximately 18 km, which depends on the height of the reliefs such that the observer or the on-board thermal detector can detect an anomaly there, such as smoke or a fire, and provide its position and description by means of a camera or photographic camera with a silver image or directly digitized. In the latter case, the image of a thermal incident departure is immediately transmitted by radio to the operational Command Post. We notice the strong overlap from one pass to the other, which eliminates the slope problems all the better, and limits positioning errors on points far from the vertical axis in the event of slight roll which would not be fully compensated by the planned vertical reference system integrated into the thermal detector calculation system. The angle α2 represents the scanning field actually used by the process of a high definition thermal detector, the overlap of one pass over the other being always ensured by a spacing of the passes of 10 km between two traces on the ground and a scanning angle of the scanner twice the useful angle. An overflight that would be carried out by an airplane not designed to fly above 4,000 meters in height, taking into account the fact that a pilot cannot make an extended flight above 3-500 meters above sea level without an oxygen mask, would be ineffective: such an airplane such as a conventional twin-engine armed watch, unpressurized, and without oxygen for the pilot, is shown to scale in Figure 4: it appears obvious that such an airplane can only be of little use at this altitude of 3-500 meters above mountains, many peaks of which in a region such as the Maritime Alps are only 800 meters lower and many slopes are between 25 and 0 ° from the vertical.

The figure diagrams the architecture of the system for detecting equipment for high-speed fast airplanes 1: an on-board computer 10 records all the information from the satellite navigation system 11 coupled to an inertial unit 12 and ensures its processing. It also receives attitude, attitude and heading information, provided by the flight director of the aircraft from the gyros 13 or from another attitude detection system. The ground height information is provided by the radiometer 14 coupled to the inertial plus satellite navigation systems of the assembly 11.

All this information is compared by the computer 16 to that provided by the computer of the thermal detector 17, and partly recorded on the margins of the image supplied by the scanner sensor by a digital recorder 18, in computer format 8 mm for example. The computer also transmits to the brewing unit the date, place and positioning information provided by the positioning and navigation system by satellites, which will appear fixed by the corresponding incrementers 19, 20 and 21 on the images transmitted by three video cameras. 22, 23, 24. VCRs 25 and 26 record images from front and rear video cameras, the professional mobile camcorder records its own images independently. There are two types of display screens: video 27 for the cameras and high-definition computer 28 for the thermal scanner. They are mounted on a console anchored on rails to the floor of the aircraft. All of the information is stored on high capacity mass storage 30. A portable printer 29 with a minimum definition of 360 x 360 dots per square inch can edit the various pieces of information at any time.

Figure 6 shows the architecture of a command post mobile: on the left at 31 ”the various telemetry antennas

(positioning, distances, etc.), providing the raw data to the computers: positioning of land vehicles as well as detection planes or water bomber planes and reception of scanners on board detection planes. These various data are preprocessed by the telemetry calculator

32, and the results accessible to the computer 37 and stored if necessary in mass storage 38, from which they can be extracted at any time for information or graphical use on the screen 36 or other.

A second high-definition computer screen 35 allows the visualization of temperature analyzes of progressing thermal phenomena, and will be switched to one of the thermal detectors on high altitude aircraft or those of close surveillance by means of the reception assembly 3 , including antennas and computer.

Two printers, one black and white 39. for editing texts and diagrams, in particular transmitted by fax, by an appropriate radio means of VHF or radiotelephone type, the other printer 40 in color, for screen copying color.

The various means of transmission used depending on the data to be transmitted are voice or radio, or radio and various portable such as VHF or UHF.

Figure 1 shows schematically the routing system of cars and assistance vehicles and / or fight against thermal incidents. A laptop computer 41 having the same operating system as the main computer 37 of the command post or an adaptation interface, equipped with a color screen of the SUPER VGA type, or better at high resolution, receives the information provided by the satellite positioning system to an onboard navigator 42, and those provided by any other transmitting means to a receiver 43 with which each car is equipped, capable of operating in differential mode, and moreover the computer will be equipped with a modem. fax compatible communication; it records the information transmitted by the detection aircraft 1 and by the mobile command post 31. with the recorded mention of the precise date and time, provided by the navigator by satellites and setting the internal clock of the computer. This various information can be transmitted by radio or by radiotelephone, or by fax by means of the radiotelephone, the whole being processed by the multifunction transmitter 44. The car manager can obtain the current position of the vehicle at any time on the screen. anomaly and / or the area of the disaster on a vectorized or scanned digital map, the current position of the vehicle, and the best route to get to the scene with the average journey times and the probable time of arrival, depending differences in time of the actual journey compared to the average time recorded on the mass memory 37- The exact time is constantly displayed, provided by the satellite navigation system, as well as the current position in clear geographic coordinates: degrees, minutes and thousandths of a minute. The computer is supplied by on-board current, but it can also operate in complete autonomy thanks to two incorporated low-voltage batteries.

A portable microcomputer with for example 8 to 20 MB of RAM, and 120 MB of mass memory, provided with a transmission modem, corresponds to this definition. At the output, the computer can be connected to a mass memory 38, if the capacity of the hard disk proves to be insufficient, which may be the case for scanned cards. In this case, an optical memory on laser discs is added to it. Furthermore, it is connected to a recorder 39 linked to the cartographic system and to the satellite navigation system, which makes it possible to record the journeys made, as a function of time, and a separate or fixed printer 40 operating on the same supply network. . This printer also makes it possible to draw the diagrams necessary for directives, while keeping the data on file, and to edit the messages received by fax, in particular coming from detection aircraft.

The method according to the invention is particularly well suited to rapid airborne detection and to the precise positioning of forest fire departures. It can be extended to:

- Preventive detection, day or night, of resumption of forest fires smoldering underground in the roots after the extinction of a major fire which generated high temperatures, and when a violent and dry wind rises again . - The precise detection and positioning of people in groups or isolated, lost or seeking to illegally cross borders or prohibited areas at night, including in mountainous areas. - The early detection of the risks of volcanic eruptions at the end of several days and the place where the molten magma risks bursting the earth's crust, in particular for volcanoes still active, and the timely organization of rescue operations.

- The detection of plane crashes, even in bad weather, this means saving several hours and therefore saving more human lives.

- Monitoring and detection of marine pollution, with exact measurement of the pollution surface, drift, evolution. - The detection and positioning of submerged and drifting heavy oil slicks, as well as their monitoring.

Detection and positioning of forest areas affected by endemic diseases.

- The precise positioning and surface of avalanches, landslides, mudslides and rocks, especially in mountainous regions, difficult to access on the ground.

- Positioning and monitoring the progression of claims occurring at high-risk sites such as thermal plants, by providing real-time maps of the temperatures reached by the various areas affected by the incident.

Claims

1. Method for systematic airborne detection and positioning of thermal anomalies (4) on the surface of the ground, thanks to the use of various planes (1) and terrestrial means, sensors adapted to the desired detection and communication systems and location, characterized in that:

- we choose airplanes (1) offering great visibility on the ground and we equip them, on the one hand, with very precise navigation means such as by satellite reference, associated with equipment for recording their position, on the other part of means (2) of thermal detection by scanner or laser scanning sensor, and finally of means of transmission to a command post on the ground;

- the number of planes required is determined based on the total area to be covered and the desired frequency of passage, and we systematically fly at high altitude over the area of the risk zone that we want to monitor, according to a predefined circuit , determined (3) as a function of the relief and of a selected maximum speed, compatible with the detection means;

- any thermal anomaly (4) is identified and interpreted according to its nature, using said detection means (2), either vertically, by means of a vertical viewfinder or a video camera in a suitable position , or when passing through, the precise coordinates of the anomaly then being supplied by the computer of the installed scanner scanning thermal detector; - the said raised position is transmitted to the command post where its clear coordinates are displayed in real time on a digital vector map of the area concerned, centered around the point of the anomaly which appears visibly;

- for the region concerned centered on this anomaly (4), we consult all the useful information previously stored in memory at said command post, and relating to all the communication and access routes to the terrain, the relief of the site and its characteristics, the location of the habitat, the obstacles that may be present in the region and all the rescue and intervention means available by area depending on the type of cause that caused the detected anomaly;

- one chooses, among these means, the availability of which one is then informed the most appropriate to combat the cause of the anomaly and the incident that may have occurred and spread, and we initiate the order of their mobilization towards the point and the area identified by this anomaly (4).

2. Airborne detection method according to claim 1, characterized in that:

- we provide the various means of intervention and control all the information necessary for their routing to the point of the anomaly (4) as soon as possible, with indication of the average journey time, the best route, their position relative to this anomaly (4), and that in real time;

- the exact and permanent position of said means of intervention and control is checked at the command post in return for information.

3- Detection method according to claim 2, characterized in that permanently and in real time records all the positions of all means of intervention and control from their departure from their place of barracks, and during all the journeys actually made with simultaneous reading of the elapsed time.

4. Detection and localization method according to any one of claims 1 to 3. characterized in that all of the planes used and the terrestrial means concerned are all equipped with identical means of navigation and very precise localization, as per satellite reference.

5- A method of systematic airborne detection and positioning of thermal anomalies according to any one of claims 1 to 4, characterized in that said predefined circuit (3) followed by aircraft systematically flying at high altitude over the surface of the area to risk that we want to monitor, is composed of a series of determined parallel passes allowing said thermal detection means (2) to scan the entire ground surface of the area to be monitored.

6. Detection and positioning method according to claim 5. and specially applied to the start of forest fires, characterized in that:

- it is noted from a close surveillance aircraft equipped with a thermal scanner, which analyzes at regular intervals and in real time the map and the trace of the fire, as well as the direction and the force of the wind according to the surrounding reliefs;

- we determine, depending on the type of vegetation attacked and the characteristics and means of control used, the precise oriented vectors on which said means must attack the fire.

7- A method of detection and positioning according to any one of claims 5 and 6, characterized in that the pilots of intervention aircraft by water bombardment are provided with the exact position of the land resources engaged on the site.

8. Detection device aérop ^systematic COPE and positioning of thermal anomalies (4) to the ground surface through the use of various aircraft (1) and terrestrial means, characterized in that it comprises:

- on board said planes (1) very precise navigation means such as by satellite reference associated with equipment for recording their position and means (2) for thermal detection by scanning or laser scanning sensors and finally means for transmission to a ground command post,

- ashore in said command post any means of communication with said planes (1) and any means of processing the information transmitted by them, with those stored in a memory of any suitable computer means corresponding to the region to be checked in order display on a screen the map thereof, centered around said point of the anomaly detected by said planes (1).

9- Device according to claim 8, characterized in that said planes (1) have a high wing or at least a median wing located very rear, preferably powered by two rear turbines equipped with pushing propellers with 5 or 6 blades, so as to offer the greatest visibility on the ground towards the front, on the sides and towards the rear, especially when cornering.

10. Device according to any one of claims 8 and 9 characterized in that said computer means comprises an expert system taking into account all the necessary parameters such as the information provided by the real-time transmission of the temperature ranges in the event of a disaster. and the measure of the speed of its evolution over time, the number and type of emergency means necessary to overcome the anomaly detected and its consequences.