Radiometric calibration method and device for space-borne fire point sensor

Abstract

The application relates to a radiation calibration method and device of a spaceborne fire point sensor. The method comprises the following steps: based on actual latitude and longitude information of a plurality of known targets, running orbit information of a satellite and an installation matrix of the fire point sensor on the satellite, generating a calibration task of each known target in sequence; acquiring medium-wave radiance and long-wave radiance of each known target; wherein the medium-wave radiance and the long-wave radiance of each known target are obtained by a detector of the fire point sensor based on corresponding calibration tasks and corresponding known targets; based on the medium-wave radiance and the long-wave radiance, calculating medium-wave brightness temperature and long-wave brightness temperature of each known target; based on actual temperatures, medium-wave brightness temperatures and long-wave brightness temperatures of any three known targets, calculating an actual calibration coefficient of the detector; and based on the actual calibration coefficient, calculating a temperature of a to-be-detected target. The method can accurately calculate the temperature of the to-be-detected target and reduce the false alarm rate.

Description

Technical Field

[0001] This invention relates to the field of remote sensing satellite technology, and in particular to a radiometric calibration method and apparatus for a spaceborne fire point sensor. Background Technology

[0002] The fire detection system is a new type of spaceborne fire detection and fire location calculation system. It can calculate the location of the fire and send the location to ground equipment so that firefighters can quickly reach the fire site and extinguish the fire, thereby protecting people's lives and property.

[0003] Typically, fire sensors use infrared detectors. When an infrared detector operates for an extended period, the pixel response of the detector will drift with changes in the substrate temperature, causing the calibration coefficient of the pixel response to change. If the calibration coefficient is not corrected, it will affect the accuracy of calculating the temperature of ground objects, and consequently affect the accuracy of ground target identification, resulting in a high false alarm rate.

[0004] Therefore, there is an urgent need for a radiation calibration method and device for spaceborne fire point sensors to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a radiation calibration method and apparatus for a spaceborne fire point sensor, which can accurately calculate the temperature of the target to be detected and reduce the false alarm rate.

[0006] In a first aspect, embodiments of the present invention provide a radiation calibration method for a spaceborne fire point sensor.

[0007] Based on the actual latitude and longitude information of multiple known targets, the satellite's orbital information, and the installation matrix of the fire sensor on the satellite, a calibration task for each known target is generated sequentially.

[0008] The mid-wave radiance and long-wave radiance of each known target are obtained; wherein the mid-wave radiance and long-wave radiance of each known target are obtained by the detector of the fire sensor based on the corresponding calibration task to detect the corresponding known target;

[0009] Based on the mid-wave radiance and the long-wave radiance, calculate the mid-wave radiance temperature and long-wave radiance temperature of each known target;

[0010] Calculate the actual calibration coefficient of the detector based on the actual temperature, mid-wave brightness temperature and long-wave brightness temperature of any three known targets;

[0011] Based on the actual calibration coefficients, the temperature of the target to be detected is calculated.

[0012] In one possible design, the calibration task includes a calibration attitude, a calibration start time, and a calibration end time corresponding to each of the known targets; wherein, when the satellite reaches the calibration start time and calibration attitude corresponding to the current known target, the known target is within the field of view of the fire sensor.

[0013] In one possible design, when the satellite reaches the calibration start time and calibration attitude corresponding to the currently known target, the field of view center of the fire sensor points to the center of the calibration area of ​​the known target, and the calibration area is determined based on the actual latitude and longitude information of the known target.

[0014] One possible design also includes:

[0015] Every preset period, the longitude and latitude of the center of the field of view of the fire sensor are calculated, and the calculation results of each preset period are sent to the fire sensor.

[0016] The fire sensor detects the mid-wave and long-wave radiance of each known target in the following manner:

[0017] Receive the calculation results for each preset period, and determine whether the field of view center of the fire sensor at the current moment points to the calibration area corresponding to any known target based on the calculation results;

[0018] If not, no detection is performed; if yes, determine whether the calibration area is obscured by clouds.

[0019] If the target is obstructed, no detection is performed; otherwise, the detector of the fire sensor is used to detect known targets within the current calibration area to obtain the mid-wave and long-wave radiance of the known target.

[0020] In one possible design, calculating the mid-wave radiance temperature and long-wave radiance temperature for each known target based on the mid-wave radiance and the long-wave radiance includes:

[0021] Based on the mid-wave radiance, the mid-wave radiance temperature of each known target is calculated using the following formula:

[0022]

[0023] Based on the long-wave radiance, the long-wave radiance temperature of each known target is calculated using the following formula:

[0024]

[0025] In the formula, T1 is the mid-wave brightness temperature, T2 is the long-wave brightness temperature, k is the Boltzmann constant, c is the speed of light, λ1 is the wavelength of the detector in the mid-wave spectrum, λ2 is the wavelength of the detector in the long-wave spectrum, h is Planck's constant, L1 is the mid-wave radiance, and L2 is the long-wave radiance.

[0026] In one possible design, calculating the actual calibration coefficients of the detector based on the actual temperature, mid-wave brightness temperature, and long-wave brightness temperature of any three known targets includes:

[0027] Based on the actual temperature, mid-wave brightness temperature, and long-wave brightness temperature of any three known targets, a set of equations is constructed to calculate the actual calibration coefficients. The set of equations is as follows:

[0028]

[0029] In the formula, T ZR1 T ZR1 、 and T ZR1 These are the actual temperatures of three known targets. and The mid-wave brightness temperatures of three known targets are respectively. and The long-wavelength brightness temperatures of the three known targets are respectively;

[0030] Solving the system of equations yields the actual calibration coefficients {A0 A1 A2} of the detector.

[0031] In one possible design, based on the actual calibration coefficients, the formula for calculating the temperature of the target to be detected is as follows:

[0032] T DM =A0+A1T 1DM +A2T 2DM ;

[0033] In the formula, T DM T represents the temperature of the target to be detected. 1DM T represents the mid-wave brightness temperature of the target to be detected. 2DM The long-wavelength brightness temperature of the target to be detected.

[0034] Secondly, embodiments of the present invention also provide a radiation calibration device for a spaceborne fire point sensor, comprising:

[0035] The generation module is used to generate a calibration task for each of the known targets in sequence, based on the actual latitude and longitude information of multiple known targets, the satellite's orbital information, and the installation matrix of the fire sensor on the satellite.

[0036] The acquisition module is used to acquire the mid-wave radiance and long-wave radiance of each of the known targets; wherein the mid-wave radiance and long-wave radiance of each of the known targets are obtained by the detector of the fire sensor based on the corresponding calibration task to detect the corresponding known targets;

[0037] The first calculation module is used to calculate the mid-wave radiance temperature and long-wave radiance temperature of each known target based on the mid-wave radiance and the long-wave radiance.

[0038] The second calculation module is used to calculate the actual calibration coefficient of the detector based on the actual temperature, mid-wave brightness temperature and long-wave brightness temperature of any three known targets.

[0039] The third calculation module is used to calculate the temperature of the target to be detected based on the actual calibration coefficient.

[0040] Thirdly, embodiments of the present invention also provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the method described in any embodiment of this specification.

[0041] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the methods described in any embodiment of this specification.

[0042] This invention provides a radiometric calibration method and apparatus for a spaceborne fire point sensor. The method is based on multiple known targets on the ground. The mid-wave and long-wave radiance of each known target is detected using the spaceborne fire point sensor, and then the mid-wave and long-wave radiance temperatures of each target are calculated. Three targets are randomly selected from the multiple known targets, and the actual temperature, mid-wave radiance temperature, and long-wave radiance temperature of these three targets are used to calculate the actual calibration coefficients of the fire point sensor detector. These calibration coefficients have eliminated the drift caused by the pixel response of the detector due to changes in substrate temperature, and are therefore relatively accurate. Finally, the temperature of the target to be detected is calculated using these calibration coefficients. The calculated temperature has higher accuracy, thus the target information is more accurately identified, thereby reducing the false alarm rate. Therefore, the method of this invention can accurately calculate the temperature of the target to be detected and reduce the false alarm rate. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a flowchart of a radiation calibration method for a spaceborne fire point sensor provided in an embodiment of the present invention;

[0045] Figure 2 This is a hardware architecture diagram of an electronic device provided in an embodiment of the present invention;

[0046] Figure 3 This is a structural diagram of a radiation calibration device for a spaceborne fire point sensor provided in an embodiment of the present invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0048] Please refer to Figure 1 This invention provides a radiation calibration method for a spaceborne fire point sensor, comprising:

[0049] Step 100: Based on the actual latitude and longitude information of multiple known targets, the satellite's orbital information, and the installation matrix of the fire sensor on the satellite, generate the calibration task for each known target in sequence.

[0050] Step 102: Obtain the mid-wave radiance and long-wave radiance of each known target; wherein, the mid-wave radiance and long-wave radiance of each known target are obtained by the detector of the fire sensor based on the corresponding calibration task to detect the corresponding known target;

[0051] Step 104: Calculate the mid-wave radiance temperature and long-wave radiance temperature for each known target based on the mid-wave radiance and long-wave radiance.

[0052] Step 106: Calculate the actual calibration coefficient of the detector based on the actual temperature, mid-wave brightness temperature and long-wave brightness temperature of any three known targets;

[0053] Step 108: Calculate the temperature of the target to be detected based on the actual calibration coefficients.

[0054] In this embodiment of the invention, firstly, based on multiple known targets on the ground, the mid-wave and long-wave radiance of each known target are detected using a spaceborne fire sensor. Then, the mid-wave and long-wave radiance temperatures of each known target are calculated. Three targets are randomly selected from the multiple known targets, and the actual temperature, mid-wave radiance temperature, and long-wave radiance temperature of these three targets are used to calculate the actual calibration coefficients of the fire sensor detector. These calibration coefficients have eliminated the drift caused by the pixel response of the detector due to changes in substrate temperature, and are therefore relatively accurate. Finally, the temperature of the target to be detected is calculated using these calibration coefficients. The calculated temperature has higher accuracy, thus the identified target information is more accurate, thereby reducing the false alarm rate. Therefore, the method of the present invention can accurately calculate the temperature of the target to be detected and reduce the false alarm rate.

[0055] The following is a detailed description Figure 1 The execution method of each step is shown.

[0056] First, for step 100, based on the actual latitude and longitude information of multiple known targets, the satellite's orbital information, and the installation matrix of the fire sensor on the satellite, a calibration task for each known target is generated sequentially.

[0057] In this step, at least three targets are known, and the actual temperature and latitude / longitude information of each target are known. Preferably, naturally uniform infrared targets, such as the ocean or a plaza, are selected to accurately determine their actual temperature and reduce the impact of systematic errors. Multiple targets are located in different regions below the satellite's orbital nadir. The satellite's orbital information includes its flight path and its speed at different times along that path. The installation matrix of the fire sensors on the satellite is known and is used to characterize the relative positional relationship between the fire sensors and the satellite.

[0058] Different known targets require different calibration tasks. During calibration, a calibration task is generated for each known target based on its actual latitude and longitude, the satellite's real-time orbit information, and the installation matrix of the fire sensors on the satellite. For example, when there are five known targets, there are also five calibration tasks.

[0059] In some implementations, the calibration task includes a calibration attitude, a calibration start time, and a calibration end time corresponding to each known target; wherein, when the satellite reaches the calibration start time and calibration attitude corresponding to the current known target, the known target is within the field of view of the fire sensor.

[0060] In this embodiment, when the satellite does not require calibration, it operates in a three-axis ground-stabilized mode, and the fire sensor is powered on. When the satellite reaches a certain position, and the field of view of the fire sensor is about to cover any one of the multiple known targets, the satellite's attitude can be adjusted to the calibration attitude. In this calibration attitude, the fire sensor can detect the known target in order to obtain the mid-wave and long-wave radiance of the known target.

[0061] It should be noted that the calibration attitude refers to the satellite's calibration roll angle, calibration pitch angle, and calibration yaw angle. Generally, the calibration pitch angle and calibration yaw angle are set to 0, while the roll angle is not 0. Under this calibration attitude, the satellite no longer operates in a three-axis Earth-oriented mode, but in a calibration mode. After completing the detection of the currently known target, it can resume the three-axis Earth-oriented operation mode until it encounters the next known target.

[0062] In some implementations, in order to detect targets more accurately, it is preferable that when the satellite reaches the calibration start time and calibration attitude corresponding to the currently known target, the field of view center of the fire sensor points to the center of the calibration area of ​​the known target, and the calibration area is determined based on the actual latitude and longitude information of the known target.

[0063] In this embodiment, the latitude and longitude range of the calibration area is greater than that of the known target, which allows the satellite to enter the calibration mode in advance, preventing missed targets or inaccurate detection.

[0064] Then, for step 102, the mid-wave radiance and long-wave radiance of each known target are obtained; wherein, the mid-wave radiance and long-wave radiance of each known target are obtained by the detector of the fire sensor based on the corresponding calibration task to detect the corresponding known target.

[0065] In some implementations, the longitude and latitude of the center of the field of view of the fire sensor are calculated every preset period, and the calculation results of each preset period are sent to the fire sensor.

[0066] In this step, the preset period duration can be 125ms or other values. Since the satellite operates at a relatively high speed, the preset period duration cannot be too long to prevent missing targets.

[0067] In some implementations, the fire sensor detects the mid-wave and long-wave radiance of each known target in the following manner:

[0068] Receive the calculation results for each preset period, and determine whether the field of view center of the fire sensor at the current moment points to the calibration area corresponding to any known target based on the calculation results;

[0069] If not, no detection will be performed; if so, determine whether the calibration area is obscured by clouds.

[0070] If the target is obstructed, no detection is performed; otherwise, the detector of the fire sensor is used to detect known targets in the current calibration area to obtain the mid-wave and long-wave radiance of the known target.

[0071] In this embodiment, target detection is only performed when the center of the fire sensor's field of view is pointing towards a known target and the target is not obscured by clouds. Once the target is obscured by clouds or the detection is complete, the satellite is adjusted to a three-axis Earth-focused mode to await detection of the next target.

[0072] Next, for step 104, based on the mid-wave radiance and long-wave radiance, the mid-wave radiance temperature and long-wave radiance temperature of each known target are calculated.

[0073] In this step, the formula for calculating the mid-wave radiance temperature of each known target based on the mid-wave radiance is as follows:

[0074]

[0075] Based on the long-wavelength radiance, the formula for calculating the long-wavelength radiance temperature of each known target is as follows:

[0076]

[0077] In the formula, t1 is the mid-wave brightness temperature, T2 is the long-wave brightness temperature, k is the Boltzmann constant, c is the speed of light, λ1 is the wavelength of the detector in the mid-wave spectrum, λ2 is the wavelength of the detector in the long-wave spectrum, h is Planck's constant, L1 is the mid-wave radiance, and L2 is the long-wave radiance.

[0078] Next, for step 104, the actual calibration coefficient of the detector is calculated based on the actual temperature, mid-wave brightness temperature and long-wave brightness temperature of any three known targets.

[0079] In this step, three known targets can be randomly selected from a pool of known targets. Then, based on the actual temperature, mid-wave brightness temperature, and long-wave brightness temperature of these three known targets, a set of equations is constructed to calculate the actual calibration coefficients. The expression for the set of equations is as follows:

[0080]

[0081] In the formula, T ZR1 T ZR1 、 and T ZR1 These are the actual temperatures of three known targets. and The mid-wave brightness temperatures of three known targets are respectively. and These are the long-wavelength brightness temperatures of three known targets.

[0082] Solving this system of equations yields the actual calibration coefficients {A0 A1 A2} of the detector, which have eliminated the influence of changes in the detector pixel response with substrate temperature.

[0083] Finally, for step 108, the temperature of the target to be detected is calculated based on the actual calibration coefficients.

[0084] In this step, the formula for calculating the temperature of the target to be detected is:

[0085] T DM =A0+A1T 1DM +A2T 2DM ;

[0086] In the formula, T DM T represents the temperature of the target to be detected. 1DM T represents the mid-wave brightness temperature of the target to be detected. 2DM The long-wavelength brightness temperature of the target to be detected.

[0087] The target temperature calculated using this actual calibration coefficient has high accuracy, which can improve the accuracy of target identification and reduce the false alarm rate.

[0088] like Figure 2 , Figure 3 As shown, this embodiment of the invention provides a radiation calibration device for a spaceborne fire point sensor. The device embodiment can be implemented through software, hardware, or a combination of both. From a hardware perspective, as... Figure 2 The diagram shown is a hardware architecture diagram of an electronic device for a radiation calibration device of a spaceborne fire point sensor provided in an embodiment of the present invention. Except for... Figure 2 In addition to the processor, memory, network interface, and non-volatile memory shown, the electronic device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing packets. Taking software implementation as an example, such as... Figure 3 As shown, a device in a logical sense is formed by the CPU of its host electronic device reading the corresponding computer program from non-volatile memory into memory and running it. This embodiment provides a radiation calibration device for a spaceborne fire point sensor, comprising:

[0089] The generation module 300 is used to generate a calibration task for each known target in sequence based on the actual latitude and longitude information of multiple known targets, the satellite's orbital information, and the installation matrix of the fire sensor on the satellite.

[0090] The acquisition module 302 is used to acquire the mid-wave radiance and long-wave radiance of each known target; wherein, the mid-wave radiance and long-wave radiance of each known target are obtained by the detector of the fire sensor based on the corresponding calibration task to detect the corresponding known target;

[0091] The first calculation module 304 is used to calculate the mid-wave radiance temperature and long-wave radiance temperature of each known target based on the mid-wave radiance and long-wave radiance.

[0092] The second calculation module 306 is used to calculate the actual calibration coefficient of the detector based on the actual temperature, mid-wave brightness temperature and long-wave brightness temperature of any three known targets.

[0093] The third calculation module 308 is used to calculate the temperature of the target to be detected based on the actual calibration coefficient.

[0094] In this embodiment of the invention, the generation module 300 can be used to execute step 100 in the above method embodiment, the acquisition module 302 can be used to execute step 102 in the above method embodiment, the first calculation module 304 can be used to execute step 104 in the above method embodiment, the second calculation module 306 can be used to execute step 106 in the above method embodiment, and the third calculation module 308 can be used to execute step 108 in the above method embodiment.

[0095] In some implementations, the calibration task includes a calibration attitude, a calibration start time, and a calibration end time corresponding to each known target; wherein, when the satellite reaches the calibration start time and calibration attitude corresponding to the current known target, the known target is within the field of view of the fire sensor.

[0096] In some implementations, when the satellite reaches the calibration start time and calibration attitude corresponding to the currently known target, the field of view center of the fire sensor points to the center of the calibration area of ​​the known target, and the calibration area is determined based on the actual latitude and longitude information of the known target.

[0097] In some implementations, the longitude and latitude of the center of the field of view of the fire sensor are calculated every preset period, and the calculation results of each preset period are sent to the fire sensor.

[0098] The fire sensor detects the mid-wave and long-wave radiance of each known target in the following manner:

[0099] Receive the calculation results for each preset period, and determine whether the field of view center of the fire sensor at the current moment points to the calibration area corresponding to any known target based on the calculation results;

[0100] If not, no detection will be performed; if so, determine whether the calibration area is obscured by clouds.

[0101] If the target is obstructed, no detection is performed; otherwise, the detector of the fire sensor is used to detect known targets in the current calibration area to obtain the mid-wave and long-wave radiance of the known target.

[0102] In some implementations, the first calculation module 304 is used to perform the following operations:

[0103] Based on the mid-wave radiance, the mid-wave radiance temperature of each known target is calculated using the following formula:

[0104]

[0105] Based on the long-wavelength radiance, the long-wavelength radiance temperature of each known target is calculated using the following formula:

[0106]

[0107] In the formula, T1 is the mid-wave brightness temperature, T2 is the long-wave brightness temperature, k is the Boltzmann constant, c is the speed of light, λ1 is the wavelength of the detector in the mid-wave spectrum, λ2 is the wavelength of the detector in the long-wave spectrum, h is Planck's constant, L1 is the mid-wave radiance, and L2 is the long-wave radiance.

[0108] In some implementations, the second calculation module 306 is used to perform the following operations:

[0109] Based on the actual temperature, mid-wave brightness temperature, and long-wave brightness temperature of any three known targets, a set of equations is constructed to calculate the actual calibration coefficients. The set of equations is as follows:

[0110]

[0111] In the formula, T ZR1 T ZR1 、 and T ZR1 These are the actual temperatures of three known targets. and The mid-wave brightness temperatures of three known targets are respectively. and The long-wavelength brightness temperatures of the three known targets are respectively;

[0112] Solve the system of equations to obtain the actual calibration coefficients {A0 A1 A2} of the detector.

[0113] In some implementations, the formula for calculating the temperature of the target to be detected, based on the actual calibration coefficient, is as follows:

[0114] T DM =A0+A1T 1DM +A2T 2DM ;

[0115] In the formula, T DM T represents the temperature of the target to be detected. 1DM T represents the mid-wave brightness temperature of the target to be detected. 2DM The long-wavelength brightness temperature of the target to be detected.

[0116] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on a radiometric calibration device for a spaceborne fire point sensor. In other embodiments of the present invention, a radiometric calibration device for a spaceborne fire point sensor may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0117] The information interaction and execution process between the modules in the above-mentioned device are based on the same concept as the method embodiment of the present invention, and the specific details can be found in the description of the method embodiment of the present invention, and will not be repeated here.

[0118] This invention also provides an electronic device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements a radiation calibration method for a spaceborne fire point sensor according to any embodiment of this invention.

[0119] This invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform a radiation calibration method for a spaceborne fire point sensor according to any embodiment of this invention.

[0120] Specifically, a system or apparatus equipped with a storage medium may be provided, on which software program code implementing the functions of any of the embodiments described above is stored, and the computer (or CPU or MPU) of the system or apparatus may read and execute the program code stored in the storage medium.

[0121] In this case, the program code read from the storage medium can itself implement the function of any of the above embodiments, and therefore the program code and the storage medium storing the program code constitute part of the present invention.

[0122] Storage media embodiments for providing program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, program code can be downloaded from a server computer via a communication network.

[0123] Furthermore, it should be clear that not only can the program code read by the computer be executed, but also the operating system or other components operating on the computer can be instructed based on the program code to perform some or all of the actual operations, thereby realizing the function of any of the embodiments described above.

[0124] Furthermore, it is understood that the program code read from the storage medium is written to the memory set in the expansion board inserted into the computer or to the memory set in the expansion module connected to the computer. Then, based on the instructions of the program code, the CPU or other components installed on the expansion board or expansion module execute some and all of the actual operations, thereby realizing the function of any of the above embodiments.

[0125] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0126] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A radiation calibration method for a spaceborne fire point sensor, characterized in that, include: Based on the actual latitude and longitude information of multiple known targets, the satellite's orbital information, and the installation matrix of the fire sensor on the satellite, a calibration task for each known target is generated sequentially. The mid-wave radiance and long-wave radiance of each known target are obtained; wherein the mid-wave radiance and long-wave radiance of each known target are obtained by the detector of the fire sensor based on the corresponding calibration task to detect the corresponding known target; Based on the mid-wave radiance and the long-wave radiance, calculate the mid-wave radiance temperature and long-wave radiance temperature of each known target; Calculate the actual calibration coefficient of the detector based on the actual temperature, mid-wave brightness temperature and long-wave brightness temperature of any three known targets; The temperature of the target to be detected is calculated based on the actual calibration coefficients. The calibration task includes a calibration attitude, calibration start time, and calibration end time corresponding to each known target; wherein, when the satellite reaches the calibration start time and calibration attitude corresponding to the current known target, the known target is within the field of view of the fire sensor; When the satellite reaches the calibration start time and calibration attitude corresponding to the currently known target, the field of view center of the fire sensor points to the center of the calibration area of ​​the known target, and the calibration area is determined based on the actual latitude and longitude information of the known target; Also includes: Every preset period, the longitude and latitude of the center of the field of view of the fire sensor are calculated, and the calculation results of each preset period are sent to the fire sensor. The fire sensor detects the mid-wave and long-wave radiance of each known target in the following manner: Receive the calculation results for each preset period, and determine whether the field of view center of the fire sensor at the current moment points to the calibration area corresponding to any known target based on the calculation results; If not, no detection is performed; if yes, determine whether the calibration area is obscured by clouds. If the target is obstructed, no detection is performed; otherwise, the detector of the fire sensor is used to detect known targets within the current calibration area to obtain the mid-wave and long-wave radiance of the known target.

2. The method according to claim 1, characterized in that, The calculation of the mid-wave radiance temperature and long-wave radiance temperature for each known target based on the mid-wave radiance and the long-wave radiance includes: Based on the mid-wave radiance, the mid-wave radiance temperature of each known target is calculated using the following formula: Based on the long-wave radiance, the long-wave radiance temperature of each known target is calculated using the following formula: In the formula, For medium wave brightness temperature, For long-wavelength brightness temperature, Boltzmann's constant, At the speed of light, The wavelength of the spectral band in the detector. The wavelength of the detector in the long-wavelength spectrum. Let be Planck's constant. For mid-wave radiance, This refers to the long-wavelength radiance.

3. The method according to claim 2, characterized in that, The calculation of the actual calibration coefficients of the detector based on the actual temperature, mid-wave brightness temperature, and long-wave brightness temperature of any three known targets includes: Based on the actual temperature, mid-wave brightness temperature, and long-wave brightness temperature of any three known targets, a set of equations is constructed to calculate the actual calibration coefficients. The set of equations is as follows: ； In the formula, , ,and These are the actual temperatures of three known targets. , and The mid-wave brightness temperatures of three known targets are respectively. , and The long-wavelength brightness temperatures of the three known targets are respectively; Solving the system of equations yields the actual calibration coefficients of the detector. .

4. The method according to claim 3, characterized in that, Based on the actual calibration coefficients, the formula for calculating the temperature of the target to be detected is as follows: In the formula, The temperature of the target to be detected. The mid-wave brightness temperature of the target to be detected. The long-wavelength brightness temperature of the target to be detected.

5. A radiation calibration device for a spaceborne fire point sensor, characterized in that, The apparatus for implementing the method as described in any one of claims 1-4 comprises: The generation module is used to generate a calibration task for each of the known targets in sequence, based on the actual latitude and longitude information of multiple known targets, the satellite's orbital information, and the installation matrix of the fire sensor on the satellite. The acquisition module is used to acquire the mid-wave radiance and long-wave radiance of each of the known targets; wherein the mid-wave radiance and long-wave radiance of each of the known targets are obtained by the detector of the fire sensor based on the corresponding calibration task to detect the corresponding known targets; The first calculation module is used to calculate the mid-wave radiance temperature and long-wave radiance temperature of each known target based on the mid-wave radiance and the long-wave radiance. The second calculation module is used to calculate the actual calibration coefficient of the detector based on the actual temperature, mid-wave brightness temperature and long-wave brightness temperature of any three known targets. The third calculation module is used to calculate the temperature of the target to be detected based on the actual calibration coefficients.

6. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the method as described in any one of claims 1-4.

7. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed in the computer, it causes the computer to perform the method of any one of claims 1-4.

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