GB 12341-1990 1:25000, 1,50000, 1:100 000 topographic map aerial photogrammetry field specifications
Some standard content:
National Standard of the People's Republic of China
1:25000, 1:50000, 1:100000
Specifications for aerophotogrammetric field work for topographic maps
1:25000, 1:50000 and 1:100000 topographic maps-Specifications for aerophotogrammetric field work 1 Subject content and scope of application
1.1 Subject content
GB12341—90
This standard specifies the specifications, accuracy and basic requirements for field work of surveying and mapping 1:25000, 1:50000 and 1:100000 topographic maps by aerial photogrammetry.
1.2 Scope of application
This standard applies to the aerial photogrammetric field work of 1:25000, 1:50000 and 1:100000 topographic maps. The topographic maps surveyed and prepared according to this standard are mainly used by various departments of the national economy for survey, planning, design, scientific research, etc., and can be used as basic data for compiling smaller-scale topographic maps or special maps. 2 Reference standards
GB123421: 25000, 1:50000, 1:100000 Topographic map diagram 3 General rules
3.1 Specifications of topographic maps
3.1.1 Projection, coordinate and elevation system
1:25000, 1:50000, 1:100000 topographic maps adopt Gauss-Kruger projection and are divided into 6° zones. The plane coordinate system adopts the 1980 Xi'an coordinate system, and the elevation system adopts the 1985 national elevation datum. 3.1.2 Division and numbering of topographic maps
1:25000, 1:50000, 1:100000 topographic maps are based on the division and numbering of international 1:1000000 topographic maps, and are divided according to the longitude and latitude differences specified in Table 1.
Table 1
Mapping scale
Longitude
Latitude
Difference
Difference
1:25000
7'30*
5＇00*
The numbering of topographic maps shall be in accordance with the provisions of Appendix B of GB12342. 3.1.3 Terrain categories
1:50000
15'00
10°00*
1:100000
30°00*
20°00
Terrain categories are divided according to the ground slope and height difference of most of the map area, as specified in Table 2. When the height difference conflicts with the ground slope, the ground slope approved by the State Administration of Technical Supervision on June 4, 1990 and implemented on December 1, 1990 shall prevail.
Terrain type
Flat
Land
Hill
Mountain
Land
High mountain
3.1.4 Basic contour interval
Ground slope
Below 2°
2°~6°
6°~25°
Above 25°wwW.bzxz.Net
GB12 341—90
Table 2
Height
Difference
1:25000, 1:50000, 1:100.000<80
80~300
300~600
>600
m
The basic contour interval varies according to the different types of terrain in the survey area. The regulations are shown in Table 3. Generally, only one basic contour interval is used in a map. When the basic contour interval cannot show the landform features, the survey interval curve should be added, and the survey auxiliary curve can be added if necessary. Table 3
Base
Contour
Terrain category
1:25.000
Flat
Hill
Mountain
Land
High mountain
5(2.5)
5
10
10
1:50000
10(5 ）
10
20
20
Distance
1:100000
20(10）
20
40
40
m
When the terrain is very flat or the map requires it, the basic contour interval can use the value in the brackets, and its elevation accuracy is the same as the accuracy requirement of the basic contour interval outside the brackets.
3.1.5 Elevation annotation points
Elevation annotation points should be selected at obvious landforms and terrain feature points, and their density is 10 to 20 for flat land and hilly land, and 8 to 15 for mountainous and high mountainous land per 100cm2 on the map. Elevation annotations are in meters, with annotations to one decimal place for 1:25000 maps and to whole meters for 1:50000 and 1:100000 maps.
3.1.6 Symbols and annotations of topographic maps
Topographic map symbols (including simplified topographic symbols) and various annotations shall be implemented in accordance with GB12342. 3.2 Accuracy of topographic maps
3.2.1 The mean error of the plane position of the terrain points on the map relative to the nearby field control points shall not exceed ±0.5mm on the map for flat and hilly areas; and shall not exceed 0.75mm on the map for mountainous and high mountainous areas. 3.2.2 The mean error of the elevation annotation points and contour lines on the map relative to the nearby field control points shall not exceed the provisions of Table 4. Elevation
Center
Error
Difference
Map scale
Terrain type
In-house encryption point
Elevation annotation point
Contour line
Flat
1.0
1.2
1.5
GB12341 —90
Table 4
1: 25000
Hill
Mound
Land
1.5
2.0
2.5
Mountain
Land
2.0
3.0
4.0
Land
Shape
Change|| tt||Change
Point
High
Mountain
Land
3.5
5.0
7.0
Land
Shape
Change
Point
Flat
Land
2.0
2.5
3. 0
1:50000
Ping
Land
3.0
4.0
5.0
Mountain
Land
4.0
6.0
8.0
Land
Shape
Change
Change||tt| |point
high
mountain
ground
7.0
10.0
14.0
ground
shape
change
point
flat
ground
4.0
5.0
6.0
1 ：100000
Ping
Mausoleum
Ground
6.0
8.0
10.0
Mountain
Ground
8.0
12.0
16.0
Ground
Shape
Change
Point|| tt||m
high
mountain
land
14.0
20.0
28.0
land
shape
change
point
When the location for measuring the elevation accuracy of the contour line cannot be directly found on the map for mountainous and high mountainous areas, the elevation accuracy can be calculated according to the formula ( 1) Calculation:
Mh=±Va2+bz.tg'a
Wherein: Mh-
a
h
Q
mean error of the first contour line elevation, m;
mean error of the elevation annotation point elevation, m,
-mean error of the plane position of the feature point, m;
ground inclination angle near the inspection point, (.). (1)
3.2.3 The mean error of the plane position of the feature point in special difficult areas (large areas of forests, deserts, Gobi, swamps, etc.) shall not be greater than ±0.75mm on the map, and the mean error of the elevation shall be relaxed by 0.5 times according to the corresponding terrain category in Table 4. Generally, it is not relaxed in high mountainous areas. 3.2.4 The mean error of the plane position of the image plane control point relative to the nearby basic control point shall not be greater than ±0.1mm on the map. Note: The basic control point refers to the control point that can be used as the starting and closing point of the first-level image control measuring disk. The mean error of the elevation measurement of the image elevation control point relative to the nearby basic control point shall not be greater than the provisions of Table 5.
Table 5
Map scale
Terrain type
Flat
Hill
Mountain
|High mountain
1:25000
0.4
0.5
0.6
1.2
The mean error of elevation measurement in special difficult areas shall be relaxed by 0.5 times according to Table 5. 3.2.5 This specification takes twice the mean error value as the maximum error. 1:50000
0.8
1.0
1.2
2.5
1:100000
1.5
2.0
2.5
5.0
m
3.3 Basic principles of photo mapping
GB12341—90
3.3.1 The mapping method can adopt the full field mapping method or the indoor and outdoor comprehensive judgment method (hereinafter referred to as the comprehensive judgment method). No matter which method is adopted, it should meet the relevant requirements of the specifications and drawings. 3.3.2 When mapping, it is necessary to meet the common requirements of the economic construction departments as a prerequisite, and make comprehensive choices for the terrain elements (land features, landform elements) according to different mapping scales. To ensure that the terrain features on the topographic map are clearly distinguished, the symbols are used appropriately, the map is clear and easy to read, and can vividly reflect the overall features of the region. 3.3.3 The terrain elements with images on the film should be accurately drawn according to the image, and the maximum displacement difference should not be greater than 0.3mm on the film. Important terrain elements without images on the film should be re-measured, and the displacement difference between the relative position of the surrounding obvious terrain features should not be greater than 0.5mm on the map, and in special difficult areas, it should not be greater than 0.75mm on the map. 3.3.4 When there are no suitable symbols available, similar symbols can be used instead, or additional symbols can be added, but they must be explained. If additional symbols are required, they must be submitted to the National Bureau of Surveying, Mapping and Geoinformation for approval at the latest before the internal map is completed. 3.4 Requirements for geodetic data
3.4.1 The density of triangulation points (including precise traverse points) in general areas should not be less than: 2 points per 1:25000 topographic map, 3 points per 1:50000 topographic map, and 6 points per 1:100000 topographic map. In general areas, the spacing of leveling routes above the fourth level shall not exceed 30km on the ground. The spacing may be appropriately relaxed in hilly, mountainous and high mountainous areas according to the situation.
For maps with insufficient points and spacing, basic control point measurement may be carried out, but the principle is to meet the needs of mapping. 3.4.2 The triangulation point and leveling point result table, network map and point record and other materials should be complete. 3.5 Requirements for aerial photography data
3.5.1 The requirements for aerial photography data refer to the "1:5000, 1:10000, 1:25000, 1:50000, 1:100000 scale aerial photography specifications" formulated by the State Administration of Surveying, Mapping and Geoinformation in 1980. 3.5.2 The aerial photography scale can be reasonably selected according to the mapping scale, accuracy, method, instrument equipment and terrain conditions of the survey area, etc., referring to Table 6. Table 6
Mapping scale
1:25000
150000
1:100000
Aerial scale
1:20000~1:50000
1:35000~1:75000
1:60000~1:100000
3.6 Requirements for other operation methods
On the premise of meeting the accuracy standards specified in this specification, new technologies and methods not included in this specification may be used, but they should be clearly specified in the technical design document.
4 Arrangement of photo control points
4.1 General provisions
4.1.1 Photo control points are the basis for encrypting control points and mapping in aerial survey. They are divided into three types: surface control points, elevation control points and level height control points.
A plane control point only measures the plane coordinates of the point. An elevation control point only measures the elevation of the point. A plane-elevation control point must measure both the plane coordinates and elevation of the point. 4.1.2 The control points to be laid out shall meet the following conditions of the film: GB12341-90
a. The target image of the selected control points of the film shall be clear and easy to distinguish. When the target conflicts with other conditions of the film, the target condition shall be given priority.
b. The control points to be laid out shall be as common as possible.
The control point shall be no less than 1cm (18cm×18cm image frame) or 1.5cm (23cm×23cm image frame) from the edge of the film.
The control point of the comprehensive method map shall be no less than half of the distance from the heading edge.
D. The control point shall be greater than 1mm away from various marks on the film.
E. The control point shall be selected near the lateral overlapping center line, and the distance from the azimuth line shall be greater than 3cm (18cm×18cm image frame) or 5cm (23cm×23cm image frame). When the lateral overlap is too large, it shall not be less than 2cm (18cm×18cm image frame) or 3cm (23cm×23cm image frame). When the points of adjacent routes cannot be shared due to the small lateral overlap and are arranged separately, the vertical distance between the two points shall not be greater than 2cm on the image.
4.1.3 Control points located at the free map edge, the edge to be mapped, and the map edge mapped by other methods shall be arranged at least 4mm outside the map outline. 4.2 Route network points
The plane and elevation errors of the encrypted points in the aerial triangulation are estimated according to formulas (2) and (3). ms=±0.28kmgn2+2n+46
mn=±0.088
H
-m.n2+23n+100
The plane mean error of the encrypted point, mm:
Where: m
mh-
The elevation mean error of the encrypted point, m;
kThe multiple of the film enlargement into a map,
HRelative flight altitude, m,
b
m.
Film baseline length, mm,
Unit weighted mean error of parallax measurement, mm;The number of baselines between adjacent control points in the route direction, bars. 4.2.1 Points are arranged according to the route:
(2)
(3)
4.2.1.1=-Generally, two maps are used as units, and three maps are used as units in difficult areas with a scale of 1:100000. Six level points are arranged on each route (Figure 1). When using a wide-angle aerial camera for photography (focal length of more than 100mm), an additional elevation point should be arranged near the center line of the two rows of level points on the route, as shown at the "×" in Figure 1. (In Figures 1 to 12: · Elevation point ○ Plane point ① Level point mouth Image main point)@
?
Figure 1
GB12341-90
4.2.1.2 The distance between two adjacent points or two pairs of control points on each route is calculated according to formula (2) (3), and can also be implemented in accordance with Appendix F. When the plane and elevation allowable distances conflict, the elevation should prevail. 4.2.1.3 In addition to meeting the general requirements, the location of the control points must also meet the following conditions: the upper and lower points at both ends of the route are located on a straight line passing through the main point and perpendicular to the azimuth line, and the deviation from each other is generally not more than half a.
baseline, and the maximum individual deviation is not more than 1 baseline; b. The two control points in the middle of the route are arranged on the center line of the control points at both ends, and their deviation is generally not more than the range of the left and right two baselines. The deviation in difficult areas shall not exceed the left and right three baselines. One of the control points is located on the center line or the two control points deviate to the opposite side of the center line at the same time. If the two control points deviate to one side of the center line at the same time, it shall not exceed 1 baseline. 4.2.1.4 If the route is short and there are only 3 to 5 baselines, 4 flat height points plus 1 elevation point can be arranged (Figure 2). The middle elevation point should be arranged on the center line, and its deviation shall not exceed 1 baseline. Figure 2
4.2.2 Control route (framework route) point layout 4.2.2.11: For difficult areas of 100,000 mapping, control routes (framework routes) perpendicular to the mapping route can be used for dense mapping. 4.2.2.2 Six level points are laid out for each control route. The distance between two adjacent control points or two pairs of control points shall comply with the provisions of 4.2.1.2. The distance between control routes can be designed according to the requirements of mapping route density in accordance with the provisions of 4.2.1.2. 4.2.2.3 The point requirements of control route control points shall comply with the provisions of 4.2.1.3. 4.3 Regional network point layout
4.3.1 Principles for the division of regional networks
4.3.1.1 The division of regional networks should be comprehensively based on the scale of the map, the scale of aerial photography, the terrain characteristics of the survey area, the actual division of the navigation area, the functions of the program, and the computer capacity. consider. You can choose the best solution to implement based on your own specific circumstances. 4.3.1.2 The shape of the area network, in order to facilitate the operation and maintain the encryption accuracy within the map, is generally two horizontal and two vertical. It is also possible to divide areas not by map frame but by route segments or aerial photography zones. 4.3.2 Regulations for the layout of regional network high points: 4.3.2.1 Regional network high points are generally laid out according to the surrounding area. 4.3.2.2 When the aerial photography scale is equal to or smaller than the chart scale, and the number of regional network routes is less than 6 (including 6), the surrounding area shall be laid out at no less than 6 horizontal height points (Figure 3, Figure 4). Figure 3 | | tt | | Figure 4 | | tt | | GB12341-90 | | tt | Less than 6 flat high points (Figure 5, Figure 6)
Figure 5
4.3.2.3
Figure 6
When the number of routes exceeds 6 (or 4), the surrounding areas are laid out at 8 flat high points (Figure 7, Figure 8) Q
Figure 7
Figure 8
4.3.3 In the regional network, the flat The number of baselines between high points and elevation points can be calculated according to formulas (2) and (3) and then appropriately relaxed. However, elevation points should be arranged at the beginning and end of each route in the regional network (see Appendix G). 4.3.4 Distribute points according to the map area
a.
b.
c.
The layout of control points shall comply with the provisions of 4.3.1.2 and 4.3.2. For layout graphics, please refer to Figures G1 and G2 in Appendix G. The requirements for the location of control points on the periphery comply with the provisions of 4.2.1.3. The internal points can be selected within the range of the two baselines on the left and right, and should be located at the side re-entry as much as possible.
4.3.5 Arrange points according to route segment zones:
a.
b.
c.
. You can also refer to Table G1 in Appendix G for execution. For layout graphics, please refer to Figures G3 and G4 in Appendix G. The position requirements of the control points at both ends are the same as the route network layout points. The middle point can generally deviate from one baseline to the left and right, but cannot deviate from a maximum of 2 baselines.
4.3.6 Irregular area mesh points
4.3.6.1 Due to restrictions on terrain and other conditions, irregular area mesh points can be used. Generally, high points are placed at the turning points of convex corners and high points are placed at the turning points of concave corners. Distribute elevation points.
4.3.6.2 If the distance between the concave corner turning point and the convex corner turning point exceeds 4 baselines, a flat high point should also be arranged at the concave corner turning point (Figure G5 in Appendix G).
4.3.6.3 When the span along the heading direction between two control points around the area exceeds 7 baselines, an additional elevation point should be added in the middle. 4.3.7 Placement of points at the junction of the make-up flight route
The points laid out at the junction of the make-up flight route in the regional network are based on the principle of ensuring the connection accuracy. Generally, a flat high point can be added at the junction (Figure G6 in Appendix G) .
4.4 Full field layout
4.4.1 Full field layout mapped by comprehensive method
GB12341-90
When providing photo correction, four photos per number One plane point is arranged on each corner (Figure 9). If band correction is required, the plane points in Figure 9 should be changed to flat and high points. When photos between routes are interlaced and control points cannot be shared, points should be placed separately. o ||tt || tt||Each stereo pair is equipped with 4 horizontal height points and 1 elevation check point (Figure 10). The elevation check point should be located roughly in the center of two horizontal points perpendicular to the heading. When deviating left or right, the lines connecting the two horizontal points perpendicular to the heading should be greater than 1/3 of the length of the baseline. If the inspection point is outside the line connecting the two elevation points on both sides of the bearing line, the distance from the connecting line shall not be greater than 1cm (Figure 11). C | Four flat and high points are arranged within the surveying range of the stereo pair (Figure 12). When surveying with a multi-magnification instrument, you can also use a double-model layout with one flat-high point at each of the four corners of the survey range of every number of photos. Figure 12 | | tt | | 4.4.4 Elevation of all field points | | tt | | The control points laid out by differential method mapping and omnipotent method mapping. If the plane position is completed by internal densification, only the elevation part will be constructed by the whole field GB12341 If -90
is measured, the horizontal height control points in Figures 10, 11, and 12 will be changed to elevation control points. 4.4.5 Requirements for point positions
In addition to meeting the general regulations, the following requirements must also be met: the distance between the point position and the straight line passing through the main point of the image and perpendicular to the azimuth line shall not be greater than 1cm. In difficult cases, individual points may not be greater than 1.5cm . The four basic orientation points should be distributed in a rectangle as much as possible, and the height difference between them should be as small as possible. However, the height difference between the elevation check point in the differential map and the four orientation points in the image pair should be as large as possible. 4.5 Point layout under special circumstances
4.5.1 Point layout at the junction of aerial photography zones
If the two navigation areas use the same type of aerial photography instrument, the difference in focal length is less than 0.03mm, the heading overlap is normal, and the side direction When the connection stagger is less than 10%, the curvature after connection is within 3%, and the altitude difference is within 1/50 of the average relative altitude during photography, it can be regarded as the same route layout. Otherwise, control points should be distributed within the overlapping portion of the navigation area boundary, and adjacent routes should be shared as much as possible. If they cannot be shared, points must be distributed separately, and care should be taken not to create control loopholes.
4.5.2 Placements with insufficient course overlap
Re-boarding rates less than 53% are considered aerial photography vulnerabilities. Points should be distributed segmentally based on the loopholes, and the loopholes should be solved using single photo mapping or tablet meter mapping methods.
4.5.3 Placement of points with insufficient side overlap
The side overlap of individual photos of the route is less than 2cm but greater than 1cm, and when the image is clear, 1 to 2 additional elevation points will be measured in the overlapping part. , if the image is unclear or the overlap is less than 1cm, the insufficient overlap can be solved by using a single photo measurement or a flatbed measurement method.
4.5.4 When the main image point or standard point is in the water, or is covered by cloud shadow, shadow, snow shadow, etc., or there is no obvious surface object, it will be regarded as Point a.
falls into the water. When the size or location of the falling water range does not affect the connection of the three-dimensional model, it can be regarded as a normal route layout. Otherwise, the route will be considered disconnected and points will be distributed in sections.
b. When no obvious target can be selected within 1cm of the main point of the image, the falling water image corresponds to the entire field layout. c. The standard point of the directional point is the falling water area. At this time, if no connection point can be selected within the overlapping range of the three pieces 4cm away from the main point of the image, the falling water image corresponds to the entire outdoor distribution point. 4.5.5 Waterfront and island layout
Waterfront and island areas are generally laid out in the entire field, based on the principle of maximizing the control of the surveying and mapping area. The land portion 1cm beyond the line connecting the control points should be measured with level points. When most of a photo is covered by water and there are only a few scattered small islands, and it is difficult to arrange the points according to regulations, the field layout should be based on the principle of controlling the size, orientation and elevation of the islands and laying out 2 to 4 high-level points as appropriate. 5Basic control point measurement
In addition to using national grade points, we can also reasonably lay out small triangular points and photoelectric ranging wire points with an error of 5" in angle measurement according to the actual situation and specific requirements of the measurement area. As well as measuring external leveling and triangulation elevation wires, it serves as the basis for photo control measurement. 5.15\level plane control measurement
5" level photoelectric distance measurement wire measurement and small triangulation measurement, its weakest point. The medium error is 0.02mm in the picture. 5.1.1 Photoelectric ranging wire measurement
Photoelectric ranging wires can be laid out as a single attached wire or a wire network with nodes. The instrument should use a Class II photoelectric rangefinder with a distance measurement error (nominal accuracy) of no more than 10mm per kilometer. 5.1.1.1 The main technical requirements for photoelectric ranging attached wires are specified in Table 7.2. When the aerial photography scale is equal to or smaller than the chart scale, and the number of regional network routes is less than 6 (including 6), the surrounding area shall be laid out at no less than 6 horizontal height points (Figure 3, Figure 4). Figure 3 | | tt | | Figure 4 | | tt | | GB12341-90 | | tt | Less than 6 flat high points (Figure 5, Figure 6)
Figure 5
4.3.2.3
Figure 6
When the number of routes exceeds 6 (or 4), the surrounding areas are laid out at 8 flat high points (Figure 7, Figure 8) Q
Figure 7
Figure 8
4.3.3 In the regional network, the flat The number of baselines between high points and elevation points can be calculated according to formulas (2) and (3) and then appropriately relaxed. However, elevation points should be arranged at the beginning and end of each route in the regional network (see Appendix G). 4.3.4 Distribute points according to the map area
a.
b.
c.
The layout of control points shall comply with the provisions of 4.3.1.2 and 4.3.2. For layout graphics, please refer to Figures G1 and G2 in Appendix G. The requirements for the location of control points on the perimeter comply with the provisions of 4.2.1.3. The internal points can be selected within the range of the two baselines on the left and right, and should be located at the side re-entry as much as possible.
4.3.5 Arrange points according to route segment zones:
a.
b.
c.
. You can also refer to Table G1 in Appendix G for execution. For layout graphics, please refer to Figures G3 and G4 in Appendix G. The position requirements of the control points at both ends are the same as the route network layout points. The middle point can generally deviate from one baseline to the left and right, but cannot deviate from a maximum of 2 baselines.
4.3.6 Irregular area mesh points
4.3.6.1 Due to restrictions on terrain and other conditions, irregular area mesh points can be used. Generally, high points are placed at the turning points of convex corners and high points are placed at the turning points of concave corners. Distribute elevation points.
4.3.6.2 If the distance between the concave corner turning point and the convex corner turning point exceeds 4 baselines, a flat high point should also be arranged at the concave corner turning point (Figure G5 in Appendix G).
4.3.6.3 When the span along the heading direction between two control points around the area exceeds 7 baselines, an additional elevation point should be added in the middle. 4.3.7 Placement of points at the junction of the make-up flight route
The points laid out at the junction of the make-up flight route in the regional network are based on the principle of ensuring the connection accuracy. Generally, a flat high point can be added at the junction (Figure G6 in Appendix G) .
4.4 Full field layout
4.4.1 Full field layout mapped by comprehensive method
GB12341-90
When providing photo correction, four photos per number One plane point is arranged on each corner (Figure 9). If band correction is required, the plane points in Figure 9 should be changed to flat and high points. When photos between routes are interlaced and control points cannot be shared, points should be placed separately. o ||tt || tt||Each stereo image pair is equipped with 4 horizontal height points and 1 elevation check point (Figure 10). The elevation check point should be located roughly in the center of two horizontal points perpendicular to the heading. When deviating left or right, the lines connecting the two horizontal points perpendicular to the heading should be greater than 1/3 of the length of the baseline. If the inspection point is outside the line connecting the two elevation points on both sides of the bearing line, the distance from the connecting line shall not be greater than 1cm (Figure 11). C | Four flat and high points are arranged within the surveying range of the stereo pair (Figure 12). When surveying with a multi-magnification instrument, you can also use a dual-model layout with one flat-high point at each of the four corners of the surveying range of every number of photos. Figure 12 | | tt | | 4.4.4 Elevation of all field points | | tt | | The control points laid out by differential method mapping and omnipotent method mapping. If the plane position is completed by internal densification, only the elevation part will be constructed by the whole field GB12341 If -90
is measured, the horizontal height control points in Figures 10, 11, and 12 will be changed to elevation control points. 4.4.5 Requirements for point positions
In addition to meeting the general regulations, the following requirements must also be met: the distance between the point position and the straight line passing through the main point of the image and perpendicular to the azimuth line shall not be greater than 1cm. In difficult cases, individual points may not be greater than 1.5cm . The four basic orientation points should be distributed in a rectangle as much as possible, and the height difference between them should be as small as possible. However, the height difference between the elevation check point in the differential method map and the four orientation points in the image pair should be as large as possible. 4.5 Point layout under special circumstances
4.5.1 Point layout at the junction of aerial photography zones
If the two navigation areas use the same type of aerial photography instrument, the difference in focal length is less than 0.03mm, the heading overlap is normal, and the side direction When the connection stagger is less than 10%, the curvature after connection is within 3%, and the altitude difference is within 1/50 of the average relative altitude during photography, it can be regarded as the same route layout. Otherwise, control points should be distributed within the overlapping portion of the navigation area boundary, and adjacent routes should be shared as much as possible. If they cannot be shared, points must be distributed separately, and care should be taken not to create control loopholes.
4.5.2 Placements with insufficient course overlap
Re-boarding rates less than 53% are considered aerial photography vulnerabilities. Points should be distributed segmentally based on the loopholes, and the loopholes should be solved using single photo mapping or tablet meter mapping methods.
4.5.3 Placement of points with insufficient side overlap
The side overlap of individual photos of the route is less than 2cm but greater than 1cm, and when the image is clear, 1 to 2 additional elevation points will be measured in the overlapping part. , if the image is unclear or the overlap is less than 1cm, the insufficient overlap can be solved by using single photo mapping or flatbed mapping.
4.5.4 When the main image point or standard point is in the water, or is covered by cloud shadow, shadow, snow shadow, etc., or there is no obvious surface object, it will be regarded as Point a.
falls into the water. When the size or location of the falling water range does not affect the connection of the three-dimensional model, it can be regarded as a normal route layout. Otherwise, the route is regarded as disconnected and points are distributed in sections.
b. When no obvious target can be selected within 1cm of the main point of the image, the falling water image corresponds to the entire field layout. c. The standard point of the directional point is the falling water area. At this time, if no connection point can be selected within the overlapping range of the three pieces 4cm away from the main point of the image, the falling water image corresponds to the entire outdoor distribution point. 4.5.5 Waterfront and island layout
Waterfront and island areas are generally laid out in the entire field, based on the principle of maximizing the control of the surveying and mapping area. The land portion 1cm beyond the line connecting the control points should be measured with level points. When most of a photo is water and there are only a few scattered small islands, and it is difficult to lay out points according to regulations, the field layout should be based on the principle of controlling the size, orientation and elevation of the islands, and lay out 2 to 4 high-level points as appropriate. 5Basic control point measurement
In addition to using national grade points, we can also reasonably lay out small triangular points and photoelectric ranging wire points with an error of 5" in angle measurement according to the actual situation and specific requirements of the measurement area. As well as measuring external leveling and triangulation elevation wires, it serves as the basis for photo control measurement. 5.15\level plane control measurement
5" level photoelectric distance measurement wire measurement and small triangulation measurement, its weakest point. The medium error is 0.02mm in the picture. 5.1.1 Photoelectric ranging wire measurement
Photoelectric ranging wires can be laid out as a single attached wire or as a wire network with nodes. The instrument should use a Class II photoelectric rangefinder with a distance measurement error (nominal accuracy) of no more than 10mm per kilometer. 5.1.1.1 The main technical requirements for photoelectric ranging attached wires are specified in Table 7.2. When the aerial photography scale is equal to or smaller than the chart scale, and the number of regional network routes is less than 6 (including 6), the surrounding area shall be laid out at no less than 6 horizontal height points (Figure 3, Figure 4). Figure 3 | | tt | | Figure 4 | | tt | | GB12341-90 | | tt | Less than 6 flat high points (Figure 5, Figure 6)
Figure 5
4.3.2.3
Figure 6
When the number of routes exceeds 6 (or 4), the surrounding areas are laid out at 8 flat high points (Figure 7, Figure 8) Q
Figure 7
Figure 8
4.3.3 In the regional network, the flat The number of baselines between high points and elevation points can be calculated according to formulas (2) and (3) and then appropriately relaxed. However, elevation points should be arranged at the beginning and end of each route in the regional network (see Appendix G). 4.3.4 Distribute points according to the map area
a.
b.
c.
The layout of control points shall comply with the provisions of 4.3.1.2 and 4.3.2. For layout graphics, please refer to Figures G1 and G2 in Appendix G. The requirements for the location of control points on the periphery comply with the provisions of 4.2.1.3. The internal points can be selected within the range of the two baselines on the left and right, and should be located at the side re-entry as much as possible.
4.3.5 Arrange points according to route segment zones:
a.
b.
c.
. You can also refer to Table G1 in Appendix G for execution. For layout graphics, please refer to Figures G3 and G4 in Appendix G. The position requirements of the control points at both ends are the same as the route network layout points. The middle point can generally deviate from one baseline to the left and right, but cannot deviate from a maximum of 2 baselines.
4.3.6 Irregular area mesh points
4.3.6.1 Due to restrictions on terrain and other conditions, irregular area mesh points can be used. Generally, the high points are placed at the turning points of convex corners and the high points are placed at the turning points of concave corners. Distribute elevation points.
4.3.6.2 If the distance between the concave corner turning point and the convex corner turning point exceeds 4 baselines, a flat high point should also be arranged at the concave corner turning point (Figure G5 in Appendix G).
4.3.6.3 When the span along the heading direction between two control points around the area exceeds 7 baselines, an additional elevation point should be added in the middle. 4.3.7 Placement of points at the junction of the make-up flight route
The points laid out at the junction of the make-up flight route in the regional network are based on the principle of ensuring the connection accuracy. Generally, a flat high point can be added at the junction (Figure G6 in Appendix G) .
4.4 Full field layout
4.4.1 Full field layout mapped by comprehensive method
GB12341-90
When providing photo correction, four photos per number One plane point is arranged on each corner (Figure 9). If band correction is required, the plane points in Figure 9 will be changed to flat and high points. When photos between routes are interlaced and control points cannot be shared, points should be placed separately. o ||tt || tt||Each stereo pair is equipped with 4 horizontal height points and 1 elevation check point (Figure 10). The elevation check point should be located roughly in the center of two horizontal points perpendicular to the heading. When deviating left or right, the lines connecting the two horizontal points perpendicular to the heading should be greater than 1/3 of the baseline length. If the inspection point is outside the line connecting the two elevation points on both sides of the bearing line, the distance from the connecting line shall not be greater than 1cm (Figure 11). C | Four flat and high points are arranged within the surveying range of the stereo pair (Figure 12). When surveying with multiplex instruments, you can also use a dual-model layout with one flat-high point at each of the four corners of the surveying range of every number of photos. Figure 12 | | tt | | 4.4.4 Elevation of all field points | | tt | | Control points laid out by differential method mapping and omnipotent method mapping. If the plane position is completed by in-house densification, only the elevation part will be constructed by the whole field GB12341 If -90
is measured, the horizontal height control points in Figures 10, 11, and 12 will be changed to elevation control points. 4.4.5 Requirements for point positions
In addition to meeting the general regulations, the following requirements must also be met: the distance between the point position and the straight line passing through the main point of the image and perpendicular to the azimuth line shall not be greater than 1cm. In difficult cases, individual points may not be greater than 1.5cm . The four basic orientation points should be distributed in a rectangle as much as possible, and the height difference between them should be as small as possible. However, the height difference between the elevation check point in the differential method map and the four orientation points in the image pair should be as large as possible. 4.5 Point layout under special circumstances
4.5.1 Point layout at the junction of aerial photography zones
If the two navigation areas use the same type of aerial photography instrument, the difference in focal length is less than 0.03mm, the heading overlap is normal, and the side direction When the connection stagger is less than 10%, the curvature after connection is within 3%, and the altitude difference is within 1/50 of the average relative altitude during photography, it can be regarded as the same route layout. Otherwise, control points should be distributed within the overlapping portion of the navigation area boundary, and adjacent routes should be shared as much as possible. If they cannot be shared, points must be distributed separately, and care should be taken not to create control loopholes.
4.5.2 Placements with insufficient course overlap
Re-boarding rates less than 53% are considered aerial photography vulnerabilities. Points should be distributed segmentally based on the loopholes, and the loopholes should be solved using single photo mapping or tablet meter mapping methods.
4.5.3 Placement of points with insufficient side overlap
The side overlap of individual photos of the route is less than 2cm but greater than 1cm, and when the image is clear, 1 to 2 additional elevation points will be measured in the overlapping part. , if the image is unclear or the overlap is less than 1cm, the insufficient overlap can be solved by using single photo mapping or flatbed mapping.
4.5.4 When the main image point or standard point is in the water, or is covered by cloud shadow, shadow, snow shadow, etc., or there is no obvious ground object, it will be regarded as Point a.
falls into the water. When the size or location of the falling water range does not affect the connection of the three-dimensional model, it can be regarded as a normal route layout. Otherwise, the route is regarded as disconnected and points are distributed in sections.
b. When no obvious target can be selected within 1cm of the main point of the image, the falling water image corresponds to the entire field layout. c. The standard point of the directional point is the falling water area. At this time, if no connection point can be selected within the overlapping range of the three pieces 4cm away from the main point of the image, the falling water image corresponds to the entire outdoor distribution point. 4.5.5 Distribution of waterfront and island locations
Waterfront and island areas are generally laid out in the entire field, based on the principle of maximizing the control of the surveying and mapping area. The land portion 1cm beyond the line connecting the control points should be measured with level points. When most of a photo is covered by water and there are only a few scattered small islands, and it is difficult to arrange the points according to regulations, the field layout should be based on the principle of controlling the size, orientation and elevation of the islands and laying out 2 to 4 high-level points as appropriate. 5Basic control point measurement
In addition to using national grade points, we can also reasonably lay out small triangular points and photoelectric ranging wire points with an error of 5" in angle measurement according to the actual situation and specific requirements of the measurement area. As well as measuring external leveling and triangulation elevation wires, it serves as the basis for photo control measurement. 5.15\level plane control measurement
5" level photoelectric distance measurement wire measurement and small triangulation measurement, its weakest point. The medium error is 0.02mm in the picture. 5.1.1 Photoelectric ranging wire measurement
Photoelectric ranging wires can be laid out as a single attached wire or a wire network with nodes. The instrument should use a Class II photoelectric rangefinder with a distance measurement error (nominal accuracy) of no more than 10mm per kilometer. 5.1.1.1 The main technical requirements for photoelectric ranging attached wires are specified in Table 7.3 regulations. You can also refer to Table G1 in Appendix G for execution. For layout graphics, please refer to Figures G3 and G4 in Appendix G. The position requirements of the control points at both ends are the same as the route network layout points. The middle point can generally deviate from one baseline to the left and right, but cannot deviate from a maximum of 2 baselines.
4.3.6 Irregular area mesh points
4.3.6.1 Due to restrictions on terrain and other conditions, irregular area mesh points can be used. Generally, the high points are placed at the turning points of convex corners and the high points are placed at the turning points of concave corners. Distribute elevation points.
4.3.6.2 If the distance between the concave corner turning point and the convex corner turning point exceeds 4 baselines, a flat high point should also be arranged at the concave corner turning point (Figure G5 in Appendix G).
4.3.6.3 When the span along the heading direction between two control points around the area exceeds 7 baselines, an additional elevation point should be added in the middle. 4.3.7 Placement of points at the junction of the make-up flight route
The points laid out at the junction of the make-up flight route in the regional network are based on the principle of ensuring the connection accuracy. Generally, a flat high point can be added at the junction (Figure G6 in Appendix G) .
4.4 Full field layout
4.4.1 Full field layout mapped by comprehensive method
GB12341-90
When providing photo correction, four photos per number One plane point is arranged on each corner (Figure 9). If band correction is required, the plane points in Figure 9 should be changed to flat and high points. When photos between routes are interlaced and control points cannot be shared, points should be placed separately. o ||tt || tt||Each stereo pair is equipped with 4 horizontal height points and 1 elevation check point (Figure 10). The elevation check point should be located roughly in the center of two horizontal points perpendicular to the heading. When deviating left or right, the lines connecting the two horizontal points perpendicular to the heading should be greater than 1/3 of the length of the baseline. If the inspection point is outside the line connecting the two elevation points on both sides of the bearing line, the distance from the connecting line shall not be greater than 1cm (Figure 11). C | Four flat and high points are arranged within the surveying range of the stereo pair (Figure 12). When surveying with a multi-magnification instrument, you can also use a dual-model layout with one flat-high point at each of the four corners of the surveying range of every number of photos. Figure 12 | | tt | | 4.4.4 Elevation of all field points | | tt | | Control points laid out by differential method mapping and omnipotent method mapping. If the plane position is completed by in-house densification, only the elevation part will be constructed by the whole field GB12341 If -90
is measured, the horizontal height control points in Figures 10, 11, and 12 will be changed to elevation control points. 4.4.5 Requirements for point positions
In addition to meeting the general regulations, the following requirements must also be met: the distance between the point position and the straight line passing through the main point of the image and perpendicular to the azimuth line shall not be greater than 1cm. In difficult cases, individual points may not be greater than 1.5cm . The four basic orientation points should be distributed in a rectangle as much as possible, and the height difference between them should be as small as possible. However, the height difference between the elevation check point in the differential method map and the four orientation points in the image pair should be as large as possible. 4.5 Point layout under special circumstances
4.5.1 Point layout at the junction of aerial photography zones
If the two navigation areas use the same type of aerial photography instrument, the difference in focal length is less than 0.03mm, the heading overlap is normal, and the side direction When the connection stagger is less than 10%, the curvature after connection is within 3%, and the altitude difference is within 1/50 of the average relative altitude during photography, it can be regarded as the same route layout. Otherwise, control points should be distributed within the overlapping portion of the navigation area boundary, and adjacent routes should be shared as much as possible. If they cannot be shared, points must be distributed separately, and care should be taken not to create control loopholes.
4.5.2 Placements with insufficient course overlap
Re-boarding rates less than 53% are considered aerial photography vulnerabilities. Points should be distributed segmentally based on the loopholes, and the loopholes should be solved using single photo mapping or tablet meter mapping methods.
4.5.3 Placement of points with insufficient side overlap
The side overlap of individual photos of the route is less than 2cm but greater than 1cm, and when the image is clear, 1 to 2 additional elevation points will be measured in the overlapping part. , if the image is unclear or the overlap is less than 1cm, the insufficient overlap can be solved by using single photo mapping or flatbed mapping.
4.5.4 When the main image point or standard point is in the water, or is covered by cloud shadow, shadow, snow shadow, etc., or there is no obvious surface object, it will be regarded as Point a.
falls into the water. When the size or location of the falling water range does not affect the connection of the three-dimensional model, it can be regarded as a normal route layout. Otherwise, the route will be considered disconnected and points will be distributed in sections.
b. When no obvious target can be selected within 1cm of the main point of the image, the falling water image corresponds to the entire field layout. c. The standard point of the directional point is the falling water area. At this time, if no connection point can be selected within the overlapping range of the three pieces 4cm away from the main point of the image, the falling water image corresponds to the entire outdoor distribution point. 4.5.5 Waterfront and island layout
Waterfront and island areas are generally laid out in the entire field, based on the principle of maximizing the control of the surveying and mapping area. The land portion 1cm beyond the line connecting the control points should be measured with level points. When most of a photo is covered by water and there are only a few scattered small islands, and it is difficult to arrange the points according to regulations, the field layout should be based on the principle of controlling the size, orientation and elevation of the islands and laying out 2 to 4 high-level points as appropriate. 5Basic control point measurement
In addition to using national grade points, we can also reasonably lay out small triangular points and photoelectric ranging wire points with an error of 5" in angle measurement according to the actual situation and specific requirements of the measurement area. As well as measuring external leveling and triangulation elevation wires, it serves as the basis for photo control measurement. 5.15\level plane control measurement
5" level photoelectric distance measurement wire measurement and small triangulation measurement, its weakest point. The medium error is 0.02mm in the picture. 5.1.1 Photoelectric ranging wire measurement
Photoelectric ranging wires can be laid out as a single attached wire or a wire network with nodes. The instrument should use a Class II photoelectric rangefinder with a distance measurement error (nominal accuracy) of no more than 10 mm per kilometer. 5.1.1.1 The main technical requirements for photoelectric ranging attached wires are specified in Table 7.3 regulations. You can also refer to Table G1 in Appendix G for execution. For layout graphics, please refer to Figures G3 and G4 in Appendix G. The position requirements of the control points at both ends are the same as the route network layout points. The middle point can generally deviate from one baseline to the left and right, but cannot deviate from a maximum of 2 baselines.
4.3.6 Irregular area mesh points
4.3.6.1 Due to restrictions on terrain and other conditions, irregular area mesh points can be used. Generally, the high points are placed at the turning points of convex corners and the high points are placed at the turning points of concave corners. Distribute elevation points.
4.3.6.2 If the distance between the concave corner turning point and the convex corner turning point exceeds 4 baselines, a flat high point should also be arranged at the concave corner turning point (Figure G5 in Appendix G).
4.3.6.3 When the span along the heading direction between two control points around the area exceeds 7 baselines, an additional elevation point should be added in the middle. 4.3.7 Placement of points at the junction of the make-up flight route
The points laid out at the junction of the make-up flight route in the regional network are based on the principle of ensuring the connection accuracy. Generally, a flat high point can be added at the junction (Figure G6 in Appendix G) .
4.4 Full field layout
4.4.1 Full field layout mapped by comprehensive method
GB12341-90
When providing photo correction, four photos per number One plane point is arranged on each corner (Figure 9). If band correction is required, the plane points in Figure 9 will be changed to flat and high points. When photos between routes are interlaced and control points cannot be shared, points should be placed separately. o ||tt || tt||Each stereo pair is equipped with 4 horizontal height points and 1 elevation check point (Figure 10). The elevation check point should be located roughly in the center of two horizontal points perpendicular to the heading. When deviating left or right, the lines connecting the two horizontal points perpendicular to the heading should be greater than 1/3 of the length of the baseline. If the inspection point is outside the line connecting the two elevation points on both sides of the bearing line, the distance from the connecting line shall not be greater than 1cm (Figure 11). C | Four flat and high points are arranged within the surveying range of the stereo pair (Figure 12). When surveying with multiplex instruments, you can also use a dual-model layout with one flat-high point at each of the four corners of the surveying range of every number of photos. Figure 12 | | tt | | 4.4.4 Elevation of all field points | | tt | | Control points laid out by differential method mapping and omnipotent method mapping. If the plane position is completed by in-house densification, only the elevation part will be constructed by the whole field GB12341 If -90
is measured, the level control points in Figures 10, 11, and 12 will be changed to elevation control points. 4.4.5 Requirements for point positions
In addition to meeting the general regulations, the following requirements must also be met: the distance between the point position and the straight line passing through the main point of the image and perpendicular to the azimuth line shall not be greater than 1cm. In difficult cases, individual points may not be greater than 1.5cm . The four basic orientation points should be distributed in a rectangle as much as possible, and the height difference between them should be as small as possible. However, the height difference between the elevation check point in the differential method map and the four orientation points in the image pair should be as large as possible. 4.5 Point layout under special circumstances
4.5.1 Point layout at the junction of aerial photography zones
If the two navigation areas use the same type of aerial photography instrument, the difference in focal length is less than 0.03mm, the heading overlap is normal, and the side direction When the connection stagger is less than 10%, the curvature after connection is within 3%, and the altitude difference is within 1/50 of the average relative altitude during photography, it can be regarded as the same route layout. Otherwise, control points should be distributed within the overlapping portion of the navigation area boundary, and adjacent routes should be shared as much as possible. If they cannot be shared, points must be distributed separately, and care should be taken not to create control loopholes.
4.5.2 Placements with insufficient course overlap
Re-boarding rates less than 53% are considered aerial photography vulnerabilities. Points should be distributed segmentally based on the loopholes, and the loopholes should be solved using single photo mapping or tablet meter mapping methods.
4.5.3 Placement of points with insufficient side overlap
The side overlap of individual photos of the route is less than 2cm but greater than 1cm, and when the image is clear, 1 to 2 additional elevation points will be measured in the overlapping part. , if the image is unclear or the overlap is less than 1cm, the insufficient overlap can be solved by using single photo mapping or flatbed mapping.
4.5.4 When the main image point or standard point is in the water, or is covered by cloud shadow, shadow, snow shadow, etc., or there is no obvious ground object, it will be regarded as Point a.
falls into the water. When the size or location of the falling water range does not affect the connection of the three-dimensional model, it can be regarded as a normal route layout. Otherwise, the route will be considered disconnected and points will be distributed in sections.
b. When no obvious target can be selected within 1cm of the main point of the image, the falling water image corresponds to the entire field layout. c. The standard position of the orientation point is the falling water area. At this time, if no connection point can be selected within the overlapping range of the three pieces 4cm away from the main point of the image, the falling water image corresponds to the entire outdoor distribution point. 4.5.5 Waterfront and island layout
Waterfront and island areas are generally laid out in the entire field, based on the principle of maximizing the control of the surveying and mapping area. The land portion 1cm beyond the line connecting the control points should be measured with level points. When most of a photo is covered by water and there are only a few scattered small islands, and it is difficult to arrange the points according to regulations, the field layout should be based on the principle of controlling the size, orientation and elevation of the islands and laying out 2 to 4 high-level points as appropriate. 5Basic control point measurement
In addition to using national grade points, we can also reasonably lay out small triangular points and photoelectric ranging wire points with an error of 5" in angle measurement according to the actual situation and specific requirements of the measurement area. As well as measuring external leveling and triangulation elevation wires, it serves as the basis for photo control measurement. 5.15\level plane control measurement
5" level photoelectric distance measurement wire measurement and small triangulation measurement, its weakest point. The medium error is 0.02mm in the picture. 5.1.1 Photoelectric ranging wire measurement
Photoelectric ranging wires can be laid out as a single attached wire or a wire network with nodes. The instrument should use a Class II photoelectric rangefinder with a distance measurement error (nominal accuracy) of no more than 10mm per kilometer. 5.1.1.1 The main technical requirements for photoelectric ranging attached wires are specified in Table 7.5-point requirements
In addition to meeting the general regulations, the following requirements must also be met: The distance between the point and the straight line that passes through the main point and is perpendicular to the azimuth line is no more than 1cm. In difficult cases, individual points can be no more than 1.5cm. The four basic orientation points should be distributed in a rectangle as much as possible, and the height difference between them should be as small as possible. However, the height difference between the elevation check point in the differential method map and the four orientation points in the image pair should be as large as possible. 4.5 Point layout under special circumstances
4.5.1 Point layout at the junction of aerial photography zones
If the two navigation areas use the same type of aerial photography instrument, the difference in focal length is less than 0.03mm, the heading overlap is normal, and the side direction When the connection stagger is less than 10%, the curvature after connection is within 3%, and the altitude difference is within 1/50 of the average relative altitude during photography, it can be regarded as the same route layout. Otherwise, control points should be distributed within the overlapping portion of the navigation area boundary, and adjacent routes should be shared as much as possible. If they cannot be shared, points must be distributed separately, and care should be taken not to create control loopholes.
4.5.2 Placements with insufficient course overlap
Re-boarding rates less than 53% are considered aerial photography vulnerabilities. Points should be distributed segmentally based on the loopholes, and the loopholes should be solved using single photo mapping or tablet meter mapping methods.
4.5.3 Placement of points with insufficient side overlap
The side overlap of individual photos of the route is less than 2cm but greater than 1cm, and when the image is clear, 1 to 2 additional elevation points will be measured in the overlapping part. , if the image is unclear or the overlap is less than 1cm, the insufficient overlap can be solved by using a single photo measurement or a flatbed measurement method.
4.5.4 When the main image point or standard point is in the water, or is covered by cloud shadow, shadow, snow shadow, etc., or there is no obvious surface object, it will be regarded as Point a.
falls into the water. When the size or location of the falling water range does not affect the connection of the three-dimensional model, it can be regarded as a normal route layout. Otherwise, the route is regarded as disconnected and points are distributed in sections.
b. When no obvious target can be selected within 1cm of the main point of the image, the falling water image corresponds to the entire field layout. c. The standard point of the directional point is the falling water area. At this time, if no connection point can be selected within the overlapping range of the three pieces 4cm away from the main point of the image, the falling water image corresponds to the entire outdoor distribution point. 4.5.5 Waterfront and island layout
Waterfront and
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