阅读说明：本技术 一种基于高精度pos构架航线的辅助空三加密联合平差方法 (Auxiliary air-to-air triple encryption joint adjustment method based on high-precision POS (point of sale) framework route ) 是由 陈小海 邓永火 曾敦梁 谢珍莲 陈正楠 何细兰 于 2021-07-30 设计创作，主要内容包括：本发明公开一种基于高精度POS构架航线的辅助空三加密联合平差方法,具体包括如下步骤：外业操作：进行多次分辨率精度递增的航摄操作；内业操作：将经过预处理后的POS数据依序进行影像点匹配、检查、自检校和再平差后输出。本发明基于高精度POS构架航线的补充航摄资料代替像控点辅助空三加密平差计算不仅能减少外业内业的工作量,还能有效提升空三平差过程的稳定性和精准性,在降低成本,提高效率方面具有显著效果。(The invention discloses an auxiliary air-triple encryption joint adjustment method based on a high-precision POS (point of sale) frame route, which specifically comprises the following steps of: and (3) field operation: performing aerial photography operation with resolution precision increasing for multiple times; and (3) field operation: and sequentially carrying out image point matching, inspection, self-checking and re-adjustment on the preprocessed POS data and then outputting the POS data. The method has the advantages that supplementary aerial photography data based on the high-precision POS framework route replaces image control points to assist the air-to-three encryption adjustment calculation, so that the workload of field operation and interior work can be reduced, the stability and the precision of the air-to-three adjustment process can be effectively improved, and the method has obvious effects on the aspects of reducing the cost and improving the efficiency.)

1. A high-precision POS (point of sale) framework route-based auxiliary air-to-air triple encryption joint adjustment method is characterized by comprising the following steps:

and (3) field operation: performing aerial photography operation with resolution precision increasing for multiple times;

and (3) field operation: and sequentially carrying out image point matching, inspection, self-checking and re-adjustment on the preprocessed POS data and then outputting the POS data.

2. The auxiliary air-triple encryption joint adjustment method based on the high-precision POS framework airlines as claimed in claim 1, wherein: the field operation step specifically comprises the following substeps:

acquiring a first round digital image of a measurement area at a first absolute altitude by using a man-machine;

and acquiring a second-wheel digital image of the survey area at a second absolute altitude by adopting the unmanned aerial vehicle.

3. The auxiliary air-triple encryption joint adjustment method based on the high-precision POS framework airlines as claimed in claim 2, wherein: the first absolute flight height is greater than the second absolute flight height.

4. The auxiliary air-triple encryption joint adjustment method based on the high-precision POS framework airlines as claimed in claim 2, wherein: the ground resolution of the first round of digital images is better than 5cm, and the ground resolution of the second round of digital images is better than 3 cm.

5. The auxiliary air-triple encryption joint adjustment method based on the high-precision POS framework airlines as claimed in claim 1, wherein: the field operation step specifically comprises the following substeps:

1) preprocessing POS data;

2) data import and parameter configuration are carried out;

3) carrying out automatic matching of the same name points of the images;

4) manually checking and eliminating flying points and rough difference points;

5) self-checking the aerial camera to obtain accurate camera parameters before relative checking;

6) updating and importing camera parameters, and adjusting and optimizing the alignment modes of all photos:

7) and repeatedly executing the steps 4) -6) until the adjustment result is output after the preset condition is met.

6. The auxiliary air-triple encryption joint adjustment method based on the high-precision POS framework airlines as claimed in claim 5, wherein: the step 1) is specifically as follows: converting and refining the plane coordinate and the elevation value of the POS data, wherein the plane coordinate adopts Gaussian-Kruger rectangular plane projection, is banded by 3 degrees, and has a central meridian of 117 degrees; and the elevation value is converted by adopting seven parameters calculated by the calculation control points of the measurement area, or the geoid refinement surface is adopted for calculation.

7. The auxiliary air-triple encryption joint adjustment method based on the high-precision POS framework airlines as claimed in claim 5, wherein: the preset conditions of the step 7) are specifically as follows: the adjustment precision meets the requirement of 1/2 pixels.

8. The auxiliary air-triple encryption joint adjustment method based on the high-precision POS framework airlines as claimed in claim 5, wherein: the step 3) is specifically as follows: and acquiring a first round digital image and a second round digital image, and performing matching connection on image homonymous points in the first round digital image and the second round digital image.

9. The auxiliary air-triple encryption joint adjustment method based on the high-precision POS framework airlines as claimed in claim 2, wherein: there is man-machine to carry on UCD aerial photography appearance that the focus is 79.8mm, unmanned aerial vehicle adopts the big Xinjiang longitude and latitude M300 that carries on the magic P1 aerial photography appearance that the focus is 35mm or the 4RTK of big Xinjiang spirit 4 that carries on the FC6310R aerial photography appearance that the focus is 8.8 mm.

10. The auxiliary air-triple encryption joint adjustment method based on the high-precision POS framework airlines as claimed in claim 2, wherein: the design of the field operation aerial photography route specifically comprises the following steps: setting baselines evenly according to the terrain, and carrying out the layout design of the framed air route in the direction vertical to the baselines, wherein one framed air route is supplemented when the average span is not more than six baselines.

Technical Field

The invention is applied to the field of novel basic mapping, and particularly relates to a high-precision POS (point of sale) framework route-based auxiliary air-to-three encryption joint adjustment method.

Background

With the development and popularization of photogrammetry, the data production by adopting the photogrammetry is more and more popular with surveying and mapping units in actual production operation. In photogrammetry, the precision of project results is determined by the work of three-dimensional encryption of interior works, and the method is a linking process from field work to interior work of aerial surveying imaging and plays a vital role in all the processes in the later period. However, the photo data acquired by the traditional aerial photography is often poor in POS precision, cannot meet the precision requirement of space-three encryption, and needs to distribute photo control points according to relevant specifications. The POS data is a positioning and attitude determination system (POS), which is an IMU/DGPS combined high-precision position and attitude measurement system. The image control point measurement has large field work load and very large work of adding control points in the field, so that the research of replacing image control point auxiliary air-to-air encryption adjustment calculation with the image control point auxiliary air-to-air encryption adjustment calculation by taking a high-precision POS framework air route as supplementary aerial data is very necessary. The air-to-air encryption software platforms at home and abroad are very many, and how to combine adjustment calculation for aerial data of different heights and different periods acquired by various aerial cameras is different in parameter setting in different software.

Disclosure of Invention

The invention aims to solve the technical problem of providing an auxiliary air-to-three encryption joint adjustment method based on a high-precision POS (point of sale) framework airline aiming at the defects of the prior art.

In order to solve the technical problem, the invention provides an auxiliary air-to-air triple encryption joint adjustment method based on a high-precision POS (point of sale) frame route, which specifically comprises the following steps:

and (3) field operation: performing aerial photography operation with resolution precision increasing for multiple times;

and (3) field operation: and sequentially carrying out image point matching, inspection, self-checking and re-adjustment on the preprocessed POS data and then outputting the POS data.

As a possible implementation manner, further, the field operation step specifically includes the following sub-steps:

acquiring a first round digital image of a measurement area at a first absolute altitude by using a man-machine;

and acquiring a second-wheel digital image of the survey area at a second absolute altitude by adopting the unmanned aerial vehicle.

As a possible implementation, further, the first absolute flight height is greater than the second absolute flight height.

As a possible implementation, further, the ground resolution of the first round digital images is better than 5cm, and the ground resolution of the second round digital images is better than 3 cm.

As a possible implementation manner, further, the field operation step specifically includes the following sub-steps:

1) preprocessing POS data;

2) data import and parameter configuration are carried out;

3) carrying out automatic matching of the same name points of the images;

4) manually checking and eliminating flying points and rough difference points;

5) self-checking the aerial camera to obtain accurate camera parameters before relative checking;

6) updating and importing camera parameters, and adjusting and optimizing the alignment modes of all photos:

7) and repeatedly executing the steps 4) -6) until the adjustment result is output after the preset condition is met.

As a possible implementation manner, further, the step 1) is specifically: converting and refining the plane coordinate and the elevation value of the POS data, wherein the plane coordinate adopts Gaussian-Kruger rectangular plane projection, is banded by 3 degrees, and has a central meridian of 117 degrees; and the elevation value is converted by adopting seven parameters calculated by the calculation control points of the measurement area, or the geoid refinement surface is adopted for calculation.

As a possible implementation manner, further, the preset conditions of step 7) are specifically: the adjustment precision meets the requirement of 1/2 pixels.

As a possible implementation manner, further, the step 3) is specifically: and acquiring a first round digital image and a second round digital image, and performing matching connection on image homonymous points in the first round digital image and the second round digital image.

As a possible implementation, further, the unmanned aerial vehicle carries the UCD aerial camera with focal length of 79.8mm, and the unmanned aerial vehicle adopts the majiang longitude and latitude M300 carrying the myth P1 aerial camera with focal length of 35mm or the majiang spirit 4RTK carrying the FC6310R aerial camera with focal length of 8.8 mm.

As a possible implementation manner, further, the design of the field operation aerial route is specifically as follows: setting baselines evenly according to the terrain, and carrying out the layout design of the framed air route in the direction vertical to the baselines, wherein one framed air route is supplemented when the average span is not more than six baselines.

By adopting the technical scheme, the invention has the following beneficial effects: the method has the advantages that supplementary aerial photography data based on the high-precision POS framework route replaces image control points to assist the air-to-three encryption adjustment calculation, so that the workload of field operation and interior work can be reduced, the stability and the precision of the air-to-three adjustment process can be effectively improved, and the method has obvious effects on the aspects of reducing the cost and improving the efficiency.

Drawings

The invention is described in further detail below with reference to the following figures and embodiments:

FIG. 1 is a schematic view of a mapping frame route according to an embodiment of the present invention;

FIG. 2 is a flowchart illustrating an embodiment of a domestic encryption operation;

FIG. 3 is a schematic view of a principal point-like coordinate value weight value interface of the frame route according to the embodiment of the present invention;

FIG. 4 is a diagram of the camera parameter configuration for framing routes and basic routes in accordance with an embodiment of the present invention;

FIG. 5 is a diagram illustrating the effect of a framed route and basic route connection points according to an embodiment of the present invention;

FIG. 6 is a diagram illustrating the effect of image matching between a frame route and a basic route according to an embodiment of the present invention;

FIG. 7 is a diagram illustrating an analysis of distortion errors of a camera according to an embodiment of the present invention;

FIG. 8 is a graph of a checkpoint profile according to an embodiment of the present invention;

FIG. 9 is a statistical table of checkpoint accuracy values according to an embodiment of the present invention;

FIG. 10 is a table of error statistics according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described in detail and completely with reference to the accompanying drawings.

The invention provides an auxiliary air-triple encryption joint adjustment method based on a high-precision POS (point of sale) frame route, which specifically comprises the following steps of:

and (3) field operation: performing aerial photography operation with resolution precision increasing for multiple times; the design of the field operation aerial photography route specifically comprises the following steps: setting baselines evenly according to the terrain, and carrying out the layout design of the framed air route in the direction vertical to the baselines, wherein one framed air route is supplemented when the average span is not more than six baselines. The method specifically comprises the following substeps:

acquiring a first round digital image of a measurement area at a first absolute altitude by using a man-machine;

and acquiring a second-wheel digital image of the survey area at a second absolute altitude by adopting the unmanned aerial vehicle.

And the height of the first absolute flight height is greater than the third absolute flight height. The ground resolution of the first round digital image is better than 5cm, and the ground resolution of the second round digital image is better than 3 cm.

Wherein, the unmanned aerial vehicle adopts the big Xinjiang longitude and latitude M300 of carrying the divine P1 aerial photography appearance that the focal length is 35mm or the big Xinjiang eidolon 4RTK of carrying the FC6310R aerial photography appearance that the focal length is 8.8mm to carry the UCD aerial photography appearance that the human machine carries the focal length is 79.8 mm.

And (3) field operation: and sequentially carrying out image point matching, inspection, self-checking and re-adjustment on the preprocessed POS data and then outputting the POS data. The method specifically comprises the following substeps:

1) preprocessing POS data; the method specifically comprises the following steps: converting and refining the plane coordinate and the elevation value of the POS data, wherein the plane coordinate adopts Gaussian-Kruger rectangular plane projection, is banded by 3 degrees, and has a central meridian of 117 degrees; and the elevation value is converted by adopting seven parameters calculated by the calculation control points of the measurement area, or the geoid refinement surface is adopted for calculation.

2) Data import and parameter configuration are carried out;

3) carrying out automatic matching of the same name points of the images; the method specifically comprises the following steps: and acquiring a first round digital image and a second round digital image, and performing matching connection on image homonymous points in the first round digital image and the second round digital image.

4) Manually checking and eliminating flying points and rough difference points;

5) self-checking the aerial camera to obtain accurate camera parameters before relative checking;

6) updating and importing camera parameters, and adjusting and optimizing the alignment modes of all photos:

7) and repeatedly executing the steps 4) -6) until the adjustment result is output after the preset condition is met. Wherein the preset conditions are specifically as follows: the adjustment precision meets the requirement of 1/2 pixels.

Example (b):

the test area is located in coastal areas of Fujian province, has flat terrain, mainly comprises urban residential areas and newly-built new areas, and has an area of about 40km². Surveying and mapping are required 1: 500 topographical map. The survey area is convenient for traffic and has more vegetation. A human-machine carried UCD aerial camera is adopted to obtain a digital image with a resolution ratio superior to 5cm in a measuring area, although POS data are carried, the coordinate positioning precision is poor, and the requirement of space-three encryption cannot be met. Therefore, the Xinjiang eidolon 4RTK and the Xinjiang longitude and latitude M300 are adopted to respectively supplement the framework route, and the aerial photography conditions are as shown in the table 1:

TABLE 1 aerial photography situation table

The frame course with the high-precision POS is designed to reduce the layout of image control points, so that the frame course is generally perpendicular to the basic course, can be flexibly designed according to the shape of a survey area, and can also be designed according to the standard requirement of image control layout, an unmanned aerial vehicle platform with a GPS-RTK function is adopted to carry an aerial photography instrument during aerial photography of the frame course, and each photo obtained in the aerial photography process can be ensured to participate in air-triple encryption adjustment. The method aims to completely replace photo control points, and has better effect on adjustment result precision and continuity between area networks by increasing the density of a framework route and high-precision POS auxiliary air-to-air triple encryption.

The survey area designs a frame route according to the standard requirement of image control layout, and an average span of 6 base lines supplements a frame route, which is basically the principle of full-area network layout control. A schematic of the frame route is shown in fig. 1.

The interior data processing firstly carries out conversion and refinement processing on the plane coordinates and the elevation values of the POS data. The plane coordinate directly adopts Gaussian-Kruger right-angle plane projection, the 3-degree banding is realized, the central meridian is 117 degrees, the elevation value is converted by adopting seven parameters calculated by a measuring area starting control point, and the POS data processing work of the part is very important. The method specifically comprises the following steps as shown in figure 2: 1) preprocessing POS data; 2) data import and parameter configuration are carried out; 3) carrying out automatic matching of the same name points of the images; 4) manually checking and eliminating flying points and rough difference points; 5) self-checking the aerial camera to obtain accurate camera parameters before relative checking; 6) updating and importing camera parameters, and adjusting and optimizing the alignment modes of all photos: 7) and repeatedly executing the steps 4) -6) until the adjustment result is output after the preset condition is met. The aerial three-dimensional encryption adjustment of the measuring area is carried out by adopting photoscan software, the software has high matching precision of the image homonymous points, good connecting effect of the matching points and high accuracy, and can meet the requirements of the operation of the method. Each step of the air-to-air triple operation is very critical, each parameter configuration cannot be wrong, images in different periods have different color differences, textures, surface feature elements and the like, and the matching error is correspondingly increased, so that high-precision POS data is required to be used as assistance, and the reliability of a matching point can be improved and the matching speed can be increased. Meanwhile, the weight of the POS data needs to be set, and the weight parameters of the principal point coordinate values of each frame route are shown in FIG. 3. The image matching points are manually checked and flying points and rough difference points are eliminated, meanwhile, self-checking is carried out on the aerial camera to obtain relatively accurate camera parameters, the camera parameters are updated and led in, all photo alignment modes are adjusted and optimized, and the working process is repeated until the adjustment precision meets the requirement of 1/2 pixels. The framed route and basic route camera parameter update configuration is shown in FIG. 4.

In the measuring area, the frame route and the basic route are different in flight height, different in aerial photographing time and large in image chromatic aberration, but after high-precision POS data assist air-to-air triple matching, the number of image matching connection points is large, the matching precision is high, and the requirement of air-to-triple encryption precision indexes is met. The effect graph of the connecting point of the framed route and the basic route is shown in FIG. 5, and the image matching effect graph of the framed route and the basic route is shown in FIG. 6.

And (3) analyzing the precision result: the space three-dimensional difference process of the measuring area needs to carry out self-checking on camera parameters and then reconfigure the parameters of the camera. We therefore first look at the camera parameter distortion error. The analysis chart of the camera distortion error of the measuring area is shown in fig. 7.

According to the actual situation of the survey area, 23 inspection areas are uniformly distributed among the construction routes, each inspection area acquires the coordinates of the characteristic points in a field department measurement mode, and the space three is imported as a check point through plane coordinate conversion and elevation refinement. The checkpoint profile is as in fig. 8: the aerial survey method is shown in the table 2 as the requirement of the adjustment precision of the industrial air-to-air encryption points in the chart:

TABLE 2 Intra-Business encryption Point accuracy requirement

The space-time-space-three encryption of the measurement area is subjected to adjustment optimization for many times, the final check point precision value is shown in figure 9, and it can be seen that the check point precision meets the requirements of table 2. And after the three blank fruits are output, carrying out three-dimensional mapping and field patrol, and editing the final DLG result of the building library forming cost project. The DLG result of the measurement area is verified by field precision, and the error in the plane absolute precision is +/-11.42 cm, the error in the plane relative precision is +/-8.07 cm, and the error in the elevation point precision is +/-11.66 cm are respectively counted. The statistical table is shown in fig. 10.

The foregoing is directed to embodiments of the present invention, and equivalents, modifications, substitutions and variations such as will occur to those skilled in the art, which fall within the scope and spirit of the appended claims.