JPH10141951A - Target for photographic survey - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a target wherein a measurement point in the picture taken in photographic measurement is accurately and easily identified. SOLUTION: A target 30 is obtained by molding a converging board which is a translucent member of acrylic resin into a disc, with an external light incident on a flat surface 32 going out of a side surface 33. On one flat surface 32 of the target 30, a reference point forming member 31 is assigned at its almost center part. The reference point forming member 31 is obtained by molding a transparent resin of a refraction factor different from the converging board, having almost hemisphere shape. The external light incident on the flat surface of the target 30 comes out of the side surface 33 and the reference point forming member 31 of the target 30. At the site of photographic survey, imaging is performed with the target 30 assigned at each measurement point, which acts as a mark for identifying visually the measurement point when the imaged picture is analyzed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a target used for specifying a measurement point in photogrammetry.

[0002]

2. Description of the Related Art Conventionally, in photogrammetry, surveying using stereo photographs and surveying using single photographs are known. In the case of a stereo photograph, the scene is photographed by two cameras at a predetermined distance at the same time, and the resulting stereo image is stereoscopically viewed with an optical machine, and points in the stereoscopic image are designated. The survey is performed by going. On the other hand, in the case of a single photograph, a standard scale is installed at the site to be photographed, the site is photographed with the optical axis of the camera having a predetermined angle with respect to the vertical direction, and the standard scale in the photographed image is taken. The surveying is performed by enlarging the photographed image based on the shrinkage ratio of the above and making a plan view of the site when viewed from the vertical direction, and pointing to points in the plan view.

For example, when measuring the distance between two points,
When a target is placed at each of the two measurement points and an image of the site is taken and a stereoscopic image or plan is analyzed, the measurement points can be determined by confirming the target in the stereoscopic image or plan view. Specifically, the distance between the two points is measured. A target called a cone having a conical shape is used as the target. Such a cone is, for example, entirely black and colored only at the vertices of the cone white, or two colors that are easily distinguishable, such as black and yellow, so that the cone can be easily distinguished from the surrounding scenery. .

[0004]

However, since such a cone has the shape of a cone, the bottom surface in contact with the measurement point is separated from the vertex of the cone specified as the measurement point in the image. Therefore, it is difficult to dispose the cone so that the vertex of the cone is located exactly on the vertical direction of the measurement point, and therefore, there has been a problem that the accuracy of the survey decreases. In addition, when the image is taken in a state where the lighting is dark, it is difficult to distinguish the cone from the surrounding scene by the color, and there is a problem that the efficiency of the surveying operation is reduced.

An object of the present invention is to solve the above problems, and an object of the present invention is to provide a target for accurately and easily specifying a measurement point in an image taken in photogrammetry.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a target which is arranged as a mark for specifying a measurement point in photogrammetry and has a reference point corresponding to the measurement point, and which is a transparent or translucent material containing a phosphor. The light-emitting device is characterized in that the light-collecting plate is made of a member, and the light-emitting plate emits fluorescent light in response to light incident from the first surface and is emitted from a second surface having a smaller area than the first surface.

[0007] Preferably, the second surface has a reference point.

[0008] The target of the present invention is a flat plate made of a light collector, for example, a concave portion whose second surface is engraved on the flat surface of the flat plate.

For example, the concave portion is a conical hole, and the apex of the hole is the reference point.

For example, the concave portion has two or more linear grooves intersecting each other, the intersection of the grooves is a reference point, and the cross-sectional shape of the linear groove is V-shaped.

The target of the present invention is preferably a flat plate made of a light collector, and a reference point is formed by disposing a transparent member having a different refractive index from the light collector on the first surface.

The target of the present invention is preferably a cone made of a light collector, and a ridge extending from a corner of the bottom surface of the cone to the vertex is formed by the second surface, and the vertex is a reference point.

[0013] For example, the cross-sectional shape of the ridge is a V-shaped groove, or each ridge is formed by a single second surface.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a bird's-eye view showing an example of the arrangement of cameras, targets, and the like at the site of photogrammetry using stereo photography. The cameras L and R are positioned at a predetermined distance d. Dotted line 1 represents the optical axis of camera L, and dotted line r represents the optical axis of camera R. Also, solid line 1
The angle θ1 between 1 and the solid line 12 is the angle of view of the camera L. Therefore, the shooting area of the camera L is represented by solid lines 11 and 12
Corresponds to the portion sandwiched by Similarly, the angle θ2 between the solid line 21 and the solid line 22 is the angle of view of the camera R,
Corresponds to a portion sandwiched between the solid line 21 and the solid line 22. An overlapping portion of the photographing regions of the camera R and the camera L is a region used for photogrammetry using stereo photography, and is hatched in FIG.

When measuring the distance between the two points A and B, when a target serving as a landmark is arranged, a stereo photograph is taken by the cameras R and L, and when the photographed image is stereoscopically viewed, The survey between two points is performed by visually specifying the target.

FIG. 2 is a perspective view of the target 30 according to the first embodiment of the present invention, FIG. 3 is a plan view of the target 30, and FIG. 4 is a sectional view taken along line XX of FIG. The target 30 is formed by forming a light collector into a disk. In this embodiment, the light collector is a member made of an acrylic resin, and as shown in FIG. 4, two cladding layers 35 and a core sandwiched between these cladding layers 35 and having a refractive index larger than that of the cladding layers 35. It is a plate-shaped member composed of the layer 34.
The clad layer is formed over the entire plane 32 (first plane) of the target 30. Further, a fluorescent material is mixed in the resin of the core layer 34 and is uniformly distributed throughout the core layer 34. The phosphor has the property of receiving light that has entered through the cladding layer 35 from the outside and emits fluorescent light isotropically secondarily. The fluorescence emitted from the phosphor is
Part of the light passes through the cladding layer 35 and exits from the plane 32, and part of the light is reflected at the interface between the cladding layer 35 and the core layer 34 or at the interface between the cladding layer 35 and the air.
4 and is emitted from the peripheral side surface 33 to the outside.

On one plane of the target 30, a reference point forming member 31 is disposed substantially at the center. The reference point forming member 31 is formed by molding a transparent resin having a different refractive index from that of the light collector, and has a substantially hemispherical shape as shown in FIG. Therefore, in the portion where the reference point forming member 31 is in contact with the cladding layer 35, the fluorescent light is
The light is not reflected at the interface between the air and the air, passes through the reference point forming member 31, and is emitted to the outside. Therefore, the reference point forming member 31
Are visible to have the fluorescent color of the phosphor and can be clearly identified from the surrounding plane.

In a site as shown in FIG. 1, such a target 30 is arranged such that respective reference points 31 are located on points A and B. Since the target 30 is translucent, even if the target 30 is disposed on a plane including the points A and B, the points A and B can be visually recognized without being obstructed by the plane portion of the target 30. Can be easily positioned. Target 3 as above
0 is placed at points A and B and images are taken with cameras R and L. Thereafter, when stereoscopically viewing a stereo photograph by the cameras R and L, the reference point 31 of the target 30 can be easily specified because the reference point 31 is photographed with higher luminance than the surrounding scenery. Therefore,
In measuring the distance between the points AB, the exact position of each point can be specified, so that the survey can be performed with high accuracy.

FIG. 5 is a perspective view showing a target 40 according to a second embodiment of the present invention. The target 40 is formed by molding a light collector into a disk, similarly to the target 30 of the first embodiment. On one plane 42 (first plane) of the target 40, a conical concave portion serving as the reference point 41 is formed. FIG. 6 is a cross-sectional view when the target 40 is cut along a line including the reference point 41. As shown in FIG.
Reaches the core layer 44, and the core layer 44 is exposed on the inner wall surface (second surface). Accordingly, the fluorescent light emitted from the phosphor is emitted from the peripheral side surface 43 as well as the target 30 and also emitted from the reference point 41, so that the reference point 41 can be clearly identified from the surrounding plane. for that reason,
When the target 40 is placed at each point in order to measure the distance between the points A and B on the site in FIG.
Is easy to position. Also,
Since fluorescent light is emitted from the reference point 41, a stereo photograph is taken with high luminance, and when performing surveying between the points A and B in a stereoscopic view, each point can be easily specified, and highly accurate surveying can be performed. Can be performed.

FIG. 7 is a plan view showing a target 50 according to a third embodiment of the present invention. The target 50 is formed by forming a light collector into a disk, similarly to the target 30 of the first embodiment and the target 40 of the second embodiment. A reference point forming portion 51 is formed on a plane 52 (first surface) of the target 50.

FIG. 8A is an enlarged view of the reference point forming portion 51 of the target 50, and FIG. 8B is a line Y in FIG.
It is arrow sectional drawing of -Y. Four linear grooves are formed in the reference point forming unit 51, and the grooves intersect at the reference point 51a. 8A, the cross-sectional shape of the vertically extending groove 51b is V-shaped as shown in FIG. 8B. Other grooves also have a V-shaped cross-section. FIG.
As shown in (b), the groove 51b reaches the core layer 54, and the inner wall surface (second surface) of the core layer 54 is exposed. Therefore, the fluorescent light emitted from the phosphor is emitted from the peripheral side surface 53 similarly to the target 30 and the target 40, and also emitted from the inner wall surface of each groove of the reference point forming unit 51. Can be clearly identified. Further, since the reference point 51a is a point where each groove intersects, identification by visual recognition is easier. As described above, since the amount of light emitted from the reference point 51a is larger than the amount of light emitted from other parts, the same effects as in the first and second embodiments can be obtained in positioning on site and photogrammetry using stereo photography. can get.

FIG. 9 is a perspective view of a target 60 according to a fourth embodiment of the present invention, and FIG. 10 is a plan view thereof. The target 60 is a combination of the same light collector as in the first to third embodiments formed into a triangular plate, and has a substantially triangular pyramid as a whole. Target 60 is 3
It is composed of three triangular plates 61, 62, 63. As described above, the triangular plates 61, 62, and 63 use the same light collector as that used in the first to third embodiments. That is, the planes 61A, 62A, 63A of each triangular plate.
On the (first surface), a cladding layer is provided on one surface, and a core layer having a phosphor is sandwiched between the cladding layers. Also, the side surfaces 61R, 61L, 62R, 62L of each triangular plate,
At 63R and 63L (second surface), the core layer is exposed.
The triangular plates 61, 62, 63 have substantially the same shape and size. In the triangular plates 61, 62, 63, the planes 61A, 62A, 63A are isosceles triangles.

The back side edge of the right side 61R of the triangular plate 61 is bonded to the back side edge of the left side 62L of the triangular plate 62,
The back side edge of the right side 62R of the triangular plate 62 is bonded to the back side edge of the left side 63L of the triangular plate 63, and the back side edge of the right side 63R of the triangular plate 63 and the left side 61L of the triangular plate 61.
Is adhered to the back side edge. In addition, these triangular plates 6
The vertices on the back side of 1, 62 and 63 are joined at the reference point 60P. Therefore, the right side 61R and the left side 62
L, the right side surface 62R and the left side surface 63L, the right side surface 63R and the left side surface 61L, and the respective bonded portions form a ridge of a cone, and the cross-sectional shape has a V-groove shape.

In each of the triangular plates, external light that enters from outside through a plane of an isosceles triangle exits from the side surface where the core layer is exposed. Therefore, the reference point 60P at which the side of each side intersects can be easily identified visually.

The target 60 is placed on the measuring points A and B in FIG. 1 and the reference point 6 on a vertical straight line including the measuring points.
Install so that 0P is located. Since the triangular plates 61, 62, 63 constituting the target 60 are translucent, the positioning can be performed while visually observing the measurement points at the time of installation. Therefore, the target 60 can be accurately set, and the points A and B can be viewed while stereoscopically viewing the photographed stereo photograph.
In the case of surveying the interval, the reference point 60P is easily specified because each side surface is photographed with high luminance, so that a highly accurate value is obtained.

FIG. 11 is a perspective view of a target 70 according to a fifth embodiment of the present invention, and FIG. 12 is a plan view thereof. The target 70 is composed of the same light collector as in the first to fourth embodiments. The target 70 includes a pair of triangular plates having a right-angled triangle plane 71C (first surface) and a side surface 71D (second surface), and a right-angled triangle plane 72C (first surface) and a side surface 72D (second surface). ) Have a shape extending radially around a square pole having the upper surface 71 </ b> P as the bottom surface. Plane 71C, 72C
The (first surface) is provided with a cladding layer on one surface,
The core layers are exposed on the side surfaces 71D and 72D (second surface). Each of the triangular plates has the same shape and size, and the angle between the triangular plate having the plane 71C and the side surface 71D and the triangular plate having the plane 72C and the side surface 72D is a right angle. In the plane of the right triangle of each triangle plate, the longer side of the two sides sandwiching the right angle extends in the vertical direction, and the side surface of the right triangle forms a cone ridge.

FIG. 13 is an exploded perspective view showing the target 70. The target 70 is configured by combining the first and second plate members 71 and 72. The flat surface 71C (first surface) of the first plate member 71 has an isosceles trapezoidal shape.
The plate member 71 has a top surface 71P from the center of the bottom surface 71A.
Is formed. Slot 7
The length of 1S is approximately half the height of the trapezoid. As described above, the cladding layer is provided on one surface of the flat surface 71C of the first plate member 71, and the side surface 71D (the second
Surface) has the core layer exposed.

On the other hand, a flat surface 72C (first surface) of the second plate member 72 has substantially the same trapezoid as the first plate member 71, and a slot 72S extending from the upper surface to the bottom surface 72A.
have. The length of the slot 72S is approximately half the height of the isosceles trapezoid. Further, as described above, the cladding layer is provided on one surface of the flat surface 72C of the second plate member 72,
The core layer is exposed on the side surface 72D (second surface) of the second plate member 72. The first plate member 71 and the second
Are assembled such that the respective slits 71S, 72S are fitted, and the end surface 71T of the slit 71S is bonded to the end surface 72T of the slit 72S. As a result, a target 70 as shown in FIGS. 11 and 12 is obtained.

Such a target 70 is used with the upper surface 71P as a reference point. That is, similarly to the fourth embodiment, the target 70 is set so that the upper surface 71P is located on a vertical straight line including the measurement points on the measurement points A and B in FIG.
Since the target 70 is configured to be translucent, it can be positioned while visually observing the measurement points at the time of installation, so that it can be accurately installed. In the case of measuring the interval, the upper surface 71P is easily specified because each side surface is photographed with high luminance, so that a highly accurate value is obtained.

According to the first to fifth embodiments, since the target is formed of a translucent member, it is easy to position the reference point of the target at the measurement point while visually observing the measurement point.

Further, according to the first to fifth embodiments, since the reference point is always photographed with a constant luminance difference without being affected by the lighting condition, the reference point can be easily specified at the time of analyzing the photograph.

According to the fourth and fifth embodiments, since the reference points 60P and 71P have a predetermined height from the bottom surface of the target, if the distance between the camera and the measurement point is large, the reference points Visual inspection is easier.

In the fourth embodiment, a cone is formed using three triangular plates, but the present invention is not limited to this.

[0034]

As described above, according to the present invention, it is possible to obtain a target which can be easily set as a mark of a measurement point in photogrammetry and can easily specify the measurement point in a photographed image.

[Brief description of the drawings]

FIG. 1 is a bird's-eye view showing an example of an arrangement state of cameras, targets, and the like at a photogrammetry site using stereo photography.

FIG. 2 is a perspective view of a target according to the first embodiment of the present invention.

FIG. 3 is a plan view of a target according to the first embodiment.

FIG. 4 is a cross-sectional view of the target according to the first embodiment.

FIG. 5 is a perspective view of a target according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view of a target according to a second embodiment.

FIG. 7 is a plan view of a target according to a third embodiment of the present invention.

FIG. 8A is an enlarged view of a reference point forming part of the target according to the third embodiment, and FIG. 8B is a cross-sectional view of the reference point forming part.

FIG. 9 is a perspective view of a target according to a fourth embodiment of the present invention.

FIG. 10 is a plan view of a target according to a fourth embodiment.

FIG. 11 is a perspective view of a target according to a fifth embodiment of the present invention.

FIG. 12 is a plan view of a target according to a fifth embodiment.

FIG. 13 is an exploded perspective view of a target according to a fifth embodiment.

[Explanation of symbols]

 30, 40, 50, 60, 70 Target 31 Reference point forming member 41, 51 Reference point forming portion 51a, 60P Reference point 51b V groove 61, 62, 63 Triangular plate 71 First plate member 72 Second plate member A, B Measurement point L, R Camera

Claims (10)

[Claims] 1. A target which is arranged as a mark for specifying a measurement point in photogrammetry and has a reference point corresponding to the measurement point, comprising a transparent or translucent member containing a phosphor, A target for photogrammetry, comprising: a light collector that emits fluorescent light emitted from the phosphor upon receiving light incident from a surface from a second surface having a smaller area than the first surface. 2. The target for photogrammetry according to claim 1, wherein the second surface has the reference point. 3. The target for photogrammetry according to claim 2, wherein the target is a flat plate made of the light collector, and the second surface is a recess formed in a plane of the flat plate. 4. The photogrammetry target according to claim 3, wherein the recess is a conical hole, and a vertex of the hole is the reference point. 5. The photogrammetry target according to claim 3, wherein the concave portion has two or more linear grooves intersecting each other, and an intersection of the grooves is the reference point. 6. The target for photogrammetry according to claim 5, wherein the cross-sectional shape of the linear groove is V-shaped. 7. A flat plate comprising the light collector, wherein the reference point is formed by disposing a transparent member having a different refractive index from the light collector on the first surface. The target for photogrammetry according to claim 1. 8. A cone comprising the light collector, wherein a ridge extending from a corner to a vertex of a bottom surface of the cone is formed by the second surface, and the vertex is the reference point. The target for photogrammetry according to claim 1. 9. The target for photogrammetry according to claim 8, wherein a cross-sectional shape of the ridge is a V-shaped groove. 10. The photogrammetric target according to claim 8, wherein each of the ridges is formed by a single second surface.