Method and device for calculating ground object height based on remote sensing image, and electronic equipment

Abstract

The invention discloses a method for calculating the height of a ground object based on a remote sensing image. The method comprises the following steps: acquiring a terminator satellite and a remote sensing image shot for a target ground object; obtaining the length, corresponding to a pixel pitch in the remote sensing image, in the real world; counting the pixel pitch number occupied by the ground shadow of the target ground object in the remote sensing image; according to the length in the real world corresponding to one pixel pitch in the remote sensing image and the pixel pitch number occupied by the ground shadow of the target ground feature in the remote sensing image, calculating to obtain the ground shadow length L of the target ground feature in the real world; calculating a solar elevation angle A according to the imaging time of the remote sensing image and the position of the morning and night satellite when the remote sensing image is shot; and according to the ground shadow length L and the solar elevation angle A of the target ground feature in the real world, calculating the height H of the target ground feature by using a formula H = L * tanA. The invention further discloses a device and electronic equipment for implementing the method.

Description

Technical Field

[0001] The present invention relates to the technical field of ground object height calculation, and in particular to a method, device and electronic equipment for calculating ground object height based on remote sensing images. Background Art

[0002] In recent years, with the development of remote sensing technology, remote sensing technology has been applied in more and more fields, for example, remote sensing technology has been applied to the field of calculating the height of ground objects. At present, the method of calculating the height of ground objects using remote sensing technology is usually based on remote sensing images of noon transit imaging to calculate the height of ground objects; however, the inventors found that the altitude angle of the sun in the remote sensing images of noon transit imaging is usually relatively high, and the higher solar altitude angle will affect the calculation accuracy for calculating the height of ground objects, especially the height of ground objects of irregular ground objects, which leads to the fact that the height of ground objects calculated by the prior art usually has a large error. Summary of the invention

[0003] The embodiments of the present invention provide a method, device and electronic device for calculating the height of ground objects based on remote sensing images, which are used to solve the problem that the height of ground objects calculated in the prior art usually has a large error.

[0004] The specific technical solutions are as follows:

[0005] In a first aspect, an embodiment of the present invention provides a method for calculating the height of a ground object based on a remote sensing image, the method comprising:

[0006] Obtain a remote sensing image taken by a morning and evening satellite targeting the target object;

[0007] Obtaining the length in the real world corresponding to a pixel spacing in the remote sensing image;

[0008] Counting the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image;

[0009] Calculate the length L of the ground shadow of the target object in the real world according to the length in the real world corresponding to one pixel spacing in the remote sensing image and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image;

[0010] Calculating the solar altitude angle A according to the imaging time of the remote sensing image and the position of the twilight satellite when taking the remote sensing image;

[0011] According to the ground shadow length L of the target object and the solar altitude angle A in the real world, the height H of the target object is calculated using the formula H=L×tanA.

[0012] Optionally, the step of calculating the solar altitude angle A according to the imaging time of the remote sensing image and the position of the twilight satellite when taking the remote sensing image comprises:

[0013] Acquiring imaging time of the remote sensing image;

[0014] According to the position of the morning and evening satellite when taking the remote sensing image, the longitude λ and latitude of the location of the target object are obtained.

[0015] Calculate the solar hour angle ω according to the imaging time of the remote sensing image and the longitude λ of the location of the target object;

[0016] Using the formula Calculate the solar declination δ on the imaging day of the remote sensing image, where N is the number of days calculated from January 1 of the year of the imaging day to the imaging day;

[0017] According to the solar hour angle ω and the latitude of the target object The solar declination δ on the day of the remote sensing image imaging is calculated using the formula Calculate the solar altitude angle A.

[0018] Optionally, the step of calculating the solar hour angle ω according to the imaging time of the remote sensing image comprises:

[0019] According to the time difference of 4 minutes for one degree of longitude difference and the longitude difference between the longitude of the location of the target object and the location of the standard time, calculate the time difference Δt between the location of the target object and the location of the standard time, where the unit of Δt is hours;

[0020] The solar hour angle ω is calculated using the formula ω=[12-(imaging time of the remote sensing image+Δt)]×15°, where the imaging time of the remote sensing image is in hours, 12 represents noon, and 15° represents the angle by which the solar hour angle ω increases every hour.

[0021] Optionally, the method further includes:

[0022] Obtain a pair of remote sensing images taken by the morning and evening satellite in opposite directions for the target object: remote sensing image 1 and remote sensing image 2;

[0023] For the remote sensing image 1, according to the length in the real world corresponding to one pixel spacing in the remote sensing image 1 and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image 1, the ground shadow length L1 of the target object in the real world corresponding to the remote sensing image 1 is calculated;

[0024] For the remote sensing image 2, according to the length in the real world corresponding to one pixel spacing in the remote sensing image 2 and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image 2, the ground shadow length L2 of the target object in the real world corresponding to the remote sensing image 2 is calculated;

[0025] Calculate the solar altitude angle A1 of the remote sensing image 1 according to the imaging time of the remote sensing image 1 and the position of the twilight satellite when the remote sensing image 1 is taken, and calculate the solar altitude angle A2 of the remote sensing image 2 according to the imaging time of the remote sensing image 2 and the position of the twilight satellite when the remote sensing image 2 is taken;

[0026] According to the remote sensing image 1, the ground shadow length L1 of the target object in the real world and the solar altitude angle A1, the first height H1 of the target object is calculated using the formula H1=L1×tanA1;

[0027] According to the remote sensing image 2, the ground shadow length L2 of the target object in the real world and the solar altitude angle A2, the second height H2 of the target object is calculated using the formula H2=L2×tanA2;

[0028] According to the first height H1 of the target object and the second height H2 of the target object, the formula The height H of the target object is obtained by calculation.

[0029] In a second aspect, an embodiment of the present invention provides a device for calculating the height of a ground object based on a remote sensing image, the device comprising:

[0030] The first acquisition module is used to acquire a remote sensing image taken by a morning and evening satellite for a target object;

[0031] A second acquisition module is used to obtain the length of a pixel spacing in the remote sensing image corresponding to the real world;

[0032] A statistical module, used for counting the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image;

[0033] A shadow calculation module, used to calculate the ground shadow length L of the target object in the real world according to the length in the real world corresponding to one pixel spacing in the remote sensing image and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image;

[0034] An altitude angle calculation module is used to calculate the solar altitude angle A according to the imaging time of the remote sensing image and the position of the twilight satellite when the remote sensing image is taken;

[0035] The height calculation module is used to calculate the height H of the target object according to the ground shadow length L and the solar altitude angle A of the target object in the real world using the formula H=L×tanA.

[0036] Optionally, the altitude angle calculation module is specifically used to:

[0037] Acquiring imaging time of the remote sensing image;

[0038] According to the position of the morning and evening satellite when taking the remote sensing image, the longitude λ and latitude of the location of the target object are obtained.

[0039] Calculate the solar hour angle ω according to the imaging time of the remote sensing image and the longitude λ of the location of the target object;

[0040] Using the formula Calculate the solar declination δ on the imaging day of the remote sensing image, where N is the number of days calculated from January 1 of the year of the imaging day to the imaging day;

[0041] According to the solar hour angle ω and the latitude of the target object The solar declination δ on the day of the remote sensing image imaging is calculated using the formula Calculate the solar altitude angle A.

[0042] Optionally, the altitude angle calculation module is further specifically used for:

[0043] According to the time difference of 4 minutes for one degree of longitude difference and the longitude difference between the longitude of the location of the target object and the location of the standard time, calculate the time difference Δt between the location of the target object and the location of the standard time, where the unit of Δt is hours;

[0044] The solar hour angle ω is calculated using the formula ω=[(imaging time of the remote sensing image+Δt)-12]×15°, where the imaging time of the remote sensing image is in hours, 12 represents noon, and 15° represents the angle by which the solar hour angle ω increases every hour.

[0045] Optionally, the first acquisition module is further used to acquire a pair of remote sensing images taken by a morning and evening satellite in opposite directions for the target object: remote sensing image 1 and remote sensing image 2;

[0046] The shadow calculation module is further used to: for the remote sensing image 1, according to the length in the real world corresponding to one pixel in the remote sensing image 1 and the number of pixels occupied by the ground shadow of the target object in the remote sensing image 1, calculate the ground shadow length L1 of the target object in the real world corresponding to the remote sensing image 1;

[0047] For the remote sensing image 2, according to the length in the real world corresponding to one pixel in the remote sensing image 2 and the number of pixels occupied by the ground shadow of the target object in the remote sensing image 2, calculate and obtain the ground shadow length L2 of the target object in the real world corresponding to the remote sensing image 2;

[0048] The altitude angle calculation module is further used to calculate the solar altitude angle A1 of the remote sensing image 1 according to the imaging time of the remote sensing image 1 and the position of the twilight satellite when the remote sensing image 1 is taken, and to calculate the solar altitude angle A2 of the remote sensing image 2 according to the imaging time of the remote sensing image 2 and the position of the twilight satellite when the remote sensing image 2 is taken;

[0049] The height calculation module is also used for:

[0050] According to the remote sensing image 1, the ground shadow length L1 of the target object in the real world and the solar altitude angle A1, the first height H1 of the target object is calculated using the formula H1=L1×tanA1;

[0051] According to the remote sensing image 2, the ground shadow length L2 of the target object in the real world and the solar altitude angle A2, the second height H2 of the target object is calculated using the formula H2=L2×tanA2;

[0052] According to the first height H1 of the target object and the second height H2 of the target object, the formula The height H of the target object is obtained by calculation.

[0053] In a third aspect, an embodiment of the present invention further provides an electronic device, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0054] The memory is used to store computer programs;

[0055] The processor is used to implement the method steps of calculating the height of ground objects based on remote sensing images as described in the first aspect when executing the program stored in the memory.

[0056] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method steps for calculating the height of ground objects based on remote sensing images described in the first aspect above are implemented.

[0057] Due to the low altitude angle of the sun in the early morning or dusk and the low light conditions, the ground shadows of the objects are long and obvious. The twilight satellite can photograph the target objects in the early morning and dusk, and the low-light imager can capture and enhance weak light signals to obtain high-quality remote sensing images. Therefore, the method provided in the embodiment of the present invention uses the low-light imager on the twilight satellite to take a remote sensing image of the target object in the early morning or dusk, and calculates the height of the object based on the remote sensing image. Due to the low altitude angle of the sun when the remote sensing image is taken, the ground shadows of the objects are long and obvious. Therefore, compared with the existing technology, the calculation accuracy can be significantly improved and the error of height calculation can be significantly reduced.

[0058] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0059] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0061] Figure 1 A schematic diagram of a flow chart of a method for calculating the height of a ground object based on a remote sensing image provided by an embodiment of the present invention;

[0062] Figure 2 It is a schematic diagram of the relationship between the height of the target object and the shadow in the remote sensing image 1;

[0063] Figure 3 is a schematic diagram of the relationship between the height of the target object and the shadow in the remote sensing image 2;

[0064] Figure 4 Another schematic diagram of a flow chart of a method for calculating the height of a ground object based on a remote sensing image provided by an embodiment of the present invention;

[0065] Figure 5 A schematic diagram of the structure of a device for calculating the height of a ground object based on a remote sensing image provided by an embodiment of the present invention;

[0066] Figure 6 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0067] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0068] A twilight satellite refers to a satellite that operates in a twilight orbit. A twilight satellite experiences sunrise and sunset in a day, and the twilight orbit plane is synchronized with the sun, allowing the twilight satellite to always be near the twilight line. Twilight satellites usually photograph the target area at dawn and dusk. The shooting time of twilight satellites is usually automatically controlled. Twilight satellites are generally equipped with high-precision clocks and sensor systems, which can automatically determine the best shooting time based on the satellite's orbital position, the position of the sun, and preset mission parameters. For example, when the satellite moves to a specific area near the twilight line, the sensor will detect whether the lighting conditions meet the requirements. When the lighting conditions meet the requirements, the camera will be automatically triggered to shoot.

[0069] A low-light imager is a device that can image in low-light conditions. It captures and enhances weak light signals and converts them into visible images. Since a low-light imager can image in low-light conditions, the sun's altitude angle is low when the low-light imager is shooting, and the ground shadows of the objects are long and obvious. Calculating the height of objects based on remote sensing images with low solar altitude angles taken by a low-light imager can significantly improve the accuracy of the calculation and significantly reduce the error of height calculation.

[0070] Based on the above characteristics and advantages of the twilight satellite and the low-light imager, in order to solve the problem that the calculated height of the ground object in the prior art usually has a large error. The method provided in the embodiment of the present invention uses the twilight satellite and the low-light imager to take a remote sensing image of the target ground object in the early morning or at dusk, and calculates the height of the ground object based on the remote sensing image. Figure 1 As shown, the method for calculating the height of ground objects based on remote sensing images proposed in an embodiment of the present invention includes the following steps:

[0071] S101: Acquire a remote sensing image taken by a morning and evening satellite for the target object;

[0072] Specifically, it is to obtain a remote sensing image of the target object taken by the low-light imager on the dawn and dusk satellite in the early morning or dusk.

[0073] Of course, in a specific embodiment, before obtaining a remote sensing image, it is necessary to establish a connection with a morning and evening satellite and send a task to the morning and evening satellite so that the morning and evening satellite uses a low-light imager to photograph the area where the target object is located in the early morning and dusk, and obtain a remote sensing image taken by the low-light imager. After obtaining the remote sensing image, the remote sensing image is also recognized to identify the target object and the ground shadow of the target object from the remote sensing image.

[0074] S102: Obtaining the length of a pixel spacing in the remote sensing image corresponding to the length in the real world;

[0075] That is, the proportional relationship between a pixel spacing in a remote sensing image and the length in the real world is known; for example, a pixel spacing represents 1 meter in the real world.

[0076] Pixel pitch is the distance between two pixels, also known as pixel span.

[0077] S103: Counting the number of pixel spacings occupied by ground shadows of target objects in the remote sensing image;

[0078] That is, the pixel span occupied by the ground shadow corresponding to the target object is counted.

[0079] S104: Calculate the length L of the ground shadow of the target object in the real world according to the length in the real world corresponding to one pixel spacing in the remote sensing image and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image;

[0080] For example, one pixel spacing in a remote sensing image corresponds to a length of 1 meter in the real world, and the pixel spacing occupied by the ground shadow of the target object is 8. Then, the length of the ground shadow of the target object in the real world is L=1×8=8 meters.

[0081] S105: Calculate the solar altitude angle A according to the imaging time of the remote sensing image and the position of the twilight satellite when the remote sensing image is taken;

[0082] In a specific embodiment, the step of calculating the solar altitude angle A according to the imaging time of the remote sensing image and the position of the twilight satellite when the remote sensing image is taken may include:

[0083] Acquisition time of remote sensing images;

[0084] According to the position of the satellite at dawn and dusk when taking remote sensing images, the longitude λ and latitude of the target object are obtained.

[0085] Calculate the solar hour angle ω according to the imaging time of the remote sensing image and the longitude λ of the target object;

[0086] Using the formula Calculate the solar declination δ on the imaging day of the remote sensing image, where N is the number of days calculated from January 1 of the imaging day to the imaging day;

[0087] According to the solar hour angle ω and the latitude of the target object The solar declination δ on the day of remote sensing image imaging is calculated using the formula Calculate the solar altitude angle A.

[0088] Specifically, the step of calculating the solar hour angle ω according to the imaging time of the remote sensing image may include:

[0089] According to the time difference of 4 minutes for each degree of longitude difference and the longitude difference between the longitude of the target object and the longitude of the standard time location, calculate the time difference Δt between the target object and the standard time location, where the unit of Δt is hour;

[0090] The solar hour angle ω is calculated using the formula ω=[12-(imaging time of the remote sensing image+Δt)]×15°, where the imaging time of the remote sensing image is in hours, 12 represents noon, and 15° represents the angle by which the solar hour angle ω increases every hour.

[0091] In practical applications, the imaging date of the image can be confirmed based on the file name of the remote sensing image. This is because the file name of the remote sensing image usually contains the following information:

[0092] 1. Satellite identification

[0093] Usually the satellite name or number is used, such as "L8" in "Landsat8", or a specific satellite number. This allows users to quickly identify which satellite acquired the image.

[0094] 2. Shooting time information

[0095] 1) Date: Generally expressed in the format of year, month, and day, such as "20240904".

[0096] 2) Time: may include hours, minutes, and seconds. For example, "153025" means 15:30:25.

[0097] 3. Geographic location information

[0098] 1) Longitude and latitude range: Use a specific encoding method to represent the longitude and latitude range covered by the image in order to determine the geographic location of the image.

[0099] 2) Region abbreviations: The abbreviations of specific regions are used to indicate the area covered by the image.

[0100] 4. Band information

[0101] If it is a multi-band remote sensing image, specific characters may be used in the file name to represent different bands, such as "B1" to represent the first band.

[0102] 5. Data type or product level

[0103] Distinguish between raw data, processed data or different product levels, such as "Level 1" for level 1 products.

[0104] For example, the file name of a remote sensing image is: "L8_20240904_153025_45N-50N_120W-125W_B3_Level1.tif", which means a first-level product image file of the third band covering the area of ​​45 to 50 degrees north latitude and 120 to 125 degrees west longitude acquired by the Landsat8 satellite at 15:30:25 on September 4, 2024. The suffix "tif" indicates that the image file format is TIFF.

[0105] The solar hour angle refers to the hour angle of the center of the solar disk, that is, the angular distance from the celestial meridian of the observation point along the celestial equator to the hour circle where the sun is located. The solar hour angle at 12 noon is 0°, the solar hour angle in the morning is negative, and the solar hour angle in the afternoon is positive. For example, at 9 am, the solar hour angle is -45°; at 3 pm, the solar hour angle is 45°.

[0106] In a specific embodiment, the standard time location may be Beijing, and the longitude of Beijing is 120° from Tokyo. For example, the longitude of the target object location is 110° from Tokyo, and the imaging time of the remote sensing image is 14:00.

[0107] The longitude difference between the target object's location and Beijing's longitude is |110°-120°|=10°. Since the time difference is 4 minutes for each degree of longitude difference, and the smaller the longitude of Tokyo, the later the time is, then the target object's location is 40 minutes later than Beijing's time, so Hour. Solar hour angle

[0108] Solar declination is the angle between the Earth's equatorial plane and the line connecting the Sun and the Earth's center.

[0109] The calculation formula of solar declination is relatively complicated, and the approximate formula is Where N is the number of days from January 1st of the imaging year to the imaging day. For example, if the imaging day is September 3rd, 2024, then N is the number of days from January 1st, 2024 to September 3rd, 2024. Specifically, N = 31 + 29 + 31 + 30 + 31 + 30 + 31 + 3 = 247. Substituting N = 247 into the formula, the solar declination δ can be calculated.

[0110] S106: According to the ground shadow length L of the target object and the solar altitude angle A in the real world, the height H of the target object is calculated using the formula H=L×tanA.

[0111] Due to the low altitude angle of the sun in the early morning or dusk and the low light conditions, the ground shadows of the objects are long and obvious. The twilight satellite can photograph the target objects in the early morning and dusk, and the low-light imager can capture and enhance weak light signals to obtain high-quality remote sensing images. Therefore, the method provided in the embodiment of the present invention uses the low-light imager on the twilight satellite to take a remote sensing image of the target object in the early morning or dusk, and calculates the height of the object based on the remote sensing image. Due to the low altitude angle of the sun when the remote sensing image is taken, the ground shadows of the objects are long and obvious. Therefore, compared with the existing technology, the calculation accuracy can be significantly improved and the error of height calculation can be significantly reduced.

[0112] In order to improve the robustness of the algorithm, the method provided in the embodiment of the present invention can use the twilight satellite and the low-light imager to respectively photograph the target object in the opposite directions at dawn and dusk to obtain a pair of remote sensing images in opposite directions: remote sensing image 1 and remote sensing image 2, which can be seen in Figure 2 and Figure 3 ,in, Figure 2 The relationship between the height and shadow of the target object in the remote sensing image 1 taken by the low-light imager in the early morning is shown. Figure 3 The relationship between the height of the target object and its shadow in remote sensing image 2 taken by the low-light imager at dusk is shown, and the height of the object is calculated based on remote sensing image 1 and remote sensing image 2. Figure 4 , a method for calculating the height of a ground object based on remote sensing image 1 and remote sensing image 2, comprising:

[0113] S401: Acquire a pair of remote sensing images taken by a morning and evening satellite in opposite directions for a target object: remote sensing image 1 and remote sensing image 2;

[0114] S402: for the remote sensing image 1 and the remote sensing image 2, respectively obtaining the length of a pixel spacing in the remote sensing image 1 and the remote sensing image 2 corresponding to the length in the real world;

[0115] S403: Counting the number of pixel spacings occupied by ground shadows of target objects in remote sensing image 1 and remote sensing image 2 respectively;

[0116] S404: for the remote sensing image 1, according to the length in the real world corresponding to one pixel spacing in the remote sensing image 1 and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image 1, calculate and obtain the ground shadow length L1 of the target object in the real world corresponding to the remote sensing image 1;

[0117] S405: for the remote sensing image 2, according to the length in the real world corresponding to one pixel in the remote sensing image 2 and the number of pixels occupied by the ground shadow of the target object in the remote sensing image 2, calculate and obtain the ground shadow length L2 of the target object in the real world corresponding to the remote sensing image 2;

[0118] S406: Calculate the solar altitude angle A1 of remote sensing image 1 according to the imaging time of remote sensing image 1 and the position of the twilight satellite when the remote sensing image 1 is taken, and calculate the solar altitude angle A2 of remote sensing image 2 according to the imaging time of remote sensing image 2 and the position of the twilight satellite when the remote sensing image 2 is taken;

[0119] In practical applications, for remote sensing image 1 and remote sensing image 2, the solar altitude angle A1 corresponding to remote sensing image 1 and the solar altitude angle A2 corresponding to remote sensing image 2 can be calculated by the following steps:

[0120] Acquisition time of remote sensing images;

[0121] According to the position of the satellite at dawn and dusk when taking remote sensing images, the longitude λ and latitude of the target object are obtained.

[0122] According to the time difference of 4 minutes for each degree of longitude difference and the longitude difference between the longitude of the target object and the longitude of the standard time location, calculate the time difference Δt between the target object and the standard time location, where the unit of Δt is hour;

[0123] The solar hour angle ω is calculated using the formula ω = [12-(imaging time of remote sensing image + Δt)] × 15°, where the imaging time of remote sensing image is in hours, 12 represents noon, and 15° represents the angle amount by which the solar hour angle ω increases every hour.

[0124] Using the formula Calculate the solar declination δ on the imaging day of the remote sensing image, where N is the number of days calculated from January 1 of the imaging day to the imaging day;

[0125] According to the solar hour angle ω and the latitude of the target object The solar declination δ on the day of remote sensing image imaging is calculated using the formula Calculate the solar altitude angle A.

[0126] S407: According to the remote sensing image 1, the ground shadow length L1 of the target object in the real world and the solar altitude angle A1, a first height H1 of the target object is calculated using the formula H1=L1×tanA1;

[0127] S408: According to the remote sensing image 2, the ground shadow length L2 of the target object in the real world and the solar altitude angle A2, a second height H2 of the target object is calculated using the formula H2=L2×tanA2;

[0128] S409: Based on the first height H1 and the second height H2 of the target object, use the formula Calculate and obtain the height H of the target object.

[0129] The method provided in this embodiment uses the low-light imager on the dawn and dusk satellite to photograph the target object in opposite directions at dawn and dusk respectively to obtain a pair of remote sensing images in opposite directions, and calculates the height of the object based on the pair of remote sensing images in opposite directions. Since the altitude angle of the sun is low when the remote sensing images are taken, the ground shadow of the object is long and has obvious characteristics. Therefore, the height of the target object calculated from the two remote sensing images is relatively accurate. However, in order to further increase the robustness of the algorithm and improve the accuracy of the algorithm, the average of the heights calculated from the two remote sensing images can be taken as the final height value of the target object. This is more conducive to reducing the error in height calculation.

[0130] In practical applications, the method provided by the embodiment of the present invention can send a task to the dawn and dusk satellite to use a low-light imager to shoot the target area; the dawn and dusk satellite will automatically trigger the low-light imager to shoot the target area in opposite directions at dawn and dusk when the lighting conditions meet the requirements according to the shooting task to obtain a pair of remote sensing images in opposite directions: remote sensing image 1 and remote sensing image 2, and then calculate the height H1 of the target object based on remote sensing image 1 and the height H2 of the target object based on remote sensing image 2, and then use the average of H1 and H2 as the height value of the target object. The method provided by the embodiment of the present invention can calculate the height of the target object based on only one remote sensing image when one of the remote sensing images 1 or 2 is unclear and cannot be used for calculation, which also makes the method provided by the embodiment of the present invention more flexible.

[0131] and Figure 1 Corresponding to the embodiment shown in FIG. 1 , the embodiment of the present invention further provides a device for calculating the height of ground objects based on remote sensing images. Figure 5 As shown, the device includes: a first acquisition module 501, a second acquisition module 502, a statistical module 503, a shadow calculation module 504, an altitude calculation module 505, and a height calculation module 506, wherein:

[0132] The first acquisition module 501 is used to acquire a remote sensing image taken by a morning and evening satellite for a target object;

[0133] The second acquisition module 502 is used to obtain the length of a pixel spacing in the remote sensing image corresponding to the real world;

[0134] A statistics module 503 is used to count the number of pixel spacings occupied by ground shadows of target objects in remote sensing images;

[0135] The shadow calculation module 504 is used to calculate the ground shadow length L of the target object in the real world according to the length in the real world corresponding to one pixel spacing in the remote sensing image and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image;

[0136] The altitude angle calculation module 505 is used to calculate the solar altitude angle A according to the imaging time of the remote sensing image and the position of the dawn and dusk satellite when the remote sensing image is taken;

[0137] The height calculation module 506 is used to calculate the height H of the target object according to the ground shadow length L and the solar altitude angle A of the target object in the real world using the formula H=L×tanA.

[0138] Optionally, the altitude angle calculation module 505 is specifically used for:

[0139] Acquisition time of remote sensing images;

[0140] According to the position of the satellite at dawn and dusk when taking remote sensing images, the longitude λ and latitude of the target object are obtained.

[0141] Calculate the solar hour angle ω according to the imaging time of the remote sensing image and the longitude λ of the target object;

[0142] Using the formula Calculate the solar declination δ on the imaging day of the remote sensing image, where N is the number of days calculated from January 1 of the imaging day to the imaging day;

[0143] According to the solar hour angle ω and the latitude of the target object The solar declination δ on the day of remote sensing image imaging is calculated using the formula Calculate the solar altitude angle A.

[0144] Optionally, the altitude angle calculation module 505 is further specifically used for:

[0145] According to the time difference of 4 minutes for each degree of longitude difference and the longitude difference between the longitude of the target object and the longitude of the standard time location, calculate the time difference Δt between the target object and the standard time location, where the unit of Δt is hour;

[0146] The solar hour angle ω is calculated using the formula ω=[(imaging time of the remote sensing image+Δt)-12]×15°, where the imaging time of the remote sensing image is in hours, 12 represents noon, and 15° represents the angle by which the solar hour angle ω increases every hour.

[0147] Optionally, the first acquisition module 501 is further used to acquire a pair of remote sensing images taken by a morning and evening satellite in opposite directions for the target object: remote sensing image 1 and remote sensing image 2;

[0148] The shadow calculation module 504 is further used to: for the remote sensing image 1, according to the length in the real world corresponding to one pixel in the remote sensing image 1 and the number of pixels occupied by the ground shadow of the target object in the remote sensing image 1, calculate the ground shadow length L1 of the target object in the real world corresponding to the remote sensing image 1;

[0149] For remote sensing image 2, according to the length in the real world corresponding to one pixel in remote sensing image 2 and the number of pixels occupied by the ground shadow of the target object in remote sensing image 2, the ground shadow length L2 of the target object in the real world corresponding to remote sensing image 2 is calculated;

[0150] The altitude angle calculation module 505 is further used to calculate the solar altitude angle A1 of the remote sensing image 1 according to the imaging time of the remote sensing image 1 and the position of the dawn and dusk satellite when the remote sensing image 1 is taken, and to calculate the solar altitude angle A2 of the remote sensing image 2 according to the imaging time of the remote sensing image 2 and the position of the dawn and dusk satellite when the remote sensing image 2 is taken;

[0151] The height calculation module 506 is further used for:

[0152] According to the remote sensing image 1, the ground shadow length L1 of the target object in the real world and the solar altitude angle A1, the first height H1 of the target object is calculated using the formula H1=L1×tanA1;

[0153] According to the remote sensing image 2, the ground shadow length L2 of the target object in the real world and the solar altitude angle A2, the second height H2 of the target object is calculated using the formula H2=L2×tanA2;

[0154] According to the first height H1 and the second height H2 of the target object, the formula Calculate and obtain the height H of the target object.

[0155] The device provided in this embodiment can use the low-light imager on the dawn and dusk satellite to respectively shoot the target object in opposite directions at dawn and dusk to obtain a pair of remote sensing images in opposite directions, and calculate the height of the object based on the pair of remote sensing images in opposite directions. Since the altitude angle of the sun is low when the remote sensing images are shot, the ground shadow of the object is long and has obvious characteristics. Therefore, the height of the target object calculated from the two remote sensing images is relatively accurate. However, in order to further increase the robustness of the algorithm and improve the accuracy of the algorithm, the average of the heights calculated from the two remote sensing images can be taken as the final height value of the target object. This is more conducive to reducing the error in height calculation.

[0156] and Figure 1 Corresponding to the embodiment shown, the embodiment of the present invention further provides an electronic device, see Figure 6 , including a processor 601, a communication interface 602, a memory 603 and a communication bus 604, wherein the processor 601, the communication interface 602, and the memory 603 communicate with each other through the communication bus 604;

[0157] Memory 603, used for storing computer programs;

[0158] The processor 601 is used to implement any method step of calculating the height of ground objects based on remote sensing images described in the above embodiments when executing the program stored in the memory.

[0159] The electronic device provided in this embodiment can use the low-light imager on the dawn and dusk satellite to respectively shoot the target object in opposite directions in the early morning and dusk to obtain a pair of remote sensing images in opposite directions, and calculate the height of the object based on the pair of remote sensing images in opposite directions. Since the altitude angle of the sun is low when the remote sensing images are shot, the ground shadow of the object is long and has obvious characteristics. Therefore, the height of the target object calculated from the two remote sensing images is relatively accurate. However, in order to further increase the robustness of the algorithm and improve the accuracy of the algorithm, the average of the heights calculated from the two remote sensing images can be taken as the final height value of the target object. This is more conducive to reducing the error in height calculation.

[0160] and Figure 1 Corresponding to the embodiment shown, an embodiment of the present invention further provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, any method step of calculating the height of ground objects based on remote sensing images described in the above embodiments is implemented.

[0161] The storage medium provided in this embodiment can utilize the low-light imager on the twilight satellite to photograph the target object in opposite directions at dawn and dusk, respectively, to obtain a pair of remote sensing images in opposite directions, and calculate the height of the object based on the pair of remote sensing images in opposite directions. Since the altitude angle of the sun is low when the remote sensing images are taken, the ground shadow of the object is long and has obvious characteristics. Therefore, the height of the target object calculated from the two remote sensing images is relatively accurate. However, in order to further increase the robustness of the algorithm and improve the accuracy of the algorithm, the average of the heights calculated from the two remote sensing images can be taken as the final height value of the target object. This is more conducive to reducing the error in height calculation.

[0162] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0163] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0164] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0165] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0166] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for calculating the height of ground objects based on remote sensing images, characterized in that: The method comprises: Obtain a remote sensing image taken by a morning and evening satellite targeting the target object; Obtaining the length in the real world corresponding to a pixel spacing in the remote sensing image; Counting the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image; Calculate the length L of the ground shadow of the target object in the real world according to the length in the real world corresponding to one pixel spacing in the remote sensing image and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image; Calculating the solar altitude angle A according to the imaging time of the remote sensing image and the position of the twilight satellite when taking the remote sensing image; According to the ground shadow length L of the target object and the solar altitude angle A in the real world, the height H of the target object is calculated using the formula H=L×tanA.

2. The method according to claim 1, characterized in that The step of calculating the solar altitude angle A according to the imaging time of the remote sensing image and the position of the twilight satellite when taking the remote sensing image comprises: Acquiring imaging time of the remote sensing image; According to the position of the morning and evening satellite when taking the remote sensing image, the longitude λ and latitude of the location of the target object are obtained. Calculate the solar hour angle ω according to the imaging time of the remote sensing image and the longitude λ of the location of the target object; Using the formula Calculate the solar declination δ on the imaging day of the remote sensing image, where N is the number of days calculated from January 1 of the year of the imaging day to the imaging day; According to the solar hour angle ω and the latitude of the target object The solar declination δ on the day of the remote sensing image imaging is calculated using the formula Calculate the solar altitude angle A.

3. The method according to claim 2, characterized in that The step of calculating the solar hour angle ω according to the imaging time of the remote sensing image comprises: According to the time difference of 4 minutes for one degree of longitude difference and the longitude difference between the longitude of the location of the target object and the location of the standard time, calculate the time difference Δt between the location of the target object and the location of the standard time, where the unit of Δt is hours; The solar hour angle ω is calculated using the formula ω=[12-(imaging time of the remote sensing image+Δt)]×15°, where the imaging time of the remote sensing image is in hours, 12 represents noon, and 15° represents the angle by which the solar hour angle ω increases every hour.

4. The method according to claim 1, characterized in that The method further comprises: Obtain a pair of remote sensing images taken by the morning and evening satellite in opposite directions for the target object: remote sensing image 1 and remote sensing image 2; For the remote sensing image 1, according to the length in the real world corresponding to one pixel spacing in the remote sensing image 1 and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image 1, the ground shadow length L1 of the target object in the real world corresponding to the remote sensing image 1 is calculated; For the remote sensing image 2, according to the length in the real world corresponding to one pixel spacing in the remote sensing image 2 and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image 2, the ground shadow length L2 of the target object in the real world corresponding to the remote sensing image 2 is calculated; Calculate the solar altitude angle A1 of the remote sensing image 1 according to the imaging time of the remote sensing image 1 and the position of the twilight satellite when the remote sensing image 1 is taken, and calculate the solar altitude angle A2 of the remote sensing image 2 according to the imaging time of the remote sensing image 2 and the position of the twilight satellite when the remote sensing image 2 is taken; According to the remote sensing image 1, the ground shadow length L1 of the target object in the real world and the solar altitude angle A1, the first height H1 of the target object is calculated using the formula H1=L1×tan A1; According to the remote sensing image 2, the ground shadow length L2 of the target object in the real world and the solar altitude angle A2, the second height H2 of the target object is calculated using the formula H2=L2×tan A2; According to the first height H1 of the target object and the second height H2 of the target object, the formula The height H of the target object is obtained by calculation.

5. A device for calculating the height of ground objects based on remote sensing images, characterized in that: The device comprises: The first acquisition module is used to acquire a remote sensing image taken by a morning and evening satellite for a target object; A second acquisition module is used to obtain the length of a pixel spacing in the remote sensing image corresponding to the real world; A statistical module, used for counting the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image; A shadow calculation module, used to calculate the ground shadow length L of the target object in the real world according to the length in the real world corresponding to one pixel spacing in the remote sensing image and the number of pixel spacings occupied by the ground shadow of the target object in the remote sensing image; An altitude angle calculation module is used to calculate the solar altitude angle A according to the imaging time of the remote sensing image and the position of the twilight satellite when the remote sensing image is taken; The height calculation module is used to calculate the height H of the target object according to the ground shadow length L and the solar altitude angle A of the target object in the real world using the formula H=L×tanA.

6. The device according to claim 5, characterized in that The altitude angle calculation module is specifically used for: Acquiring imaging time of the remote sensing image; According to the position of the morning and evening satellite when taking the remote sensing image, the longitude λ and latitude of the location of the target object are obtained. Calculate the solar hour angle ω according to the imaging time of the remote sensing image and the longitude λ of the location of the target object; Using the formula Calculate the solar declination δ on the imaging day of the remote sensing image, where N is the number of days calculated from January 1 of the year of the imaging day to the imaging day; According to the solar hour angle ω and the latitude of the target object The solar declination δ on the day of the remote sensing image imaging is calculated using the formula Calculate the solar altitude angle A.

7. The device according to claim 5, characterized in that The altitude angle calculation module is further specifically used for: According to the time difference of 4 minutes for one degree of longitude difference and the longitude difference between the longitude of the location of the target object and the location of the standard time, calculate the time difference Δt between the location of the target object and the location of the standard time, where the unit of Δt is hours; The solar hour angle ω is calculated using the formula ω=[(imaging time of the remote sensing image+Δt)-12]×15°, where the imaging time of the remote sensing image is in hours, 12 represents noon, and 15° represents the angle by which the solar hour angle ω increases every hour.

8. The device according to claim 5, characterized in that The first acquisition module is further used to acquire a pair of remote sensing images taken by a morning and evening satellite in opposite directions for the target object: remote sensing image 1 and remote sensing image 2; The shadow calculation module is further used to: for the remote sensing image 1, according to the length in the real world corresponding to one pixel in the remote sensing image 1 and the number of pixels occupied by the ground shadow of the target object in the remote sensing image 1, calculate the ground shadow length L1 of the target object in the real world corresponding to the remote sensing image 1; For the remote sensing image 2, according to the length in the real world corresponding to one pixel in the remote sensing image 2 and the number of pixels occupied by the ground shadow of the target object in the remote sensing image 2, calculate and obtain the ground shadow length L2 of the target object in the real world corresponding to the remote sensing image 2; The altitude angle calculation module is further used to calculate the solar altitude angle A1 of the remote sensing image 1 according to the imaging time of the remote sensing image 1 and the position of the twilight satellite when the remote sensing image 1 is taken, and to calculate the solar altitude angle A2 of the remote sensing image 2 according to the imaging time of the remote sensing image 2 and the position of the twilight satellite when the remote sensing image 2 is taken; The height calculation module is also used for: According to the remote sensing image 1, the ground shadow length L1 of the target object in the real world and the solar altitude angle A1, the first height H1 of the target object is calculated using the formula H1=L1×tan A1; According to the remote sensing image 2, the ground shadow length L2 of the target object in the real world and the solar altitude angle A2, the second height H2 of the target object is calculated using the formula H2=L2×tan A2; According to the first height H1 of the target object and the second height H2 of the target object, the formula The height H of the target object is obtained by calculation.

9. An electronic device, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; The memory is used to store computer programs; The processor is used to implement the method steps described in any one of claims 1-4 when executing the program stored in the memory.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method steps described in any one of claims 1 to 4 are implemented.

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