Instrument landing system glide path extension method

Abstract

This invention belongs to the field of avionics display and control technology, specifically relating to a method for extending the glide path of an instrument landing system. First, it collects the aircraft's radio altitude, pitch angle, vertical velocity, and pitch rate. Then, it calculates the aircraft's altitude and vertical velocity at the glide path antenna. Next, based on the aircraft's reference glide path angle, glide path deviation, glide path signal correction, and glide path signal acquisition status parameters, it calculates the aircraft's vertical deviation relative to the ideal trajectory. It then calculates the inertial fusion vertical deviation and inertial fusion vertical velocity, identifying abnormal glide path deviation signals. Finally, based on the inertial fusion vertical deviation, the aircraft's altitude at the glide path antenna, the reference glide path angle, and the glide path signal correction, it obtains the inertial fusion glide path deviation. This invention comprehensively utilizes radio altitude, inertial data, and aircraft configuration information to further extend the glide path signal to the runway, thereby improving the success rate of aircraft landing.

Description

Technical Field

[0001] This invention belongs to the field of avionics display and control technology, specifically relating to a method for extending the glide path of an instrument landing system. Background Technology

[0002] During the approach and landing of civil aircraft, the Instrument Landing System (ILS) is commonly used as an external guidance signal to determine the aircraft's position relative to the runway. In practical applications, interference can lead to ILS signal loss, beam bending, noise, multipath effects, and other issues. Using an unprocessed ILS will introduce errors. Furthermore, the glide slope signal of a normal Category I I ILS becomes unstable below 140 feet, failing to provide the aircraft with accurate glide slope deviation signals. Summary of the Invention

[0003] In view of this, the present invention provides a glide slope extension method for an instrument landing system, which comprehensively utilizes radio altitude, inertial data and aircraft configuration information to further extend the glide slope signal to the runway, thereby improving the success rate of aircraft landing.

[0004] The specific technical solution adopted in this invention is as follows:

[0005] A method for extending the glide slope of an instrument landing system includes the following steps:

[0006] 1) Collect the aircraft's radio altitude, pitch angle, vertical speed and pitch rate; collect the X-axis and Z-axis positions of the glide slope antenna in the body coordinate system; collect the X-axis and Z-axis positions of the radio altimeter in the body coordinate system; collect the X-axis position of the inertial reference system in the body coordinate system; and calculate the aircraft's altitude and vertical speed at the glide slope antenna based on the collected information.

[0007] 2) Collect the aircraft reference glide slope angle, glide slope deviation, glide slope signal correction, glide slope signal acquisition status parameters, and aircraft altitude at the glide slope antenna, and calculate the inertial fusion vertical deviation of the aircraft relative to the ideal trajectory based on the collected information.

[0008] 3) Based on the vertical velocity at the aircraft glide path antenna, the inertial fusion vertical deviation of the aircraft relative to the ideal trajectory, and the preset judgment conditions, determine whether the current glide path deviation signal of the aircraft is in a normal state; and turn on or off the acquisition of glide path deviation according to the judged glide path deviation signal state.

[0009] 4) Based on the current inertial fusion vertical deviation, the aircraft altitude at the glide slope antenna, the reference glide slope angle, and the glide slope signal correction, calculate the required extended inertial fusion glide slope deviation.

[0010] Furthermore, the calculation process for the aircraft altitude and vertical velocity at the glide slope antenna in step 1) is as follows:

[0011] A1. Based on the aircraft's radio altitude h R Aircraft pitch angle θ, and the X-axis position of the glide slope antenna in the airframe coordinate system. GSAnt The Z-axis position of the glide slope antenna in the body coordinate system. GSAnt The position of the radio altimeter on the X-axis in the body coordinate system. RA and the Z-axis position of the radio altimeter in the body coordinate system. RA Obtain the aircraft altitude h at the glide slope antenna. GSAnt Specifically:

[0012] h GSAnt =h R +(X GSAnt -X RA )sinθ-(Z GSAn tZ RA cosθ;;

[0013] A2. Based on the aircraft's vertical speed Aircraft pitch rate X-axis position of the inertial reference system in the body coordinate system IRS And the X-axis position of the glide slope antenna in the body coordinate system. GSAnt Obtain the vertical velocity at the glide slope antenna. Specifically:

[0014]

[0015] Furthermore, the calculation process for the vertical deviation of the aircraft relative to the ideal trajectory in step 2) is as follows:

[0016] B1. Based on the aircraft altitude h at the glide slope antenna. GSAnt Reference glide slope angle γ REF Glide slope deviation ε GS and glide slope signal correction γ corr Obtain the horizontal distance R between the aircraft and the glide slope antenna. estGS Specifically:

[0017] R estGS =h GSAnt / tan((γ corr +γ REF )+ε GS );

[0018] B2. Based on the horizontal distance R between the aircraft and the glide slope antenna estGS and glide slope deviation ε GSTo obtain the vertical deviation d of the aircraft relative to the ideal flight path v_ANT Specifically:

[0019] d v_ANT =R estGS ×ε GS .

[0020] Furthermore, the calculation process for determining whether the glide slope deviation signal is in an abnormal state in step 3) is as follows:

[0021] C1. Based on the vertical deviation d of the aircraft relative to the ideal trajectory v_ANT Vertical velocity at the glide slope antenna And the default state P of the glide slope deviation signal, to obtain the inertial fusion vertical deviation d v_ANT_f Specifically:

[0022]

[0023] C2. Based on the vertical velocity at the glide slope antenna Vertical deviation d of the aircraft from the ideal trajectory v_ANT Inertial fusion vertical deviation d v_ANT_f And the default state P of the glide slope deviation signal, to obtain the inertial fusion vertical velocity. Specifically:

[0024]

[0025] C3. Based on the vertical deviation d of the aircraft relative to the ideal trajectory v_ANT Inertial fusion vertical deviation d v_ANT_f Vertical deviation threshold Δ dev_1 Vertical velocity at the glide slope antenna Inertial fusion vertical velocity and vertical velocity threshold Δ dev_2 Update the signal state P, specifically as follows:

[0026]

[0027]

[0028] P = P1||P2;

[0029] Where: when P=0, the acquisition of the glide slope deviation is turned off; when P=1, the acquisition of the glide slope deviation is turned on.

[0030] Furthermore, the calculation process for the extended inertial fusion glide slope deviation required in step 4) is as follows: based on the inertial fusion vertical deviation d... v_ANT_f Aircraft altitude X at the glide slope antenna GSAnt Reference glide slope angle γREF and glide slope signal correction γ corr Calculate the inertial fusion glide slope deviation ε GS_f Specifically:

[0031]

[0032] The beneficial effects of this invention are as follows: First, this invention collects the aircraft's radio altitude, pitch angle, vertical velocity, and pitch rate. Then, using the configuration data of the radio altimeter, glide slope antenna, and inertial reference system installed on the aircraft, it calculates the aircraft's altitude and vertical velocity at the glide slope antenna. Next, based on the aircraft's reference glide slope angle, glide slope deviation, glide slope signal correction, and glide slope signal acquisition status parameters, it calculates the aircraft's vertical deviation relative to the ideal trajectory. It then calculates the inertial fusion vertical deviation and inertial fusion vertical velocity, identifying abnormal glide slope deviation signals. Finally, based on the inertial fusion vertical deviation, the aircraft's altitude at the glide slope antenna, the reference glide slope angle, and the glide slope signal correction, it obtains the inertial fusion glide slope deviation, thus achieving glide slope extension. This invention's instrument landing system glide slope extension method comprehensively utilizes radio altitude, inertial data, and aircraft configuration information to further extend the glide slope signal towards the runway, thereby improving the success rate of aircraft landing. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram illustrating the principle of the glide slope extension method for the instrument landing system of the present invention;

[0035] Figure 2 This is a flowchart of the glide slope extension method for the instrument landing system in an embodiment of the present invention. Detailed Implementation

[0036] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0037] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0038] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0039] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. The drawings only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0040] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0041] In one embodiment of the present invention, a method for extending the glide slope of an instrument landing system is proposed, comprising the following steps:

[0042] 1) Collect the aircraft's radio altitude, pitch angle, vertical speed and pitch rate; collect the X-axis and Z-axis positions of the glide slope antenna in the body coordinate system; collect the X-axis and Z-axis positions of the radio altimeter in the body coordinate system; collect the X-axis position of the inertial reference system in the body coordinate system; and calculate the aircraft's altitude and vertical speed at the glide slope antenna based on the collected information.

[0043] 2) Collect the aircraft reference glide slope angle, glide slope deviation, glide slope signal correction, glide slope signal acquisition status parameters, and aircraft altitude at the glide slope antenna, and calculate the inertial fusion vertical deviation of the aircraft relative to the ideal trajectory based on the collected information.

[0044] 3) Based on the vertical velocity at the aircraft glide path antenna, the inertial fusion vertical deviation of the aircraft relative to the ideal trajectory, and the preset judgment conditions, determine whether the current glide path deviation signal of the aircraft is in a normal state; and turn on or off the acquisition of glide path deviation according to the judged glide path deviation signal state.

[0045] 4) Based on the current inertial fusion vertical deviation, the aircraft altitude at the glide slope antenna, the reference glide slope angle, and the glide slope signal correction, calculate the required extended inertial fusion glide slope deviation.

[0046] In this embodiment, the calculation process for the aircraft altitude and vertical velocity at the glide slope antenna in step 1) is as follows:

[0047] A1. Based on the aircraft's radio altitude h R Aircraft pitch angle θ, and the X-axis position of the glide slope antenna in the airframe coordinate system. GSAnt The Z-axis position ZG of the glide slope antenna in the body coordinate system SAnt The position of the radio altimeter on the X-axis in the body coordinate system. RA and the Z-axis position of the radio altimeter in the body coordinate system. RA Obtain the aircraft altitude h at the glide slope antenna. GSAnt Specifically:

[0048] h GSAnt =h R +(X GSAnt -X RA )sinθ-(Z GSAnt -Z RA cosθ;;

[0049] A2. Based on the aircraft's vertical speed Aircraft pitch rate X-axis position of the inertial reference system in the body coordinate system IRS And the X-axis position of the glide slope antenna in the body coordinate system. GSAnt Obtain the vertical velocity at the glide slope antenna. Specifically:

[0050]

[0051] In this embodiment, the calculation process for the vertical deviation of the aircraft relative to the ideal trajectory in step 2) is as follows:

[0052] B1. Based on the aircraft altitude h at the glide slope antenna. GSAnt Reference glide slope angle γ REF Glide slope deviation ε GS and glide slope signal correction γ corr Obtain the horizontal distance R between the aircraft and the glide slope antenna. estGS Specifically:

[0053] R estGS =-h GSAnt / tan((γ corr +γ REF )+ε GS );

[0054] B2. Based on the horizontal distance R between the aircraft and the glide slope antenna estGS and glide slope deviation ε GS To obtain the vertical deviation d of the aircraft relative to the ideal flight path v_ANT Specifically:

[0055] d v_ANT =R estGS ×ε GS .

[0056] In this embodiment, the calculation process for determining whether the glide slope deviation signal is in an abnormal state in step 3) is as follows:

[0057] C1. Based on the vertical deviation d of the aircraft relative to the ideal trajectory v_ANT Vertical velocity at the glide slope antenna And the default state P of the glide slope deviation signal, to obtain the inertial fusion vertical deviation d v_ANT_f Specifically:

[0058]

[0059] C2. Based on the vertical velocity at the glide slope antenna Vertical deviation d of the aircraft from the ideal trajectory v_ANT Inertial fusion vertical deviation d v_ANT_f And the default state P of the glide slope deviation signal, to obtain the inertial fusion vertical velocity. Specifically:

[0060]

[0061] C3. Based on the vertical deviation d of the aircraft relative to the ideal trajectory v_ANT Inertial fusion vertical deviation d v_ANT_f Vertical deviation threshold Δ dev_1 Vertical velocity at the glide slope antenna Inertial fusion vertical velocity and vertical velocity threshold Δ dev_2 Update the signal state P, specifically as follows:

[0062]

[0063]

[0064] P = P1||P2;

[0065] Where: when P=0, the acquisition of the glide slope deviation is turned off; when P=1, the acquisition of the glide slope deviation is turned on.

[0066] In this embodiment, the calculation process for the extended inertial fusion glide slope deviation required in step 4) is as follows: based on the inertial fusion vertical deviation d... v_ANT_f The aircraft altitude h at the glide slope antenna GSAnt Reference glide slope angle γ REF and glide slope signal correction γ corr Calculate the inertial fusion glide slope deviation ε GS_f Specifically:

[0067]

[0068] The principle of the glide slope extension method of the instrument landing system in this embodiment is as follows: Figure 1 As shown, the aircraft altitude and vertical velocity at the glide slope antenna are calculated using the radio altitude output from the radio altimeter, the pitch angle, vertical velocity, and pitch rate output from the inertial reference system, and the aircraft configuration data. Then, the vertical deviation of the aircraft relative to the ideal trajectory is calculated using the glide slope deviation output from the multi-mode receiver, the glide slope angle, and the glide slope signal correction output from the flight management system. The inertial fusion vertical deviation and inertial fusion vertical velocity are calculated to identify abnormal glide slope deviation signal states. Based on the inertial fusion vertical deviation, the aircraft altitude at the glide slope antenna, the reference glide slope angle, and the glide slope signal correction, the inertial fusion glide slope deviation is obtained.

[0069] like Figure 2 As shown, the specific steps of this embodiment are as follows:

[0070] 1. Calculate the aircraft's altitude and vertical velocity at the glide slope antenna.

[0071] This step requires collecting the aircraft's radio altitude, pitch angle, vertical speed, and pitch rate; the X-axis and Z-axis positions of the glide slope antenna in the body coordinate system; the X-axis and Z-axis positions of the radio altimeter in the body coordinate system; and the X-axis position of the inertial reference system in the body coordinate system. Based on the collected information, the aircraft's altitude and vertical speed at the glide slope antenna are calculated.

[0072] This embodiment obtains the radio altitude h from a radio altimeter. R Obtain the pitch angle θ and aircraft vertical velocity from the inertial reference system. Pitch rate X-axis position of the glide slope antenna in the body coordinate system GSAnt The Z-axis position of the glide slope antenna in the body coordinate system. GSAnt The position of the radio altimeter on the X-axis in the body coordinate system. RA The Z-axis position of the radio altimeter in the body coordinate system. RA Obtain the aircraft altitude h at the glide slope antenna. GSAnt First, use the aircraft's radio altitude h output from the radio altimeter. R The aircraft pitch angle θ output by the inertial reference system, and the X-axis position X of the glide slope antenna in the body coordinate system. GSAnt The Z-axis position of the glide slope antenna in the body coordinate system. GSAnt The position of the radio altimeter on the X-axis in the body coordinate system. RA The Z-axis position of the radio altimeter in the body coordinate system. RA Obtain the aircraft altitude h at the glide slope antenna. GSAnt Then use the vertical velocity output by the inertial reference system. Aircraft pitch rate X-axis position of the inertial reference system in the body coordinate system IRS X-axis position of the glide slope antenna in the body coordinate system GSAnt Obtain the vertical velocity at the glide slope antenna.

[0073] h GSAnt =h R +(X GSAnt -X RA )sinθ-(Z GSAnt -Z RA cosθ

[0074]

[0075] 2. Calculate the vertical deviation of the aircraft relative to the ideal flight path.

[0076] This step requires collecting the aircraft's reference glide slope angle, glide slope deviation, and glide slope signal correction.

[0077] This embodiment obtains the reference glide slope angle γ from the flight management system. REF Glide slope signal correction γ corr Obtain the glide slope deviation ε from the multimode receiver GS First, the reference glide slope angle γ output by the flight management system is used.REF The glide slope deviation ε of the multimode receiver output GS The aircraft altitude h at the glide slope antenna GSAnt Glide slope signal correction γ corr， Obtain the horizontal distance R between the aircraft and the glide slope antenna estGS Then, the glide slope deviation ε output by the multimode receiver is used. GS The horizontal distance R between the aircraft and the glide slope antenna estGS ,

[0078] Obtain the vertical deviation d of the aircraft relative to the ideal trajectory v_ANT .

[0079] R estGS =-h GSAnt / tan(γ corr +γ REF )+K cap ε GS );

[0080] d v_ANT =R estGS ×ε GS .

[0081] 3. Determine if the glide slope deviation signal is in an abnormal state.

[0082] This step requires collecting the vertical deviation d of the aircraft relative to the ideal flight path. v_ANT Vertical velocity at the glide slope antenna The default state of the glide slope deviation signal is P.

[0083] In this embodiment, the vertical deviation d of the aircraft relative to the ideal flight path is... v_ANT Vertical velocity at the glide slope antenna The default value for the glide slope deviation signal P is an intermediate calculation value.

[0084] First, using the vertical deviation d of the aircraft relative to the ideal trajectory v_ANT Vertical velocity at the glide slope antenna The glide slope deviation signal is in its default state P, and the inertial fusion vertical deviation d is obtained. v_ANT_f ,

[0085]

[0086] Then, based on the vertical velocity at the glide slope antenna... Vertical deviation d of the aircraft from the ideal trajectory v_ANT Inertial fusion vertical deviation d v_ANT_f The glide slope deviation signal is in its default state P, and the inertial fusion vertical velocity is obtained.

[0087]

[0088] Then, based on the vertical deviation d of the aircraft relative to the ideal trajectory v_ANT Inertial fusion vertical deviation d v_ANT_f Vertical deviation threshold Δ dev_1 Vertical velocity at the glide slope antenna Inertial fusion vertical velocity Vertical velocity threshold Δ dev_2 Update the glide slope deviation signal status P.

[0089]

[0090]

[0091] P = P1||P2.

[0092] 4. Calculate the required extended inertial fusion glide slope deviation.

[0093] This step requires collecting the inertial fusion vertical deviation d. v_ANT_f The aircraft altitude h at the glide slope antenna GSAnt h GSAnt Reference glide slope angle γ REF Glide slope signal correction γ corr .

[0094] In this embodiment, the inertial fusion vertical deviation d v_ANT_f The aircraft altitude h at the glide slope antenna GSAnt For intermediate calculations, refer to the glide slope angle γ. REF Glide slope signal correction γ corr Data collected from the flight management system.

[0095] Based on inertial fusion vertical deviation d v_ANT_f The aircraft altitude h at the glide slope antenna GSAnt Reference glide slope angle γ REF Glide slope signal correction γ corr Calculate the inertial fusion glide slope deviation ε GS_f .

[0096]

[0097] This embodiment utilizes radio altitude, inertial data, and aircraft configuration information to further extend the glide slope signal to the runway, thereby improving the success rate of aircraft landing.

[0098] This embodiment extends the instrument landing system based on the obtained inertial fusion glide slope deviation, thereby improving the success rate of aircraft landing.

[0099] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for extending the glide path of an instrument landing system, characterized in that, Includes the following steps: 1) Collect the aircraft's radio altitude, pitch angle, vertical speed and pitch rate; collect the X-axis and Z-axis positions of the glide slope antenna in the body coordinate system; collect the X-axis and Z-axis positions of the radio altimeter in the body coordinate system; collect the X-axis position of the inertial reference system in the body coordinate system; and calculate the aircraft's altitude and vertical speed at the glide slope antenna based on the collected information. 2) Collect the aircraft reference glide slope angle, glide slope deviation, glide slope signal correction, glide slope signal acquisition status parameters, and aircraft altitude at the glide slope antenna, and calculate the inertial fusion vertical deviation of the aircraft relative to the ideal trajectory based on the collected information. 3) Based on the vertical velocity at the aircraft glide path antenna, the inertial fusion vertical deviation of the aircraft relative to the ideal trajectory, and the preset judgment conditions, determine whether the current glide path deviation signal of the aircraft is in a normal state; and turn on or off the acquisition of glide path deviation according to the judged glide path deviation signal state. 4) Based on the current inertial fusion vertical deviation, the aircraft altitude at the glide slope antenna, the reference glide slope angle, and the glide slope signal correction, calculate the required extended inertial fusion glide slope deviation.

2. The glide slope extension method for an instrument landing system according to claim 1, characterized in that, The calculation process for the aircraft altitude and vertical velocity at the glide slope antenna in point 1) is as follows: A1. Based on the aircraft's radio altitude h R Aircraft pitch angle θ, and the X-axis position of the glide slope antenna in the body coordinate system. GSAnt The Z-axis position of the glide slope antenna in the body coordinate system. GSAnt The position of the radio altimeter on the X-axis in the body coordinate system. RA and the Z-axis position of the radio altimeter in the body coordinate system. RA Obtain the aircraft altitude h at the glide slope antenna. GSAnt Specifically: h GSAnt =h R +(X GSAnt -X RA )sinθ-(Z GSAnt -Z RA )cosθ; A2. Based on the aircraft's vertical speed Aircraft pitch rate X-axis position of the inertial reference system in the body coordinate system IRS And the X-axis position of the glide slope antenna in the body coordinate system. GSAnt Obtain the vertical velocity at the glide slope antenna. Specifically:

3. The glide slope extension method for an instrument landing system according to claim 2, characterized in that, The calculation process for the vertical deviation of the aircraft relative to the ideal trajectory in section 2) is as follows: B1. Based on the aircraft altitude h at the glide slope antenna. GSAnt Reference glide slope angle γ REF Glide slope deviation ε GS and glide slope signal correction γ corr Obtain the horizontal distance R between the aircraft and the glide slope antenna. estGS Specifically: R estGS =-h GSAnt / tan((γ corr +g REF )+e GS ); B2. Based on the horizontal distance R between the aircraft and the glide slope antenna estGS and glide slope deviation ε GS To obtain the vertical deviation d of the aircraft relative to the ideal flight path v_ANT Specifically: d v_ANT =R estGS ×ε GS 。 4. The glide slope extension method for an instrument landing system according to claim 3, characterized in that, The calculation process for determining whether the glide slope deviation signal is in an abnormal state in step 3) is as follows: C1. Based on the vertical deviation d of the aircraft relative to the ideal trajectory v ANT Vertical velocity at the glide slope antenna And the default state P of the glide slope deviation signal, to obtain the inertial fusion vertical deviation d v_ANT_f Specifically: C2. Based on the vertical velocity at the glide slope antenna Vertical deviation d of the aircraft from the ideal trajectory v ANT Inertial fusion vertical deviation d v_ANT_f And the default state P of the glide slope deviation signal, to obtain the inertial fusion vertical velocity. Specifically: C3. Based on the vertical deviation d of the aircraft relative to the ideal trajectory v ANT Inertial fusion vertical deviation d v_ANT_f Vertical deviation threshold Δ dev_1 Vertical velocity at the glide slope antenna Inertial fusion vertical velocity and vertical velocity threshold Δ dev_2 Update the signal state P, specifically as follows: P = P1||P2; Where: when P=0, the acquisition of the glide slope deviation is turned off; when P=1, the acquisition of the glide slope deviation is turned on.

5. The glide slope extension method for an instrument landing system according to claim 4, characterized in that, The calculation process for the inertial fusion glide slope deviation required in section 4) is as follows: based on the inertial fusion vertical deviation d... v_ANT_f The aircraft altitude h at the glide slope antenna GSAnt Reference glide slope angle γ REF and glide slope signal correction γ corr Calculate the inertial fusion glide slope deviation ε GS_f Specifically:

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