Some standard content:
National Standard of the People's Republic of China
Specifications for close-range photogrammetry
Specifications for close-range photogrammetry1 Subject content and scope of application
GH/T 12979—91
This standard specifies the accuracy requirements and specifications required for close-range photogrammetry. It proposes methods for acquiring and processing image data. This standard applies to the application of close-range photogrammetry technology in the morphological measurement and recording of buildings and structures. Its principles can also be used as a reference when applied in other fields.
2 Referenced standards
GB79301*5001*10001:2000 Internal specifications for aerial photogrammetry of topographic maps 3 General provisions
3.1 Definition
Close-range photogrammetry is a branch of photogrammetry. It does not use topographic maps as its daily basis, but uses the images obtained by photographing close-range targets within 300m to determine their morphology, geometric position and size. The target it photographs can be an object or a thing, static or dynamic, and the image it obtains can be a video or a digital image. It can provide a variety of results and data, such as a plane map, a stereo map, a cross-section map, two-dimensional coordinates of a date point, three-dimensional coordinates, and four-dimensional parameters including time, as well as other parameters of engineering construction. 3.2 Content classification
Close-range photogrammetry includes ancient building photogrammetry, industrial photogrammetry, and biomedical photogrammetry. 3.2.1 Ancient building photogrammetry
Ancient building photogrammetry refers to the photogrammetry work in cultural relics and archaeology. It includes the measurement of cultural relics (historical monuments), archaeological measurement, and site measurement.
The main content of ancient building photogrammetry is the surveying and mapping of ancient building and cultural relics facades, plane maps, contour maps, and image maps, as well as the determination of the main structural data of ancient buildings. The data has archival value. 3.2.2 Industrial photogrammetry
Industrial photogrammetry refers to the photogrammetry of machinery, automobiles, shipbuilding, aviation, and construction engineering. It provides the coordinates, length, angle, shape, volume, displacement, deformation, and even trajectory of the target object through photogrammetry. It is often used for product quality control, model design, traffic accident records, and deformation measurement of structures (such as dams, high-rise buildings, and bridges). From the perspective of close-up photogrammetry, the target sizes that can be accepted are classified into: large targets (20-300m) - including cooling tower shape measurement, hull joint matching measurement, tanker and oil tank volume measurement, high-rise buildings and human-shaped structure deformation measurement, etc.; medium-sized targets (2-20m) - including aircraft assembly inspection, ship propeller shape measurement, large communication antenna testing, automobile shell quality control, etc., including engineering model design, body motion space analysis, ship model measurement, etc.; small targets (0.2-2 m) - emblem-shaped targets (below 0.2 m) - including precision parts and sample measurement.
Approved by the State Administration of Technical Supervision on June 6, 1991 and implemented on March 1, 1992
GE/T12979-91
In most cases, analytical processing methods should be used, including the conventional offline or online analytical photogrammetry system, and even the real-time photogrammetry system.
3.2.3 Biomedical Photogrammetry
Biomedical photogrammetry is the spatial or spatiotemporal analysis of medical objects and various biological forms and functions through photogrammetry. For example, the measurement of human body shape or animal body, the measurement of gum model, the measurement of pollen morphology and other static oral landmarks, as well as the measurement of dynamic landmarks such as the growth process or movement trajectory of various organisms. According to the characteristics of biomedical photogrammetry, in addition to conventional simulation or analytical processing methods, unconventional photogrammetry methods are also applied. 3.3 Accuracy
Accuracy requirements are often expressed as the relative mean error of the photographic distance (m,/v), generally: 1/1000~1/50000: It can also be expressed as the point mean error.
3.3.1 Simulation method accuracy
The point mean error is not greater than 0.5 mm×M (M is the denominator of the map scale) The relative mean error is 1/1000~1/5000. 3.3.2 Analytical method accuracy
According to the purpose and the measured date standard, the point mean error can be divided into: high precision, high precision and low precision. Low-precision ear tag
Medium-precision Japanese tag
Commercial precision target
Within 10m
Within 5 mm
Within 1mm
The relative error is generally
1/500～1/50 000
3.4 Optimization design of near-range photogrammetry
Optimization design of near-range photogrammetry network: generally includes accuracy optimization, reliability optimization, economic optimization and testability design, so as to provide guiding suggestions for practical work, improve economic benefits and meet user requirements. Multiple photogrammetry is an important measure taken in near-range photogrammetry to improve accuracy and reliability indicators. Its meaning involves acquisition stations, multiple frames (multiple photography in the same orientation), multiple measurements (or the selection of photography and measurement equipment with a higher accuracy), multiple control methods and even multi-functional programs.
For close-up photography of service items, in addition to the methods specified in the specification, other new technologies and methods that have been verified in actual combat and can meet the accuracy of this specification and the requirements of users can also be used. Users can propose other technical requirements not included in this specification. 4 Object space control
Object space control includes control points and relative control. 4.1 Accuracy requirements for object space control
The accuracy of object control is generally less than 1/3 of the total accuracy requirements. 4.2 Coordinate system and projection surface
4.2.1 Selection of coordinate system
An independent coordinate system (Figure 1) is used, and it can also be measured in conjunction with other reference systems when necessary. 4.2.2 Selection of projection surface
CB/T 12979—91
The selection of projection surface should follow the principle of making the projection metrical, intuitive and easy to draw, reducing projection deformation and ensuring mathematical accuracy.
When a building has only one facade, a coordinate system plane parallel to the facade should be selected as the projection surface. When the exterior surface of a building is a curved surface or irregular multi-facade, it can be regarded as a building composed of several single facades, and multiple corresponding projections should be selected.
4.2.3 Transformation of coordinate system
When the selected coordinate system is not parallel to the projection surface of the building, the coordinate system must be transformed, that is, the coordinates of the control points must be changed to the projection surface of the building facade to be measured.
4.3 Object space control layout
In order to incorporate the established model into a unified object space coordinate system or to enhance the inherent strength of the model, object space control should be laid out. 4.3.1 Object space control layout requirements
4.3.1.1 When mapping by simulation method, within the range of the stereo model of the individual image pair, when relative control is not used, at least three control points should be laid out around the object to be photographed. When the depth of field of the target is large, the points should be evenly distributed in the front and back depths of field. For complex facades or parts of buildings with large curvatures, additional control points should be set. When there are multiple image pairs, if there are obvious points in the overlapping range of adjacent image pairs, marking points for connection should be arranged
4.3.1.2 The object control of the analytical method should be determined according to different methods, and refer to the requirements in 6.2.3. 4.3.2 Relative control can be used for the object control of the plane type sun mark. Relative control includes the known length and angle of the object. 4.3.3 For small moon marks, an active control system can be used. 4.3.4 Artificial marks should be used as the object control points as much as possible. Where artificial marks cannot be arranged, obvious points can be used as the object control points. When obvious points are selected as control points, the points should be marked on the film, and a sketch of the points and a brief text description should be drawn on the back of the film. 4.4 Control measurement method
4.4.1 Determination of three-dimensional coordinates of object control points
Object control measurement is generally to first measure the traverse points around the object to be measured, and the elevation is measured by direct leveling. Or use photoelectric ranging traverse measurement, or use indirect leveling, and then use forward intersection and trigonometric height method to determine the three-dimensional coordinates of the object control points at the traverse points. 4.4.2 Close-range object control measurement
In close-range photogrammetry with high accuracy requirements, close-range object control measurement methods are often used. This method is to establish an assumed one-dimensional coordinate system with the help of standard rulers CB/T 12979-91
(such as Geneva rulers, indium steel rulers and height calipers), and incorporate the theodolite station into this coordinate system. Finally, the coordinates of each control point are determined by the station.
a.Use a long level to level the standard ruler, and take the reverse edge of the standard ruler with the scaled lines as the X-axis of the assumed spatial coordinate system. The Y-axis and the X-axis are on the same horizontal plane, and the plumb line is the 2nd axis: b. Take a certain number of scaled lines on the standard ruler as known plane control points, usually at both ends and the center of the ruler! c. Place two theodolites at appropriate positions on one side of the standard ruler. You can also place two theodolites on both sides of the vernier ruler as needed. When placing, you need to consider the front intersection. The angle of the rear intersection is based on the selected points on the standard ruler. Implement the rear intersection, or use the front intersection method to solve the distance between the two end points of the known length, and gradually change the distance between the stations on both sides to determine the plane position of the vertical axis of the theodolite; Determine the elevation of the intersection of the horizontal and vertical axes of the theodolite: Use the vernier height caliper as a measuring tool, and use the theodolite leveling method to determine the height difference between the two theodolites:
T. The plane coordinates of the object control point can be determined by the front intersection method; The elevation of the object control point is determined by the indirect elevation method. 4.4.3 Analysis The use of relative control for the control measurement base is an effective method to improve accuracy and strength. Common relative control is to apply the known distance contained in the measured object itself or the photographic range, such as measuring the distance between a series of artificial marking points, affixing artificial markings to the integer-marked parts of the standard ruler, or regular geometric figures, such as rectangles and cubes, can all be used as relative controls. 4.5 Artificial markings 4.5.1 Shape of the marking The shape of the artificial marking can be designed according to actual needs. See Figure 2. Figure 3. Figure 4 and Figure 5. Figure 2 The center circle diameter D of the reading mark can be calculated according to formula (1): Figure 4 Where: D - center diameter, m; y - photographic distance, m; GB/T 12979-91 d - measuring mark diameter of the photogrammetric instrument, mm: f Camera principal distance, mm.
In large-angle cross-directional photography, artificial signs need to be made into three-dimensional shapes: such as spherical signs and cylindrical signs made of plastic. In special cases, luminous signs can be used.
4.5.2 Color of signs
The sign image and its background color should have appropriate contrast to facilitate identification and measurement. When the background is the sky, it is advisable to set up red and white signs; when the background is vegetation and dark-toned soil and rocks, white and yellow signs are used; when the background is buildings (charcoal and yellow), black and white or blue signs are generally used. 4.5.3 Sign materials
The sign material can be printed paper, that is, made by photography. It can also be painted directly on the photographic mark. For permanent artificial measurement signs, metal materials are suitable. Three-dimensional artificial signs can be made of plastic materials. When there is a special need, luminous materials are used.
5 Acquisition of close-range images
5.1 Camera system
In close-range photogrammetry, measurement, semi-measurement, non-measurement cameras and solid-state cameras (such as (CI) cameras) can be used to acquire photographic images.
5. 1. 1 Measurement camera
5.1.1.1 Measurement cameras are cameras specially designed for photogrammetry, and can be divided into two categories: single measurement cameras and stereo measurement cameras.
5. 1. 1. 2 Measurement cameras should have the following basic conditions: typical. The camera has a frame mark, the camera's internal orientation elements (%, 3, at) are known, there are orientation and leveling devices, b, the objective lens distortion is strictly controlled within the allowable range (usually micron level). 5.1.1.3 When using analog mapping and high-precision measurement, measurement cameras can be used. When selecting the required distance, the size of the target and the distance to the object should be considered. For long-distance and high-precision deformation observation, cameras with long focal length and large image format should be used as much as possible. When taking close-up photos in rocks, caves, and tunnels, short-distance cameras should be used: 5.1.1.4 Characteristics of a single measurement camera:. The baseline value or the object distance can be changed at will: b Vertical photography, cross-directional photography, multi-station photography, etc. can be performed. 5.1.1.5 Characteristics of stereo measurement cameras: a It can be used for vertical stereo photography with a fixed baseline, and the photography distance is generally small; the photogrammetry processing is simpler and the speed is faster. b.
5.1.2 Semi-metric camera
5.1.21 Semi-metric camera is a camera with a mark on the glass support to correct the background distortion. 5.1.2.2 Semi-metric camera has the following features: a
The camera glass support frame is engraved with grid lines: b.
The internal position element (,) of the camera is generally unknown; without a level and orientation device, the external position element of the light moment cannot be determined. 5.1.3 Non-metric camera
GB/T 12979—91
5.1.3.1 Non-metric camera is a camera not specially designed for photogrammetry, including various ordinary cameras, movie cameras and high-speed cameras.
5.1.3.2 Non-metric camera has the following characteristics:. The camera has no right frame mark:
b. The camera's internal orientation elements (, %) are unstable, there is no flattening device, and the distortion is relatively large: c. There is no leveling screen and directional device, and the light position cannot be determined when operating the light! d. Lightweight, can be focused at will, and some can take photos continuously or synchronously. 5.1.3.3 Non-measurement cameras are suitable for:
a, medium and low precision photogrammetry tasks:
b Photography to provide auxiliary data for detailed mapping; center, in special environments, can complete tasks that are not suitable for measurement cameras. 5.2 Camera calibration
Camera calibration refers to the detection of parameters related to the shape of the constructed beam. The basic parameters include: soil point coordinates and upper distance (3); objective lens distortion coefficient (, ke,, p,) non-orthogonality coefficient dβ and scale difference coefficient ds. For body cameras, it is also necessary to include the detection of some external orientation element values.
5.2.1 Camera calibration method
Camera calibration methods include photogrammetric analytical method and special optical mechanical calibration instrument method. Among them, photogrammetric analytical method can be divided into: two-dimensional control field method in the laboratory (single-piece space resection method); b. analytical plumb line method;
c. various analytical white calibration methods;
d. direct linear transformation solution method;
e. Combined with task calibration.
Single-piece space resection calibration method and first line linear transformation calibration method can refer to Appendix C (reference) for implementation. 5.2.2 Calibration accuracy requirements for camera internal orientation elements a. The principal distance is +0.02~±0.01 mm. b. The principal point is ±0.02 mm.
5.2.3 Determination of the eccentricity of the front node of the objective lens
In deformation measurement and other high-precision measurements, the eccentricity EC of the front node of the camera objective lens relative to the rotation center should be determined. 5.2.3.1 For a measuring camera whose vertical rotation axis intersects with the horizontal rotation axis, the relationship between the projection center (the front node of the objective lens) coordinate XYZ and the rotation center R coordinate XR,Y,Zr is calculated by formula (2): X = Xn + HCsingeosw
Ys = Yh + ECcosycosa
Z, - Zk + ECsinu
In the formula, Xs,Ys.Zs---the coordinates of the front node of the objective lens, mm 1Xk,Yk-Z--the coordinates of the instrument rotation center, mmFE
--the eccentricity value caused by the non-coincidence of the front node of the objective lens and the instrument rotation center + mm. For a camera whose vertical and horizontal rotation axes do not intersect, the following formula (3) is used for calculation: X, = X+ Ecasinsicosa
Y, = Y. + FChcosbrose
Z. - Zh + ECusine
Where: EC-.,EC, are the horizontal eccentricity and vertical eccentricity, mm respectively. -(2)
5.2.3.2 The measurement accuracy of the eccentricity of the front node of the objective lens should correspond to the object control accuracy. For deformation observations with low accuracy requirements, the horizontal baseline ruler can be photographed at different known distances. After calculating the distance obtained by photogrammetry, the difference between the two is EC. CB/T 12979—91
In high-precision deformation observations, an external focusing collimator is used to directly measure the eccentricity (see Figure 6). F
The center distance EC is calculated by formula (4)
EC = t -f
Where: 1. Use the outer adjustment screw of the collimator tube to allow the observer to measure the distance from the national standard S to the cross-wire plate F, which is the main distance of the camera. mm,
Use a caliper to measure the distance from the film frame F to the rotation center, mm1Use a caliper to measure the distance from the film frame F to the cross-wire plate F, + mm5.3Photographic station layout and photography force formula
5.3.1 Principles of Photo Station Arrangement
a. The arrangement of photo stations and the selection of photo modes should be based on the principle of ensuring accuracy, reliability and obtaining the most effective photo coverage. Avoid barriers as much as possible to prevent blind spots in photography. b. Photo stations can be set up on the ground and buildings, or scaffolding, lifts, tethered balloons and other low-altitude aircraft can be used as photo platforms.
Photo station arrangement methods
can be divided into single-station arrangement, double-station arrangement and multi-station arrangement. 5.3.2.1 Single-station arrangement
Photographing from a photo station, or taking multiple shots of a target (such as deformation measurement) is called zero baseline photography; it is suitable for measuring the one-dimensional change of a target point, and is also suitable for the two-dimensional measurement of a plane target. 5.3.2.2 Double-station arrangement
For targets with complex shapes or when the three-dimensional coordinates of a target point need to be measured, the measured object should be photographed from both ends of the baseline to form a stereo pair.
You can also use a single camera to keep the position still, take photos before and after the object moves a certain distance or rotates a certain angle, and obtain a stereo pair of images.
5. 3.2.3 Arrangement of multiple camera stations
For complex facades, such as long strip national standards, cylindrical day standards, and curved targets, multiple stations can be arranged. For high-precision deformation observation, zero-station photogrammetry is mostly used: the arrangement of photo stations is generally to arrange multiple photo stations around the measured object, and each photo station takes one or several photos. The selection of stations should make multiple photos cover the object for multiple times, but it is not necessarily required that the intervals between the stations are equal and the photography direction lines are parallel to each other: 5.3.3 Determination of photography method
The choice of photography method should be determined according to the size and shape of the measured object and its environmental conditions, the type of camera used, the performance of the internal mapping instrument, and the photogrammetry processing method of close-range photos. Normally, upright photography is adopted, and equal-inclined photography, cross-directional photography or other photography methods can also be selected.
GB/T12979—91
When mapping with an analog plotter, upright photography is required; when using an analytical plotter or analytical method to process images, this restriction does not apply. The use of multi-station cross-directional photography for deformation observation can improve accuracy. 5.3.4 Determination of the best photography parameters
5.3.4.1 Selection range of photography coefficient
The photography coefficient K (i.e. the ratio of the photography distance to the photography baseline B) is generally selected within the range of 4 to 15. For planar targets, the K value is allowed to be less than F4.
5.3.4.2 Determination of the upright photography baseline B
The optimal value of the upright photography baseline is calculated by formula (5): Bn= Az: /T + a/Ar Az
Wherein:
Length of the photography baseline, m
Ax is the width of the object to be measured along the axis, meα is the image size of the camera in the horizontal direction, m. 5.4 Requirements and working procedures for on-site photography
5.4.1 Preparation before photography
: Before photography, the camera and related instruments must be calibrated, h. Arrangement and field space
Check whether the dark box is leaking light;
d. Use the exposure meter to take a test shot to determine the appropriate exposure. 5.4.2 Exposure precautions
Attention should be paid to the light conditions that affect the target surface. It is best to choose direct light to avoid shadows covering details, and try to avoid top light and back light. Outdoor photography must be carried out when the light is good: when shooting on a cloudy day, attention should be paid to the clarity of the atmosphere and the contrast of the control point marks on the object side. Indoor photography, light sources should be set at different positions to make the illumination of the target uniform. When taking color and infrared photography, attention should be paid to whether the color temperature of the light source matches the model of the photosensitive material.
When photographing dynamic targets, the determination of the exposure time should consider making the size of the image blur circle within the allowable range. 5.4.3 Target surface treatment
You can use methods such as target projection grids, spots or coating patterns to enhance the contrast of the target surface to improve the accuracy of indoor stereo measurement.
On-site photography work procedures
Select the appropriate camera station location and lay out the photography baseline. Before photography, the necessary photography data (such as principal distance value, gasket thickness, focus adjustment, plate or film placement number, etc.) should be recorded, and all measurable external orientation elements, including Xs, Ys, Zs, and, and photography line B should be recorded; Take photos:
Carry out on-site photography processing in a simple darkroom in the field and check the photography quality: e.
After the quality of the photography film is tested, print a set of photos for use in controlling the turning point and on-site recording. 5.5 Accuracy estimation
Before the operation, the accuracy should be estimated according to the photography method used to ensure the quality and economic indicators of the photography. 5.5.1 Formula for estimating the accuracy of upright photography
mx =±K2Ki(X/T)\ +m
my =± K,Kam
Where: Ki=y/B
J-photographic distance, m
X, z --
photographic potential line, m,
camera principal distance, m;
image point coordinate tangent;
CB/T 12979—91
m -upper KVK(ZIDm +
Parallax observation error, Intn.
5.5.2 Cross-photography accuracy estimation formula
The accuracy estimation of any point in the photographed area of cross-photography (see Figure 7) can be calculated by symmetrical photography direction angle and baseline whitening base, according to formulas (9), (10) and (11):
nx = y/f -(l + tga ·tgp)/tl — tg(αa —g) . tgpmmy = 2 yr /Bf .(1 + tga · tgp)/(1 — tg(a -p)tg] mw /f-sec/[1 - tg(a —p)tgp) ·mIn the formula, — describes the angle of the point, gB/2y, (°)B is the length of a line, m,
Photographic distance m:
-camera principal distance, m
-photographic direction angle. (\).
6 Processing of close-range images
There are two methods for processing close-range images: simulation and analysis. When necessary, the two methods can be used in combination. 6.1 Simulation processing
(11)
When the close-range image is taken by a measuring camera and the output is represented in the form of a diagram (line drawing), the simulation method is generally used. 6 .1.1 Scale series
6.1.1.1 Map scale
According to the size of the lunar mark and the design requirements, the map scale series is generally: 1:1, 12, 1:5, 1:10.1*20.150, 1-100.1:200.
Other scales can be added when there is a special need. For miniature lunar marks, the enlarged scale should also be used for mapping. 6.1.1.2 Image scale requirements
The image scale ratio of the elevation map and contour map should be determined according to the mapping accuracy requirements and the magnification of the instrument used, and is generally 1 3--1 6.
GB/T 12979.91
6.1.1.3 Format specifications
The size of the drawing shall be selected according to the provisions of Table 1. The format specifications and formats are shown in Figure 8. Table 1
Basic format
841X118 9
473×420
591X420:
841X420
594×B41
420X594
297×420
297210
The format codes A0, A1, A2, A3 and A4 in Table 1 are the standard formats stipulated by the state. 0.625.0.75 are the codes for the conventional formats of design drawings.
Under special circumstances, the length and width of A1 to A3 drawings can be extended. No. 0 drawings can only be extended, and the size of the extended part should be 1/8 of the side length and its multiples.
Due to the diversity of near-field targets, the format specifications proposed by the user can also be used when necessary. The icons can be arranged at any appropriate position in the four corners of the format. The icon content includes: map name, camera type, plotter type, map type (if it is an equal-valued velvet map, the equal-valued distance should be noted), survey unit, scale, operation period, etc. 6.1.2 Mapping with precision stereo plotter
6. 1.2.1. Preparation for work
Collect field data: field technical design book, control observation and calculation chain, field control film and investigation description data, and make necessary analysis of the data;
b. Write the internal technical design book;
Check the photographic negative or the copied transparent positive film. The image should be clear, rich in layers, moderate in contrast, and the image of the optical frame mark should be clear and aligned with the map plate display points. The map plate should be made of old wool-surface polyester film or engraved film. The control points should not be missed or mis-displayed, and there should be enough orientation points. According to the map scale and the area of the figure, determine the coordinates of the map rate points. Generally, a grid mark should be set on the map, and the grid points should be displayed every 10cm so as to fit closely with the 10cm×10cm standard grid. The pinhole and display point errors should be within 0.1.mm. 6.1.2.2 Instrument calibration and placement
The precision stereo plotter should be kept in good working condition. The instrument should be calibrated and the zero position should be determined. Only after passing the calibration can it be operated. a
Calculate the model scale.
Mu = Y/z
+++(12)
Where: M = Y/z
+++(12)
The denominator of the model scale is tY, which is the average photographic distance m,
GB/T 12979-91
2 ~ the average distance of the instrument used + m. C. When placing photographic negatives or transparent positive films, the marks should be strictly aligned with the corresponding marking lines of the film tray. d. Set the main distance, and the left and right projectors are respectively set with the corrected upper distance. The kidney value is calculated according to formula (13) to 0.01mm or the minimum scale value of the instrument.
f = x/Lx+f)
f /-f
Where: f, f, principal distance after correction, mmtxt-film frame standard length, mm,
Lx, Ly. Camera frame standard length, mm
f Camera principal distance, mm.
e. Install the model baseline pole, and its installation value is calculated by formula (14). B = B/Mm
Where: bx-model baseline, mm
B photography baseline, mm,
model scale denominator.
6.1.2.3 Film orientation
a The residual up and down parallax of each point after relative orientation shall not be greater than 0.02mm, and the residual parallax allocation shall be reasonable. (13)
b The plane point error of absolute determination is generally not greater than 0.6mm on the map, and the elevation orientation error is generally not greater than half of the contour interval.
6.1.2.4 Selection of contour intervals
Contour lines must be able to fully display the shape and characteristics of the object being photographed. The contour interval is calculated according to formula (15). AY C/ Bf- mr = Cmy
Where:
Equal value interval, m;
y—photographic distance, m,
B—photographic baseline, m
f—camera principal distance, m
me—instrument parallax measurement accuracy, mm;
photographic accuracy of the measuring point, mm;
constant, varies with the slope of the object being photographed, generally 2 to 4.6.1.2.5 Surveying and mapping of contour lines and isolines. For objects such as stone carvings and sculptures, contour lines and isolines can be surveyed and mapped according to user requirements. If the structure of the surface of the object is complex and broken, and the slope changes greatly, the contour line should be drawn first. h.
Before mapping and mapping the isolines, the Y-axis data of the points should be measured at the characteristic parts. When drawing the isolines, the standard model should be used, and the error of the contour line drawing shall not exceed one-half of the equal value interval. (15)
The edges of objects are mostly "steep" and the contour lines overlap. They should be represented by a combined curve at the steep part and explained clearly. In flat areas with characteristic undulations, a half-contour interval curve or a quarter-contour interval curve should be measured. In the damaged and broken parts of the object, the contour lines should be depicted on the same map according to the shape at the time of photography. The contour lines should be matched with the contour lines naturally and reasonably. If the contour lines are complex, the same image pair must be used when surveying and mapping with the contour lines. The matching error should not exceed 0.2 mm. For contour line maps, see Appendix B (reference).
6.1.2.6 Methods and requirements for surveying and mapping of ancient building elevations a. A representative location should be selected within the scope of the ancient building to determine the starting datum plane of the building. The elevation is GB/T 12979-91
±0.00. And the absolute elevation of the datum surface shall be noted in the final data description, that is, 0.00 is equal to the altitude of ×××. b. When surveying and mapping, the main outline shall be drawn first to control the overall situation, and then the details shall be depicted. The names of the various parts of the building represented on the map shall be consistent with the names of professional terms. In order to correctly master the representation method of building structure and the reasonable selection of details, the surveying personnel are required to master the general knowledge of building structure. t. The point position accuracy requirement on the map should be within 0.5 m, and the point position accuracy of the main structures such as columns, beams, eaves, oaks, main door and window frames, and brackets shall be within 0.3 mum. . The main grips shall be marked with dimensions, and obvious signs shall be provided. The details of ancient buildings, such as brackets, door nests, floral decorations, brick carvings, wood carvings, kiss beasts, etc., can be added according to the requirements of the unit using the map. When surveying and mapping, the opinions of cultural and museum units shall be sought, and attention shall be paid to reflecting the artistic styles of different historical periods. h. When depicting details, photos of people should be printed for reference. i. Specific requirements for surveying and mapping building elevations are shown in Appendix A (supplement). 6.1.2.7 Revision of original drawings
a. After the original drawings are completed, the revision and supplementary survey should be conducted after the opinions of the drawing user are generally sought. h. When drawing contour drawings and contour maps, efforts should be made to be faithful to the original drawings and to modify the lines and perform artistic processing. c. When drawing the original drawings, the center position offset of the control points shall not exceed 0.1 mm, and the offset of other characteristic elements shall not exceed 0.2 mm. 6.1.2.8 Surveying and mapping of series drawings
Building drawings include: elevation drawings, plan drawings, section drawings, structural drawings, perspective drawings, etc. a. Drawing of elevation drawings. Use close-up photographs and conduct surveying and mapping on a surveying instrument. For ancient buildings, wheel lines are used to indicate them, and for precious historical relics such as stone carvings and sculptures, contour lines and contour lines are surveyed and mapped. b. Surveying and mapping of plan drawings. For the plane structure of buildings, low-altitude photography or conventional measurement methods can be used. ℃. Surveying and mapping of section drawings. According to the surveying and mapping surface drawings and plan drawings, relevant dimensions, especially the surveying and mapping dimensions of cornices and edge details, can be obtained, and some on-site measurement data (cooperated with construction professionals) can be supplemented to draw the internal section of the building. The series of drawings provided by the surveying and mapping personnel should not only have accurate geometric dimensions, but also reflect the artistic style and characteristics of different periods, and meet the requirements of cultural relics, archaeology and architectural design departments. 6.1.3 Digital mapping of analytical plotters
6.1.3.1 Operation preparation
The data preparation work shall be carried out in accordance with 6.1.2.1. 6.1.3.2 Instrument calibration and placement
a. The mainframe of the analytical plotter, electronic computer, CNC drawing table and other peripheral equipment should be in good working condition and can be operated. The operation room should have the temperature, humidity and clean conditions that the computer room should have. 5. During operation, the instrument operating procedures should be followed and the relevant parameters should be entered one by one. 6.1.3.3 Photographic orientation
Internal orientation: Place the negative or transparent film with the X direction roughly parallel to the instrument X direction. Call the corresponding program to strictly align the remote point of the measuring mark with the frame mark, and the coordinate measurement error of the measuring mark shall not be greater than 0.01mm. b. For relative orientation, at least 6 to 9 orientation points evenly distributed at different levels shall be used for orientation, and the residual up and down parallax of each point shall not be greater than 0.008 tmam
The plane coordinate error of absolute orientation shall not exceed 0.4 m on the map. The error of the distance from the process shall generally not be greater than half, the equal distance. c. After the orientation is completed, the relevant parameters and results shall be printed and stored. e. For the drawing table, the error of the point on the surface shall not be greater than 0.4 tmn on the map. The error shall be reasonably allocated before mapping. 6.1.3.4 Stereo Mapping
There are two methods of mapping: direct mapping and storage mapping. 8. Direct mapping shall comply with the provisions of 6.1.2.4 to 6.1.2.6. b. Storage mapping shall not only use the corresponding keys on the function keyboard, but also generate a batch point file and a
GB/T 12979—91
2 ~ Average distance of the instrument used + m. C. Place the photographic film or transparent film so that the mark is strictly aligned with the corresponding mark line of the film plate. d Place the main distance, and place the corrected upper distance of the left and right projectors respectively. The value of the setting is calculated according to formula (13) to 0.01mm or the minimum scale value of the instrument.
f = x/Lx+f)
f /-f
Where: f, f, corrected main distance, mmtxt—film frame standard distance, mm,
Lx, Ly. Camera frame standard distance, mm
f Camera main distance, mm.
e. Install the rough model baseline pole, and its setting value is calculated according to formula (14). = B/Mm
Wherein, bx-model baseline, mm
B photography baseline, mm,
model scale denominator.
6.1.2.3 Photo Orientation
a The residual vertical parallax of each point after relative orientation shall not be greater than 0.02mm, and the residual parallax allocation shall be reasonable. (13)
b The plane point error of absolute orientation is generally not greater than 0.6mm on the map, and the elevation orientation error is generally not greater than half of the isointerval.
6.1.2.4 Selection of isointerval
The isoline must be able to fully display the shape and characteristics of the object being photographed. Its isointerval is calculated according to formula (15). AY C/ Bf- mr = Cmy
Where:
Equal value interval, m;
y—photographic distance, m,
B—photographic baseline, m
f—camera principal distance, m
me—instrument parallax measurement accuracy, mm;
photographic accuracy of the measuring point, mm;
constant, varies with the slope of the object being photographed, generally 2 to 4.6.1.2.5 Surveying and mapping of contour lines and isolines. For objects such as stone carvings and sculptures, contour lines and isolines can be surveyed and mapped according to user requirements. If the structure of the surface of the object is complex and broken, and the slope changes greatly, the contour line should be drawn first. h.
Before mapping and mapping the isolines, the Y-axis data of the points should be measured at the characteristic parts. When drawing the isolines, the standard model should be used, and the error of the contour line drawing shall not exceed one-half of the equal value interval. (15)www.bzxz.net
The edges of objects are mostly "steep" and the contour lines overlap. They should be represented by a combined curve at the steep part and explained clearly. In flat areas with characteristic undulations, a half-contour interval curve or a quarter-contour interval curve should be measured. In the damaged and broken parts of the object, the contour lines should be depicted on the same map according to the shape at the time of photography. The contour lines should be matched with the contour lines naturally and reasonably. If the contour lines are complex, the same image pair must be used when surveying and mapping with the contour lines. The matching error should not exceed 0.2 mm. For contour line maps, see Appendix B (reference).
6.1.2.6 Methods and requirements for surveying and mapping of ancient building elevations a. A representative location should be selected within the scope of the ancient building to determine the starting datum plane of the building. The elevation is GB/T 12979-91
±0.00. And the absolute elevation of the datum surface shall be noted in the final data description, that is, 0.00 is equal to the altitude of ×××. b. When surveying and mapping, the main outline shall be drawn first to control the overall situation, and then the details shall be depicted. The names of the various parts of the building represented on the map shall be consistent with the names of professional terms. In order to correctly master the representation method of building structure and the reasonable selection of details, the surveying personnel are required to master the general knowledge of building structure. t. The point position accuracy requirement on the map should be within 0.5 m, and the point position accuracy of the main structures such as columns, beams, eaves, oaks, main door and window frames, and brackets shall be within 0.3 mum. . The main grips shall be marked with dimensions, and obvious signs shall be provided. The details of ancient buildings, such as brackets, door nests, floral decorations, brick carvings, wood carvings, kiss beasts, etc., can be added according to the requirements of the unit using the map. When surveying and mapping, the opinions of cultural and museum units shall be sought, and attention shall be paid to reflecting the artistic styles of different historical periods. h. When depicting details, photos of people should be printed for reference. i. Specific requirements for surveying and mapping building elevations are shown in Appendix A (supplement). 6.1.2.7 Revision of original drawings
a. After the original drawings are completed, the revision and supplementary survey should be conducted after the opinions of the drawing user are generally sought. h. When drawing contour drawings and contour maps, efforts should be made to be faithful to the original drawings and to modify the lines and perform artistic processing. c. When drawing the original drawings, the center position offset of the control points shall not exceed 0.1 mm, and the offset of other characteristic elements shall not exceed 0.2 mm. 6.1.2.8 Surveying and mapping of series drawings
Building drawings include: elevation drawings, plan drawings, section drawings, structural drawings, perspective drawings, etc. a. Drawing of elevation drawings. Use close-up photographs and conduct surveying and mapping on a surveying instrument. For ancient buildings, wheel lines are used to indicate them, and for precious historical relics such as stone carvings and sculptures, contour lines and contour lines are surveyed and mapped. b. Surveying and mapping of plan drawings. For the plane structure of buildings, low-altitude photography or conventional measurement methods can be used. ℃. Surveying and mapping of section drawings. According to the surveying and mapping surface drawings and plan drawings, relevant dimensions, especially the surveying and mapping dimensions of cornices and edge details, can be obtained, and some on-site measurement data (cooperated with construction professionals) can be supplemented to draw the cross-section of the building's interior. The series of drawings provided by surveying and mapping personnel should not only have accurate geometric dimensions, but also reflect the artistic styles and characteristics of different periods, and meet the requirements of cultural relics, archaeology and architectural design departments. 6.1.3 Digital mapping of analytical plotters
6.1.3.1 Operation preparation
The data preparation work shall be carried out in accordance with 6.1.2.1. 6.1.3.2 Instrument calibration and placement
a. The mainframe of the analytical plotter, electronic computer, CNC drawing table and other peripheral equipment should be in good working condition and can be operated. The operation room should have the temperature, humidity and clean conditions that the computer room should have. 5. During operation, the instrument operating procedures should be followed and the relevant parameters should be entered one by one. 6.1.3.3 Photographic orientation
Internal orientation: Place the negative or transparent film with the X direction roughly parallel to the instrument X direction. Call the corresponding program to strictly align the remote point of the measuring mark with the frame mark, and the coordinate measurement error of the measuring mark shall not be greater than 0.01mm. b. For relative orientation, at least 6 to 9 orientation points evenly distributed at different levels shall be used for orientation, and the residual up and down parallax of each point shall not be greater than 0.008 tmam
The plane coordinate error of absolute orientation shall not exceed 0.4 m on the map. The error of the distance from the process shall generally not be greater than half, the equal distance. c. After the orientation is completed, the relevant parameters and results shall be printed and stored. e. For the drawing table, the error of the point on the surface shall not be greater than 0.4 tmn on the map. The error shall be reasonably allocated before mapping. 6.1.3.4 Stereo Mapping
There are two mapping methods: direct mapping and storage mapping. 8. Direct mapping shall comply with the provisions of 6.1.2.4~6.1.2.6. b. Storage mapping shall not only use the corresponding keys on the function keyboard, but also generate a batch point file and a
GB/T 12979—91
2 ~ Average distance of the instrument used + m. C. Place the photographic film or transparent film so that the mark is strictly aligned with the corresponding mark line of the film plate. d Place the main distance, and place the corrected upper distance of the left and right projectors respectively. The value of the setting is calculated according to formula (13) to 0.01mm or the minimum scale value of the instrument.
f = x/Lx+f)
f /-f
Where: f, f, corrected main distance, mmtxt—film frame standard distance, mm,
Lx, Ly. Camera frame standard distance, mm
f Camera main distance, mm.
e. Install the rough model baseline pole, and its setting value is calculated according to formula (14). = B/Mm
Wherein, bx-model baseline, mm
B photography baseline, mm,
model scale denominator.
6.1.2.3 Photo Orientation
a The residual vertical parallax of each point after relative orientation shall not be greater than 0.02mm, and the residual parallax allocation shall be reasonable. (13)
b The plane point error of absolute orientation is generally not greater than 0.6mm on the map, and the elevation orientation error is generally not greater than half of the isointerval.
6.1.2.4 Selection of isointerval
The isoline must be able to fully display the shape and characteristics of the object being photographed. Its isointerval is calculated according to formula (15). AY C/ Bf- mr = Cmy
Where:
Equal value interval, m;
y—photographic distance, m,
B—photographic baseline, m
f—camera principal distance, m
me—instrument parallax measurement accuracy, mm;
photographic accuracy of the measuring point, mm;
constant, varies with the slope of the object being photographed, generally 2 to 4.6.1.2.5 Surveying and mapping of contour lines and isolines. For objects such as stone carvings and sculptures, contour lines and isolines can be surveyed and mapped according to user requirements. If the structure of the surface of the object is complex and broken, and the slope changes greatly, the contour line should be drawn first. h.
Before mapping and mapping the isolines, the Y-axis data of the points should be measured at the characteristic parts. When drawing the isolines, the standard model should be used, and the error of the contour line drawing shall not exceed one-half of the equal value interval. (15)
The edges of objects are mostly "steep" and the contour lines overlap. They should be represented by a combined curve at the steep part and explained clearly. In flat areas with characteristic undulations, a half-contour interval curve or a quarter-contour interval curve should be measured. In the damaged and broken parts of the object, the contour lines should be depicted on the same map according to the shape at the time of photography. The contour lines should be matched with the contour lines naturally and reasonably. If the contour lines are complex, the same image pair must be used when surveying and mapping with the contour lines. The matching error should not exceed 0.2 mm. For contour line maps, see Appendix B (reference).
6.1.2.6 Methods and requirements for surveying and mapping of ancient building elevations a. A representative location should be selected within the scope of the ancient building to determine the starting datum plane of the building. The elevation is GB/T 12979-91
±0.00. And the absolute elevation of the datum surface shall be noted in the final data description, that is, 0.00 is equal to the altitude of ×××. b. When surveying and mapping, the main outline shall be drawn first to control the overall situation, and then the details shall be depicted. The names of the various parts of the building represented on the map shall be consistent with the names of professional terms. In order to correctly master the representation method of building structure and the reasonable selection of details, the surveying personnel are required to master the general knowledge of building structure. t. The point position accuracy requirement on the map should be within 0.5 m, and the point position accuracy of the main structures such as columns, beams, eaves, oaks, main door and window frames, and brackets shall be within 0.3 mum. . The main grips shall be marked with dimensions, and obvious signs shall be provided. The details of ancient buildings, such as brackets, door nests, floral decorations, brick carvings, wood carvings, kiss beasts, etc., can be added according to the requirements of the unit using the map. When surveying and mapping, the opinions of cultural and museum units shall be sought, and attention shall be paid to reflecting the artistic styles of different historical periods. h. When depicting details, photos of people should be printed for reference. i. Specific requirements for surveying and mapping building elevations are shown in Appendix A (supplement). 6.1.2.7 Revision of original drawings
a. After the original drawings are completed, the revision and supplementary survey should be conducted after the opinions of the drawing user are generally sought. h. When drawing contour drawings and contour maps, efforts should be made to be faithful to the original drawings and to modify the lines and perform artistic processing. c. When drawing the original drawings, the center position offset of the control points shall not exceed 0.1 mm, and the offset of other characteristic elements shall not exceed 0.2 mm. 6.1.2.8 Surveying and mapping of series drawings
Building drawings include: elevation drawings, plan drawings, section drawings, structural drawings, perspective drawings, etc. a. Drawing of elevation drawings. Use close-up photographs and conduct surveying and mapping on a surveying instrument. For ancient buildings, wheel lines are used to indicate them, and for precious historical relics such as stone carvings and sculptures, contour lines and contour lines are surveyed and mapped. b. Surveying and mapping of plan drawings. For the plane structure of buildings, low-altitude photography or conventional measurement methods can be used. ℃. Surveying and mapping of section drawings. According to the surveying and mapping surface drawings and plan drawings, relevant dimensions, especially the surveying and mapping dimensions of cornices and edge details, can be obtained, and some on-site measurement data (cooperated with construction professionals) can be supplemented to draw the internal section of the building. The series of drawings provided by the surveying and mapping personnel should not only have accurate geometric dimensions, but also reflect the artistic style and characteristics of different periods, and meet the requirements of cultural relics, archaeology and architectural design departments. 6.1.3 Digital mapping of analytical plotters
6.1.3.1 Operation preparation
The data preparation work shall be carried out in accordance with 6.1.2.1. 6.1.3.2 Instrument calibration and placement
a. The mainframe of the analytical plotter, electronic computer, CNC drawing table and other peripheral equipment should be in good working condition and can be operated. The operation room should have the temperature, humidity and clean conditions that the computer room should have. 5. During operation, the instrument operating procedures should be followed and the relevant parameters should be entered one by one. 6.1.3.3 Photographic orientation
Internal orientation: Place the negative or transparent film with the X direction roughly parallel to the instrument X direction. Call the corresponding program to strictly align the remote point of the measuring mark with the frame mark, and the coordinate measurement error of the measuring mark shall not be greater than 0.01mm. b. For relative orientation, at least 6 to 9 orientation points evenly distributed at different levels shall be used for orientation, and the residual up and down parallax of each point shall not be greater than 0.008 tmam
The plane coordinate error of absolute orientation shall not exceed 0.4 m on the map. The error of the distance from the process shall generally not be greater than half, the equal distance. c. After the orientation is completed, the relevant parameters and results shall be printed and stored. e. For the drawing table, the error of the point on the surface shall not be greater than 0.4 tmn on the map. The error shall be reasonably allocated before mapping. 6.1.3.4 Stereo Mapping
There are two mapping methods: direct mapping and storage mapping. 8. Direct mapping shall comply with the provisions of 6.1.2.4~6.1.2.6. b. Storage mapping shall not only use the corresponding keys on the function keyboard, but also generate a batch point file and aFor objects such as stone carvings and sculptures, contour lines and isolines can be measured according to user requirements. If the surface structure of an object is complex and broken, and the slope changes greatly, the contour line should be drawn first. h.
Before measuring and drawing the isoline, the Y-axis data of the points should be measured at the characteristic parts first. When drawing the isoline, the standard model should be used. The error of drawing the isoline should not exceed one-half of the isoline interval. (15)
The edges of objects are mostly "steep" and the isolines overlap. They should be represented by a combined curve at the steep parts and explained clearly. In flat areas with characteristic undulations, a half isoline interval curve or a quarter isoline interval curve should be added. In the damaged and fractured parts of the object, the isolines should be drawn on the same map according to the shape at the time of photography. The isolines should be coordinated with the contour lines naturally and reasonably. If the contour line is complex, when it is measured and drawn separately from the isoline, the same image pair must be used, and the matching error should not exceed 0.2 mm. See Appendix B (reference) for contour maps.
6.1.2.6 Methods and requirements for surveying and mapping of elevations of ancient buildings a. A representative location should be selected within the scope of the ancient buildings to be surveyed to determine the starting datum plane of the building, and the elevation should be GB/T 12979-91
0.00. The absolute elevation of the datum plane should be noted in the final data description, that is, 0.00 is equal to the altitude ×××. b. When surveying and mapping, the main outline should be drawn first to control the overall situation, and then the details should be described. The names of the various parts of the building represented on the map should be consistent with the names of professional terms. In order to correctly master the representation methods of building structures and the reasonable selection of details, surveyors are required to master the general knowledge of building structures. t. The point position accuracy requirement on the map should be within 0.5 m, and the point position accuracy of the main structures such as columns, beams, eaves, oaks, main door and window frames, brackets, etc. should be within 0.3 mum. . The main grip should be marked with dimensions, and obvious marks should be provided. The details of ancient buildings, such as brackets, door nests, floral decorations, brick carvings, wood carvings, kiss beasts, etc., can be measured and detailed according to the requirements of the unit using the map. When surveying and mapping, the opinions of cultural and museum units should be sought, and attention should be paid to reflecting the artistic styles of different historical periods. h. When depicting details, photos of people should be printed for reference. i. The specific requirements for surveying and mapping of building elevations are shown in Appendix A (Supplement). 6.1.2.7 Revision of original drawings
a. After the original drawings are completed, the opinions of the unit using the drawings should generally be sought before revision and supplementary survey. h. When drawing contour drawings and contour maps, efforts should be made to be faithful to the original drawings and to perform line modification and artistic processing. c. When drawing the original drawings, the center position offset of the control points shall not exceed 0.1 mm, and the offset of other characteristic elements shall not exceed 0.2 mm. 6.1.2.8 Surveying and mapping of series drawings
Building drawings include: elevations, plan views, sections, structural drawings, perspective views, etc. a. Drawing of elevations. Use close-up photographs to conduct surveying and mapping on a surveying instrument. Ancient buildings are represented by wheel lines, and precious historical relics such as stone carvings and sculptures are mapped with contour lines and contour lines. b. Surveying and mapping of plan views. For the plane structure of buildings, low-altitude photography or conventional measurement methods can be used. ℃. Surveying and mapping of sections. Obtain relevant dimensions based on the surveyed surface drawings and plan views, especially the surveyed dimensions of eaves and edge details, and supplement certain on-site measurement data (in cooperation with construction professionals) to draw the internal section view of the building. The series of drawings provided by surveying and mapping personnel should not only have accurate geometric dimensions, but also reflect the artistic styles and characteristics of different periods, and meet the requirements of cultural relics, archaeology and architectural design departments. 6.1.3 Digital Mapping with Analytical Plotter
6.1.3.1 Preparation for Operation
Data preparation shall be carried out in accordance with 6.1.2.1. 6.1.3.2 Calibration and Installation of Instruments
a. The mainframe of the analytical plotter, electronic computer, CNC drawing table and other peripheral equipment shall be in good working condition and the film can be operated. The operation room shall have the same temperature, humidity and clean conditions as the computer room. 5. During operation, the instrument operation procedures shall be followed and relevant parameters shall be input one by one. 6.1.3.3 Orientation of Film
Internal Orientation: The X direction of the negative film or transparent positive film shall be roughly parallel to the X direction of the instrument. Call the corresponding program to strictly align the remote point of the measuring mark with the frame mark, and the coordinate measurement error of the holding mark shall not be greater than 0.01mm. b. During relative orientation, at least 6 to 9 orientation points evenly distributed at different levels should be used for orientation. The residual vertical parallax of each point shall not be greater than 0.008 tmam
. The plane coordinate error of absolute orientation shall not exceed 0.4 m on the map. The error of the distance from the center of the map shall generally not be greater than half of the equal distance. c. After orientation is completed, the relevant parameters and results should be printed and stored. e. During the drawing table orientation, the error of the nearly facing point should not be greater than 0.4 tmn on the map. The error should be reasonably allocated before mapping. 6.1.3.4 Stereo mapping
Mapping methods include direct mapping and storage mapping. 8. Direct mapping shall comply with the provisions of 6.1.2.4~～6.1.2.6. b. In addition to using the corresponding keys on the function keyboard, storage mapping shall also generate a batch point file and aFor objects such as stone carvings and sculptures, contour lines and isolines can be measured according to user requirements. If the surface structure of an object is complex and broken, and the slope changes greatly, the contour line should be drawn first. h.
Before measuring and drawing the isoline, the Y-axis data of the points should be measured at the characteristic parts first. When drawing the isoline, the standard model should be used. The error of drawing the isoline should not exceed one-half of the isoline interval. (15)
The edges of objects are mostly "steep" and the isolines overlap. They should be represented by a combined curve at the steep parts and explained clearly. In flat areas with characteri
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