A method for eliminating gross errors in aerial triangulation of pseudo-fixed data from RTK UAV POS

Abstract

The present invention discloses a method for eliminating gross errors in aerial triangulation of RTK UAV POS pseudo-fixed data. The method comprises the following steps: firstly, performing preliminary aerial triangulation processing and quality report analysis on the photographs collected by the RTK UAV operation and the corresponding POS data converted into the engineering coordinate system, then performing POS pseudo-fixed gross error data statistics and weight reduction processing on the data that fails the aerial triangulation quality report, that is, the POS data recorded during the RTK UAV operation are all RTK fixed solutions and the geo-registration root mean square error is large, and the processed POS data is re-aerial triangulated in a custom precision manner to generate a product. The present invention solves the problems of stretching and deformation, misalignment and stratification, and substandard coordinate accuracy of partial areas of orthophotos and real-life three-dimensional models caused by pseudo-fixed solutions of POS data; the present invention does not require frequent field rework and has the advantages of reliable technology, convenient operation, improved work efficiency, and reduced costs.

Description

Technical Field

[0001] The present invention relates to the field of photogrammetry, and more specifically, to a method for reducing the weight of pseudo-fixed gross error data from RTK UAV POS systems. More specifically, it relates to a method for eliminating gross errors from aerial triangulation of pseudo-fixed data from RTK UAV POS systems. Background Art

[0002] RTK (Real-time kinematic, carrier phase difference) drone low-altitude photogrammetry technology has become increasingly mature in the surveying and mapping field, with a comprehensive workflow. The process involves determining the photography area, planning the flight path, setting overlap, determining the flight altitude, setting the camera, deploying control points, measuring checkpoints, connecting to a CORS (Continuously Operating Reference Stations) network using multi-base RTK technology, and conducting field surveys. The collected data is then subjected to aerial triangulation and optimized for control points to generate the product.

[0003] In the above process, aerial triangulation encryption processing generally uses the POS (Position and Orientation System, a high-precision position and attitude measurement system combined with IMU / DGPS) data collected when the drone is fixed during RTK and the corresponding photos for bundle weighted adjustment. However, it has been found through practice that RTK drone operations often record some photos whose POS fixed solution positioning coordinate data is inconsistent with the corresponding calculated position coordinate data, and the difference is large, resulting in stretching deformation, misalignment and stratification in some areas of the generated orthophotos and real-life 3D models, and poor coordinate accuracy. This is especially true in areas affected by ionospheric interference or weak communication signals, or in areas where geological disasters require emergency mapping. The problem is very prominent, affecting the accuracy and reliability of surveying and mapping products, increasing the workload of field rework, and even rework still cannot solve the problem, delaying the best time for emergency rescue.

[0004] Therefore, it is necessary to develop a method that can solve the problem that the POS fixed solution positioning coordinate data of some recorded photos in RTK UAV operations are inconsistent with the corresponding calculated position coordinate data and the difference is large, resulting in stretching deformation, misalignment and stratification, and poor coordinate accuracy in some areas of the generated orthophoto and real-life three-dimensional model, and can improve the detection efficiency. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the background technology and provide a method for eliminating gross errors in aerial triangulation of RTK UAV POS pseudo-fixed data. The main principle is to reduce the weight of the gross error data of the POS pseudo-fixed solution (the pseudo-fixed solution data refers to the erroneous data recorded when the CORS network signal connected during drone operation is in the RTK fixed solution state, which is not the solution value calculated by the internal processing software) so that the spatial coordinate value of the photographic center of the POS gross error data is replaced by the software calculated value and adjusted as an additional observation value, thereby eliminating the gross errors in aerial triangulation caused by the adjustment of the connection point matching errors caused by the recorded POS pseudo-fixed solution data as the additional observation value, thereby improving the accuracy of aerial triangulation. The present invention solves the problems of stretching deformation, misalignment and stratification, and substandard coordinate accuracy of orthophotos and some areas of real-life three-dimensional models (POS pseudo-fixed gross error data areas) caused by the pseudo-fixed solution of POS data only through internal processing. It has the characteristics of high precision and reliability of surveying and mapping products, and does not require frequent field rework. Especially in areas subject to abnormal ionospheric interference, areas with weak communication signals, or geological disaster emergency surveying and mapping areas, the present invention has a very obvious effect in improving the precision and reliability of surveying and mapping products, and has the characteristics of reliable technology, convenient operation, improved work efficiency, and reduced costs.

[0006] In order to achieve the above object, the technical solution of the present invention is: a method for eliminating gross errors in aerial triangulation encryption of pseudo-fixed data of RTK UAV POS, characterized by comprising the following steps:

[0007] Step 1: Import the block images and corresponding POS data collected by the RTK drone into the DJI Terra software for preliminary aerial triangulation and check the aerial triangulation quality report.

[0008] The route planning for RTK UAV operations can be two-way or multi-way;

[0009] POS data is the positioning and attitude data collected when the RTK drone connects to the CORS network and receives the corresponding base station signal;

[0010] Use DJI Terra software to perform only preliminary aerial triangulation processing, without performing point optimization, to obtain an aerial triangulation quality report.

[0011] The post-calculation aerial triangulation quality report mainly checks the georeferencing root mean square error and the number of images in the RTK fixed solution state.

[0012] Step 2: Import the block images and corresponding POS data from the unqualified aerial triangulation report into PIX4D software for preliminary aerial triangulation. Adjustment is then performed to calculate the spatial coordinates of the photographic center of all images (i.e., all images taken for the block being solved). The aerial triangulation in step 2 is used to calculate the spatial coordinates of the photographic center of all images, which are then compared with the initial position coordinates of the photographic center (POS data) to generate gross error data.

[0013] Step 3: Count the POS pseudo-fixed gross error data with large differences between the initial position coordinates and the calculated position coordinates of the photographic center;

[0014] Step 4: Weight reduction processing is performed on the statistically calculated POS pseudo-fixed gross error data; the present invention can identify POS pseudo-fixed solution gross error data, define the pseudo-fixed solution as having no positioning solution weight, define the horizontal accuracy as 2 meters, and define the vertical accuracy as 10 meters; the weights of other non-gross error POS data remain unchanged, with a horizontal accuracy of 0.03 meters and a vertical accuracy of 0.06 meters;

[0015] Step 5: Use DJI Terra software to import the deweighted POS data and the corresponding images with custom precision, re-triangulate them, optimize the image control points, and generate a qualified product. The aerotriangulation in Step 5 encrypts the reweighted (deweighted) POS gross error data with custom precision. This resolves issues such as stretching, deformation, misalignment, and substandard coordinate accuracy in parts of the orthophotos and real-life 3D models caused by the pseudo-fixed solution of the POS data, eliminating the need for frequent field rework.

[0016] The downgraded POS data is all POS data including the gross error downgraded data and the non-gross error data.

[0017] In the above technical solution, in step 2, the data that fails the aerial triangulation quality report is that the image POS data recorded during the RTK UAV operation are all RTK fixed solutions, and the root mean square error of the geo-registration is greater than 2 meters.

[0018] In the above technical solution, in step 3, the POS pseudo-fixed gross error data is the pseudo-fixed data caused by abnormal ionospheric interference or weak communication signals, resulting in a continuous decrease in the accuracy of the RTK fixed solution state; the amount of POS pseudo-fixed gross error data should be within 1 / 2 of the total POS data volume;

[0019] The specific statistical method for POS pseudo-fixed gross error data is:

[0020] S31. The initial position coordinates of the photographic center are the POS coordinate data recorded during RTK UAV operation, and they correspond one to one. The POS data coordinate system is the converted engineering coordinate system. The POS coordinate system is converted to the Bursa seven parameters, which converts the longitude and latitude coordinates into plane projection coordinates and the geodetic height into normal height. The conversion can be performed using three or more control points with the same name.

[0021] S32, performing statistics on POS pseudo-fixed gross error data whose difference between the initial position coordinates of the photographic center and the calculated position coordinates in any direction of X and Y is greater than 0.3 meters, and calculating the POS pseudo-fixed gross error data.

[0022] In the above technical solution, in step five, the product is an orthophoto and a real-scene three-dimensional model;

[0023] Qualified products are orthophotos and real-life three-dimensional models without stretching deformation, dislocation or stratification, and the accuracy of the comparison of the coordinate difference between the illustrated points and the measured points in the POS pseudo-fixed gross error data area meets the statistical standards.

[0024] In the above technical solution, in step 2 and step 5, the aerial triangulation encryption processing method is the bundle method with weighted adjustment.

[0025] PIX4D and DJI Map are collectively referred to as photogrammetry office processing software.

[0026] The present invention has the following advantages:

[0027] (1) It can solve the problem of stretching, deformation, dislocation and stratification of block POS pseudo-fixed gross error data areas, and the accuracy of the comparison of the coordinate difference between the diagram point and the measured point is statistically up to standard, so that the plane elevation accuracy of the digital line drawing is high and meets the accuracy requirements of water conservancy specifications; the orthophoto and real-scene three-dimensional model products generated by the present invention are free of deformation, dislocation and stratification, and the surveying and mapping products are accurate and reliable. Only through internal processing, the problems of stretching, deformation, dislocation and stratification of some areas of the orthophoto and real-scene three-dimensional model caused by the pseudo-fixed solution of POS data are solved;

[0028] (2) The problem of incorrect matching of aerotriangulated connection points is solved by simply downgrading the POS pseudo-fixed gross error data, without the need for manual and time-consuming removal of incorrect connection points.

[0029] (3) There is no need for frequent field rework, especially in areas with abnormal ionospheric interference, areas with weak communication signals, or geological disaster emergency mapping areas. The present invention significantly improves the accuracy and reliability of mapping products.

[0030] (4) The technology is reliable and easy to operate, which can greatly improve work efficiency and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the process of the present invention;

[0032] Figure 2 This is an example diagram of orthophoto stretching deformation caused by using the existing RTK UAV operation POS pseudo-fixed gross error data in an embodiment of the present invention;

[0033] Figure 3 This is an example diagram of the dislocation and layering of a real-scene 3D model caused by using the existing RTK UAV operation POS pseudo-fixed gross error data in an embodiment of the present invention;

[0034] Figure 4This is an example diagram of the distribution of coordinate plane and elevation differences between illustrated points (errors) and measured points caused by using existing RTK UAV operation POS pseudo-fixed gross error data in an embodiment of the present invention;

[0035] Figure 5 This is an example of a product without stretching deformation and dislocation and delamination generated after aerial triangulation and gross error removal using the method of the present invention in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following detailed description of the embodiments of the present invention is given in conjunction with the accompanying drawings, which do not limit the present invention but are merely examples. The description makes the advantages of the present invention clearer and easier to understand.

[0037] Referring to the accompanying drawings, a method for eliminating gross errors in aerial triangulation of pseudo-fixed data of an RTK UAV POS system is provided, comprising the following steps:

[0038] a. Import the block images and corresponding POS data collected by the RTK drone into the DJI Terra software for preliminary aerial triangulation processing and check the aerial triangulation quality report;

[0039] b. Import the images of the blocks that fail the aerial triangulation quality report and the corresponding POS data into the PIX4D software for preliminary aerial triangulation encryption;

[0040] c. Collect statistics on POS pseudo-fixed gross error data with large differences between the initial position coordinates of the photographic center and the calculated position coordinates;

[0041] d. Reduce the weight of POS pseudo-fixed gross error data and define it as the weight of the non-positioning solution;

[0042] e. Use DJI Terra software to customize the accuracy of the imported de-weighted POS data and the corresponding images for re-aerial triangulation, optimize the image control points, and generate qualified products;

[0043] Furthermore, step a specifically includes:

[0044] a1. RTK UAV flight path planning can be two-way or multi-way;

[0045] a2. The POS data is the positioning and attitude data collected when the RTK drone is connected to the CORS network and receives the corresponding base station signal;

[0046] a3. Only preliminary aerotriangulation processing is performed using DJI Terra software; no point optimization is required.

[0047] a4. The post-calculation aerial triangulation quality report mainly checks the georeferencing root mean square error and the number of images in the RTK fixed solution state.

[0048] Furthermore, step b specifically includes:

[0049] b1. The data that failed the aerial triangulation quality report mentioned above is that the image POS data recorded during RTK UAV operation is all RTK fixed solution, and the georeferencing root mean square error is greater than 2 meters;

[0050] b2. Use PIX4D software to perform preliminary aerial triangulation and adjust the spatial coordinates of the photographic centers of all images.

[0051] Furthermore, step c specifically includes:

[0052] c1. The initial position coordinates of the photographic center are the POS coordinate data recorded during RTK UAV operation, and they correspond one to one;

[0053] c2. Collect statistics on the POS pseudo-fixed gross error data where the difference between the initial position coordinates of the photographic center and the calculated position coordinates in any direction of X or Y is greater than 0.3 meters.

[0054] Furthermore, step d specifically includes:

[0055] The statistically obtained POS pseudo-fixed gross error data is weighted down, and its horizontal accuracy is defined as 2 meters and its vertical accuracy is defined as 10 meters.

[0056] The weights of other non-gross error POS data remain unchanged, with a horizontal accuracy of 0.03 meters and a vertical accuracy of 0.06 meters;

[0057] Furthermore, step e specifically includes:

[0058] The downgraded POS data is all POS data including the gross error downgraded data and the non-gross error data.

[0059] Furthermore, the products are orthophotos and real-life three-dimensional models.

[0060] Furthermore, the qualified products are orthophotos and real-scene three-dimensional models without stretching deformation, dislocation and stratification, and the accuracy statistics of the comparison of the coordinate differences between the graphical points and the actual measured points in the POS pseudo-fixed gross error data area meet the standards.

[0061] Furthermore, the POS data coordinate system is a converted engineering coordinate system.

[0062] Furthermore, the POS data coordinate system is converted into the latitude and longitude coordinates into plane projection coordinates, and the geoid height into normal height, and the conversion can be performed by using the Bursa seven parameters solved by 3 or more control points with the same name.

[0063] Furthermore, the POS pseudo-fixed gross error data is pseudo-fixed data caused by abnormal ionospheric interference or weak communication signals and continuous reduction in RTK fixed solution state accuracy; the amount of POS pseudo-fixed gross error data should account for less than 1 / 2 of the total POS data volume.

[0064] Furthermore, the aerial triangulation processing is a bundle method with weighted adjustment.

[0065] The above description is only a preferred exemplary embodiment of the present invention, and those skilled in the art may make various changes and modifications to the present invention. Any modifications and variations made within the spirit and scope of the present invention shall be included in the scope of protection of the present invention.

[0066] Example

[0067] The present invention is now described in detail by taking the application of the present invention in a river flood control project to perform aerial triangulation and gross error elimination as an example. The present invention can also serve as a guide for applying the present invention to other survey projects to perform aerial triangulation and gross error elimination.

[0068] In this example, the primary task of a river flood control project is flood prevention. Floodwaters in this river converge quickly, but the river channel is not discharging smoothly, making the embankment area prone to flooding. Surveying and mapping results, as fundamental data, ensure satisfactory accuracy, a fundamental guarantee for downstream professionals to carry out their work.

[0069] At present, this embodiment has adopted drone operations to survey a river flood control project. During the RTK drone shooting, the weather conditions were poor (ionosphere anomaly) and the communication signal in the survey area was weak, which affected the GPS module positioning accuracy. Therefore, when the RTK drone was connected to the CORS measurement, the aerial triangulation encryption of the collected data frequently showed gross errors, and the generated products (orthophotos, real-life 3D models) showed local dislocation, stratification, and distortion (such as Figure 2 、 Figure 3 As shown, in Figure 2 The orthophoto images in the product are stretched, deformed and misplaced. Figure 3 There are problems such as misalignment and stratification of products in the project), and low accuracy of digital line drawings produced based on the products; taking the project block A as an example (the block is a plain area with a contour interval of 1 meter and a mapping scale of 1:2000), through comparative analysis with the measured points, it is statistically concluded that the minimum plane difference of the deformed area is about 0.09 meters, the maximum difference is about 14.48 meters, and the average difference is about 5.34 meters; the minimum elevation difference is about 1.42 meters, the maximum difference is about 2.62 meters, and the average difference is about 1.86 meters (the difference distribution map is shown in the figure). Figure 4 As shown, from Figure 4It can be seen that the plane difference of the data processed after the operation of the RTK drone in the prior art is mainly distributed in the range of 5 to 9 meters, and the elevation difference is mainly distributed in the range of 1 to 3 meters. The coordinate accuracy is not up to standard), and it cannot meet the corresponding water conservancy specification requirements of the 1:2000 scale digital line drawing. The problem product generated by the data processing of block A after the operation of the RTK drone in the present embodiment using the prior art cannot be solved by software iterative calculation. Frequent rework is time-consuming and labor-intensive, increasing costs. Even after rework, the solution still fails, which not only delays the construction period, but also affects work morale and wastes resources. In particular, the flood control project of a certain river in this embodiment is in an inconvenient and difficult area for rework, which is costly.

[0070] The applicant's analysis revealed that poor weather conditions during filming (such as geomagnetic explosions and thunderstorms) affected ionospheric stability. The drone's RTK module was subject to abnormal ionospheric interference when receiving GNSS satellite signals, resulting in large errors in the RTK fixed solution (pseudo-fixed solution), which seriously affected the accuracy of the spatial coordinate values ​​(Xs, Ys, Zs) of the photographic center in the POS data and significantly impacted the solution results. Furthermore, when the communication signal in the survey area was weak and RTK module communication anomalies occurred during drone operation, the drone would automatically maintain the current RTK fixed solution state, but positioning accuracy would continue to decline. If the drone was not connected to the CORS base station for more than 10 minutes, it would automatically exit RTK mode and enter attitude mode. This continued decline in positioning accuracy would also cause large errors in POS positioning data, significantly impacting the solution results.

[0071] Similarly, when the RTK drone is shooting in this embodiment, the weather conditions are poor (ionosphere anomaly) and the communication signal in the survey area is weak. This embodiment adopts the method of the present invention to remove gross errors in aerial triangulation. The specific method is as follows:

[0072] (1) Perform preliminary aerotriangulation analysis on the problematic data (where the POS data has been converted to the engineering coordinate system). The initial position (POS recorded data) of the spatial coordinates (Xs, Ys, Zs) of the center of the image in this embodiment differs significantly from the calculated position, with the X-axis difference reaching 19.25 meters.

[0073] (2) All gross error POS data with a difference of more than 0.3 meters in either the X or Y axis of the center of the image were collected. A total of 587 images were taken in Block A, of which 109 contained gross error POS data.

[0074] (3) Reduce the weight of the problematic POS data and recalculate the aerial triangulation. Reduce the weight of the problematic POS data for the 109 images obtained. Reduce the horizontal accuracy of the problematic data to 2 meters and the vertical accuracy to 10 meters. Maintain the horizontal accuracy of the other non-gross error data at 0.03 meters and the vertical accuracy at 0.06 meters. All gross error data and non-gross error data are imported into the calculation. The software automatically identifies the data accuracy and reduces the weight, recalculates the aerial triangulation, and reconstructs the results.

[0075] (4) Verify the countermeasures and objectives. Check the calculated results for deformation, compare and analyze the coordinates of the measured points with the illustrated points, and perform error statistics. Planar accuracy is ≤ 1.2 meters, and elevation annotation accuracy is ≤ 0.3 meters. The tolerance requirements for water conservancy and hydropower engineering surveying specifications are shown in Table 1 below.

[0076] Table 1 Table of tolerance requirements for water conservancy and hydropower engineering measurement specifications

[0077]

[0078] This embodiment adopts the embodiment of the present invention and the effect is as follows Figure 5 As shown, after the POS data is de-weighted, the aerotriangulation encryption and puncture point solution results show that the entire block A in this embodiment has no tensile deformation or dislocation and delamination.

[0079] The coordinate values ​​of the graphic points of the qualified results solved by the present invention in this embodiment are averaged and compared with the measured points (POS pseudo-fixed gross error data area). It is found that: relative to the measured points, after the present invention is used to eliminate the gross errors of aerial triangulation, the minimum plane difference is 0.01 meter, the maximum is 0.21 meter, and the average is 0.13 meter. The mean error of the plane position of the feature point relative to the adjacent map control point is ±0.1 meter, which is less than the limit of 1.2 meters; the minimum value of the elevation difference (absolute value) is 0.01 meter, the maximum value is 0.32 meter, and the average is 0.09 meter. The mean error of the elevation annotation point relative to the adjacent map control point is ±0.08 meter, which is less than the limit of 0.3 meter.

[0080] From the above, it can be seen that this embodiment adopts the method of the present invention to solve the qualified results through internal processing without stretching deformation, dislocation and stratification, and the graphical coordinates of the ground feature points are compared with the measured points. The mean error statistics meet the requirements of water conservancy specifications and are better than the 1 / 3 limit error. The solution result is excellent.

[0081] At the same time, the applicant adopted the method of field re-flight to eliminate the gross errors of aerial triangulation. After 5 re-flights, the qualified products and coordinate accuracy calculated were up to standard only 2 times, and still failed 3 times, with a failure rate of up to 60% (i.e., the qualified rate of field re-flight was as low as 40%). Moreover, the field re-flight method requires selecting good weather for re-flight, and the field re-flight operation takes more than 5 days, and the field re-flight operation cost is relatively high (the re-flight cost is about 15,000 yuan / time). In this embodiment, the qualified result accuracy calculated after the internal processing of the present invention is equivalent to the qualified result accuracy of the field re-flight, but the internal processing of the present invention does not require field rework compared to the field re-flight, which greatly saves time and cost, and can achieve the effects of fast, efficient (the internal processing of the present invention takes about 1 hour), zero cost, and high qualified rate (up to 98%).

[0082] Table 2 shows the qualified results of the POS data blocks with problems in the aerial survey of a river flood control project in this embodiment before and after the method of the present invention is used to remove gross errors in aerial triangulation.

[0083] Table 2 Statistics of block solution qualification rates before and after the method of the present invention is used to remove gross errors in aerial triangulation

[0084]

[0085] As can be seen from Table 2 above, 117 of the 120 blocks in the aerial survey of a river flood control project in this embodiment were qualified after the aerial triangulation and densification errors were eliminated using the method of the present invention. The results showed no tensile deformation or dislocation stratification, and the accuracy statistics met the standards. The qualified rate was much higher than that of the existing drone internal processing. The qualified rate of the solution using the method of the present invention reached 98%. Only 3 blocks failed to be solved. Analysis of these 3 failed blocks showed that these blocks not only had POS data problems, but also had problems with poor image quality, mist obstruction, and blurring.

[0086] Other contents not described in detail in the present invention belong to the prior art.

Claims

1. A method for eliminating gross errors in aerial triangulation of pseudo-fixed data from RTK UAV POS, characterized by: The following steps are included: Step 1: Import the block images and corresponding POS data collected by the RTK drone into the DJI Terra software for preliminary aerial triangulation and check the aerial triangulation quality report. The route planning for RTK UAV operations is two-way or multi-way; POS data is the positioning and attitude data collected when the RTK drone connects to the CORS network and receives the corresponding base station signal; Use DJI Terra software to perform preliminary aerial triangulation and obtain an aerial triangulation quality report. Check the georeferencing RMS error and the number of images in the RTK fixed solution state in the aerotriangulation quality report after solution. Step 2: Import the block images and corresponding POS data of the unqualified aerial triangulation reports into PIX4D software for preliminary aerial triangulation encryption processing, and calculate the spatial coordinates of the photographic centers of all images through adjustment; Step 3: Count the POS pseudo-fixed gross error data with large differences between the initial position coordinates and the calculated position coordinates of the photographic center; Step 4: Perform weight reduction processing on POS pseudo-fixed gross error data; The weight of the statistically obtained POS pseudo-fixed gross error data is reduced and defined as the weight of the non-positioning solution; The weights of other non-gross error POS data remain unchanged; Step 5: Use DJI Terra software to customize the precision and import the de-weighted POS data and the corresponding photos for aerobatic triangulation. Optimize the image control points to generate a qualified product. The downgraded POS data is all POS data including the gross error downgraded data and the non-gross error data.

2. The method for eliminating gross errors in aerial triangulation of pseudo-fixed data of RTK UAV POS according to claim 1 is characterized in that: In step 2, the data that failed the aerial triangulation quality report was that the image POS data recorded during the RTK UAV operation were all RTK fixed solutions, and the geo-registration root mean square error was greater than 2 meters.

3. The method for eliminating gross errors in aerial triangulation of pseudo-fixed data of RTK UAV POS according to claim 1 or 2, characterized in that: In step 3, the POS pseudo-fixed gross error data is the pseudo-fixed data caused by abnormal ionospheric interference or weak communication signals, resulting in a continuous decrease in the accuracy of the RTK fixed solution state. The amount of POS pseudo-fixed gross error data should be within 1 / 2 of the total POS data volume. The specific statistical method for POS pseudo-fixed gross error data is: S31. The initial position coordinates of the photographic center are the POS coordinate data recorded during RTK UAV operation, and they correspond one to one. The POS data coordinate system is the converted engineering coordinate system. The POS coordinate system is converted to the Bursa seven parameters by converting the longitude and latitude coordinates into plane projection coordinates, and the geodetic height into normal height, using three or more control points with the same name. S32, collecting statistics on POS pseudo-fixed gross error data with a difference of more than 0.3 meters between the initial position coordinates of the photographic center and the calculated position coordinates in any direction of X or Y.

4. The method for eliminating gross errors in aerial triangulation of pseudo-fixed data of RTK UAV POS according to claim 3 is characterized by: In step five, qualified products are orthophotos and real-scene three-dimensional models without stretching deformation, dislocation and stratification, and the accuracy statistics of the comparison of the coordinate difference between the illustrated points and the measured points in the POS pseudo-fixed gross error data area meet the standards.

5. The method for eliminating gross errors in aerial triangulation of pseudo-fixed data of RTK UAV POS according to claim 4 is characterized in that: In steps 2 and 5, the aerial triangulation encryption processing method is the bundle method with weighted adjustment.

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