other information
drafter:Liu Bo, Shao Jian, Li Yingcheng, Yang Jun, Li Guanshi, Lu Guonian, Zhu Xiang'e, Xu Jiangang, Sheng Yehua, Xue Yanli, Cai Yong, Ren Yafeng, Wang Yanning, Ding Longyuan, Xia Xiaoli, Dai Liangliang, Gong Weilong, Li Xianhu, Wang Zhiwei
Drafting unit:Jiangsu Provincial Institute of Surveying and Mapping, China Surveying and Mapping (Beijing) Remote Sensing Technology Co., Ltd., Shanghai Hangyao Information Technology Co., Ltd., Nanjing Normal University, Nanjing Ubiquitous Geographic Information
Focal point unit:National Geographic Information Standardization Technical Committee (SAC/TC 230)
Proposing unit:Ministry of Natural Resources of the People's Republic of China
Publishing department:State Administration for Market Regulation National Standardization Administration
Some standard content:
ICS07.040
National Standard of the People's Republic of China
GB/T39610—2020
Technical specifications for oblique digital aerial photography
photography2020-12-14Release
State Administration for Market Regulation
Standardization Administration of the People's Republic of China
2020-12-14Implementation
Normative reference documents
Terms and definitions
Abbreviations
Basic requirements
Performance requirements for tilted digital aerial cameras
Calibration of tilted digital aerial cameras
Airborne IMU/GNSS system·
Aerial photography planning and design
Aerial photography planning
Aerial photography design
Aerial photography implementation
Flight quality requirements
Image quality requirements
IMU/GNSS
Quality inspection of results
Inspection items
Inspection methods
Quality inspection report||tt| |Results collation
Image numbering
IMU/GNSS data
Image data storage and outer packaging
Document collation
Results acceptance
Acceptance procedure:
Acceptance document·
Acceptance report
Data transfer
Appendix A (Informative Appendix)
Appendix B (Informative Appendix)
Appendix C (Informative Appendix)
Appendix D (Informative Appendix)
Common calculation formulas for aerial photography
Aerial photography flight record
Schematic diagram of camera position relationship
Aerial photography data transfer book
GB/T39610—2020
This standard was drafted in accordance with the rules given in GB/T1.1-2009. This standard was proposed by the Ministry of Natural Resources of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee for Geographic Information Standardization (SAC/TC230). GB/T39610—2020
The drafting units of this standard are: Jiangsu Institute of Surveying and Mapping, China Surveying and Mapping (Beijing) Remote Sensing Technology Co., Ltd., Shanghai Hangyao Information Technology Co., Ltd., Nanjing Normal University, Nanjing Ubiquitous Geographic Information Industry Research Institute Co., Ltd., and Beijing Gas and Thermal Engineering Design Institute Co., Ltd.
The main drafters of this standard: Liu Bo, Shao Jian, Li Yingcheng, Yang Jun, Li Guanshi, Jian Guonian, Zhu Xiang'e, Xu Jiangang, Sheng Yehua, Xue Yanli, Cai Yong, Ren Yafeng, Wang Yanning, Ding Longyuan, Xia Xiaoli, Dai Liangliang, Gong Weilong, Li Xianhu, Zhu Zhiweim
1 Scope
Technical specification for oblique digital aerial photography
GB/T39610—2020
This standard specifies the basic requirements, aerial photography plan and design, aerial photography implementation, quality inspection of results, results collation, results acceptance and data transfer for aerial photography using oblique digital aerial cameras. This standard applies to aerial photography work that uses oblique digital aerial cameras to produce basic surveying and mapping products and real-scene three-dimensional digital products. 2
Normative referenced documents
The following documents are indispensable for the application of this document. For all dated referenced documents, only the dated version applies to this document. For any undated referenced document, the latest version (including all amendments) shall apply to this document. GB/T18316—2008 Quality inspection and acceptance of digital surveying and mapping results GB/T27919—2011 Technical specification for IMU/GPS-assisted aerial photography GB/T27920.1—2011 Specification for digital aerial photography Part 1: Frame-type digital aerial photography CH/T1029.2—2013 Technical specification for quality inspection of aerial photography results Part 2: Frame-type digital aerial photography CH/T8021 Verification procedure for digital aerial camera
Terms and definitions
The following terms and definitions apply to this document. 3.1
Oblique digital aerial camera is composed of two vertical cameras and multiple oblique cameras: digital aerial photography equipment and instruments for photographing the ground from multiple perspectives 3.2
Oblique digital aerial photography is the photographic work or activity carried out using an oblique digital aerial camera. 3.3
Oblique camera angle oblique camera angle The angle between the main optical axis of the oblique camera and the main optical axis of the vertical camera. 3.4
vertical photograph
Vertical image
Image taken by a vertical camera
Oblique image oblique photograph
Image taken by an oblique camera.
Tilt angle of photograph The angle between the main optical axis of the aerial camera and the plumb line in aerial photography or the angle of the main optical axis of the camera relative to the horizontal plane in ground photography.
GB/T39610—2020
Image swing angle swing angle; yaw
In the plane of the photograph, the angle at which the selected photograph coordinate axis rotates around the main optical axis. 3.8
Strip deformation
The maximum deviation of the line connecting the principal points of each photograph in a photographic route to the principal points of the first and last two photographs. 4 Abbreviations
The following abbreviations apply to this document.
DEM: Digital Elevation Model DSM: Digital Surface Model GNSS: Global Navigation Satellite System IMU: Inertial Measurement Unit PPK: Post Processing Kinematic RTK: Real Time Kinematic 5 Basics Performance requirements for oblique digital aerial cameras. The basic performance of oblique digital aerial cameras should meet the following requirements: a) The intrinsic orientation elements and camera distortion parameters of each camera can be accurately measured; b) The pixel of each camera is not less than 20 million; It is equipped with an exposure signal feedback device, which can stably output and record exposure pulses; c) The relative position and attitude relationship between cameras in an aerial camera composed of multiple cameras is rigidly stable; d) The exposure time difference of each camera is not greater than 120ms; The ground resolution of the center point of the oblique image should not be lower than that of the center point of the vertical image. Calibration of tilt digital aerial camera
The calibration items and methods of tilt digital aerial camera shall comply with CH/T8021. Calibration shall be carried out in any of the following situations: a)
Not calibrated or the calibration validity period has expired;
b) After major repair or disassembly and replacement of major components; c) After severe vibration during use or transportation; d) Other situations that may affect the stability of tilt digital aerial camera 3 Airborne IMU/GNSS system
The airborne IMU/GNSS system shall meet the requirements of GB/T27919-2011. When taking large-scale aerial photography, the data recording frequency of IMU should not be less than 200Hz. UAV aerial photography can be configured with PPK, and RTK6 can also be used for small-scale operations. Aerial photography planning and design
Aerial photography plan
Aerial photography plan should be formulated according to mission requirements, and should include the following contentsa) Scope of the photography area and landform features;
b) Type and technical parameters of the flight platform;
Ground resolution of vertical images;
Route laying method, heading and lateral re-entry degree of vertical images: season, climate and time of aerial photography missions;
Type, technical parameters and parameters of aerial photography auxiliary instruments;g)
Type, name and quantity of aerial photography results, etc. 6.2 Aerial photography design
6.2.1 Selection of basic geographic data for design GB/T39610—2020
The basic geographic data for design should be the latest topographic map, image map, DEM and DSM of the photography area. The scale of topographic map and image map should not be less than 1:10000, and the scale of DEM and DSM should not be less than 1:50000.6.2.2 Division of aerial photography zones
Division of aerial photography zones should follow the following principles:a) The division of aerial photography areas should generally be in accordance with GB/T27920.1-2011 implementation; b) Under the premise of meeting the requirements of resolution and overlap, the span of the aerial photography zone should be as large as possible. 6.2.3 Determination of the base plane height of the zone
The base plane height of the zone is determined based on the terrain undulations of the zone, flight safety conditions, etc. Generally, the average elevation of the low point in the zone should be selected as the base plane height.
6.2.4 Requirements for coverage of shooting areas and sub-zone routes
The requirements for coverage of shooting area sub-zone routes are as follows
a) The heading coverage of the shooting area should exceed the boundary line of the shooting area by a certain number of baselines, and the lateral coverage should exceed the boundary line of the shooting area by a certain number of routes. For the commonly used calculation formulas for aerial photography, please refer to formula (A.2) and formula (A.3) in Appendix A. b) The requirements for sub-zone coverage are the same as those for shooting area coverage. 6.2.5 Route laying method
The route laying should comply with the following principles:
The route is laid in a straight line according to the characteristics of the shooting area; b) The distribution of exposure points is designed using DEM or DSM according to the terrain and the height of buildings; c)
When the shooting area contains water areas, the route should try to avoid the main point of the vertical image falling into the water. When aerial photography results are used for 3D modeling, the route laying should also follow the following principles: a) For areas with low and sparse buildings, the route can be laid according to the distribution, orientation and terrain of the buildings in the sky; b) For areas with tall and dense buildings, it is advisable to lay the route vertically and horizontally or increase the lateral overlap of the route. 6.2.6 Selection of aerial photography season and time
The selection of aerial photography season and time should follow the following principles: a) Aerial photography should be selected in the season with favorable meteorological conditions in the photography area, and the adverse effects of snow, floods, sand blowing, etc. on photography should be avoided or reduced as much as possible to ensure that the aerial photography images can truly show the detailed features of the surface; b) The aerial photography time should generally be based on the solar altitude angle or shadow of the photography area specified in Table 2. Determination of multiples: 3
GB/T39610—2020
Steep mountainous areas and areas with dense high-rise buildings should be photographed within 1 hour before and after local noon. Table 2 Solar altitude angle and shadow multiples in the photographing area
Terrain category
Hills, general townsbzxZ.net
Mountains, large and medium-sized cities
6.2.7 Image overlap requirements
Image re-registration requirements are as follows:
Solar altitude angle
Shadow multiple (times)
Vertical image: The heading overlap is generally not less than 60%; the lateral overlap should generally be designed to be 40% to 80%, and the minimum is not less than a
30%. In steep mountainous areas and areas with dense high-rise buildings, the heading overlap is designed to be 70% to 80%. b) Oblique image: When the vertical image overlap is met, the heading and lateral overlap of the oblique image can no longer be redesigned. 7 Aerial photography implementation
Flight quality requirements
Vertical image inclination
The vertical image inclination should generally not be greater than 6°. The maximum should not be greater than 10°. 7.1.2 Vertical image rotation angle
The vertical image rotation angle should meet the following conditions: a) The vertical image rotation angle should generally not be greater than 25°. The maximum should not be greater than 35° while ensuring that the image heading and lateral overlap meet the requirements;
b) When the aerial photography results are used to produce basic surveying and mapping products, the vertical image rotation angle should meet the requirements of GB/T27920.1-2011. 7.1.3 Route curvature
Route curvature should not exceed 1%. When the route length is less than 5000m, the maximum route curvature should not exceed 3%. 7.1.4 Altitude maintenance
The altitude difference between adjacent images on the same route should not exceed 30m, the difference between the maximum altitude and the minimum altitude should not exceed 50m, and the difference between the actual altitude and the designed altitude should not exceed 50m.
7.1.5 Area and sub-area coverage guarantee
The area and sub-area coverage should comply with 6.2.4.
7.1.6 Filling in flight record data
At the end of each flight, the photographer should fill in the aerial photography flight record form. The format of the aerial photography flight record form is shown in Appendix B4
2 Image quality requirements
Image quality requirements are as follows:
GB/T39610—2020
a) The image should be clear, with rich layers, moderate contrast, and soft tones. It should be able to identify small ground objects that are suitable for ground resolution and be able to establish a clear three-dimensional model. b) The image should not have defects such as clouds, cloud shadows, smoke, large-area reflections, stains, etc. Although there are a few defects, if they do not affect the connection and mapping of the three-dimensional model, it is considered that it can be used for surveying and drawing lines. c) Ensure that the image point displacement caused by the aircraft ground speed at the moment of exposure is generally not greater than 1 pixel, and the maximum should not be greater than 1.5 pixels.
3IMU/GNSS
IMU/GNSS data processing requirements are as follows:
a) Vertical image IMU/GNSS data processing is carried out in accordance with Chapter 7 IMU/GPS data processing of GB/T27919-2011;
Oblique image IMU/GNSS data is obtained by solving the IMU/GNSS data of the vertical image and the b)
relative position and attitude relationship between the oblique camera and the vertical camera. 7.4 Supplementary photography
7.4.1 Supplementary photography should be carried out in the following situations:
Aerial photography images have relative or absolute loopholes: b) The number of consecutive missed images of the oblique camera at the same viewing angle in high mountainous areas and areas with dense buildings is greater than 2. 7.4.2 The following principles should be followed when supplementing photography:
a) The same type of tilted digital aerial camera used in the previous aerial photography flight should be used for supplementing photography; b) Supplementing photography of loopholes should be carried out according to the original design requirements; c
The two ends of the supplementary photography route should extend beyond the loophole by at least one baseline. Results quality inspection
Inspection items
Result quality inspection items include aerial photography design, image overlap, coverage integrity, image inclination, image rotation, route curvature, altitude maintenance, coverage integrity of the photography area, image quality, IMU/GNSS results, and accessory quality. 8.2 Inspection methods
The aerial photography implementation unit should conduct a comprehensive inspection of the results quality. The inspection methods for image overlap, image inclination, and altitude maintenance should comply with the requirements of 6.2 in GB/T27920.1-2011. The inspection methods for aerial photography design, image rotation angle, route curvature, coverage integrity of the photographic area, image quality, and accessory quality shall comply with the requirements of 6.2, 6.3, and 6.5 of CH/T1029.2-2013. The quality inspection of IMU/GNSS results shall comply with the requirements of Chapter 8 of GB/T27919-2011. 8.3 Quality inspection report
The content and format of the inspection report and test report shall comply with the requirements of GB/T18316-2008. 5
GB/T39610—2020
9Results summary
Image number
Image numbering rules are as follows:
Image number consists of 16 Arabic numerals, using a serial number based on the route. The image number from left to right is the first digit a)
5 is the shooting area code, the sixth to seventh digits are the partition number, the eighth to tenth digits are the route number, the eleventh to twelfth digits are the route number, and the eleventh to twelfth digits are the route number. The first digit is the camera number, and the 13th to 16th digits are the image serial number, as shown in Figure 2; Xxxxx
XXXXXXX
Photographing area code
Division numberRoute numberCamera numberPeng Image serial numberFigure 2 Image number
b) The flight direction shall be the increasing direction of the number; c) The image number within the same route shall not be repeated; when there is a supplementary flight route, the image serial number of the supplementary flight route shall be increased by 5000 on the basis of the original serial number. d)
2IMU/GNSS data
IMU/GNSS data processing shall be carried out in accordance with the following requirements: a) The image name number in the IMU/GNSS data is consistent with the image number; b) The IMU/GNSS needs to indicate the coordinate system, the angle system and the corresponding unit. 3 Image data storage and outer packaging
Image data storage and outer packaging shall be carried out in accordance with the following requirements: Storage paths shall be established according to the cameras of the tilted digital aerial camera, and the images obtained by the corresponding cameras shall be stored in the corresponding paths. a)
The file should be in a regular image format, and the file name should be consistent with the image number. Generally, it should be stored in a hard disk, which should be stored in a paper or plastic box. The general information section specifically includes:
Shooting area name;
Shooting area code;
Shooting area area;
Aerial photography time;
Vertical image ground resolution;
Oblique digital aerial camera type, number and main distance; number of routes, number of vertical images and number of oblique images; aerial photography unit.
The loading content specifically includes:
Disk number (disk sequence number/total number of disks);
Image type and format;
Route number;
Image start and end film numbers;
Remarks.
9.4 Documentation and Data Arrangement
Documentation and data shall be arranged in accordance with the following requirements: a) Documentation and data arrangement shall comply with the requirements of 7.1.4 of GB/T27920.1-2011; the specific correspondence of image numbers shall be stated in the submitted documents and aerial photography record form; b) The installation diagram of the camera shall be added to the quantity
Documentation and data, and the representation method shall refer to Figure C.1 of Appendix C; d) The relative position relationship diagram of each camera shall be added to the document, and the representation method shall refer to Figure C.2 Results Acceptance
Acceptance Procedure
Results Acceptance Procedure includes:
GB/T39610-2020
The aerial photography execution unit shall check all aerial photography results and data item by item in accordance with the provisions of this specification and the aerial photography contract. After the aerial photography execution unit passes the quality inspection, all results and data shall be arranged and submitted to the aerial photography entrusting unit for acceptance. The aerial photography entrusting unit or the entrusted surveying and mapping product quality inspection agency shall inspect and accept all the results data in accordance with the provisions of this specification and the aerial photography contract. The two parties shall negotiate to deal with the problems found in the inspection and acceptance work. The aerial photography entrusting unit or the entrusted surveying and mapping product quality inspection agency shall finally give the quality assessment results of the results data.
C) After the results quality acceptance is qualified, both parties shall sign the handover book and go through the handover procedures. 10.2
Acceptance documents
Necessary documents should be provided during acceptance, including: a)
Technical design book:;
b) Flight record;
Aerial camera technical parameter calibration report;
Route and photo combination diagram;
Shooting area range;
Completion status diagram;
Results data handover book;
Quality inspection (test) report.
Acceptance report
The contents of the report should mainly include:
Overview of acceptance work, including acceptance time, acceptance location, acceptance method, acceptance personnel, etc.a)
Acceptance basis, including aerial photography contract, reference standards, technical design documents, etc.;b)
Overview of results, including survey area location, aerial photography area, aerial photography unit and qualification level, production time, form of results, etc.;d)
Flight quality, including calibration of aerial photography instrument technical parameters, zoning of photography area, number of routes (including supplementary flights), flight time (including supplementary flights), maximum and minimum overlap, difference between maximum and minimum altitude, rotation angle, route curvature, etc.;e)
Image quality elements, including image resolution, contrast, color tone, clarity, etc.;IMU/GNSS quality inspection report;
Results quality evaluation;
Existing problems and handling opinions.
GB/T39610—2020
Data Handover
After the acceptance is completed, the aerial photography data handover book should be submitted, and the format is shown in Appendix D. The main contents include: a)
Technical design book of tilted digital aerial photography; Calibration report of tilted digital aerial camera;
Aerial photography approval:
Aerial photography flight record form;
Vertical image and tilted image data;
Vertical browsing image;
Aerial photography center point coordinate data;
Route and image combination map;
Photography area completion map;
Aerial photography data handover book;
Aerial photography data confidentiality review report;
IMU/GNSS, RTK, PPK related data; other relevant information.
Appendix A
(Informative Appendix)
Common calculation formulas for aerial photography
A.1 The heading and lateral coverage should exceed a certain baseline number of the partition boundary line, calculated according to formula (A.1): tano
2tan(β/2)×（1-P）
Where:
—theoretical excess value, in bars;
Tilt camera angle, in degrees (°); Tilt Camera field of view, in degrees (°); B
Heading or lateral overlap
GB/T39610—2020
In actual flight, due to the influence of various factors such as the atmosphere, the actual value of the heading or lateral coverage beyond the boundary line is generally calculated according to formula (A.2) and formula (A.3):
N#=N+2
Where:
Number of baselines;
Number of routes.
......(A.2)
..................(A.3)
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