METHOD FOR CONSTRUCTING A SIMPLIFIED REPRESENTATION OF OBSTACLES NEAR AN AIRPORT

Abstract

A simplified representation of obstacles around an airport runway is constructed by: obtaining (101) terrain elevation information around the airport runway; applying (102) filtering using a cone-shaped filter profile with its apex at one end of the runway, the cone's axis of revolution perpendicular to the runway, and the cone's outer surface forming a predetermined angle α with the runway; the filtering eliminating (103) terrain elevation information with an altitude lower than said filter profile. The remaining terrain elevation information after filtering is stored as relevant obstacle information. Thus, the volume of elevation data to be stored and processed during takeoff or landing is reduced. Figure to be published with the abbreviation: Fig. 1

Description

Title of the invention: METHOD FOR CONSTRUCTING A SIMPLIFIED REPRESENTATION OF OBSTACLES IN THE SURROUNDINGS OF AN AIRPORT Technical field

[0001] At least one embodiment disclosed herein relates to a method for constructing a simplified representation of obstacles in the vicinity of an airport runway, retaining only terrain elevation information relevant to a takeoff, landing or go-around of an aircraft.

[0002] At least one embodiment disclosed herein relates to a method of using the simplified representation of obstacles in the vicinity of an airport runway thus obtained. STATE OF THE PRIOR ART

[0003] For various applications in aeronautics, in particular to perform a calculation or a tracking of a flyable trajectory, terrain information is used. This terrain information provides in particular terrain elevation indications and, more generally: locations and heights of buildings, trees, mountainous areas, and, more generally, obstacles that may be encountered by aircraft in flight. These terrain elevation indications are in particular stored in databases on board aircraft, in order to allow the pilots or the avionics of these aircraft to calculate or track a flyable trajectory. A flyable trajectory is a trajectory which at any point has a minimum (or predetermined) distance margin relative to any identified obstacle (relief...) and that the aircraft can follow given its operational status (possible depressurization, loss of an engine, etc.).

[0004] In the vicinity of airports and runways, an accurate representation of the surrounding terrain is used, due to the complexity of the environment in terms of potential obstacles. One problem is that this represents a large volume of data, to be stored in a database, on the one hand, and to be processed at the departure and / or arrival of flights, on the other hand. It is therefore desirable to overcome this drawback of the state of the art. Statement of the invention

[0005] A method for constructing a simplified representation of obstacles in the vicinity of an airport runway is proposed here, the method being implemented by a system in the form of electronic circuitry, the method comprising the following steps: obtaining terrain elevation information in the vicinity of the airport runway; applying filtering by following a filtering profile having a shape of cone having its apex placed at one end of the airport runway, the axis of revolution of the cone being perpendicular to the airport runway, the cone having an outer surface forming a predetermined angle a with the airport runway, the filtering eliminating terrain elevation information having an altitude lower than said filtering profile; and storing, as relevant obstacle information, the terrain elevation information remaining after filtering. Thus, the volume of terrain elevation data to be stored and processed during takeoff or landing is reduced.

[0006] According to a particular embodiment, at a distance d, the cone shape reaches a predetermined height h corresponding to a saturation threshold, and beyond the distance d from the end of the airport runway, the filtering profile is flat.

[0007] According to a particular embodiment, the system applies a said filtering profile to each end of the airport runway.

[0008] According to a particular embodiment, the system obtains a filtering profile to be applied for the entire airport runway, called an individual filtering profile, by combining a first filtering sub-profile defined for one end of the airport runway and a second filtering sub-profile defined for the other end of the airport runway, such that terrain elevation information whose altitude is lower than the lowest altitude filtering sub-profile is eliminated.

[0009] According to a particular embodiment, when at least one other airport runway is nearby, the system defines a said individual filtering profile for each airport runway, and the system obtains a global filtering profile to be applied for all the airport runways, by combining said individual filtering profiles, so that terrain elevation information whose altitude is lower than the lowest altitude individual filtering profile is eliminated.

[0010] Also proposed here is a method for determining or tracking an aircraft trajectory in the vicinity of an airport, in which a system in the form of electronic circuitry determines or performs aircraft trajectory tracking using a simplified representation of obstacles in the vicinity of the airport runway which is obtained by the method presented above, in any one of its embodiments.

[0011] Also provided herein is a computer program product comprising program code instructions causing an implementation of either of the above methods, in any of their embodiments, when said instructions are executed by a processor. Also provided herein is an information storage medium storing such program code instructions.

[0012] Also proposed here is a system in the form of electronic circuitry configured to construct a simplified representation of obstacles in the vicinity of an airport runway, by implementing the following steps: obtaining elevation information of terrain in the vicinity of the airport runway; applying filtering by following a filtering profile having a cone shape whose apex is placed at one end of the airport runway, the axis of revolution of the cone being perpendicular to the airport runway, the cone having an outer surface forming a predetermined angle a with the airport runway, the filtering eliminating terrain elevation information having an altitude lower than said filtering profile; and storing, as relevant obstacle information, the terrain elevation information remaining after filtering. Brief description of the drawings

[0013] The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of at least one exemplary embodiment, said description being made in relation to the attached drawings, among which:

[0014] [Fig.l] schematically illustrates an algorithm for selecting relevant terrain elevation information to be stored;

[0015] [Fig.2] schematically illustrates a conical filter shape applicable for se selecting relevant terrain elevation information to store, in one embodiment;

[0016] [Fig.3A] schematically illustrates a first example of a filtering profile applied to the surroundings of an airport runway;

[0017] [Fig.3B] schematically illustrates a second example of a filtering profile applied to the surroundings of an airport runway;

[0018] [Fig.3C] schematically illustrates a third example of a filtering profile applied to the surroundings of an airport runway;

[0019] [Fig.4] schematically illustrates, in side view, an aircraft having a avionics configured to use stored relevant terrain elevation information; and

[0020] [Fig.5] schematically illustrates an example of a hardware platform usable for select the relevant terrain elevation information to be stored and / or use the stored relevant terrain elevation information.

[0021] DETAILED DESCRIPTION OF EMBODIMENTS

[0022] [Fig.l] thus schematically illustrates an algorithm for selecting relevant terrain elevation information to be stored. The algorithm of [Fig.l] is implemented by a system in the form of electronic circuitry, such as for example a computer system. The algorithm of [Fig.l] thus makes it possible to construct a simplified representation of obstacles in the vicinity of an airport runway. In a particular embodiment, the algorithm of [Fig.l] is repeated for several airport runways, in order to construct a database of representations simplified obstacle clearances around said airport runways.

[0023] In a step 101, the system obtains terrain elevation information in the vicinity of the airport runway. The terrain elevation information is for example obtained from a database referencing the topology of the airport environment, obtained using satellite images and / or terrain surveys.

[0024] In a step 102, the system applies a filtering profile to the terrain elevation information. The filtering profile has a cone shape whose apex is placed at one end of the airport runway and whose axis of revolution is perpendicular to the airport runway. The outer surface of the cone defines a slope that forms an angle α with the airport runway. The angle α is predetermined. For example, the angle α complies with regulatory minimum takeoff and / or approach slopes.

[0025] Preferably, the angle a complies with a minimum regulatory approach (landing) slope. Indeed, the slope at takeoff is typically steeper than at landing. In addition, aircraft taking off typically do not go to the opposite threshold of the airport runway, whereas aircraft are more likely to land from this airport runway threshold in the opposite direction.

[0026] Knowing that this minimum regulatory approach slope is very usually 3 degrees, a conservative value of the angle a is for example 2 degrees.

[0027] In a particular embodiment, the angle value a used is specific to each airport runway, related to approach (landing) constraints associated with that airport runway, instead of using a single angle value a for building the entire database.

[0028] For illustration purposes, a filtering profile 202 is schematically illustrated in [Fig. 2]. The filtering profile 202 has a cone shape (having an axis of revolution 203) whose outer surface forms an angle α with an airport runway 201. The filtering profile 202 is represented over a distance d (radius of the base of the cone).

[0029] By applying the filtering profile, the system eliminates, in a step 103, the terrain elevation information having an altitude lower than said filtering profile. Thus, in a step 104, the system retains (eg, stores) as relevant obstacle information the remaining terrain elevation information, i.e. that of altitude greater than or equal to the filtering profile.

[0030] The relevant obstacle information thus stored can be used to determine or follow a flyable trajectory in the vicinity of an airport, whether during a takeoff phase, during an approach phase, or during a go-around procedure.

[0031] In a particular embodiment, the relevant obstacle information obtained using the filtering profile detailed here is stored in a database of an avionics system 401 of an aircraft 400, as schematically illustrated in [Fig.4]. Thus, the avionics 401 can determine a flyable trajectory in real time with a reduced amount of relevant obstacle information to manipulate.

[0032] [Fig. 3A] schematically illustrates a first example of a filtering profile 303a applied to the surroundings of a landing runway 301. By applying a filtering profile in the form of a cone, terrain elevation information 302 to the surroundings of the airport runway 301 is filtered, so that only terrain elevation information having an altitude greater than or equal to said cone is retained. Thus, terrain elevation information 303a, 303b is retained (altitude greater than or equal to the cone), while terrain elevation information 304 (altitude lower than the cone) is eliminated.

[0033] [Fig.3B] schematically illustrates a second example of filtering profile 303b applied to the vicinity of the airport runway 301. In this second example, at a distance d, the cone reaches a predetermined height h corresponding to a saturation threshold. Then, beyond the distance d from the end of the airport runway 301, the filtering profile 303b is flat (fixed altitude). Thus, terrain elevation information 305a, 305b, 305c is retained (altitude greater than or equal to the filtering profile), while terrain elevation information 306 (altitude lower than the filtering profile) is eliminated.

[0034] [Fig.3C] schematically illustrates a third example of filtering profile 303c applied to the surroundings of the airport runway 301. In this third example, filtering in the form of a cone, possibly with a saturation threshold, is applied to each end of the airport runway 301.

[0035] In a particular embodiment, the filtering profile to be applied is here obtained by combining a first filtering sub-profile 303d defined for one end of the airport runway 301 and a second filtering sub-profile 303e defined for the other end of the airport runway 301, so that terrain elevation information whose altitude is lower than the lowest altitude filtering sub-profile (among the first filtering sub-profile 303d and the second filtering sub-profile 303e) is eliminated. The system thus obtains an individual filtering profile, to be applied for the entire airport runway. Thus, terrain elevation information 305a, 305b, 305c, 305d, 305e is retained (altitude greater than or equal to the filtering profile), while terrain elevation information 307 (altitude lower than the filtering profile) is eliminated.

[0036] Alternatively, filtering according to the first filtering sub-profile 303d is performed for one end of the airport runway 301 and, independently, filtering according to the second filtering sub-profile 303e is performed for the other end of the airport runway 301, and the terrain elevation information remaining after each of these filterings is grouped as relevant obstacle information.

[0037] In a particular embodiment, when at least one other airport runway is nearby, an individual filtering profile is defined for each airport runway (as explained above), and a global filtering profile is obtained by combining the individual filtering profiles, so that terrain elevation information whose altitude is lower than the lowest altitude individual filtering profile is eliminated. The global filtering profile is thus applicable to all the airport runways in question.

[0038] [Fig. 5] schematically illustrates an example of a hardware platform 500 usable for selecting the relevant terrain elevation information to be stored, by applying the filtering profile detailed above, in any of its embodiments. The hardware platform 500 is also usable for using this relevant terrain elevation information once stored.

[0039] The example hardware platform 500 can in particular be used as a component of a ground-based computerized system.

[0040] The example hardware platform 500 can notably be used as a component of the avionics 401.

[0041] In [Fig. 5], the hardware platform 500 comprises, connected by a communication bus 510: a processor or CPU (Central Processing Unit) 501; a random access memory (RAM) 502; a read only memory (ROM) 503, for example a Flash memory; a data storage device, such as a hard disk drive (HDD), or a storage media reader, such as an SD card reader (Secure Digital) 504; at least one COM communication interface 505 and / or an input / output set (I / O).

[0042] The COM communication interface 505 and / or an input-output set LO allow the hardware platform 500 to interact with third-party equipment, for example via ground-to-air communications.

[0043] The processor 501 is capable of executing instructions loaded into the RAM 502 from the ROM 503, an external memory, a storage medium, such as an SD card, or a communications network. When the hardware platform 500 is powered on, the processor 501 is capable of reading instructions from the RAM 502 and executing them. These instructions form a computer program causing the processor 501 to implement the behaviors, steps, and algorithms described herein.

[0044] All or part of the behaviors, steps and algorithms described herein can thus be implemented in software form by executing a set of instructions by a programmable machine, such as a DSP (Digital Signal Processor) or a microcontroller, or be implemented in hardware form by a machine or a dedicated component (“chip” in English) or a set of components (“chipset” in English), such as an FPGA (“Field-Programmable Gate Array” in English) or an ASIC (“Application-Specified Integrated Circuit” in English). Generally speaking, the hardware platform 500 constitutes a system in the form of electronic circuitry arranged and configured to implement the behaviors, steps and algorithms described herein.

Claims

Claims

1. Method for constructing a simplified representation of obstacles in the vicinity of an airport runway (201, 301), the method being implemented by a system (500) in the form of electronic circuitry, the method comprising the following steps: - obtaining (101) terrain elevation information in the vicinity of the airport runway (201, 301); - applying (102) a filtering by following a filtering profile (303a, 303b, 303c) having a cone shape whose apex is placed at one end of the airport runway (301), the axis of revolution (203) of the cone being perpendicular to the airport runway (201, 301), the cone having an outer surface forming a predetermined angle a with the airport runway (201, 301), the filtering eliminating terrain elevation information having an altitude lower than said filtering profile (303a, 303b, 303c);and - storing, as relevant obstacle information, the terrain elevation information remaining after filtering.;

2. A method according to claim 1, wherein, at a distance d, the cone shape reaches a predetermined height h corresponding to a saturation threshold, and beyond the distance d from the end of the airport runway (201, 301), the filtering profile (303b) is flat.

3. Method according to one of claims 1 and 2, wherein the system (500) applies a said filtering profile (303a, 303b) to each end of the airport runway (201, 301).

4. The method of claim 3, wherein the system (500) obtains a filtering profile to be applied for the entire airport runway (201, 301), called an individual filtering profile (303c), by combining a first filtering sub-profile (303d) defined for one end of the airport runway (301, 301) and a second filtering sub-profile (303e) defined for the other end of the airport runway (201, 301), such that terrain elevation information having an altitude lower than the lowest altitude filtering sub-profile (303d, 303e) is eliminated.

5. A method according to claim 4, wherein, when at least one other airport runway is nearby, the system (500) defines a said individual filtering profile for each airport runway, and the system (500) obtains a global filtering profile to be applied for all of the airport runways, by combining said individual filtering profiles (303c), so that terrain elevation information whose altitude is lower than the lowest altitude individual filtering profile (303c) is eliminated.

6. A method of determining or tracking an aircraft trajectory (400) in the vicinity of an airport, in which a system (500) in the form of electronic circuitry determines or performs aircraft trajectory tracking using a simplified representation of obstacles in the vicinity of the airport runway which is obtained by the method according to any one of claims 1 to 5.

7. A computer program product comprising program code instructions causing an implementation of the method according to any one of claims 1 to 5 or according to claim 6, when said instructions are executed by a processor.

8. An information storage medium storing program code instructions causing an implementation of the method according to any one of claims 1 to 5 or according to claim 6, when said instructions are read and executed by a processor.

9. System (500) in the form of electronic circuitry configured to construct a simplified representation of obstacles in the vicinity of an airport runway (201, 301), by implementing the following steps: - obtaining (101) terrain elevation information in the vicinity of the airport runway (201, 301); - applying (102) filtering by following a filtering profile (303a, 303b, 303c) having a cone shape whose apex is placed at one end of the airport runway (201, 301), the axis of revolution (203) of the cone being perpendicular to the airport runway (201, 301), the cone having an outer surface forming a predetermined angle a with the airport runway (201, 301), the filtering eliminating terrain elevation information having an altitude lower than said filtering profile (303a, 303b, 303c); and - storing, as relevant obstacle information, the terrain elevation information remaining after filtering.

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