JPH04164275A - Optical tracker for remote position - Google Patents

Abstract

PURPOSE:To enable a remote object position to be easily observed even at a small-scale earth station on a real time basis by using a telescope on the earth for catching an optical signal emitted from a remote observed object toward the earth, and computing the predetermined optical position of the object. CONSTITUTION:A beam 8 from a projector 2 on a lunar roving vehicle 1 is always directed toward the earth 5 via an earth tracking device 4. The beam 8 from the moon 13 and sunlight reflected on the lunar surface enter a telescope 3 on the earth 5. When a filter selector device 20 locates the hole 22 of a filter 21 in front of a detector 23, a normal image such as a crater is displayed on a monitor TV 25 and recorded, as the reflected sunlight and the beam 8 first enter the telescope 3. Thereafter, when the filter 21 is positioned within a light path, only the beam 8 is detected by the detector 23 in the range of one to four picture elements 1 to 4, and the picture element data is displayed with luminescent points on the monitor TV 25 via an image processing device 24. In this case, when the recorded normal image and the luminescent points are superposed with the device 24, the position of the lunar roving vehicle 1 is shown with the luminescent points within the displayed normal lunar surface image such as a crater.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention is a remote location system for observing the position of objects located far from the earth, such as lunar rovers and artificial satellites, on the earth. This relates to optical observation equipment.

=4- ``Prior art'' Location of objects that exist in hundreds of thousands of remote locations, such as vehicles moving on the lunar surface, facilities installed on the lunar surface, and artificial satellites in space. Conventionally, the method of observing in real time on Earth was to directly observe it using a telescope.

``Problem to be solved by the invention'' The theoretical resolution of a telescope, whether optical or radio, is determined by the aperture of the telescope and the wavelength of the light. In the visible light range,
The theoretical resolution of the largest telescopes currently installed on Earth is about 0.02 arc seconds, which is equivalent to about 40 meters on the moon's surface, which is 380,000 miles away. This is several tens of meters on the lunar surface.
It was not possible to identify the following objects, let alone determine whether they existed.

It is also possible to receive radio waves emitted from a lunar rover using multiple radio telescopes and determine the lunar rover's position using triangulation, but this method requires the use of a single station on a large scale. There were problems such as the need for equipment.

An object of the present invention is to obtain a device that can easily observe the position of a remote object in real time even with a small-scale ground station.

``Means for Solving the Problems'' The present invention provides a projector installed on a remote object to be observed that emits an optical signal toward the earth, an earth tracking device that directs the projector toward the earth, and an earth tracking device installed on the earth. It consists of a telescope, an image processing device that calculates and outputs a predetermined optical position based on optical signals captured by the telescope, and a display device that displays the obtained optical position.

``Operation'' For example, when trying to observe the current position of a lunar surface on the earth, a lunar surface projector and an earth tracking device are used to constantly emit light beams of a specific wavelength towards the earth.

The beam of light from the floodlight spreads 380,000 degrees ahead, and its diameter is approximately the same as the earth. The distance is set to OOOkm.

A telescope on Earth displays a normal image of a lunar surface within a range of several hundred meters to several hundred meters on a TV monitor. In addition, this telescope uses a switching device to insert a filter into the optical path to receive only light of a specific wavelength, thereby obtaining an image of only a bright spot. Then, when these images are superimposed, the position where the lunar surface type exists is displayed as a bright spot superimposed on the normal image, making it possible to see the position.

"Example" Embodiments of the present invention will be described below based on the drawings.

1 to 4 show a first embodiment of the present invention. Of these, Figures 1 and 2 show a lunar surface type (1) and a projector (2) as objects to be observed, and Figures 3 and 4 show a telescope on Earth (3).

Observed? The lunar type (1), which is a ltq object, is equipped with a floodlight (2), and this floodlight (2) is equipped with an earth tracking device (
4), it is controlled to always point towards the earth (5). As shown in FIG.
4, OX 1019 photon/5ee) laser or the like, and an optical system (9) that directs the generated light beam (8) toward the earth (5) with an appropriate spread. That is, this optical system (9) has a transmission hole (10
), and a secondary mirror (]2) facing the light generating section (7).

The spread O of the ray (8) is determined by these optical systems (9) as the distance from the moon (13) to the earth (5) (approximately 380,000 km)
) whose diameter is approximately the same as that of Earth (5) 12. OOOkm
It is set so that The diameter of the ray (8) is the diameter of the earth (
By making the diameter approximately the same as that of the earth tracking device (4), the configuration of the earth tracking device (4) can be simplified.

The telescope (3) has an aperture of, for example, 0.65 m and a synthetic F
The ratio is 10, and an optical system (18) consisting of a primary mirror (16) and a secondary mirror (17) having a transmission hole (15) is provided in the cylinder (14) as shown in FIG. and a fluctuation correction device (19) that corrects deterioration in resolution due to atmospheric fluctuations.
is provided. This fluctuation correction device (19) includes:
The so-called adaptive optics method corrects atmospheric inhomogeneity by integrating it along the path so that one point light source becomes a point image, and a microlens array is placed at the primary mirror image position, and the reference point light source is also a beam splitter. The so-called Shack-Hartmann method is known and is used as appropriate, in which the image is formed with a microlens array through the lens, and the difference between the image formation position of the object to be observed and the image formation position of the reference point light source is corrected by calculation. .

18= A filter (21) that is switched by a filter switching device (20) is interposed on the way to the focal point of the optical system (18) of the telescope (3). This is a filter that only passes a specific wavelength (800 nm in this example).
21) and a hole (22) which transmits all incident light to obtain a normal image. A detector (23) is provided at the focal point of the telescope (3). This detector (23) is made of, for example, CO■, has a size of 0 mm x 1.0 mm, and has a pixel count of 1°24.
Let it be X 1024. This detector (23) is coupled to a monitor TV (25) via an image processing device (24).

Next, the operation of the first embodiment configured as above will be explained.

Regardless of whether the lunar type (1) is moving on the lunar surface or not, the light beam (8) of the projector (2) is always directed toward the earth (5) by the earth tracking device (4). 8) is the secondary mirror (1
2) and the earth (5) reflected by the optical system (9) of the primary mirror (11).
) is being fired towards.

A telescope (3) on the earth (5) receives light rays (8) from the moon (13) and sunlight reflected on the moon's surface.

When the filter switching device (20) positions the hole (22) on the oil surface of the detector (23), both the sunlight reflected from the moon (13) and the light beam (8) are incident. , as shown in FIG. 5(b) on the monitor TV (25).
A normal image, such as a crater (26), is displayed. This normal image data is stored in memory.

Next, when the filter (21) is switched by the filter switching device (20) so that the filter (21) is located in the optical path, the detector (23)
Only the 800 nm light beam (8) is detected. Specifically, if the aperture of the telescope (3) is 0.65 m, the amount of light ray (8) that can be received by this telescope (3) is expressed by the following equation.

4, OX 10”9X (0,65/ (1,2X 1
07))2=] , 2 X 10'photon/se
eThe telescope (3) is equipped with a fluctuation correction device (19), which reduces the amount of light received by half (6X] O'ph
oton/5ec) is focused on a spora 1~ with a diameter determined by the theoretical resolution on the focal plane of the detector (23).

The wavelength of the telescope (3) with a diameter of 0.65m is 800n.
The theoretical resolution for the ray (8) of m is 0.3 arc seconds, and the combined focal length is 6.5 m, so the spot diameter on the focal plane is about 10 μm.

Since the size of one pixel of the detector (23) is 10 μm×10 μm according to the specific embodiment, the focused light beam (8) is detected by 1 to 4 pixels. The data of these pixels is sent to the monitor TV (
25), it is displayed as a bright spot (27) as shown in FIG. 5(a). Then, when the images in Figures 5(a) and (b) are superimposed using the image processing device (24), as shown in Figure 5(c), normal lunar surfaces such as craters (26) are shown. In the image, the position of the lunar rover (1) is displayed as a bright spot (27).

When a bright spot occupies multiple pixels, for example, when the bright spot (27) has 14 pixels as shown in FIG.
The brightest point, ie, the position of the optical center of gravity, is determined by an image processing device (24) and displayed on a monitor TV (25).

That is, the coordinates of each pixel are (X j, l Y ],
), the amount of charge is Ci, and the number of pixels is n, then the center of gravity position (X
.

Since Y) is calculated by
), and based on the data, a bright spot (27) representing the position of the lunar rover (1) is displayed on the monitor TV (25) as appropriate position information.

Next, a second embodiment of the present invention will be described based on FIGS. 7 to 12.

The projector (2) in this second embodiment includes a reflecting mirror (2a
) and a vibration device (2b). In addition, the earth tracking device (4) is further equipped with a sun tracking device (4a), which detects the positions of the sun and the earth (5).
Even if the lunar rover (1) moves, the reflected light beam (8) from the reflector (2a) is always directed toward the earth (5).

The spread of the reflected ray (8) is 380,000 - in the distance, the earth (
5) The diameter should be approximately 1.2,000 mm so as to surround the entire area. Further, the reflecting mirror (2a) is moved to a frequency f by a vibration device (2b). As shown in Figure 8, there is a case where the reflected light beam (8) irradiates the entire earth (5), and a case where the reflected beam (8) irradiates the entire earth (5).
5) When the frequency deviates from f. It is designed to be repeated.

The detector (23) at the rear stage of the telescope (3) on the earth (5) is installed at one of the focal positions via a semi-transparent mirror (28), as shown in Fig. 9, for normal image detection. CCD (23
a) and an image dissector tube (hereinafter referred to as IDT) (23b) for position detection provided on the other side. As shown in FIG. 10, this IDT (23b) consists of an image section (31) and a multiplication section (32), and is set so that its focal plane coincides with the photocathode (30). The x, y scanning output end of this I D T (23b) is coupled to the image processing device (24), and the I D T (2
The output end of 3b) is coupled to an image processing bag Ft (24) via a spectrum analyzer (33), and further coupled to a monitor TV (25).

The operation of the second embodiment of the present invention configured as above will be explained.

Reflected sunlight (8) is emitted toward the earth (5) by the reflector (2a) of the projector (2) of the lunar rover (1).

The intensity of sunlight with a wavelength of 400 nm to 700 nm in Earth orbit is approximately 500 V/m, so a reflector (2a
) is 50 countries, and the angle between the perpendicular to the mirror surface and the sunlight is 4
5 degrees, approximately 70 degrees of reflected rays (8) are obtained.

This reflected light beam (8) is moved to a frequency f by a vibration device (2b). The intensity of the reflected ray (8), which is vibrated at and detected by the telescope (3) on the earth (5), is also at the frequency f. Modulated by

In the optical system (1B) of the telescope (3), the incident light from the moon (13) reflected by the semi-transparent mirror (28) is detected by the CCD (23a) and transmitted through the image processing device (24) as shown in Fig. 5(b).
A normal image like this will be obtained. When the incident light that has passed through the semi-transparent mirror (28) forms an image on the photocathode (30) in the image section (31) of IDT (23b),
Photoelectrons are emitted from here, and an electron image is focused on the aperture plate (34a)l by an electron lens. From the aperture (34) of the aperture plate (34a), only the electrons in a minute area of the electron image are taken into the multiplier (32) and multiplied, and the dynote (35) and anode (34)
6), the signal is multiplied and extracted. Here, the image part (
The electron image at 31) is moved on the aperture plate (34a) by the deflection coil (37) as shown in FIG. 11, and the area on the photocathode (30) where photoelectrons can pass through the aperture (34) is X, Y-scanned. This I
The output signal from DT (23b) is sent to a spec1-ram analyzer (33), where it determines the modulation frequency f of the light beam (8) emitted from the projector (2) of the lunar rover (1). The intensity of the component is measured. In other words, this floodlight (2)
1 frequency f at the condensing position of the light emitted from. The intensity of the component becomes maximum. The image processing device (24) has a focal plane of 2
Compare the intensity of the frequency fo component at each point obtained by scanning dimensionally, and output the point giving the maximum value as the position of the lunar rover (1), and display it on the monitor TV (25). Figure 5 (
A bright spot (27) as shown in a) is displayed. These Figure 5 (
When images a) and (b) are superimposed, the position of the lunar rover (1) is displayed as a bright spot (27) on a normal image like (c).

FIG. 12 shows I D T as a position detector (23).
An example is shown in which the brightest point (center of gravity W) is determined using a semiconductor device detection element (hereinafter referred to as PSD) (23c) instead of (23b). In this figure, P S D
(23c)-15= Four electrodes (X, ) (x2) (y□) (Y2) are provided, and when a bright spot (27) modulated at frequency f is imaged, A photocurrent is generated from the imaging position, and each electrode (X
, ) (X2) (Y) Output to (Y2). These outputs are respectively connected to preamplifiers (38a) (38b) (3
8c) (38d) and is amplified at the center frequency f. band pass filter (39a) (39b) (39c)
(39d), the amplitudes are Axl and IAx 2, respectively.
．． A y 1. The output is A y . These data are sent to the image processing device (24), where calculations are performed to obtain the center of gravity position (x, y), and defocusing etc. are corrected. In addition, in the formula 1, L is PSD (23
c).

FIG. 13 shows a third embodiment of the present invention, in which a solar tracking device (4a) is provided with a sunlight concentrator (41) consisting of an optical system (40) such as a parabolic mirror and a Fresnel lens. Similarly, the earth tracking device (4) is also provided with a floodlight (2) consisting of an optical system (9) such as a parabolic mirror and a Fresnel lens. The opening of the sunlight concentrator (41) and the floodlight (2) is transmitted through the bundle fiber (42), and a rotating disk (43) is connected to the output of the bundle fiber (42).
Chopper device (45) with holes (44) drilled at regular intervals
The intensity of the light is modulated by interposing the light. In this case, a telescope (3) or a detector (2) on Earth is used.
The structure and operation of 3) etc. are the same as in the second embodiment.

In the embodiment described above, the case where the lunar rover (1) is used as the object to be observed is explained, but the object is not limited to this, and the object can be used as it is even if it is a probe for another star, an artificial satellite, or the like.

In the first embodiment, the wavelength band of the light emitted from the projector (2) was assumed to have a peak only at one specific frequency, but in order to determine a more reliable observation position, It emits light with peaks in multiple wavelength bands such as f□, f2, f3, etc.
) is equipped with a device N that detects light in a wavelength band equal to the wavelength band of the light from the light projector (2), and compares multiple images obtained for each wavelength band to find the most reliable observed object. Get the position of an object. In Figures 14 and 15, a telescope (3) is equipped with a plurality of filters (46a), (46b), and (46c), and these filters (46a), (46b, and 46c) are sequentially switched by a switching device to select each wavelength. An image is captured by a detector (23) for each band, and an image processing device (24) compares these plurality of bright spots to determine the position of the observed object.

Of these, FIG. 14 shows each filter (46a) (46
b) Shift the data corresponding to f, F2, and F3 in (46c) to shift registers (47a) (47b) (47c)
These data are stored in memory using image processing bag W (24), and a two-dimensional correlation is calculated between all the images.
This is a method of finding the pixel that gives the maximum value.

FIG. 15 shows a comparator (49) that compares the images f1, F2, and F3 of each wavelength band with the light intensity thresholds set as F□, F2, and F3 by the threshold value setter (48) for each wavelength band. ) and compare
A binarization process is performed in which only pixels whose brightness exceeds a threshold value are set to 1, and the outputs of all binarized images are ANDed by an AND circuit (50). In this way, the output will be output only when all are 1, resulting in more reliable data.

FIG. 16 shows that the IDT (23b) two-dimensionally scans a minute area on the focal plane of the telescope (3), and out of the light intensity of the minute area, the light emitted from the projector (2) is The intensity of the frequency component equal to each modulation frequency is measured with a spectrum analyzer (33), and these are memorized in each shift register (47a) (47b) (47c), and the focal point where these intensities are maximum is measured. The position of the observed object corresponding to the position on the surface is output as the position of the observed object (1) equipped with the projector (2), and the position is determined for each wavelength band of the light emitted by the projector (2). This is a method in which the positions of the observed object (1) are compared to determine the most probable position.

Next, the lunar rover (1) and the earth (5) as objects to be observed.
If two-way communication devices are installed on each of them, it will be possible to control the lunar rover (1) while checking its position from Earth. In this communication device, the moon surface (]:l
) to the earth (5), the signal is superimposed on the intensity of the light emitted from the projector (2), and the communication from the earth (5) , , I::
The telescope (3) may be used to receive the signal. moreover,
A TV camera is mounted on the lunar rover (1), and a video signal is superimposed on the intensity of the light emitted from the floodlight (2).
5), the T of the lunar rover (1) on Earth (5)
It is possible to control the lunar rover while observing images captured by the V-camera.

``Effects of the invention'' (1) The position of small objects to be observed can be observed with a telescope on the earth whose resolution is not high.

(2) Telescopes and other facilities on Earth can be small-scale.

(3) If the optical center of gravity position can be calculated using an image processing device, a more accurate position can be displayed even if the bright spot is large due to defocusing of the telescope or other causes.

(4) Not only one type of light is emitted from the floodlight, but also
By using a plurality of types, bright spots due to noise or the like can be eliminated and more accurate positions can be determined.

[Brief explanation of drawings]

Figures 1 to 4 show the first embodiment of the present invention. Figures 1 to 4 are illustrations of the lunar rover, Figure 2 is a sectional view of the floodlight, and Figure 3 is an illustration of the telescope on the ground. Figure 4 is an explanatory diagram of the equipment on the ground, Figures 5 (a), (b), and (c) are explanatory diagrams of a bright spot image, a normal image, and their superimposed images, respectively, and Figure 6 is an explanatory diagram of the CCD. Explanatory diagrams of bright spots, Figures 7 to H
The figures show a second embodiment of the present invention; FIG. 7 is an explanatory diagram of the projector, FIG. 8 is an explanatory diagram of the vibration of synchrotron radiation, FIG. 9 is an explanatory diagram of the equipment on the ground, and FIG. Diagram of IDT, Part 1
The figure is an explanatory diagram of X and Y scanning, Fig. 12 is an explanatory diagram of detection by PSD, Fig. 13 is an explanatory diagram of the third embodiment of the present invention, and Figs. FIG. 3 is a block diagram showing still another embodiment of the invention. (1) Object to be observed (lunar rover), (2) Floodlight, (3) Telescope, (4) Earth tracking device, (5
)...Earth, (8) Rays of light, (9)...Optical system, (13
)...moon, (18)...optical system, (19)...
Fluctuation correction device, (21)...filter, (23)...
Detector, (23a) -CCD, (23b) -ID
T, (23c)-PSD, (24)...Image processing device, (25)...Monitor TV, (26)・Crater-1 (27)...Bright spot, (28)...・Semi-transparent mirror, (
30)...Photocathode, (33)...Spectrum analyzer, (42)...Bundle fiber. ■---------"

Claims (15)

[Claims] (1) A floodlight installed on a remote object to be observed and emits an optical signal toward the earth, an earth tracking device that directs this floodlight toward the earth, a telescope installed on the earth, and an optical signal captured by this telescope. 1. A remote optical observation device comprising: an image processing device that calculates and outputs a predetermined optical position based on an optical signal; and a display device that displays the obtained optical position. (2) Claim (2) wherein the image processing device displays the bright spot on the focal plane of the telescope by calculating the position of the optical center of gravity.
1) The remotely located optical observation device described above. (3) The remote location according to claim (1), wherein the bright spot representing the position of the observed object determined by the image processing device and the background image obtained by the telescope are superimposed and displayed on the display device. Optical observation device. (4) The intensity of the light emitted from the projector is modulated at a predetermined frequency, a minute area on the image dissector installed at the focal plane of the telescope is two-dimensionally scanned, and the light intensity of the minute area is , the remote control according to claim 1, wherein the intensity of a frequency component equal to the modulation frequency is measured by a spectrum analyzer, and the position on the focal plane where the intensity is maximum is displayed as the position of the observed object. Optical observation device of position. (5) The projector emits light of a predetermined wavelength, and has a filter in the optical path of the telescope that allows only the light emitted by the projector to pass through, and a switching device for switching between a state in which the filter is not present, and the light from the projector is 2. The remote optical observation device according to claim 1, wherein a bright spot passed through a filter and a normal image are obtained. (6) The floodlight and earth tracking device consist of a reflector that reflects sunlight and a device that detects the positions of the sun and the earth and directs the reflected light toward the earth regardless of whether the observed object is moving or not. A remotely located optical observation device according to claim (1). (7) Modulating the intensity of the reflected light at a predetermined frequency by slightly vibrating the reflecting mirror, two-dimensionally scanning a minute area on an image dissector installed at the focal plane of the telescope;
Of the light intensity in the minute area, the intensity of the frequency component equal to the modulation frequency is measured using a spectrum analyzer, and the position on the focal plane where the intensity is maximum is displayed as the position of the observed object. A remotely located optical observation device according to claim (1). (8) Floodlights and earth tracking devices detect the position of the sun, track the sun, always collect sunlight regardless of whether the observed object is moving, and always project the focused sunlight toward the earth. A remote optical observation device according to claim 1, comprising a device that emits light. (9) The projector emits light in a plurality of wavelength bands, and the telescope is equipped with a plurality of filters that pass the light in the respective wavelength bands from the projector, a switching device that sequentially switches these filters, and an image processing device. 2. The remote optical observation device according to claim 1, wherein the optical observation device compares a plurality of images obtained for each wavelength band and outputs the position of the observed object. (10) Comparison of images obtained for each wavelength band by the image processing device is performed by binarizing the pixels whose brightness exceeds the light intensity threshold set for each wavelength band as 1. 11. The remote optical observation device according to claim 10, wherein a logical product is performed between the binarized images. (11) Comparison of images obtained for each wavelength band by the image processing device is performed by calculating a two-dimensional correlation among all the images, and determining the pixel that gives the maximum value (
10) The remotely located optical observation device described above. (12) The intensity of the light emitted from the projector is modulated at multiple frequencies, two-dimensionally scans a minute area on the image dissector installed at the focal plane of the telescope, and the light intensity of the minute area is , measure the intensity of the frequency component equal to each modulation frequency using a spectrum analyzer, find the position on the focal plane where the intensity is maximum for each modulation frequency, and compare these positions to find the most likely target. 10. A remote optical observation device according to claim 9, wherein the remote position optical observation device is configured to determine the position of an observation object. (13) The object to be observed is equipped with a two-way communication device with the earth, and the object to be observed can be controlled while confirming the position of the object on the earth. Remotely located optical observation device. (14) Of the communications between the earth and the earth using communication devices, communication from the observed object to the earth is carried out by superimposing a signal on the intensity of the light emitted from the projector and receiving it with a telescope on earth. The remote optical observation device according to claim (15). (15) A TV camera is mounted on the object to be observed, and the video signal is superimposed on the intensity of light emitted from the projector and transmitted to the earth. Claim (13) capable of controlling objects
The remotely located optical observation device described.