Urban cadastral surveying and mapping imaging method and system based on ground feature boundary contour extraction

Abstract

The invention discloses an urban cadastral surveying and mapping imaging method and system based on ground feature boundary contour extraction, relates to the field of geographic information, and solves the problem that the urban cadastral surveying and mapping imaging method is poor in surveying and mapping effect. S2, respectively acquiring a first flight height value and a second flight height value according to the flight environment data to adjust the flight height of the flight surveying and mapping equipment; s3, acquiring a first shooting focal length distance and a second shooting focal length distance according to the flight environment data and the second flight height value, and performing real-time shooting focal length adjustment on the flight surveying and mapping equipment; s4, acquiring a regional surveying and mapping image according to the second flight height value and the second shooting focal section distance; and S5, establishing an image detection model to detect the regional surveying and mapping image in real time to obtain a detected regional surveying and mapping image, the urban cadastral surveying and mapping efficiency can be effectively improved, and the accuracy and reliability of a surveying and mapping result are ensured.

Description

Technical Field

[0001] The invention belongs to the field of geographic information, and relates to cadastral surveying and mapping technology, in particular to an urban cadastral surveying and mapping imaging method and system based on the extraction of land feature boundary contours. Background Art

[0002] Urban cadastre is a type of cadastre, and its objects are specific to the land under the jurisdiction of cities and towns, as well as land for industrial and mining enterprises, railways, roads, etc. that are independent of towns. The establishment and management of this cadastre is aimed at unified management and utilization of these land resources. Urban cadastre not only involves the science and management of land, but is also one of the important contents of land surveying and mapping. It covers information on land ownership, natural and economic conditions, and is the basis for national and local governments to carry out land management, planning, taxation, etc.

[0003] The existing urban cadastral mapping imaging methods have the following defects:

[0004] 1. The existing urban cadastral mapping imaging method requires manual operation of flying mapping equipment, which has high labor costs and low work efficiency;

[0005] 2. Traditional urban cadastral mapping imaging methods are usually unable to achieve autonomous detection and evaluation of mapping images, and cannot promptly discover and correct possible problems, resulting in the inability to guarantee imaging quality;

[0006] To this end, we propose an urban cadastral mapping imaging method and system based on object boundary contour extraction. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention aims to provide an urban cadastral mapping imaging method and system based on the extraction of land feature boundary contours. The present invention obtains flight environment data based on respectively obtaining a first area peak height, a first area valley height, a first real-time flight wind force value, a first real-time flight humidity value and a first real-time flight visibility value, and respectively obtains a first flight altitude value and a second flight altitude value according to the flight environment data to adjust the flight altitude of a flight mapping device, obtains a first shooting focal length and a second shooting focal length according to the flight environment data and the second flight altitude value to adjust the real-time shooting focal length of the flight mapping device, and maps a ji cadastral mapping sub-area according to the second flight altitude value and the second shooting focal length to obtain a regional mapping image.

[0008] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: the urban cadastral surveying and mapping imaging method based on the extraction of the boundary contour of the land object comprises the following specific steps:

[0009] Step S1: Divide the target city into m cadastral survey sub-areas, obtain the jthi The first area peak height, the first area valley height, the first real-time flight wind value, the first real-time flight humidity value, and the first real-time flight visibility value corresponding to the cadastral mapping sub-area are used to obtain flight environment data;

[0010] Step S2: acquiring a first flight altitude value and a second flight altitude value respectively according to the flight environment data, and adjusting the flight altitude of the flight mapping equipment according to the first flight altitude value and the second flight altitude value;

[0011] Step S3: acquiring a first shooting focal length and a second shooting focal length according to the flight environment data and the second flight altitude value, respectively, and adjusting the shooting focal length of the flight mapping device according to the first shooting focal length and the second shooting focal length;

[0012] Step S4: The flight surveying and mapping equipment performs a mapping of the jth image according to the second flight altitude value and the second shooting focal length. i The cadastral surveying and mapping sub-areas are surveyed and mapped to obtain regional surveying images;

[0013] Step S5: Establish an image detection model to perform real-time detection on the regional mapping image to obtain the detected regional mapping image.

[0014] Furthermore, the step S1 further includes the following specific steps:

[0015] Step S11: Obtain an existing surveying and mapping map of the target city, extract the boundary contour in the surveying and mapping map of the target city, obtain the boundary contour of the target city, and divide the cadastral surveying and mapping area of ​​the target city into j m cadastral survey sub-areas and name them j1 to j m cadastral mapping sub-areas;

[0016] Step S12: For the jth i The cadastral survey sub-area performs flight environment analysis to obtain the peak height of the first area and the valley height of the first area;

[0017] Step S13: Obtain the i A real-time wind force value at a flight altitude of a flight surveying and mapping device flying over the cadastral surveying and mapping sub-area, to obtain a first real-time flight wind force value;

[0018] Step S14: Obtain the i A real-time ambient humidity value of a flight altitude of a flight surveying and mapping device flying over the cadastral surveying and mapping sub-area, to obtain a first real-time flight humidity value;

[0019] Step S15: Get the jth iThe flight visibility value corresponding to the cadastral survey sub-area is used to obtain a first real-time flight visibility value;

[0020] Step S16: define the first area peak altitude, the first area valley altitude, the first real-time flight wind value, the first real-time flight humidity value and the first real-time flight visibility value as flight environment data.

[0021] Furthermore, the step S12 further includes the following specific steps:

[0022] Step S121: Fly the flight surveying and mapping equipment to the jth i Above the cadastral survey sub-area, when the flight survey equipment can obtain the jth i When mapping the global landscape of a sub-area, a laser radar is used to emit k laser beams from a laser emission point to the sub-area. n and label them as k1 to k n emitting a laser beam;

[0023] Step S122: Receive k1 to k n The emitted laser beam is reflected by the ground landscape to the kn reflected laser beams of the flight mapping equipment, and they are named k1 to k n Reflecting laser beams;

[0024] Step S123: Set the k1th to kth n The laser points where the emitted laser beam contacts the ground landscape are named k1 to k n Laser contact point position;

[0025] Step S124: acquiring the height of the k1th laser contact point from the ground according to the k1th emitted laser beam and the k1th reflected laser beam to obtain a height value of the k1th contact point;

[0026] Step S125: respectively perform the calculations on the k2th to kth n The height above the ground corresponding to the laser contact point is obtained to obtain the k2 to k n Contact point height value;

[0027] Step S126: The k1th to kth n The contact point height values ​​are compared, and the contact point height value with the largest value is named the peak height of the first region, and the contact point height value with the smallest value is named the valley height of the first region.

[0028] Furthermore, the step S124 further includes the following specific steps:

[0029] Step S1241: draw a straight line through the laser emission point that is parallel to the ground and has the same flight angle as the flight surveying and mapping equipment to obtain an angle reference line, obtain the angle between the k1th emitted laser beam and the angle reference line to obtain a first characteristic angle, obtain the angle between the k1th reflected laser beam and the angle reference line to obtain a second characteristic angle, obtain the angle formed by the k1th emitted laser beam and the k1th reflected laser beam to obtain a third characteristic angle, and obtain angle values ​​of the first characteristic angle, the second characteristic angle, and the third characteristic angle respectively;

[0030] Step S1242: obtaining a time value corresponding to when the laser emission point emits the k1th emitted laser beam to obtain a first time value, obtaining a time value corresponding to when the flight surveying and mapping device receives the k1th reflected laser beam to obtain a second time value, obtaining a line connecting the position point from the first time value to the second time value of the flight surveying and mapping device to obtain a characteristic flight straight line, and obtaining a length value of the characteristic flight straight line to obtain a length value of the characteristic flight straight line;

[0031] Step S1243: obtaining a first contact point line through a perpendicular line passing through the k1th laser contact point and the angle reference line;

[0032] Step S1244: in the triangle where the characteristic flight line, the k1th reflected laser beam, the outer angle corresponding to the first characteristic angle and the third characteristic angle are located, the length value corresponding to the k1th reflected laser beam is calculated by the sine theorem;

[0033] Calculate the length value corresponding to the k1th reflected laser beam. The specific formula is as follows:

[0034]

[0035] Among them, Fj1 is the length value corresponding to the k1th reflected laser beam, j1 is the angle value corresponding to the first characteristic angle, j3 is the angle value corresponding to the third characteristic angle, and Tfc is the characteristic flight straight line length value;

[0036] Step S1245: Obtain the time difference between the first time value and the second time value, obtain the characteristic time length value, obtain the propagation speed of the laser beam in the air, calculate the product of the characteristic time length value and the propagation speed of the laser beam in the air, and then calculate the difference between the obtained product and the length value corresponding to the k1th reflected laser beam to obtain the length value corresponding to the k1th emitted laser beam;

[0037] Step S1246: Calculate the angle value corresponding to the first characteristic angle and the length value corresponding to the k1th emitted laser beam to obtain the k1th contact point height value;

[0038] Calculate the height value of the k1th contact point, and the specific formula is configured as follows:

[0039] Jcg1 = Tj1 × sin(180°-j1);

[0040] Among them, Jcg1 is the height value of the k1th contact point, Tj1 is the length value corresponding to the k1th emitted laser beam, and j1 is the angle value corresponding to the first characteristic angle.

[0041] Furthermore, the step S15 further includes the following specific steps:

[0042] Step S151: In the jth i Mark multiple visibility measurement marking points in the cadastral survey sub-area, and name them as the first to pth measurement marking points respectively;

[0043] Step S152: Mark a circle of pixel comparison areas around the first to pth measured mark points, obtain an image of each measured mark point and the corresponding pixel comparison area, and obtain the first to pth sample comparison images;

[0044] Step S153: respectively obtaining the difference between the pixel depth value of the visibility measurement mark point and the pixel depth value of the pixel comparison area in the first to pth sample comparison images, obtaining p sample pixel depth differences, and averaging them to obtain the sample average pixel contrast difference;

[0045] Step S154: photographing an image of the location of the first measurement mark point from the current flight altitude using the flight surveying and mapping equipment to obtain a first measurement point mark image;

[0046] Step S155: performing region segmentation on the region where the first measurement mark point is located in the first measurement point mark image to obtain a first measurement point region, randomly selecting a number of pixel points in the first measurement point region, respectively obtaining a pixel depth value of each pixel point to obtain a plurality of pixel depth values, and averaging the pixel depth values ​​to obtain a first average pixel depth value;

[0047] Step S156: selecting a plurality of comparison pixel points in the pixel corresponding area of ​​the first measurement point mark image, respectively obtaining a pixel depth value corresponding to each comparison pixel point, obtaining a plurality of pixel depth values, and calculating an average of the values ​​to obtain a second average pixel depth value;

[0048] Step S157: Calculate the difference between the first average pixel depth value and the second average pixel depth value to obtain a first pixel contrast difference, and obtain the pixel contrast differences corresponding to the second to p-th measurement mark points respectively to obtain the second to p-th pixel contrast differences;

[0049] Step S158: Calculate the average of the first pixel contrast difference to the pth pixel contrast difference to obtain a real-time average pixel contrast difference;

[0050] Step S159: Calculate the ratio of the sample average pixel contrast difference to the real-time average pixel contrast difference to obtain a first real-time flight visibility value.

[0051] Furthermore, the step S2 further includes the following specific steps:

[0052] Step S21: Acquire flight environment data;

[0053] Step S22: acquiring a first area peak altitude, a first real-time flight wind value, a first real-time flight humidity value, and a first real-time flight visibility value according to the flight environment data;

[0054] Step S23: Calculate the first real-time flight wind speed value, the first real-time flight humidity value, and the first real-time flight visibility value to obtain the jth i Flight altitude adjustment factor corresponding to cadastral survey sub-area;

[0055] Calculate the flight altitude adjustment coefficient. The specific formula is as follows:

[0056]

[0057] Wherein, Fgt is the flight altitude adjustment coefficient, Fl1 is the first real-time flight wind value, Sd1 is the first real-time flight humidity value, Nj1 is the first real-time flight visibility value, a1 is the set proportional coefficient and a1 is greater than 0;

[0058] Step S24: Get the jth i The real-time flight altitude value of the flight surveying and mapping equipment corresponding to the cadastral surveying and mapping sub-area is used to obtain a first flight altitude value;

[0059] Step S25: Calculating the peak height of the first area and the flight height adjustment coefficient to obtain a reference flight height value of the flight mapping equipment, and naming it as a second flight height value;

[0060] Calculate the reference flight altitude value of the flight mapping equipment. The specific formula is as follows:

[0061] Fjg=Qg1×(1+Fgt);

[0062] Among them, Fjg is the reference flight altitude value of the flight mapping equipment, Qg1 is the peak altitude of the first area, and Fgt is the flight altitude adjustment coefficient;

[0063] Step S26: adjusting the flight altitude of the flight surveying and mapping equipment according to the first flight altitude value and the second flight altitude value;

[0064] The details are as follows:

[0065] Step S261: when the first flight altitude value is greater than the second flight altitude value, the real-time flight altitude corresponding to the flight surveying and mapping equipment is adjusted downward until the real-time flight altitude reaches the second flight altitude value;

[0066] Step S262: When the first flight altitude value is less than the second flight altitude value, the real-time flight altitude corresponding to the flight surveying and mapping equipment is adjusted upward until the real-time flight altitude reaches the second flight altitude value.

[0067] Furthermore, the step S3 further includes the following specific steps:

[0068] Step S31: obtaining a second flight altitude;

[0069] Step S32: obtaining a preset focal length corresponding to the second flight altitude value of the flight surveying and mapping device;

[0070] Step S33: Obtain flight environment data, obtain the peak height of the first region and the valley height of the first region according to the flight environment data, calculate the difference between the peak height of the first region and the valley height of the first region, and then take the absolute value of the obtained difference to obtain the jth i The height difference of the surveyed terrain corresponding to the cadastral survey sub-area;

[0071] Step S34: obtaining a first real-time flight visibility value according to the flight environment data;

[0072] Step S35: Get the jth i The real-time light intensity value corresponding to the cadastral surveying sub-area is obtained, and the real-time shooting focal length corresponding to the flight surveying equipment is obtained to obtain the first shooting focal length;

[0073] Step S36: obtaining a shooting focal length adjustment coefficient by calculating the real-time illumination intensity value, the first real-time flight visibility value, and the height difference of the surveyed terrain;

[0074] Calculate the shooting focal length adjustment coefficient, the specific formula configuration is as follows:

[0075]

[0076] Among them, Pjx is the shooting focal length adjustment coefficient, Gxc is the height difference of the surveyed terrain, Nj1 is the first real-time flight visibility value, Gzq is the real-time light intensity value, b1 is the set proportional coefficient and b1 is greater than 0;

[0077] Step S37: Calculate the product of the preset focal length and the shooting focal length adjustment coefficient to obtain a second shooting focal length;

[0078] Step S38: adjusting the shooting focal length of the flight surveying and mapping equipment in real time according to the first shooting focal length and the second shooting focal length;

[0079] The step S38 further includes the following specific steps:

[0080] Step S381: when the first shooting focal length is greater than the second shooting focal length, the real-time shooting focal length of the flight surveying and mapping device is adjusted downward until the real-time shooting focal length of the flight surveying and mapping device is equal to the second shooting focal length;

[0081] Step S382: When the first shooting focal length is smaller than the second shooting focal length, the real-time shooting focal length of the flight surveying and mapping device is adjusted upward until the real-time shooting focal length of the flight surveying and mapping device is equal to the second shooting focal length.

[0082] Furthermore, the step S4 further includes the following specific steps:

[0083] Step S41: obtaining a second flight height value and a second shooting focal length;

[0084] Step S42: In the jth i When the cadastral surveying sub-area is surveyed, the flying surveying equipment automatically flies to the second flying altitude value, and the shooting equipment is automatically adjusted to the second shooting focal length. i The cadastral surveying and mapping sub-areas are surveyed and mapped to obtain regional surveying images;

[0085] Step S43: Perform imaging detection on the regional mapping image. If the imaging detection is qualified, i The cadastral survey sub-area is completed. If the imaging test fails, continue to i The cadastral survey sub-area is surveyed until the imaging test is qualified.

[0086] Furthermore, the step S5 further includes the following specific steps:

[0087] Step S51: obtaining a plurality of qualified historical surveying and mapping images as sample surveying and mapping images, and dividing the sample surveying and mapping images into an image test set and an image training set according to a preset division ratio;

[0088] Step S52: Establish an image detection model through the existing artificial intelligence platform, use the image training set to train the image detection model, and after the training is completed, use the image test set to perform a qualification test on the image detection model, and obtain the numerical value of the test result to obtain the test result index value;

[0089] Step S53: if the test result index value is greater than or equal to the preset test index value, the image detection model training is completed; if the test result index value is less than the preset test index value, the image detection model continues to be qualified by using the image test set until the test result index value is greater than or equal to the preset test index value;

[0090] Step S54: Use the trained image detection model to identify the regional mapping image. If the test result output by the image detection model is qualified, the imaging detection is qualified. i After the cadastral survey sub-area is completed, if the test result output by the image detection model is unqualified, the imaging detection is unqualified, and the jth area is continued. i The cadastral survey sub-area is surveyed until the imaging test is qualified.

[0091] Furthermore, the urban cadastral mapping imaging method based on the extraction of the boundary contour of the object includes:

[0092] Data acquisition module: used to respectively acquire the peak height of the first area, the valley height of the first area, the first real-time flight wind value, the first real-time flight humidity value and the first real-time flight visibility value to obtain flight environment data;

[0093] Altitude adjustment module: obtains the first flight altitude value and the second flight altitude value according to the flight environment data to adjust the flight altitude of the flight mapping equipment;

[0094] Focus adjustment module: obtains the first shooting focal length and the second shooting focal length according to the flight environment data and the second flight altitude value, respectively, and adjusts the shooting focal length of the flight mapping equipment in real time;

[0095] Surveying and mapping imaging module: regional cadastral surveying and mapping is performed according to the second flight altitude value and the second shooting focal length distance to obtain a regional surveying and mapping image.

[0096] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0097] 1. The present invention automatically adjusts the flight altitude and shooting focal length of the flight surveying and mapping equipment by acquiring flight environment data, which can effectively improve the surveying and mapping efficiency of urban cadastral land, and avoid the problem of unstable imaging quality caused by human control;

[0098] 2. The present invention detects regional surveying and mapping images by establishing an image detection model, which can effectively guarantee the imaging quality of regional surveying and mapping, ensure the accuracy and reliability of surveying and mapping results, and improve the availability and application scope of surveying and mapping data. BRIEF DESCRIPTION OF THE DRAWINGS

[0099] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0100] Figure 1 It is a diagram of the implementation steps of the present invention;

[0101] Figure 2 is the overall system block diagram of the present invention;

[0102] Figure 3 A flight schematic diagram of the flight mapping equipment of the present invention;

[0103] Figure 4 This is a schematic diagram of the measurement marking points in the present invention;

[0104] In the figure, 1 is the k1th laser emission point, 2 is the characteristic flight straight line, 3 is the k1th emitted laser beam, 4 is the k1th reflected laser beam, 5 is the first characteristic angle, 6 is the second characteristic angle, 7 is the third characteristic angle, 8 is the laser contact point position line, 9 is the laser receiving point, and 10 is the laser contact point position. DETAILED DESCRIPTION

[0105] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0106] Embodiment 1

[0107] See also Figure 1 , the present invention provides a technical solution: an urban cadastral surveying and mapping imaging system based on the extraction of the boundary contour of the land object, comprising a data acquisition module, a height adjustment module, a focal length adjustment module, a surveying and mapping imaging module and a server, wherein the data acquisition module, the height adjustment module, the focal length adjustment module and the surveying and mapping imaging module are respectively connected to the server;

[0108] The data acquisition module acquires flight environment data;

[0109] Obtain the existing surveying and mapping map of the target city, extract the boundary contour in the surveying and mapping map of the target city, obtain the boundary contour of the target city, and divide the cadastral surveying and mapping area of ​​the target city into j m cadastral survey sub-areas and name them j1 to j m cadastral mapping sub-areas;

[0110] It should be noted here that:

[0111] In this application, j mSpecifically, it is the quantity value corresponding to the divided cadastral surveying sub-area, and j m is an integer greater than 0;

[0112] In this application, there are j1 to j m Cadastral survey sub-area, in this implementation, the i-th cadastral survey sub-area is selected as the implementation sample;

[0113] For the jth i The cadastral survey sub-area performs flight environment analysis to obtain the peak height of the first area and the valley height of the first area;

[0114] The details are as follows:

[0115] Fly the flight mapping equipment to the jth i Above the cadastral survey sub-area, when the flight survey equipment can obtain the jth i When mapping the global landscape of a sub-area, a laser radar is used to emit k laser beams from a laser emission point to the sub-area. n and label them as k1 to k n emitting a laser beam;

[0116] Receive the k1 to kn transmitted laser beams respectively and reflect them from the ground landscape to the kth of the flight mapping equipment n The reflected laser beams are named k1 to k n Reflecting laser beams;

[0117] Set the k1 to k n The laser points where the emitted laser beam contacts the ground landscape are named k1 to k n Laser contact point position;

[0118] It should be noted here that:

[0119] In this application, the acquisition of the jth i The global landscape of the cadastral surveying sub-area is specifically the image acquisition field of view corresponding to the flight altitude of the flying surveying equipment that can cover the jth i cadastral mapping of the entire landscape of the sub-region;

[0120] The height of the k1th laser contact point from the ground is acquired according to the k1th emitted laser beam and the k1th reflected laser beam, so as to obtain a height value of the k1th contact point;

[0121] The details are as follows:

[0122] A straight line is drawn through the laser emission point, which is parallel to the ground and has the same flight angle as the flight surveying and mapping equipment, to obtain an angle reference line, to obtain the angle between the k1th emitted laser beam and the angle reference line, to obtain a first characteristic angle, to obtain the angle between the k1th reflected laser beam and the angle reference line, to obtain a second characteristic angle, to obtain the angle formed by the k1th emitted laser beam and the k1th reflected laser beam, to obtain a third characteristic angle, and angle values ​​of the first characteristic angle, the second characteristic angle, and the third characteristic angle are obtained respectively;

[0123] Obtain the time value corresponding to when the laser emission point emits the k1th emitted laser beam to obtain the first time value, obtain the time value corresponding to when the flight surveying and mapping device receives the k1th reflected laser beam to obtain the second time value, obtain the line connecting the position point from the first time value to the second time value of the flight surveying and mapping device to obtain the characteristic flight straight line, and obtain the length value of the characteristic flight straight line to obtain the length value of the characteristic flight straight line;

[0124] A perpendicular line passing through the k1th laser contact point and the angle reference line is used to obtain a first contact point line;

[0125] See also Figure 3 , in the triangle where the characteristic flight straight line, the k1th reflected laser beam, the outer angle corresponding to the first characteristic angle and the third characteristic angle are located, the length value corresponding to the k1th reflected laser beam is calculated by the sine theorem;

[0126] Calculate the length value corresponding to the k1th reflected laser beam. The specific formula is as follows:

[0127]

[0128] Among them, Fj1 is the length value corresponding to the k1th reflected laser beam, j1 is the angle value corresponding to the first characteristic angle, j3 is the angle value corresponding to the third characteristic angle, and Tfc is the characteristic flight straight line length value;

[0129] It should be noted here that:

[0130] The laser receiving point is also the intersection of the k1th emitted laser line and the characteristic flight line;

[0131] The angle reference line and the characteristic flight line are the same line

[0132] Obtaining a time difference between the first time value and the second time value to obtain a characteristic time length value, obtaining a propagation speed of the laser beam in the air, calculating the product of the characteristic time length value and the propagation speed of the laser beam in the air, and then calculating the difference between the obtained product and the length value corresponding to the k1th reflected laser beam to obtain the length value corresponding to the k1th emitted laser beam;

[0133] The angle value corresponding to the first characteristic angle and the length value corresponding to the k1th emitted laser beam are calculated to obtain the height value of the k1th contact point;

[0134] Calculate the height value of the k1th contact point, and the specific formula is configured as follows:

[0135] Jcg1 = Tj1*sin(180°-j1);

[0136] Among them, Jcg1 is the height value of the k1th contact point, Tj1 is the length value corresponding to the k1th emitted laser beam, and j1 is the angle value corresponding to the first characteristic angle;

[0137] For k2 to k n The height above the ground corresponding to the laser contact point is obtained to obtain the height values ​​of the contact points from k2 to kn;

[0138] Set the k1 to k n The contact point height values ​​are compared, the contact point height value with the largest value is named as the peak height of the first region, and the contact point height value with the smallest value is named as the valley height of the first region;

[0139] Get the jth i A real-time wind force value at a flight altitude of a flight surveying and mapping device flying over the cadastral surveying and mapping sub-area, to obtain a first real-time flight wind force value;

[0140] Get the jth i A real-time ambient humidity value of a flight altitude of a flight surveying and mapping device flying over the cadastral surveying and mapping sub-area, to obtain a first real-time flight humidity value;

[0141] Get the jth i The flight visibility value corresponding to the cadastral survey sub-area is used to obtain a first real-time flight visibility value;

[0142] The details are as follows:

[0143] In the j i Mark multiple visibility measurement marking points in the cadastral survey sub-area, and name them as the first to pth measurement marking points respectively;

[0144] See also Figure 4 , mark a circle of pixel comparison areas around the first to pth measured mark points, obtain an image of each measured mark point and the corresponding pixel comparison area, and obtain the first to pth sample comparison images;

[0145] Obtain the difference between the pixel depth value of the visibility measurement mark point and the pixel depth value of the pixel comparison area in the first to pth sample comparison images respectively, obtain p sample pixel depth differences, and calculate the average thereof to obtain the sample average pixel contrast difference;

[0146] An image of a position of a first measurement mark point is captured by a flight surveying and mapping device from a current flight altitude to obtain a first measurement point mark image;

[0147] Performing a region segmentation on the region where the first measurement point mark point is located in the first measurement point mark image to obtain a first measurement point region, randomly selecting a number of pixel points in the first measurement point region, respectively obtaining a pixel depth value of each pixel point to obtain a plurality of pixel depth values, and performing an average calculation on the pixel depth values ​​to obtain a first average pixel depth value;

[0148] Selecting a plurality of comparison pixel points in the pixel corresponding area of ​​the first measurement point mark image, respectively obtaining a pixel depth value corresponding to each comparison pixel point, obtaining a plurality of pixel depth values, and calculating an average of the values ​​to obtain a second average pixel depth value;

[0149] Calculating a difference between a first average pixel depth value and a second average pixel depth value to obtain a first pixel contrast difference;

[0150] Acquire the pixel contrast differences corresponding to the second to p-th measured mark points respectively to obtain the second to p-th pixel contrast differences;

[0151] Calculate the average of the first pixel contrast difference to the pth pixel contrast difference to obtain a real-time average pixel contrast difference;

[0152] Calculate the ratio of the sample average pixel contrast difference to the real-time average pixel contrast difference to obtain a first real-time flight visibility value;

[0153] defining a first region peak altitude, a first region valley altitude, a first real-time flight wind value, a first real-time flight humidity value, and a first real-time flight visibility value as flight environment data;

[0154] The data acquisition module acquires the flight environment data and transmits it to the altitude adjustment module and the focal length adjustment module;

[0155] The altitude adjustment module adjusts the altitude of the flight mapping equipment according to the flight environment data to obtain a second flight altitude value;

[0156] Obtain flight environment data;

[0157] Acquire a first area peak altitude, a first real-time flight wind value, a first real-time flight humidity value, and a first real-time flight visibility value according to the flight environment data;

[0158] The first real-time flight wind speed value, the first real-time flight humidity value and the first real-time flight visibility value are calculated to obtain the jth i Flight altitude adjustment factor corresponding to cadastral survey sub-area;

[0159] Calculate the flight altitude adjustment coefficient. The specific formula is as follows:

[0160]

[0161] Wherein, Fgt is the flight altitude adjustment coefficient, Fl1 is the first real-time flight wind value, Sd1 is the first real-time flight humidity value, Nj1 is the first real-time flight visibility value, a1 is the set proportional coefficient and a1 is greater than 0;

[0162] Get the jth i The real-time flight altitude value of the flight surveying and mapping equipment corresponding to the cadastral surveying and mapping sub-area is used to obtain a first flight altitude value;

[0163] The peak height of the first area and the flight height adjustment coefficient are calculated to obtain a reference flight height value of the flight mapping equipment, and the reference flight height value is named as the second flight height value;

[0164] Calculate the reference flight altitude value of the flight mapping equipment. The specific formula is as follows:

[0165] Fjg=Qg1×(1+Fgt);

[0166] Among them, Fjg is the reference flight altitude value of the flight mapping equipment, Qg1 is the peak altitude of the first area, and Fgt is the flight altitude adjustment coefficient;

[0167] When the first flight altitude value is greater than the second flight altitude value, the real-time flight altitude corresponding to the flight surveying and mapping equipment is adjusted downward until the real-time flight altitude reaches the second flight altitude value;

[0168] When the first flight altitude value is less than the second flight altitude value, the real-time flight altitude corresponding to the flight surveying and mapping equipment is adjusted upward until the real-time flight altitude reaches the second flight altitude value;

[0169] The height adjustment module obtains the second flight height value and transmits it to the focal length adjustment module;

[0170] The focus adjustment module adjusts the focus of the flight mapping equipment according to the flight environment data and the second flight altitude value;

[0171] Obtaining a second flight altitude;

[0172] Obtaining a preset focal length distance corresponding to the second flight altitude value of the flight mapping device;

[0173] It should be noted here that:

[0174] The preset focal length involved here is the default focal length of the flight mapping equipment when it is at the second flight altitude;

[0175] Obtain flight environment data, obtain the peak height of the first area and the valley height of the first area according to the flight environment data, calculate the difference between the peak height of the first area and the valley height of the first area, and then take the absolute value of the obtained difference to obtain the jth i The height difference of the surveyed terrain corresponding to the cadastral survey sub-area;

[0176] Acquiring a first real-time flight visibility value according to the flight environment data;

[0177] Get the jth i The real-time light intensity value corresponding to the cadastral surveying sub-area is obtained, and the real-time shooting focal length corresponding to the flight surveying equipment is obtained to obtain the first shooting focal length;

[0178] The real-time illumination intensity value, the first real-time flight visibility value and the height difference of the surveyed terrain are calculated to obtain a shooting focal length adjustment coefficient;

[0179] Calculate the shooting focal length adjustment coefficient, the specific formula configuration is as follows:

[0180]

[0181] Among them, Pjx is the shooting focal length adjustment coefficient, Gxc is the height difference of the surveyed terrain, Nj1 is the first real-time flight visibility value, Gzq is the real-time light intensity value, b1 is the set proportional coefficient and b1 is greater than 0;

[0182] Calculate the product of the preset focal length and the shooting focal length adjustment coefficient to obtain a second shooting focal length;

[0183] When the first shooting focal length is greater than the second shooting focal length, the real-time shooting focal length of the flight surveying and mapping device is adjusted downward until the real-time shooting focal length of the flight surveying and mapping device is equal to the second shooting focal length;

[0184] When the first shooting focal length is smaller than the second shooting focal length, the real-time shooting focal length of the flight surveying and mapping device is adjusted upward until the real-time shooting focal length of the flight surveying and mapping device is equal to the second shooting focal length;

[0185] The focal length adjustment module acquires the second shooting focal length and transmits it to the surveying and mapping imaging module;

[0186] The surveying and mapping imaging module detects the jth i The cadastral survey sub-area is surveyed and imaged;

[0187] Obtain a second flight altitude value and a second shooting focal length distance;

[0188] In the j i When the cadastral surveying sub-area is surveyed, the flying surveying equipment automatically flies to the second flying altitude value, and automatically adjusts the shooting equipment to the second shooting focal length. i The cadastral surveying and mapping sub-areas are surveyed and mapped to obtain regional surveying images;

[0189] The regional mapping image is imaged and tested. If the image is qualified, the jth i The cadastral survey sub-area is completed. If the imaging test fails, continue to i The cadastral survey sub-area is surveyed and mapped until the imaging test is qualified;

[0190] Perform imaging detection on regional mapping images, as follows:

[0191] Acquire multiple qualified historical surveying and mapping images as sample surveying and mapping images, and divide the sample surveying and mapping images into an image test set and an image training set according to a preset division ratio;

[0192] An image detection model is established through an existing artificial intelligence platform, and the image detection model is trained using an image training set. After the training is completed, the image detection model is qualified tested using an image test set, and the test result is numerically obtained to obtain a test result index value. If the test result index value is greater than or equal to a preset test index value, the image detection model training is completed. If the test result index value is less than the preset test index value, the image detection model is continuously qualified tested using the image test set until the test result index value is greater than or equal to the preset test index value.

[0193] It should be noted here that:

[0194] The existing artificial intelligence platform involved here may be TensorFlow;

[0195] In this application, the preset division ratio is three to seven, and the preset test index value is 90%. The preset division ratio and preset test index value set here are only applicable to this embodiment. In actual situations, they need to be set accordingly according to actual conditions;

[0196] Use the trained image detection model to identify the regional mapping image. If the test result output by the image detection model is qualified, the imaging detection is qualified. If the test result output by the image detection model is unqualified, the imaging detection is unqualified.

[0197] In this application, if corresponding calculation formulas appear, the above calculation formulas are all dimensionless and take their numerical calculations. The weight coefficients, proportional coefficients and other coefficients in the formulas are set to a result value obtained by quantifying each parameter. The size of the weight coefficient and the proportional coefficient can be determined as long as it does not affect the proportional relationship between the parameter and the result value.

[0198] Embodiment 2

[0199] Based on another concept of the same invention, a method for urban cadastral surveying and mapping based on the extraction of boundary contours of land objects is proposed, comprising the following steps:

[0200] Step S1: Acquire flight environment data;

[0201] Step S11: Obtain an existing surveying and mapping map of the target city, extract the boundary contour in the surveying and mapping map of the target city, obtain the boundary contour of the target city, and divide the cadastral surveying and mapping area of ​​the target city into j m cadastral survey sub-areas and name them j1 to j m cadastral mapping sub-areas;

[0202] Step S12: For the jth i The cadastral survey sub-area performs flight environment analysis to obtain the peak height of the first area and the valley height of the first area;

[0203] The step S12 further includes the following specific steps:

[0204] Step S121: Fly the flight surveying and mapping equipment to the jth i Above the cadastral survey sub-area, when the flight survey equipment can obtain the jth i When mapping the global landscape of a sub-area, a laser radar is used to emit k laser beams from a laser emission point to the sub-area. n The laser beams are labeled as k1 to k n emitting a laser beam;

[0205] Step S122: Receive k1 to k n The laser beam is reflected by the ground landscape to the flying mapping equipment. n The reflected laser beams are named k1 to k n Reflecting laser beams;

[0206] Step S123: Set the k1th to kth n The laser points where the emitted laser beam contacts the ground landscape are named k1 to k n Laser contact point position;

[0207] Step S124: acquiring the height of the k1th laser contact point from the ground according to the k1th emitted laser beam and the k1th reflected laser beam to obtain a height value of the k1th contact point;

[0208] The step S124 further includes the following specific steps:

[0209] Step S1241: draw a straight line through the laser emission point that is parallel to the ground and has the same flight angle as the flight surveying and mapping equipment to obtain an angle reference line, obtain the angle between the k1th emitted laser beam and the angle reference line to obtain a first characteristic angle, obtain the angle between the k1th reflected laser beam and the angle reference line to obtain a second characteristic angle, obtain the angle formed by the k1th emitted laser beam and the k1th reflected laser beam to obtain a third characteristic angle, and obtain angle values ​​of the first characteristic angle, the second characteristic angle, and the third characteristic angle respectively;

[0210] Step S1242: obtaining a time value corresponding to when the laser emission point emits the k1th emitted laser beam to obtain a first time value, obtaining a time value corresponding to when the flight surveying and mapping device receives the k1th reflected laser beam to obtain a second time value, obtaining a line connecting the position point from the first time value to the second time value of the flight surveying and mapping device to obtain a characteristic flight straight line, and obtaining a length value of the characteristic flight straight line to obtain a length value of the characteristic flight straight line;

[0211] Step S1243: obtaining a first contact point line through a perpendicular line passing through the k1th laser contact point and the angle reference line;

[0212] Step S1244: in the triangle where the characteristic flight line, the k1th reflected laser beam, the outer angle corresponding to the first characteristic angle and the third characteristic angle are located, the length value corresponding to the k1th reflected laser beam is calculated by the sine theorem;

[0213] Calculate the length value corresponding to the k1th reflected laser beam. The specific formula is as follows:

[0214]

[0215] Among them, Fj1 is the length value corresponding to the k1th reflected laser beam, j1 is the angle value corresponding to the first characteristic angle, j3 is the angle value corresponding to the third characteristic angle, and Tfc is the characteristic flight straight line length value;

[0216] Step S1245: Obtain the time difference between the first time value and the second time value, obtain the characteristic time length value, obtain the propagation speed of the laser beam in the air, calculate the product of the characteristic time length value and the propagation speed of the laser beam in the air, and then calculate the difference between the obtained product and the length value corresponding to the k1th reflected laser beam to obtain the length value corresponding to the k1th emitted laser beam;

[0217] Step S1246: Calculate the angle value corresponding to the first characteristic angle and the length value corresponding to the k1th emitted laser beam to obtain the k1th contact point height value;

[0218] Calculate the height value of the k1th contact point, and the specific formula is configured as follows:

[0219] Jcg1 = Tj1 × sin(180°-j1);

[0220] Among them, Jcg1 is the height value of the k1th contact point, Tj1 is the length value corresponding to the k1th emitted laser beam, and j1 is the angle value corresponding to the first characteristic angle;

[0221] Step S125: respectively perform the calculations on the k2th to kth n The height above the ground corresponding to the laser contact point is obtained to obtain the height values ​​of the contact points from k2 to kn;

[0222] Step S126: The k1th to kth n The contact point height values ​​are compared, the contact point height value with the largest value is named as the peak height of the first region, and the contact point height value with the smallest value is named as the valley height of the first region;

[0223] Step S13: Obtain the i A real-time wind force value at a flight altitude of a flight surveying and mapping device flying over the cadastral surveying and mapping sub-area, to obtain a first real-time flight wind force value;

[0224] Step S14: Obtain the i A real-time ambient humidity value of a flight altitude of a flight surveying and mapping device flying over the cadastral surveying and mapping sub-area, to obtain a first real-time flight humidity value;

[0225] Step S15: Get the jth i The flight visibility value corresponding to the cadastral survey sub-area is used to obtain a first real-time flight visibility value;

[0226] The step S15 further includes the following specific steps:

[0227] Step S151: In the jth i Mark multiple visibility measurement marking points in the cadastral survey sub-area, and name them as the first to pth measurement marking points respectively;

[0228] Step S152: Mark a circle of pixel comparison areas around the first to pth measured mark points, obtain an image of each measured mark point and the corresponding pixel comparison area, and obtain the first to pth sample comparison images;

[0229] Step S153: respectively obtaining the difference between the pixel depth value of the visibility measurement mark point and the pixel depth value of the pixel comparison area in the first to pth sample comparison images, obtaining p sample pixel depth differences, and averaging them to obtain the sample average pixel contrast difference;

[0230] Step S154: photographing an image of the location of the first measurement mark point from the current flight altitude using the flight surveying and mapping equipment to obtain a first measurement point mark image;

[0231] Step S155: performing region segmentation on the region where the first measurement mark point is located in the first measurement point mark image to obtain a first measurement point region, randomly selecting a number of pixel points in the first measurement point region, respectively obtaining a pixel depth value of each pixel point to obtain a plurality of pixel depth values, and averaging the pixel depth values ​​to obtain a first average pixel depth value;

[0232] Step S156: selecting a plurality of comparison pixel points in the pixel corresponding area of ​​the first measurement point mark image, respectively obtaining a pixel depth value corresponding to each comparison pixel point, obtaining a plurality of pixel depth values, and calculating an average of the values ​​to obtain a second average pixel depth value;

[0233] Step S157: Calculate the difference between the first average pixel depth value and the second average pixel depth value to obtain a first pixel contrast difference, and obtain the pixel contrast differences corresponding to the second to p-th measurement mark points respectively to obtain the second to p-th pixel contrast differences;

[0234] Step S158: Calculate the average of the first pixel contrast difference to the pth pixel contrast difference to obtain a real-time average pixel contrast difference;

[0235] Step S159: Calculate the ratio of the sample average pixel contrast difference to the real-time average pixel contrast difference to obtain a first real-time flight visibility value;

[0236] Step S16: defining the first area peak altitude, the first area valley altitude, the first real-time flight wind value, the first real-time flight humidity value, and the first real-time flight visibility value as flight environment data;

[0237] Step S2: adjusting the altitude of the flight mapping equipment according to the flight environment data to obtain a second flight altitude value;

[0238] Step S21: Acquire flight environment data;

[0239] Step S22: acquiring a first area peak altitude, a first real-time flight wind value, a first real-time flight humidity value, and a first real-time flight visibility value according to the flight environment data;

[0240] Step S23: Calculate the first real-time flight wind speed value, the first real-time flight humidity value, and the first real-time flight visibility value to obtain the jth i Flight altitude adjustment factor corresponding to cadastral survey sub-area;

[0241] Calculate the flight altitude adjustment coefficient. The specific formula is as follows:

[0242]

[0243] Wherein, Fgt is the flight altitude adjustment coefficient, Fl1 is the first real-time flight wind value, Sd1 is the first real-time flight humidity value, Nj1 is the first real-time flight visibility value, a1 is the set proportional coefficient and a1 is greater than 0;

[0244] Step S24: Get the jth i The real-time flight altitude value of the flight surveying and mapping equipment corresponding to the cadastral surveying and mapping sub-area is used to obtain a first flight altitude value;

[0245] Step S25: Calculating the peak height of the first area and the flight height adjustment coefficient to obtain a reference flight height value of the flight mapping equipment, and naming it as a second flight height value;

[0246] Calculate the reference flight altitude value of the flight mapping equipment. The specific formula is as follows:

[0247] Fjg=Qg1×(1+Fgt);

[0248] Among them, Fjg is the reference flight altitude value of the flight mapping equipment, Qg1 is the peak altitude of the first area, and Fgt is the flight altitude adjustment coefficient;

[0249] Step S26: adjusting the flight altitude of the flight surveying and mapping equipment according to the first flight altitude value and the second flight altitude value;

[0250] The details are as follows:

[0251] Step S261: when the first flight altitude value is greater than the second flight altitude value, the real-time flight altitude corresponding to the flight surveying and mapping equipment is adjusted downward until the real-time flight altitude reaches the second flight altitude value;

[0252] Step S262: When the first flight altitude value is less than the second flight altitude value, the real-time flight altitude corresponding to the flight surveying and mapping equipment is adjusted upward until the real-time flight altitude reaches the second flight altitude value;

[0253] Step S3: adjusting the focal length of the flight mapping equipment according to the flight environment data and the second flight altitude value;

[0254] Step S31: obtaining a second flight altitude;

[0255] Step S32: obtaining a preset focal length corresponding to the second flight altitude value of the flight surveying and mapping device;

[0256] Step S33: Obtain flight environment data, obtain the peak height of the first region and the valley height of the first region according to the flight environment data, calculate the difference between the peak height of the first region and the valley height of the first region, and then take the absolute value of the obtained difference to obtain the jth i The height difference of the surveyed terrain corresponding to the cadastral survey sub-area;

[0257] Step S34: obtaining a first real-time flight visibility value according to the flight environment data;

[0258] Step S35: Get the jth i The real-time light intensity value corresponding to the cadastral surveying sub-area is obtained, and the real-time shooting focal length corresponding to the flight surveying equipment is obtained to obtain the first shooting focal length;

[0259] Step S36: obtaining a shooting focal length adjustment coefficient by calculating the real-time illumination intensity value, the first real-time flight visibility value, and the height difference of the surveyed terrain;

[0260] Calculate the shooting focal length adjustment coefficient, the specific formula configuration is as follows:

[0261]

[0262] Among them, Pjx is the shooting focal length adjustment coefficient, Gxc is the height difference of the surveyed terrain, Nj1 is the first real-time flight visibility value, Gzq is the real-time light intensity value, b1 is the set proportional coefficient and b1 is greater than 0;

[0263] Step S37: Calculate the product of the preset focal length and the shooting focal length adjustment coefficient to obtain a second shooting focal length;

[0264] Step S38: adjusting the shooting focal length of the flight surveying and mapping equipment in real time according to the first shooting focal length and the second shooting focal length;

[0265] The step S38 further includes the following specific steps:

[0266] Step S381: when the first shooting focal length is greater than the second shooting focal length, the real-time shooting focal length of the flight surveying and mapping device is adjusted downward until the real-time shooting focal length of the flight surveying and mapping device is equal to the second shooting focal length;

[0267] Step S382: when the first shooting focal length is smaller than the second shooting focal length, the real-time shooting focal length of the flight surveying and mapping device is adjusted upward until the real-time shooting focal length of the flight surveying and mapping device is equal to the second shooting focal length;

[0268] Step S4: performing regional cadastral mapping according to the second flight altitude value and the second shooting focal length distance to obtain a regional mapping image;

[0269] Step S41: obtaining a second flight height value and a second shooting focal length;

[0270] Step S42: In the jth i When the cadastral surveying sub-area is surveyed, the flying surveying equipment automatically flies to the second flying altitude value, and automatically adjusts the shooting equipment to the second shooting focal length. i The cadastral surveying and mapping sub-areas are surveyed and mapped to obtain regional surveying images;

[0271] Step S5: Establish an image detection model to perform real-time detection on the regional mapping image to obtain the detected regional mapping image.

[0272] Step S51: obtaining a plurality of qualified historical surveying and mapping images as sample surveying and mapping images, and dividing the sample surveying and mapping images into an image test set and an image training set according to a preset division ratio;

[0273] Step S52: Establish an image detection model through the existing artificial intelligence platform, use the image training set to train the image detection model, and after the training is completed, use the image test set to perform a qualification test on the image detection model, and obtain the numerical value of the test result to obtain the test result index value;

[0274] Step S53: if the test result index value is greater than or equal to the preset test index value, the image detection model training is completed; if the test result index value is less than the preset test index value, the image detection model continues to be qualified by using the image test set until the test result index value is greater than or equal to the preset test index value;

[0275] Step S54: Use the trained image detection model to identify the regional mapping image. If the test result output by the image detection model is qualified, the imaging detection is qualified. i After the cadastral survey sub-area is completed, if the test result output by the image detection model is unqualified, the imaging detection is unqualified, and the jth area is continued. i The cadastral survey sub-area is surveyed and mapped until the imaging test is qualified.

[0276] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An urban cadastral surveying and mapping imaging method based on feature boundary contour extraction, characterized in that: include: Step S1: Divide the target city into m cadastral survey sub-areas, obtain the jth i The first area peak height, the first area valley height, the first real-time flight wind value, the first real-time flight humidity value, and the first real-time flight visibility value corresponding to the cadastral mapping sub-area are used to obtain flight environment data; Step S2: acquiring a first flight altitude value and a second flight altitude value respectively according to the flight environment data, and adjusting the flight altitude of the flight mapping equipment according to the first flight altitude value and the second flight altitude value; Step S3: acquiring a first shooting focal length and a second shooting focal length according to the flight environment data and the second flight altitude value, respectively, and adjusting the shooting focal length of the flight mapping device according to the first shooting focal length and the second shooting focal length; Step S4: The flight surveying and mapping equipment performs a measurement on the jth image according to the second flight altitude value and the second shooting focal length. i The cadastral surveying and mapping sub-areas are surveyed and mapped to obtain regional surveying images; Step S5: Establish an image detection model to perform real-time detection on the regional mapping image to obtain the detected regional mapping image.

2. The urban cadastral surveying and mapping imaging method based on feature boundary contour extraction according to claim 1 is characterized in that: The step S1 further includes the following specific steps: Step S11: Obtain an existing surveying and mapping map of the target city, extract the boundary contour in the surveying and mapping map of the target city, obtain the boundary contour of the target city, and divide the cadastral surveying and mapping area of ​​the target city into j m cadastral survey sub-areas and name them j1 to j m cadastral mapping sub-areas; Step S12: For the jth i The cadastral survey sub-area performs flight environment analysis to obtain the peak height of the first area and the valley height of the first area; Step S13: Obtain the i A real-time wind force value at a flight altitude of a flight surveying and mapping device flying over the cadastral surveying and mapping sub-area, to obtain a first real-time flight wind force value; Step S14: Obtain the i A real-time ambient humidity value of a flight altitude at which a flight surveying and mapping device flying over the cadastral surveying and mapping sub-area is located, to obtain a first real-time flight humidity value; Step S15: Get the jth i The flight visibility value corresponding to the cadastral survey sub-area is used to obtain a first real-time flight visibility value; Step S16: define the first area peak altitude, the first area valley altitude, the first real-time flight wind value, the first real-time flight humidity value and the first real-time flight visibility value as flight environment data.

3. The urban cadastral surveying and imaging method based on feature boundary contour extraction according to claim 2 is characterized in that: The step S12 further includes the following specific steps: Step S121: Fly the flight surveying and mapping equipment to the jth i Above the cadastral survey sub-area, when the flight survey equipment can obtain the jth i When mapping the global landscape of a sub-area, a laser radar is used to emit k laser beams from a laser emission point to the sub-area. n and label them as k1 to k n emitting a laser beam; Step S122: Receive k1 to k n The emitted laser beam is reflected by the ground landscape to the kn reflected laser beams of the flight mapping equipment, and they are named k1 to k n Reflecting laser beams; Step S123: Set the k1th to kth n The laser points where the emitted laser beam contacts the ground landscape are named k1 to k n Laser contact point position; Step S124: acquiring the height of the k1th laser contact point from the ground according to the k1th emitted laser beam and the k1th reflected laser beam to obtain a height value of the k1th contact point; Step S125: respectively perform the calculations on the k2th to kth n The height above the ground corresponding to the laser contact point is obtained to obtain the k2 to k n Contact point height value; Step S126: The k1th to kth n The contact point height values ​​are compared, and the contact point height value with the largest value is named the peak height of the first region, and the contact point height value with the smallest value is named the valley height of the first region.

4. The urban cadastral surveying and mapping imaging method based on feature boundary contour extraction according to claim 3 is characterized in that: The step S124 further includes the following specific steps: Step S1241: draw a straight line through the laser emission point that is parallel to the ground and has the same flight angle as the flight surveying and mapping equipment to obtain an angle reference line, obtain the angle between the k1th emitted laser beam and the angle reference line to obtain a first characteristic angle, obtain the angle between the k1th reflected laser beam and the angle reference line to obtain a second characteristic angle, obtain the angle formed by the k1th emitted laser beam and the k1th reflected laser beam to obtain a third characteristic angle, and obtain angle values ​​of the first characteristic angle, the second characteristic angle, and the third characteristic angle respectively; Step S1242: obtaining a time value corresponding to when the laser emission point emits the k1th emitted laser beam to obtain a first time value, obtaining a time value corresponding to when the flight surveying and mapping device receives the k1th reflected laser beam to obtain a second time value, obtaining a line connecting the position point from the first time value to the second time value of the flight surveying and mapping device to obtain a characteristic flight straight line, and obtaining a length value of the characteristic flight straight line to obtain a length value of the characteristic flight straight line; Step S1243: obtaining a first contact point line through a perpendicular line passing through the k1th laser contact point and the angle reference line; Step S1244: in the triangle where the characteristic flight line, the k1th reflected laser beam, the outer angle corresponding to the first characteristic angle and the third characteristic angle are located, the length value corresponding to the k1th reflected laser beam is calculated by the sine theorem; Calculate the length value corresponding to the k1th reflected laser beam. The specific formula is as follows: Among them, Fj1 is the length value corresponding to the k1th reflected laser beam, j1 is the angle value corresponding to the first characteristic angle, j3 is the angle value corresponding to the third characteristic angle, and Tfc is the characteristic flight straight line length value; Step S1245: Obtain the time difference between the first time value and the second time value, obtain the characteristic time length value, obtain the propagation speed of the laser beam in the air, calculate the product of the characteristic time length value and the propagation speed of the laser beam in the air, and then calculate the difference between the obtained product and the length value corresponding to the k1th reflected laser beam to obtain the length value corresponding to the k1th emitted laser beam; Step S1246: Calculate the angle value corresponding to the first characteristic angle and the length value corresponding to the k1th emitted laser beam to obtain the k1th contact point height value; Calculate the height value of the k1th contact point, and the specific formula is configured as follows: Jcg1 = Tj1 × sin(180°-j1); Among them, Jcg1 is the height value of the k1th contact point, Tj1 is the length value corresponding to the k1th emitted laser beam, and j1 is the angle value corresponding to the first characteristic angle.

5. The urban cadastral surveying and imaging method based on feature boundary contour extraction according to claim 2 is characterized in that: The step S15 further includes the following specific steps: Step S151: In the jth i Mark multiple visibility measurement marking points in the cadastral survey sub-area, and name them as the first to pth measurement marking points respectively; Step S152: Mark a circle of pixel comparison areas around the first to pth measured mark points, obtain an image of each measured mark point and the corresponding pixel comparison area, and obtain the first to pth sample comparison images; Step S153: respectively obtaining the difference between the pixel depth value of the visibility measurement mark point and the pixel depth value of the pixel comparison area in the first to pth sample comparison images, obtaining p sample pixel depth differences, and averaging them to obtain the sample average pixel contrast difference; Step S154: photographing an image of the location of the first measurement mark point from the current flight altitude using the flight surveying and mapping equipment to obtain a first measurement point mark image; Step S155: performing region segmentation on the region where the first measurement mark point is located in the first measurement point mark image to obtain a first measurement point region, randomly selecting a number of pixel points in the first measurement point region, respectively obtaining a pixel depth value of each pixel point to obtain a plurality of pixel depth values, and averaging the pixel depth values ​​to obtain a first average pixel depth value; Step S156: selecting a plurality of comparison pixel points in the pixel corresponding area of ​​the first measurement point mark image, respectively obtaining a pixel depth value corresponding to each comparison pixel point, obtaining a plurality of pixel depth values, and calculating an average of the values ​​to obtain a second average pixel depth value; Step S157: Calculate the difference between the first average pixel depth value and the second average pixel depth value to obtain a first pixel contrast difference, and obtain the pixel contrast differences corresponding to the second to p-th measurement mark points respectively to obtain the second to p-th pixel contrast differences; Step S158: Calculate the average of the first pixel contrast difference to the pth pixel contrast difference to obtain a real-time average pixel contrast difference; Step S159: Calculate the ratio of the sample average pixel contrast difference to the real-time average pixel contrast difference to obtain a first real-time flight visibility value.

6. The urban cadastral surveying and imaging method based on feature boundary contour extraction according to claim 1, characterized in that: The step S2 further includes the following specific steps: Step S21: Acquire flight environment data; Step S22: acquiring a first area peak altitude, a first real-time flight wind value, a first real-time flight humidity value, and a first real-time flight visibility value according to the flight environment data; Step S23: Calculate the first real-time flight wind speed value, the first real-time flight humidity value, and the first real-time flight visibility value to obtain the jth i Flight altitude adjustment factor corresponding to cadastral survey sub-area; Calculate the flight altitude adjustment coefficient. The specific formula is as follows: Wherein, Fgt is the flight altitude adjustment coefficient, Fl1 is the first real-time flight wind value, Sd1 is the first real-time flight humidity value, Nj1 is the first real-time flight visibility value, a1 is the set proportional coefficient and a1 is greater than 0; Step S24: Get the jth i The real-time flight altitude value of the flight surveying and mapping equipment corresponding to the cadastral surveying and mapping sub-area is used to obtain a first flight altitude value; Step S25: Calculating the peak height of the first area and the flight height adjustment coefficient to obtain a reference flight height value of the flight mapping equipment, and naming it as a second flight height value; Calculate the reference flight altitude value of the flight mapping equipment. The specific formula is as follows: Fjg=Qg1×(1+Fgt); Among them, Fjg is the reference flight altitude value of the flight mapping equipment, Qg1 is the peak altitude of the first area, and Fgt is the flight altitude adjustment coefficient; Step S26: adjusting the flight altitude of the flight surveying and mapping equipment according to the first flight altitude value and the second flight altitude value; The details are as follows: Step S261: when the first flight altitude value is greater than the second flight altitude value, the real-time flight altitude corresponding to the flight surveying and mapping equipment is adjusted downward until the real-time flight altitude reaches the second flight altitude value; Step S262: When the first flight altitude value is less than the second flight altitude value, the real-time flight altitude corresponding to the flight surveying and mapping equipment is adjusted upward until the real-time flight altitude reaches the second flight altitude value.

7. The urban cadastral surveying and imaging method based on feature boundary contour extraction according to claim 1 is characterized in that: The step S3 further includes the following specific steps: Step S31: obtaining a second flight altitude; Step S32: obtaining a preset focal length corresponding to the second flight altitude value of the flight surveying and mapping device; Step S33: Obtain flight environment data, obtain the peak height of the first region and the valley height of the first region according to the flight environment data, calculate the difference between the peak height of the first region and the valley height of the first region, and then take the absolute value of the obtained difference to obtain the jth i The height difference of the surveyed terrain corresponding to the cadastral survey sub-area; Step S34: obtaining a first real-time flight visibility value according to the flight environment data; Step S35: Get the jth i The real-time light intensity value corresponding to the cadastral surveying sub-area is obtained, and the real-time shooting focal length corresponding to the flight surveying equipment is obtained to obtain the first shooting focal length; Step S36: obtaining a shooting focal length adjustment coefficient by calculating the real-time illumination intensity value, the first real-time flight visibility value, and the height difference of the surveyed terrain; Calculate the shooting focal length adjustment coefficient, the specific formula configuration is as follows: Among them, Pjx is the shooting focal length adjustment coefficient, Gxc is the height difference of the surveyed terrain, Nj1 is the first real-time flight visibility value, Gzq is the real-time light intensity value, b1 is the set proportional coefficient and b1 is greater than 0; Step S37: Calculate the product of the preset focal length and the shooting focal length adjustment coefficient to obtain a second shooting focal length; Step S38: adjusting the shooting focal length of the flight mapping device in real time according to the first shooting focal length and the second shooting focal length; The step S38 further includes the following specific steps: Step S381: when the first shooting focal length is greater than the second shooting focal length, the real-time shooting focal length of the flight surveying and mapping device is adjusted downward until the real-time shooting focal length of the flight surveying and mapping device is equal to the second shooting focal length; Step S382: When the first shooting focal length is smaller than the second shooting focal length, the real-time shooting focal length of the flight surveying and mapping device is adjusted upward until the real-time shooting focal length of the flight surveying and mapping device is equal to the second shooting focal length.

8. The urban cadastral surveying and imaging method based on feature boundary contour extraction according to claim 1, characterized in that: The step S4 further includes the following specific steps: Step S41: obtaining a second flight height value and a second shooting focal length; Step S42: In the jth i When the cadastral surveying sub-area is surveyed, the flying surveying equipment automatically flies to the second flying altitude value, and automatically adjusts the shooting equipment to the second shooting focal length. i The cadastral surveying sub-area is surveyed and mapped to obtain a regional surveying image.

9. The urban cadastral surveying and imaging method based on feature boundary contour extraction according to claim 1, characterized in that: The step S5 further includes the following specific steps: Step S51: obtaining a plurality of qualified historical surveying and mapping images as sample surveying and mapping images, and dividing the sample surveying and mapping images into an image test set and an image training set according to a preset division ratio; Step S52: Establish an image detection model through the existing artificial intelligence platform, use the image training set to train the image detection model, and after the training is completed, use the image test set to perform a qualification test on the image detection model, and obtain the numerical value of the test result to obtain the test result index value; Step S53: if the test result index value is greater than or equal to the preset test index value, the image detection model training is completed; if the test result index value is less than the preset test index value, the image detection model continues to be qualified by using the image test set until the test result index value is greater than or equal to the preset test index value; Step S54: Use the trained image detection model to identify the regional mapping image. If the test result output by the image detection model is qualified, the imaging detection is qualified. i After the cadastral survey sub-area is completed, if the test result output by the image detection model is unqualified, the imaging detection is unqualified, and the jth area is continued. i The cadastral survey sub-area is surveyed and mapped until the imaging test is qualified.

10. An urban cadastral surveying and mapping imaging system based on feature boundary contour extraction, applicable to the urban cadastral surveying and mapping imaging method based on feature boundary contour extraction according to any one of claims 1 to 9, characterized in that: include: Data acquisition module: used to respectively acquire the peak height of the first area, the valley height of the first area, the first real-time flight wind value, the first real-time flight humidity value and the first real-time flight visibility value to obtain flight environment data; Altitude adjustment module: obtains the first flight altitude value and the second flight altitude value according to the flight environment data to adjust the flight altitude of the flight mapping equipment; Focus adjustment module: obtains the first shooting focal length and the second shooting focal length according to the flight environment data and the second flight altitude value, respectively, and adjusts the shooting focal length of the flight mapping equipment in real time; Surveying and mapping imaging module: regional cadastral surveying and mapping is performed according to the second flight altitude value and the second shooting focal length distance to obtain a regional surveying and mapping image.

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