JPH06222482A - Aerial photographing method - Google Patents

Abstract

PURPOSE:To eliminate the need of mosaic process and distortion correction at the time of preparing a photographic map, etc., from an aerial photograph. CONSTITUTION:An aircraft and the positions and postures of a camera for taking the aerial photography, etc., mounted on the aircraft are detected according to three-dimensional geodesic coordinates and the aircraft and the positions and postures of the camera are controlled according to the result of the detection, thereby the principal points P of aerial phtographs F1-F3 by the camera are specified as the center of the drawing of photographic maps M1-M3 to photograph the aerial photographs F1-F3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aerial photography method, and more particularly to an aerial photography method used when an aerial photograph is taken on the basis of a photo map or the like partitioned by a public survey coordinate mesh.

[0002]

2. Description of the Related Art Aerial photography by aircraft and the like has been widely performed. As a conventional general aerial photography method, two or more prominent targets on the ground are selected, the straight line connecting them is taken as the shooting course, and this shooting course is used at a constant altitude for an aircraft equipped with a camera for shooting. A method is used in which the camera is kept in a vertical position while flying, and the ground is continuously photographed so that the photographs overlap each other at a constant rate.

Then, based on the aerial photograph having a large amount of information obtained in this way, that is, a mosaic, a photographic drawing, a photographic map or the like is created so as to have the effect of the map while keeping the characteristics of the aerial photograph. Mosaic is a general term for a mosaic, a semi-strict mosaic, and a strict mosaic.
The abbreviated mosaic is a print of the photo that is put on the feature as it is, and the semi-strict mosaic is a mosaic that determines the position and orientation of each photo by the rhombus chain method. This is a mosaic in which the image is corrected like a vertical photograph by the deviation correction, and the position is adjusted based on the reference point. In addition, the photograph diagram is a mosaic representation of place names, boundaries, divisions of buildings, etc. that do not appear in the photograph. In addition, the photographic map is a orthographic projection photo (orthophoto), which is a orthographic projection, in which a portion of the aerial photo is redrawn into a vertical photo, and the parts are displaced to a certain scale according to the height of the landform. Note, symbols, or contour lines, if necessary.

The feature of the above-mentioned photographic map is that a large amount of information is expressed as it is without omission, and in addition, it is excellent in simultaneity, which is important in capturing changes in topography and features. In order to utilize such characteristics, there are various demands for using photographic maps, and there is a survey work etc. for evaluation of fixed asset taxation by local governments.

For example, in the above-mentioned survey for assessing fixed asset taxation, in order to investigate the change between the photo map (photo map divided by the public survey coordinate mesh) already created and the actual feature, this photo map is used. An aerial photograph is taken on the basis of the aerial photographs, and the photograph map is repeatedly created by the photographed aerial photographs at each survey time point.

When the photograph map is created as described above, as shown in FIG. 4, the camera 1 is used to cover the entire drawings m1 to m3 of the photograph map m partitioned by the public survey coordinate mesh. Many aerial photographs f1
A method is used in which images a to f8 are taken while overlapping or side lapping, and these newly taken aerial photos f1 to f8 are joined by a mosaic method. In the figure, the shaded portion is the mosaic joining portion at that time, and the reference numeral 1b is the camera lens.

[0007]

However, although errors such as overlap in each aerial photograph are small one by one, the error accumulates as the number of aerial photographs taken continuously increases. To be done. For this reason, a complicated mosaic process is required when creating a new photographic map based on these aerial photographs, and the obtained photographic map and the like cannot avoid unevenness in shade due to the mosaic and a difference in pasting.

Further, the conventional method is to hold the camera vertically, that is, to take an image by vertically setting the optical axis 1a of the camera 1 with respect to the reference horizontal plane 200 as shown in FIG. Therefore, when photographing the sloping ground surface 201, the picture m4 of the photographic map
The camera optical axis 1a is tilted with respect to a plane representing the ground surface 201 surrounded by, and thus the photographic drawing f9 created by the aerial photograph is shown in FIG. As indicated by the dotted line, the map drawing m indicated by the solid line is distorted. That is, since the lengths a ′ and b ′ on the photographic drawing f9 are distorted with respect to the lengths a and b on the map drawing m corresponding to the two points A and B on the ground surface 201, distortion of the photographic scale occurs. Will end up. Therefore, there is also a problem that this distortion needs to be corrected by a partial distortion correction machine or the like when creating a photo map.

It is an object of the present invention to provide an aerial photography method that does not require the above-mentioned mosaic process and bias distortion correction.

[0010]

According to the present invention, the position and orientation of an aircraft and an aerial photography camera mounted on the aircraft are detected based on three-dimensional geodetic coordinates, and the position and orientation of the camera are detected based on the detection result. To navigate the aircraft,
Further, there is provided an aerial photography method characterized in that the principal point of the aerial photograph taken by the camera is designated as the center of the image on the photographic map, and the camera takes an image in a predetermined course.
The detection of the position and orientation of an aircraft or the like based on the above three-dimensional geodetic coordinates, that is, the detection of the position and orientation of an aircraft or a camera on the three-dimensional geodetic coordinates is performed by, for example, GPS (global).
It can be easily performed by using the l positioning system).

According to the present invention, the position and attitude of the aircraft and the camera for aerial photography mounted on the aircraft are detected based on the three-dimensional geodetic coordinates, and the navigation of the aircraft is performed based on the detection result. The navigation is performed, the main point of the aerial photograph taken by the camera is designated as the drawing center of the photograph map, and the optical axis of the camera is position-controlled perpendicularly to the average ground plane based on the detection result, and the predetermined point is given by the camera. An aerial photography method is obtained which is characterized by taking pictures in the course. In this case, it suffices to photograph from a distance according to the photographing scale, or an altitude of a distance that can effectively cover the image of the photographic map with one aerial photograph.

[0012]

As described above, the aircraft and the camera are controlled based on the three-dimensional geodetic coordinate space, and the principal point of the aerial photograph by the camera is designated as the drawing center of the photographic map and photographed. It is possible to match the principal points of the aerial photograph taken in the center of the picture of the photographic map partitioned by the convertible public survey coordinate mesh. Therefore, the need for a mosaic process in creating a photo map is eliminated, and the efficiency of creating a photo map can be improved. In addition to this, it is possible to eliminate unevenness in the density of the photo image due to the mosaic and the discrepancy due to the pasting, and it is possible to create a high-quality photo map.

On the other hand, as described above, by taking the image center of the image of the photographic map as the principal point of the image and photographing in the direction perpendicular to the plane representing the ground surface in the image, distortion due to the central projection does not occur. Therefore, the process of correcting partial distortion in creating a photo map is not required. By omitting the partial distortion process, work efficiency can be improved and production efficiency can be improved. Further, it is possible to prevent the effective shooting area from being reduced due to the inclination of the camera axis.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a navigation system mounted on an aircraft and a camera for taking aerial photographs (aerial camera).
It shows a control system. In the figure, at least one servomotor is attached to the mount of the camera 1 and the like, whereby the posture can be adjusted based on the three-dimensional geodetic coordinate system, and its optical axis can be controlled. Further, data regarding the direction of the optical axis of the camera 1 and the attitude of the camera 1 are sequentially input to the control device 3.

The GPS receiver 2 receives a signal from GPS via the antenna 21, and sequentially detects the three-dimensional position of the aircraft in real time by this signal. This position detection signal is sequentially input to the control device 3 including a microcomputer or the like.

The control device 3 has preset data relating to a photographing course, data relating to a photographic map partitioned by a public survey coordinate mesh in this photographing course, and the position of the camera 1 provided on the aircraft and its optical axis. Data about the direction and the like are stored and held.
The data on the photo map includes data on the inclination of the ground surface (average ground plane) on the photo map, data on the drawing center in the map drawing of the photo map, and the like.

These data are input to the control device 3 in advance or are sequentially input from an external device. Then, based on these data, the control device 3 displays on the monitor 4 for navigation the currently flying point, the course to fly, the altitude and the speed in real time on the screen.

In the navigation system and camera control system configured as described above, the pilot of the aircraft flies the photographing course at a predetermined altitude and speed based on the screen information displayed on the monitor 4. In this case, the optical axis of the camera 1 is controlled by the control signal from the control device 3 so that it is always perpendicular to the average ground surface. When the aircraft reaches the center of the drawing in the shooting course, the shutter of the camera 1 is pressed by the control signal from the control device 3. As a result, aerial photographs for each map drawing in the shooting course are continuously taken with the drawing center of each map drawing as its main point.

FIG. 2 shows the correspondence between the aerial photographs F1 to F3 continuously photographed as described above and the map drawings M1 to M3 of the photograph map M. The main point P of each aerial photograph F1 to F3 is shown. Corresponds to the drawing center of each map drawing M1 to M3.

FIG. 3 is a photograph drawing F4 of an aerial photograph and a map drawing M of a photograph map when the ground surface is inclined.
4 shows the correspondence with 4
A "and b" on the photographic drawing f9 having the lengths corresponding to a and b on the map drawing m corresponding to the two points A and B are obtained.

Further, Tables 1 and 2 show a comparison between the conventional method and the aerial photography method of the present invention. Here, Table 1 corresponds to the method of the present invention shown in FIG. 2 and the conventional method shown in FIG. 4, and Table 2 also shows the method of the present invention shown in FIG. 3 and the conventional method shown in FIG. It corresponds to the method of.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

As described above, according to the present invention, since a mosaic process is not required when creating a photographic map or the like from an aerial photograph, the efficiency of photographic map creation can be improved and the density of a photographic image by the mosaic can be improved. You can eliminate unevenness and discrepancies and create high quality photo maps. Also, by controlling the optical axis of the camera perpendicularly to the average ground plane,
Uneven correction is no longer necessary, so work efficiency can be improved,
Further, the production efficiency is increased and the reduction of the effective shooting area is prevented.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a navigation system and a camera control system system according to the present invention.

FIG. 2 is an explanatory diagram showing the correspondence between aerial photographs and photograph maps taken by the method of the present invention.

3 (a) and 3 (b) are explanatory views showing the correspondence between aerial photographs taken by the method of the present invention and photograph maps.

FIG. 4 is an explanatory diagram showing a correspondence between an aerial photograph taken by a conventional method and a photograph map.

5A and 5B are explanatory views showing the correspondence between aerial photographs and photograph maps taken by a conventional method.

[Explanation of symbols]

 1 camera 2 GPS receiver 3 controller 4 monitor

Claims (2)

[Claims] 1. The position and orientation of an aircraft and a camera for aerial photography mounted on the aircraft are detected based on three-dimensional geodetic coordinates, and the aircraft is navigated based on the detection result. An aerial photography method, characterized in that a main point of the aerial photography is designated as a center of a drawing on a photographic map, and the photograph is taken in a predetermined course by the camera. 2. The position and orientation of an aircraft and a camera for aerial photography mounted on the aircraft are detected based on three-dimensional geodetic coordinates, the aircraft is navigated based on the detection result, and the airborne by the camera is detected. The main point of the photograph is designated as the drawing center of the photograph map, and the optical axis of the camera is position-controlled perpendicularly to the average ground plane based on the detection result, so that the camera can photograph in a predetermined course. A unique aerial photography method.