Environmental reinforcement type common-aperture multispectral-hyperspectral imaging loading method

Abstract

The invention discloses an environment-reinforced common-aperture multispectral-hyperspectral imaging load method, which is characterized in that an active air pump is utilized to purge and clean an optical window based on the imaging stability of a common-aperture optical system in a severe environment, and a window state image is acquired through an airborne monitoring camera, so that a basis is provided for light transmission detection; the method comprises the following steps: performing brightness characteristic and pollution distribution analysis on a state image, calculating a pollution area proportion and a brightness offset, fusing to form a purging clean score, entering a light path standby mechanism, uniformly collecting incident light beams by a main telescope, dividing wavebands by a dichroic beam splitter, introducing the wavebands into corresponding light path channels, obtaining incident irradiance and signal-to-noise ratios in each channel, and finally obtaining the state image according to the incident irradiance and the signal-to-noise ratios. The optical path energy transfer efficiency index is comprehensively generated, the optical path energy transfer level is evaluated, and long-term reliable operation of a high-precision optical instrument in a severe industrial environment is ensured.

Description

Technical Field

[0001] This invention relates to the field of data prediction and updating, and more specifically, to a common aperture multispectral-hyperspectral imaging payload method. Background Technology

[0002] In multispectral-hyperspectral imaging missions, common aperture optical systems are widely used in UAV platforms due to their small size, light weight and strong multispectral compatibility. However, in complex or harsh industrial environments, factors such as sand, smoke, oil mist and dust can cause contamination of the optical window surface, thereby affecting the incident light flux and reducing imaging quality and spectral accuracy.

[0003] The existing technology has the following shortcomings:

[0004] Currently, existing technologies mainly rely on manual cleaning or mechanical cleaning of optical windows at fixed time intervals. They lack real-time monitoring and quantitative assessment methods for optical window contamination, making it difficult to achieve dynamic cleaning and intelligent control of optical path energy transfer efficiency in harsh industrial environments. This leads to a decrease in the accuracy of multispectral-hyperspectral imaging and a reduction in the reliability of spectral data. Therefore, an environmentally hardened co-aperture multispectral-hyperspectral imaging payload method is proposed.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art, this invention provides an environmentally hardened co-aperture multispectral-hyperspectral imaging payload method. This method employs an active air pump to purge and clean the co-aperture optical window, an airborne monitoring camera to acquire window status images, a purge cleanliness score generated based on the proportion of contaminated area and brightness offset, and a dynamic optical path control method for evaluating the optical path energy transfer efficiency index, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] An environmentally hardened co-aperture multispectral-hyperspectral imaging payload method includes the following steps:

[0009] Step S1: Before the UAV performs the imaging mission, it enters the purging process stage, triggering the active air pump device to purge the surface of the common aperture optical window. After the purging process is completed, the status image of the common aperture optical window is acquired by the airborne monitoring camera.

[0010] Step S2: Identify the proportion of contaminated area and brightness offset in the status image, analyze the window light transmission characteristics using the proportion of contaminated area, fuse the window light transmission characteristics and brightness offset to generate a purge cleanliness score and determine whether to enter the optical path standby mechanism.

[0011] Step S3: When entering the optical path standby mechanism, the incident beam of the area to be imaged is collected and passed into the dichroic beam splitter to divide the incident beam into beam bands. Different beam bands are introduced into the optical path transmission channels according to the different beam bands.

[0012] Step S4: Obtain the incident irradiance and channel signal-to-noise ratio of the optical path transmission channel, analyze the spectral transmittance using the incident irradiance, generate the optical path energy transfer efficiency index by combining the channel signal-to-noise ratio and the spectral transmittance, and analyze the optical energy transfer level.

[0013] Preferably, in step S1, before the UAV performs the imaging task, it enters the purging process stage, using an active air pump device to output pulsed cleaning airflow to the surface of the main optical window.

[0014] After the purging process is completed, the surface of the main optical window is captured by an airborne monitoring camera to obtain a status image of the common aperture optical window, including the pixel brightness of each pixel.

[0015] Preferably, in step S2, the pixel brightness of the state image is standardized to obtain the brightness coefficient of each pixel, and a brightness histogram is constructed based on the brightness coefficient, including multiple statistical intervals set according to the brightness coefficient values, and each statistical interval corresponds to the number of pixels with the brightness coefficient.

[0016] The range of brightness coefficients within the preset brightness range in the brightness histogram is taken as the main peak range of brightness.

[0017] The luminance coefficient of the luminance peak interval is classified as a clean region, and pixels with luminance coefficients lower than the lower boundary or higher than the upper boundary of the luminance peak interval are classified as polluted regions.

[0018] Preferably, in step S2, the ratio of the number of pixels in the polluted area to the total number of pixels in the status image is used as the polluted area percentage.

[0019] The brightness offset of the state image is calculated based on the average brightness and the preset brightness threshold.

[0020] After standardizing the pollution area ratio, the pollution area coefficient is obtained, and the difference between 1 and the pollution area coefficient is used as the window light transmission characteristic.

[0021] The purge cleanliness score is calculated by combining the light transmission characteristics of the fusion window and the brightness offset.

[0022] If the purge cleanliness score is greater than or equal to the preset cleanliness threshold, then the optical path standby mechanism is entered.

[0023] Conversely, if the condition is not met, the process is considered to have entered the purging stage and purging is performed.

[0024] Preferably, in step S3, when entering the optical path standby mechanism, the common aperture optical system collects the light beam of the area to be imaged, and the common aperture optical window acquires the incident light beam of the area to be imaged.

[0025] By using a common-aperture main telescope to converge, collimate, and perform primary imaging on the incident beam, the incident beam can form a uniform optical image plane along the same optical axis.

[0026] Preferably, in step S3, the incident beam output from the common aperture main telescope is introduced into the dichroic beam splitter, which physically separates the different wavelength components of the incident beam in the spectral direction.

[0027] The short-wavelength light of the incident beam is extracted through the reflection channel as the short-wavelength beam band, and the long-wavelength light of the incident beam is extracted through the transmission channel as the long-wavelength beam band.

[0028] Preferably, in step S3, for the incident beam within the short-wavelength beam band range, the beam is passed through the reflection channel of the dichroic beam splitter into the first optical path transmission channel.

[0029] For incident beams within the long-wavelength beam band, the beam is transmitted through the transmission channel of the dichroic beam splitter into the second optical path transmission channel.

[0030] Preferably, in step S4, the incident irradiance and channel signal-to-noise ratio are obtained through an optical detector in the optical path transmission channel;

[0031] Incident irradiance refers to the light energy arrival rate of a light beam after passing through a common aperture optical window, a common aperture main telescope, and a dichroic beam splitter.

[0032] Channel signal-to-noise ratio (SNR) refers to the ratio of the effective signal strength to the noise strength output by an optical detector.

[0033] The ratio of incident irradiance to a preset irradiance threshold is used as the spectral transmittance.

[0034] Preferably, in step S4, the spectral transmittance and channel signal-to-noise ratio are standardized to obtain the spectral transmittance coefficient and channel signal-to-noise ratio, respectively.

[0035] The product of the spectral transmittance coefficient and the channel signal-to-noise ratio is used as the optical path energy transfer efficiency index.

[0036] If the optical path energy transfer efficiency index is greater than the preset imaging transfer threshold, the optical energy transfer level is judged to be a high transmission level.

[0037] Conversely, the light energy transfer level is judged to be low transmission level.

[0038] The technical effects and advantages of this invention are as follows:

[0039] This invention analyzes the imaging stability of a common-aperture optical system in harsh environments. It utilizes an active air pump to purge and clean the common-aperture optical window, and an onboard monitoring camera acquires window status images to provide optical observation data for subsequent light transmission detection. Optical analysis of the status images is performed on brightness characteristics and contamination distribution, calculating the contamination area ratio and brightness shift, which are then fused to form a purging cleanliness score. After entering the optical path standby mechanism, the common-aperture main telescope uniformly collects the incident beam, uses a dichroic beam splitter to divide the beam bands, and sends them to the corresponding optical path transmission channels to complete spectral allocation. Incident irradiance and channel signal-to-noise ratio are acquired in each optical path transmission channel, and a comprehensive optical path energy transfer efficiency index is generated to evaluate the current optical path energy transfer level, ensuring the long-term reliable operation of high-precision optical instruments in extremely harsh industrial environments. Attached Figure Description

[0040] Figure 1 This is a flowchart illustrating the implementation of an environmentally hardened co-aperture multispectral-hyperspectral imaging payload method according to the present invention.

[0041] Figure 2 This is a schematic diagram illustrating the steps of an environmentally hardened co-aperture multispectral-hyperspectral imaging payload method according to the present invention. Detailed Implementation

[0042] 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 only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] This invention analyzes the imaging stability of a common-aperture optical system in harsh environments. It utilizes an active air pump to purge and clean the common-aperture optical window, and an onboard monitoring camera acquires window status images to provide optical observation data for subsequent light transmission detection. Optical analysis of brightness characteristics and contamination distribution is performed on the status images, calculating the contamination area ratio and brightness shift, which are then fused to form a purge cleanliness score. After entering the optical path standby mechanism, the common-aperture main telescope uniformly collects the incident beam, uses a dichroic beam splitter to divide the beam bands, and sends them to the corresponding optical path transmission channels to complete spectral allocation. Incident irradiance and channel signal-to-noise ratio are acquired in each optical path transmission channel, and a comprehensive optical path energy transfer efficiency index is generated to evaluate the current optical path energy transfer level.

[0044] Example 1, such as Figures 1 to 2 As shown, an environmentally hardened co-aperture multispectral-hyperspectral imaging payload method includes the following steps:

[0045] Step S1: Before the UAV performs the imaging mission, it enters the purging process stage, triggering the active air pump device to purge the surface of the common aperture optical window. After the purging process is completed, the status image of the common aperture optical window is acquired by the airborne monitoring camera.

[0046] Step S2: Identify the proportion of contaminated area and brightness offset in the status image, analyze the window light transmission characteristics using the proportion of contaminated area, fuse the window light transmission characteristics and brightness offset to generate a purge cleanliness score and determine whether to enter the optical path standby mechanism.

[0047] Step S3: When entering the optical path standby mechanism, the incident beam of the area to be imaged is collected and passed into the dichroic beam splitter to divide the incident beam into beam bands. Different beam bands are introduced into the optical path transmission channels according to the different beam bands.

[0048] Step S4: Obtain the incident irradiance and channel signal-to-noise ratio of the optical path transmission channel, analyze the spectral transmittance using the incident irradiance, generate the optical path energy transfer efficiency index by combining the channel signal-to-noise ratio and the spectral transmittance, and analyze the optical energy transfer level.

[0049] The specific implementation is as follows:

[0050] In step S1, before the UAV carries the common aperture optical system to perform the mission, the UAV's environmental hardening module is activated. The environmental hardening module refers to the structural reinforcement unit used to improve the stability of the optical load in external environments such as dusty, strong vibration and drastic temperature fluctuations. It includes a sealed protective structure to reduce the probability of external particulate matter intrusion, a vibration damping support structure to suppress the impact of body vibration on the stability of the optical path, and an active air pump device for automatically cleaning the optical window.

[0051] The common aperture optical window in the common aperture optical system is cleaned to eliminate the attenuation effect of dust and particulate matter in the construction area on the incident beam quality; after receiving the optical path start command, the UAV payload enters the purging process stage and uses an active air pump to output pulsed cleaning airflow to the surface of the common aperture optical window.

[0052] A common-aperture optical system refers to a type of optical system that uses a single main optical path structure to achieve multi-channel optical imaging. By setting up a shared common-aperture optical window and a main telescope, all incident beams entering the system converge, collimate, and undergo primary imaging processing on the same optical axis. A dichroic beam splitter is then used to separate the beams spectrally after they share a common image plane, guiding optical signals of different wavelengths into the optical path transmission channel or hyperspectral detection channel respectively. This achieves pixel-level co-registration of multispectral and hyperspectral data, improving spectral fusion quality and the structural compactness of the optical system.

[0053] The pulsed cleaning airflow consists of multiple continuous short-duration high-pressure air pulses that act on the entire surface of the transparent substrate of the optical window. This allows the attached dust particles to be peeled off by the airflow and discharged from the window edge without contacting the optical components, thus avoiding scratches or secondary pollution that may be introduced by mechanical contact.

[0054] After the purging process is completed, the surface of the common aperture optical window is captured by an airborne monitoring camera to obtain a status image of the common aperture optical window, including the pixel brightness of each pixel. The status image is a visual imaging data that reflects the surface cleanliness, brightness distribution and local transmission anomalies of the common aperture optical window.

[0055] It should be noted that the common aperture optical window refers to an integrated transparent window structure installed at the incident end of the main optical path of the common aperture optical system. It is used to achieve sealing and protection of the internal optical components of the main telescope without changing the optical path structure. In this embodiment, it serves as the incident surface shared by multispectral and hyperspectral systems. The active air pump device refers to a miniature airflow output device integrated inside the payload housing. It can output pulsed airflow with specific pressure and duration for non-contact cleaning of the optical window surface. The airborne monitoring camera is installed at a fixed viewing angle position outside the common aperture optical window. Its focal length and optical axis are calibrated at the factory so that it can acquire the status image of the common aperture optical window without interfering with the optical path.

[0056] The status images collected by the airborne monitoring camera include residual contamination spots after purging, surface brightness distribution, reflective texture, and local light transmission differences. The purging effect is judged by identifying these differences.

[0057] Through the above-mentioned purging operation and status image acquisition, active cleaning and real-time status detection of the common aperture optical window can be achieved before the imaging task begins. This enables the common aperture optical system to obtain a stable and clean optical incident interface before entering the beam acquisition stage, thereby effectively reducing the adverse effects of factors such as dust and high-frequency vibration in the construction environment on the subsequent optical path energy transfer quality.

[0058] In step S2, contamination detection and brightness feature analysis are performed on the state image to quantify the light transmission state of the optical window after the purging process;

[0059] After standardizing the pixel brightness of the state image, the brightness coefficient of each pixel is obtained. A brightness histogram is constructed based on the brightness coefficient. The brightness histogram is a brightness distribution map constructed by statistically analyzing the brightness coefficient of each pixel in the state image. It includes multiple statistical intervals set according to the brightness coefficient values, and each statistical interval corresponds to the number of pixels with the brightness coefficient.

[0060] The range of brightness coefficients within the preset brightness range in the brightness histogram is taken as the main peak range of brightness.

[0061] The brightness peak range corresponds to the normal transmission area of ​​the common aperture optical window, where the brightness is stable and concentrated; while contaminants are usually distributed in the image as dark spots or brightness abrupt changes, causing the brightness to deviate from the peak range.

[0062] The brightness coefficient of the main brightness peak interval is divided into clean regions, and pixels with brightness coefficients lower than the lower boundary of the main brightness peak interval or higher than the upper boundary of the main brightness peak interval are divided into polluted regions.

[0063] The polluted area includes dark areas caused by dust obstruction or areas with abnormal brightness caused by localized enhanced scattering.

[0064] The number of pixels in the polluted area is counted, and the ratio of the number of pixels in the polluted area to the total number of pixels in the status image is used as the percentage of polluted area.

[0065] The average value of each brightness coefficient is used as the average brightness of the status image;

[0066] The brightness offset of the state image is calculated based on the average brightness and a preset brightness threshold: ,in, This is the brightness offset. The average brightness of the status image. The preset brightness threshold;

[0067] Brightness offset is used to reflect the abnormal scattering and transmission caused by residual contamination or microstructure on the surface after purging. The larger the brightness offset, the more obvious the difference between the overall brightness of the status image and the preset brightness threshold. There may still be strong scattering or occlusion on the surface of the common aperture optical window. The smaller the brightness offset, the closer the transmission state of the common aperture optical window is to the preset brightness threshold. The scattering and occlusion effects are weaker.

[0068] After standardizing the pollution area ratio, the pollution area coefficient is obtained. The difference between 1 and the pollution area coefficient is used as the window light transmission characteristic. The larger the window light transmission characteristic, the better the light transmission ability of the common aperture window.

[0069] The purge cleanliness score is calculated by combining the light transmission characteristics of the fusion window and the brightness offset. ,in, To score the cleanliness of the blowdown, and For preset weighting coefficients, Features of a window that allows light to pass through;

[0070] The purge cleanliness score is compared with a preset cleanliness threshold to determine whether to enter the optical path standby mechanism.

[0071] If the purge cleanliness score is greater than or equal to the preset cleanliness threshold, then the optical path standby mechanism is entered.

[0072] Conversely, if the condition does not meet the requirements, the process is considered to have entered the purging stage and purging is performed.

[0073] When the purge cleanliness score is greater than or equal to the preset cleanliness threshold, it indicates that the sealing and cleanliness of the common aperture optical system meet the optical path requirements in harsh environments, and it can enter the optical path standby mechanism.

[0074] It should be noted that standardization methods include, but are not limited to, standard linear transformations based on interval scaling and statistical methods. The standardization method or the normalization method based on the nonlinear mapping function will not be elaborated here. The preset brightness range is used to limit the brightness coefficient range of the normal transmission area, which can be set according to the imaging dynamic range of the airborne monitoring camera and the historical statistical characteristics of the light incident conditions. The preset brightness threshold can be set according to the calibrated brightness value under the window clean state or the long-term operation statistical brightness value. The preset weighting coefficient can be set according to the sensitivity of the influence of the proportion of contaminated area and brightness offset on the window light transmission performance under different contamination scenarios. The preset cleanliness threshold can be set according to the minimum light transmission requirements of the optical path, the signal-to-noise ratio requirements of the spectrometer, or empirical calibration data.

[0075] This step uses a brightness histogram to accurately divide clean and contaminated areas, enabling precise identification of subtle optical transmission anomalies such as dust obstruction and enhanced local scattering before the optical system is started. By comprehensively calculating the proportion of contaminated area and brightness offset, the cleaning and protection effect and transmission performance of the optical window are determined. When the window transmission status does not meet the requirements, the cleaning cycle is started in advance to reduce optical performance loss and light energy transmission deviation, thereby improving the optical path transmission stability and transmission data reliability of the common aperture optical system under harsh outdoor conditions such as construction environments.

[0076] In step S3, when the optical path standby mechanism is entered, the common aperture optical system collects the light beam of the area to be imaged, and the common aperture optical window acquires the incident light beam of the area to be imaged. The incident light beam refers to the multi-wavelength electromagnetic radiation that reaches the common aperture optical window from the area to be imaged, including visible light, near infrared and other spectral components supported by the system. The incident light beam enters the common optical path after passing through the common aperture optical window.

[0077] By using a common-aperture main telescope to converge, collimate, and perform primary imaging on the incident beam, the incident beam can form a uniform optical image plane along the same optical axis.

[0078] The incident beam output from the common aperture main telescope is guided into a dichroic beam splitter. The dichroic beam splitter physically separates the different wavelength components of the incident beam in the spectral direction. Specifically, the short-wavelength light of the incident beam is extracted through the reflection channel as the short-wavelength beam band, and the long-wavelength light of the incident beam is extracted through the transmission channel as the long-wavelength beam band. This divides the entire incident beam into two spectral sub-beams, a short-wavelength range and a long-wavelength range, according to the spectral splitting characteristics of the film layer.

[0079] The common-aperture main telescope consists of a cemented doublet lens group and a mirror structure. This shared optical group is used for beam focusing and primary imaging, maintaining beam converging accuracy even in dusty environments. The dichroic beam splitter is a spectral splitting device that selectively separates the reflection and transmission of light beams of different wavelengths by depositing multiple interference films on the surface of optical elements. It includes a reflection channel and a transmission channel, enabling the incident beam to physically separate the reflection and transmission paths according to wavelength at the same incident interface. The reflection channel is the optical path in the dichroic beam splitter used to reflect specific short-wavelength light; the transmission channel is the optical path in the dichroic beam splitter used to transmit specific long-wavelength light.

[0080] For incident beams within the short-wavelength beam band, the beam is guided from the reflection channel of the dichroic beam splitter to the first optical path transmission channel; for incident beams within the long-wavelength beam band, the beam is guided from the transmission channel of the dichroic beam splitter to the second optical path transmission channel.

[0081] Among them, the first optical path transmission channel and the second optical path transmission channel refer to the optical detection paths configured according to the different beam bands after separation by the dichroic beam splitter, so that the separated incident beams can complete imaging in the optical structure of the corresponding beam band, thereby improving the optical path transmission efficiency and band consistency of the common aperture optical system in different beam band ranges.

[0082] The optical path transmission channel is pre-configured according to the center wavelength and bandwidth of its beam band, so that each detection channel can receive the optical radiation of the corresponding band.

[0083] Through the above-mentioned band division and beam introduction process, beams from the same target area and imaging through the same optical path can be introduced into the corresponding detection channels in different band ranges, realizing the synchronous acquisition of multispectral data and optical path-level band matching.

[0084] In step S4, to evaluate the light energy transfer capability of the common aperture optical system under the current environmental conditions, the incident irradiance and channel signal-to-noise ratio of each band are obtained and analyzed.

[0085] Incident irradiance and channel signal-to-noise ratio are obtained through optical detectors within the optical path transmission channel;

[0086] Among them, incident irradiance refers to the light energy arrival rate of the beam after passing through the common aperture optical window, the common aperture main telescope and the dichroic beam splitter, reflecting the overall transmission performance of the current optical path; channel signal-to-noise ratio refers to the ratio of the effective signal strength output by the optical detector to the noise strength. The higher the channel signal-to-noise ratio, the more it indicates that the vibration resistance design and the stray light suppression effect of the beam splitter meet the requirements, and the environmental hardening design of the common aperture optical system is effective.

[0087] The ratio of incident irradiance to a preset irradiance threshold is used as the spectral transmittance. The spectral transmittance reflects the proportion of light energy transmitted in that spectral band under the current purging and optical alignment conditions.

[0088] After standardizing the spectral transmittance and channel signal-to-noise ratio respectively, the spectral transmittance coefficient and channel signal-to-noise ratio are obtained.

[0089] The product of the spectral transmittance coefficient and the channel signal-to-noise ratio is used as the optical path energy transfer efficiency index.

[0090] The optical path energy transfer efficiency index reflects the light energy utilization capability and optical path operation reliability of a common aperture optical system in the corresponding beam band. The higher the optical path energy transfer efficiency index, the better the energy transfer efficiency and imaging stability of the common aperture optical system under the current conditions.

[0091] The optical path energy transfer efficiency index is compared with a preset imaging transfer threshold to analyze the optical energy transfer level.

[0092] If the optical path energy transfer efficiency index is greater than the preset imaging transfer threshold, the optical energy transfer level is judged to be a high transmission level.

[0093] Conversely, the light energy transfer level is judged to be a low transmission level.

[0094] When the light energy transfer level is high transmission level, it indicates that the common aperture optical system is in a good transmission state, with high energy measurement accuracy and band response stability in the optical path transmission link.

[0095] When the light energy transfer level is low, it indicates that there may be optical abnormalities such as decreased transmittance, increased stray light, residual contamination on the surface of optical components, or slight tilting of the optical axis in the optical path. The process should be restarted and purged.

[0096] It should be noted that an optical detector is an optical signal acquisition element located at the end of the optical path transmission channel, used to convert the light energy of the incident beam into an electrical signal. It can measure the incident irradiance and channel signal-to-noise ratio of each spectral channel. The preset irradiance threshold can be set according to the actual optical flux requirements of the common aperture optical system. The preset imaging transmission threshold can be set according to the optical path performance requirements.

[0097] Finally, it should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0098] 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 limitation, 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.

[0099] In this document, the singular forms “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that terms such as “comprising / including” or “having” specify the presence of the stated features, integrals, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integrals, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0100] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0101] The above description of the disclosed embodiments will enable those skilled in the art to make or use various modifications to these embodiments. It will be readily apparent to those skilled in the art that the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An environmentally hardened co-aperture multispectral-hyperspectral imaging payload method, characterized in that: Includes the following steps: Step S1: Before the UAV performs the imaging mission, it enters the purging process stage, triggering the active air pump device to purge the surface of the common aperture optical window. After the purging process is completed, the status image of the common aperture optical window is acquired by the airborne monitoring camera. Step S2: Identify the proportion of contaminated area and brightness offset in the status image, analyze the window light transmission characteristics using the proportion of contaminated area, fuse the window light transmission characteristics and brightness offset to generate a purge cleanliness score and determine whether to enter the optical path standby mechanism. Step S3: When entering the optical path standby mechanism, the incident beam of the area to be imaged is collected and passed into the dichroic beam splitter to divide the incident beam into beam bands. Different beam bands are introduced into the optical path transmission channels according to the different beam bands. Step S4: Obtain the incident irradiance and channel signal-to-noise ratio of the optical path transmission channel, analyze the spectral transmittance using the incident irradiance, generate the optical path energy transfer efficiency index by combining the channel signal-to-noise ratio and the spectral transmittance, and analyze the optical energy transfer level.

2. The environmentally hardened co-aperture multispectral-hyperspectral imaging payload method according to claim 1, characterized in that: In step S1, before the UAV performs the imaging task, it enters the purging process stage, using an active air pump device to output pulsed cleaning airflow to the surface of the main optical window. After the purging process is completed, the surface of the main optical window is captured by an airborne monitoring camera to obtain a status image of the common aperture optical window, including the pixel brightness of each pixel.

3. The environmentally hardened co-aperture multispectral-hyperspectral imaging payload method according to claim 1, characterized in that: In step S2, the pixel brightness of the state image is standardized to obtain the brightness coefficient of each pixel. A brightness histogram is constructed based on the brightness coefficient, including multiple statistical intervals set according to the brightness coefficient values. Each statistical interval corresponds to the number of pixels with the brightness coefficient. The range of brightness coefficients within the preset brightness range in the brightness histogram is taken as the main peak range of brightness. The luminance coefficient of the luminance peak interval is classified as a clean region, and pixels with luminance coefficients lower than the lower boundary or higher than the upper boundary of the luminance peak interval are classified as polluted regions.

4. The environmentally hardened co-aperture multispectral-hyperspectral imaging payload method according to claim 3, characterized in that: In step S2, the ratio of the number of pixels in the polluted area to the total number of pixels in the status image is used as the percentage of the polluted area. The brightness offset of the state image is calculated based on the average brightness and the preset brightness threshold. After standardizing the pollution area ratio, the pollution area coefficient is obtained, and the difference between 1 and the pollution area coefficient is used as the window light transmission characteristic. The purge cleanliness score is calculated by combining the light transmission characteristics of the fusion window and the brightness offset. If the purge cleanliness score is greater than or equal to the preset cleanliness threshold, then the optical path standby mechanism is entered. Conversely, if the condition is not met, the process is considered to have entered the purging stage and purging is performed.

5. The environmentally hardened co-aperture multispectral-hyperspectral imaging payload method according to claim 1, characterized in that: In step S3, when the optical path standby mechanism is entered, the common aperture optical system collects the light beam of the area to be imaged, and the common aperture optical window acquires the incident light beam of the area to be imaged. By using a common-aperture main telescope to converge, collimate, and perform primary imaging on the incident beam, the incident beam can form a uniform optical image plane along the same optical axis.

6. The environmentally hardened co-aperture multispectral-hyperspectral imaging payload method according to claim 5, characterized in that: In step S3, the incident beam output from the common aperture main telescope is introduced into the dichroic beam splitter, which physically separates the different wavelength components of the incident beam in the spectral direction. The short-wavelength light of the incident beam is extracted through the reflection channel as the short-wavelength beam band, and the long-wavelength light of the incident beam is extracted through the transmission channel as the long-wavelength beam band.

7. The environmentally hardened co-aperture multispectral-hyperspectral imaging payload method according to claim 6, characterized in that: In step S3, for the incident beam within the short-wavelength beam band range, it is passed into the first optical path transmission channel through the reflection channel of the dichroic beam splitter. For incident beams within the long-wavelength beam band, the beam is transmitted through the transmission channel of the dichroic beam splitter into the second optical path transmission channel.

8. The environmentally hardened co-aperture multispectral-hyperspectral imaging payload method according to claim 1, characterized in that: In step S4, the incident irradiance and channel signal-to-noise ratio are obtained through an optical detector in the optical path transmission channel; Incident irradiance refers to the light energy arrival rate of a light beam after passing through a common aperture optical window, a common aperture main telescope, and a dichroic beam splitter. Channel signal-to-noise ratio (SNR) refers to the ratio of the effective signal strength to the noise strength output by an optical detector. The ratio of incident irradiance to a preset irradiance threshold is used as the spectral transmittance.

9. The environmentally hardened co-aperture multispectral-hyperspectral imaging payload method according to claim 8, characterized in that: In step S4, the spectral transmittance and channel signal-to-noise ratio are standardized to obtain the spectral transmittance coefficient and channel signal-to-noise ratio, respectively. The product of the spectral transmittance coefficient and the channel signal-to-noise ratio is used as the optical path energy transfer efficiency index. If the optical path energy transfer efficiency index is greater than the preset imaging transfer threshold, the optical energy transfer level is judged to be a high transmission level. Conversely, the light energy transfer level is judged to be low transmission level.

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