JPS58223079A - Measurement collation system for remote object - Google Patents

Abstract

PURPOSE:To achieve an effective and highly reliable decision on the bearing of a known object by a method wherein a possible observation angle of many different objects is made known while the locus of a running time of many different objects has been assumed to be estimated with a correlator. CONSTITUTION:An extremely short optical pulse (laser) is transmitted to an object like an aircraft through a control unit 12 from a pulse light source 2. The mark of a running time reflected from the object is detected from a circular scan locus tube 11 through a beam splitter 4. Deflection systems X1...Y2 of the track tube 11 operates permanently by a signal from a time base generator 3 in such a manner that an electron beam 6 radiated from an optical cathode 5 moves on circumference in the output of the track tube 11 with an incident light signal. An LED 13 driven by a signal from a circular light detector 9 irradiates a CCD register 15. Then, this light charge is shifted per 1 pixel.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method in which an image, a spacecraft, or an object having an image size smaller than the smallest pixel that can be represented, for example, is radiated by an electromagnetic impulse, preferably a light pulse. , relates to a measurement matching scheme located at a remote location, such that the reflected impulses are received and evaluated by a radiation detector.

Equipped with an object measurement system known as dating,
Imaging system is used. An image of the observed object is outlined by an optical system on the detector array or membrane, and this image is evaluated during object matching. The resolution is limited by the quality of the optical system, the effects of refraction, the pixel size of the film, or the grain boundary size, and in the case of imaging systems objects smaller than the resolution of the optical system can no longer be detected. An object of the present invention is to provide a method that can verify such a small object and perform measurement verification despite the above.

This task is solved by irradiating the object with a very simple radiation impulse, and the een pulses reflected from the surface of different parts of the object at different times are used to calculate the measured travel time root ball and the stored travel time. By affecting the correlation for object matching with the root ball, and by affecting the object measurement by the travel time difference,
The transit times of the individual impulses shifted relative to each other as a function of time are determined as a function of the transit time difference by the geometry of the object as a root ball (travel time spectrum).

A device for obtaining a transit time root ball by the method according to claim 1 is provided in which the reflected travel time root ball is detected by a circular scanning trajectory tube, and the reflected travel time root ball emits light from a photocathode. of the trajectory tube in such a way that the electron beam moves around the circumference at the output of the trajectory tube, an amplifier amplifies the electron beam, and the resulting light flash is coupled via an optical fiber to a circular photodetector array. The deflection system is characterized in that it operates permanently using the signal from the time base generator.

Further devices for influencing the correlation according to the method according to claim 1 are described in claim 2.

The present method and the associated devices envisaged have a very wide range of applications and a wide variety of applications.

The essential advantage of the invention lies in this fact and in the ability to match images of objects that cannot be deciphered beforehand. Thus, the transit time roots of representative geometries of unknown objects, such as satellites, can be recorded on Earth in this way. (These geometries cannot be deciphered by conventional imaging optics.) By comparing these roots of various unknown satellites, it is possible to distinguish between satellites by classifying them by the same morphology.

Apart from such classification of unknown objects, unknown objects can also be measured. This is influenced by recording multiple travel time roots of one object observed from different directions, which allows conclusions to be drawn regarding the geometry of the object.

The possible viewing angles of a number of different objects are known;
The objects can be conveniently determined by assuming that the transit time roots of many different objects are predefined by the correlator. The system then determines which object is being observed at that moment.

Orientation of known objects can also be determined effectively and reliably. When providing the travel time root ball for various observation directions of a known object to the correlator, this system allows the observation angle to be determined by the measured travel time root ball sag, and it is possible to determine the observation angle with respect to the object relative to the observer. The position can be determined.

Finally, regarding the possibility of Rusk scanning object search method,
There are many possible advantages for the application, which must be considered in considerable detail.

If you have to scan a defined frame for one or several different objects,
The frame can be scanned point by point with a laser beam to cover the relevant area. Thereby, a travel time root ball is generated for each frame, which is compared in a correlator with the recorded travel time root ball of the object being observed.

This rootball method has the great advantage of being able to record the rootball of an object at a distance ranging from a few centimeters to several hundredths of a kilometer. This method works as long as only a few (approximately a few hundred photons) reflected by the object can be received.

The principle on which the invention is based is illustrated in FIGS. 1(a) and 1(b). The object to be verified or measured, for example the aircraft lO represented in FIG. 2, is illuminated by a very simple impulse l via the beam splitter 4. Depending on the position of the partial surfaces of the aircraft IO that are reflecting the light pulse l, e.g. A light pulse is incident at a certain time. Consequently, depending on the geometry of the aircraft IO, transit time differences occur between pulses reflected from any partial surface of the aircraft IO. The total reflected light pulse is obtained by superposition of the individual pulses, shifted with respect to each other as a function of time, so that the transit time root ball depends only on the geometry, the angle of observation, and the degree of reflection of the object. arises depending on This travel time root ball does not depend on the distance of the object. The mutual distance ΔS of the individual reflecting partial surfaces is determined by the transit time difference T between the impulses of these partial surfaces.
It is easily determined from Here, Δ5=(c ・ΔT
) i/2 C: The length l of the light-speed aircraft lO is approximately 12-
It is given by (c - Tll1ax )/2 and -.

The resolution of the system is determined by the pulse length and the resolution of the hour hand that records the transit time root ball. Hour hands with a time resolution of up to 2 ps can be used in this application, corresponding to an internal depth resolution of 0.3 mm. number p
Laser pulses with pulse lengths varying from s to several hundred ps can be obtained, which has an inner depth resolution of m
This means that values up to several centimeters from m are possible.

The object verification device is illustrated in the block diagram in FIG. 2 as well as in FIG.

Extremely short optical pulses, such as 10 to 100 ps, can be controlled from a pulsed optical meter such as a laser (Uniso).
12 in the direction of the object to be irradiated, such as the aircraft 1o. The traveling time root ball reflected by the object is detected by a circular scanning trajectory tube (circular scanning streak tube) 11 via a beam splinter 4 . FIG. 4 is a diagram illustrating a design example of the circular scanning trajectory tube 11. trajectory tube 110
) Deflection system x1...Y2 is configured to deflect the signal from the time-height generator 3 in such a way that the electron beam 6 emitted from the photocathode 5 moves on the circumference at the output of the trajectory tube 11 due to the incident optical signal. works permanently. An amplifier 7 of the trajectory tube 11 amplifies the electron beam 6 before it impinges on the phosphor screen at the output of the trajectory tube 11 . The amplification is such that individual photons can be decoded. The resulting light flash is coupled by an optical fiber system 8 to a circular photodetector array 9, whereby the native photoelectrons are deposited therein in the cells of the photodetector array 9 and contribute to the reception of the entire echo. It is then read out. To create a complete transit time root ball of the object, the following equation must be applied to the time loft for a complete rotation of the electron beam on the output display of the trajectory tube.

Trot = (2* jri /
c where: p: length of the object in the direction of the incident beam C: speed of light The travel time plate' trace recorded by the object is shown in Figure 1(b)
can be read out with the aid of a photodetector array 9 as shown in FIG.

In order to match the objects, a correlation is required between the measured travel time root strength and the stored travel time root strength compared with said root ball; for example, this correlation can be They represent different objects.

These long running times were confirmed by Kay Promberg et al.
, 5PIE, Vol. 180, pp. 107-113, published in 1979. One method that can perform non-coherent optical correlation of two two-dimensional images with each other is presented in the said article. This method is based on the following principle. A gray level filter mask is placed in front of a photodetector array with mak pixels. The detector array is illuminated non-coherently by LEDs.

A yask contains a gray level pattern representing one of the two images to be correlated. The other image is serially scanned pixel by pixel and the gray level of the pixel is converted to the appropriate brightness value of the LED. As the LED transitions from one pixel value to the next, C
The photocharges previously stored in the OD register are shifted upward one pixel at a time in the -dimension or two dimensions. After scanning the entire image, the correlation function is obtained at the output of the COD register.

If we adopt the following one-dimensional parallel method, we can find the correlation between transit times.

One-dimensional correlation system between functions g(x') and h(x') (
x) is found by solving the following known integral:

k (x), = f′″″g (x+x') h
(x) d x 'If the functions g and h are not continuous and are defined by n pixels, then a correlation function is applied to the following equation.

k(x')=Σg (x+i)h (i) A one-dimensional correlation system similar to Promberg's two-dimensional system is shown in FIG. 5, but please also refer to FIG. 3.

Function h (B determines the brightness of LED13,
irradiates the CCD register 15 having m pixels through a mask 14g(x). The photocharges in the CCD register 15 shift position by position as the function h(t) changes from one pixel to the next. After m shift operations, the correlation function is obtained at CCD1'5. The configuration is given in FIG. 6, whereby the linear CCD registers 15 are arranged one after the other in parallel.

A different mask with the function gi (x) (1≦i≦n) is placed in front of each of these COD registers.

All n CCD registers 15 have a function h (t)
Accordingly, the light is irradiated simultaneously by the LBD 13, so that, for example, n different functions gi(x) and h(t) can be obtained simultaneously. Using a COD configuration with 100OX1000 pixels, 1000 different correlations can be taken in a period of approximately 80 μs, e.g.
The received root ball is compared with 1000 different root balls within this period.

[Brief explanation of the drawing]

FIG. 1(a) shows the time spectrum of the emitted light pulse. FIG. 1(b) is a time spectrum of a received optical pulse reflected by a conventional aircraft. FIG. 2 shows the basic configuration of a device for object detection. FIG. 3 is a related block diagram. FIG. 4 shows an example of the structure of a circular scanning trajectory tube. FIG. 5 is an example of one-dimensional correlation. FIG. 6 is an example of an n-time parallel, -dimensional correlation system. l... Impulse 2... Pulse light source 3
... Time base generator 4 ... Beam splitter ... Photocathode 6 ... Electron beam 7.
...Amplifier 8...Optical fiber system 9.
...Photodetector array 10...Aircraft II...
・Root tube (streak tube) 12...Control unit 13...LED' 14...Mask 15...CCD register

Claims (1)

Claims: +11 There is a remote object, e.g. a spacecraft or an object with an image size smaller than the smallest pixel that can be represented, whereby said object receives an electromagnetic impulse, Preferably said □impulses illuminated by light and reflected are received and evaluated by a radiation detection device, such that the impulses reflected from different parts of the surface of said object at different times are compared with each other as a function of time. The transit time spectrum (travel time spectrum) of each shifted impulse is determined as a function of the transit time difference (Tmax) caused by the geometry of the object, and for the detection of the object, the measured An object in a remote location, characterized in that the object is measured based on the time difference (TmaX), and the object is measured based on the time difference (Tma measurement verification method. (2) The system as set forth in claim 1, comprising a device for obtaining a travel time plate trace, wherein the reflected travel time plate trace is detected by a circular scanning trajectory tube,
An electron beam emitted from the photocathode due to the reflected transit time plate moves on the circumference by the output of the trajectory tube, an amplifier amplifies the electron beam, and the resulting light flash is transmitted to the photocathode through an optical fiber. characterized in that the deflection system (Xl, . . . Y2) of said trajectory tube is configured to operate permanently with a signal from a time base generator in such a way that it is coupled to a circular photodetector array. A measurement verification method for objects in remote locations. (3) The method described in claim 1,
The device for correlation contains a mask with the gray level pattern of the spectrum to be correlated, whereby the other spectra are scanned in series from pixel to pixel using a COD register to obtain various linear CODs.
The D-registers are arranged parallel to each other and are irradiated simultaneously, so that different masks are applied to each CC.
A remote object measurement verification method characterized by a configured Q-taco as obtained for different root balls in front of the D-distor. (4) A system according to claims 1 to 3, wherein the device is configured such that the pulsed radiation source is
Tmax), the trajectory tube generates different individual transit times of each time interval Tmax, such that the spectral range (multispectral transit time root ball) is recorded differently. The travel time root ball generated by combining the root balls is recorded, and the multispectral travel time root ball is configured to be correlated to the same multispectral reference root ball when the root ball is combined. Measurement verification method for objects in remote locations.