JP3487295B2 - Image target detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image target detecting device for detecting and determining a target from an image signal.

[0002]

2. Description of the Related Art FIG. 27 is a diagram showing a conventional image target detecting apparatus. In FIG. 27, 1 is an infrared imaging unit, 3 is a target determination unit, and 16 is a threshold value calculation unit.

Next, the operation of FIG. 27 will be described. The infrared imaging unit 1 outputs infrared rays from the outside world as an infrared image signal. The threshold calculator 16 calculates a threshold t from the input image signal. As an example of the threshold value calculation method, "Equation 1" is used. The target determination unit 3 binarizes the image signal using the threshold value calculated by the threshold value calculation unit 16, and determines a significant target from this. As an example, a case where the infrared imaging unit 1 is sensitive to far infrared rays and a case where the infrared imaging unit 1 is sensitive to mid infrared rays will be described below. 28 and 2
Reference numeral 9 is an example of a far-infrared ray image signal and a mid-infrared ray image signal and a binary image when the same background is imaged. As shown in FIG. 28, when far infrared rays are used, only the target signal is binarized and determined as the target. On the other hand, when mid-infrared rays are used as shown in FIG. 29, the target signal and the cloud signal (clutter) other than the target are binarized and determined as the target. Thus, in a system using only mid-infrared rays, if there is a high-intensity object other than the target, such as a cloud that reflects sunlight, the probability of erroneously detecting a signal component other than these targets as the target (hereinafter, false alarm There is a problem that the probability is high).

[0004]

[Equation 1]

FIG. 30 shows an example of transmittances in the summer and winter in the range of 1 to 15 [μm]. As shown in this figure, the mid-infrared ray has a stable transmittance throughout the year, but the far-infrared ray has a significantly lower transmittance in the summer than in the winter. As an example, with a slant path with an altitude of 60 [m] in the mid-latitude region of LOWTRAN,
In the mid-infrared region, summer transmittance can be secured at 75% in winter, while in the far-infrared region, summer transmittance can be secured at only 40% in winter. This is because far infrared rays have a large absorption due to the molecular weight of water. Therefore, the system using far infrared rays has a problem that it is more difficult to secure the performance in summer or in the sea where the water molecular weight is large compared with the system using mid infrared rays.

The conventional image target detecting apparatus as described above has the following problems. That is, for example, when performing target determination using only image signals in the mid-infrared region,
If there is a high-intensity object other than the target, such as a cloud that reflects sunlight,
There was a problem that the false alarm probability increased. Further, for example, when the target determination is performed using only the image signal in the far infrared region, there is a problem that it is difficult to secure the performance in the summer when the amount of water molecules is large or in the sea.

In order to solve the above problems, Japanese Patent Laid-Open No. 61-769
2 of the 3-5 μm band and the 8-12 μm band shown in Japanese Patent Publication No. 70
An infrared detection device has been invented that uses one infrared wavelength band and enables target detection regardless of the season place day or night. A block diagram of the present invention is shown in FIG. In FIG. 31, 5 is an optical system, 9 is an amplifier section, 32 is a light detecting element, 33 is a scan converting means, 34 is a target detecting means, 35 is a level comparing means, 3
6 is a determination means.

The operation of FIG. 31 will be described. Optical system 5
Infrared that has passed through the infrared ray has a different sensitivity wavelength
It is incident on a and 32b. The output signals of the respective photo-sensing elements are amplified by the amplifier section 9, scan-converted by the scan conversion means 33 and converted into serial video signals for output. Upon receiving one output of the conversion unit 33, the target detection unit 34 detects the target. The level comparing means 35 measures the level of each serial video signal and compares how high or low the level of one is with respect to the other.
Specifically, the signal intensity in the 3-5 μm band is divided by the signal intensity in the 8-12 μm band. The determination means 36 is the target detection means 3
The detection signal from 4 is received, and it is judged whether or not it is a target based on the division value of the level comparison means 35. That is, if the division value in the target signal portion is less than or equal to the reference value, it is determined as the target. This will be described with reference to FIGS. 28 and 29. When the target is cloud clutter, it is observed in the 3-5 μm band but not in the 8-12 μm band, and the division value becomes a very large value. However, when the target is an aircraft, the division value falls within a certain value because it is observed in both wavelength bands. However, when the target is flying at a speed sufficiently higher than the cruising speed, the use of afterburners (A / B), missile launch, etc.
If the signal intensity in the m band is high compared to the signal intensity in the 8 to 12 μm band, the system removes the target as a clutter. In addition, in summer or in the sea where the molecular weight of water is high, the target which is not observed in the 8 to 12 μm band but is observed only in the 3 to 5 μm band is also removed.

[0009]

The conventional image target detecting device as described above has the following problems. Generally, when the detection target is an aircraft, the degree of threat is high when the enemy approaches rapidly by using A / B or launches an anti-aircraft missile. Therefore, it is desirable to effectively guard against such aircraft trends. However, with the device shown in FIG. 31, not only this determination is possible, but also targets with high threat levels are removed as clutter. Therefore, for this vigilance, it is a pilot not to visually check the target brightness change of the infrared image signal, or to take an evasive action by assuming a missile launch when being tracked by an enemy radar, and be wary of launching an anti-aircraft missile. It was a heavy burden for me.

The present invention has been made to solve the above problems, and an object of the present invention is to provide means for monitoring a target trend.

[0011]

An image target detecting apparatus according to the present invention comprises a RAM for storing maximum brightness, average brightness, area, etc. of a tracking target for a plurality of frames, and an average brightness per minute time of the RAM. The product of the area or the rise time measuring unit that measures the time from when the increase rate of the maximum brightness or the like becomes equal to or greater than the threshold value until the value becomes maximum, and the target trend is determined by the output of the rise time measuring unit. It is composed of a discriminating section for judging.

The image target detecting apparatus of the present invention comprises a RAM for storing the maximum brightness, the average brightness, the area, etc. of the tracking target for a plurality of frames, and the product of the average brightness and the area per minute time of the RAM, or the maximum value. A maximum value maintenance time measuring unit that measures the time when the rate of increase in brightness or the like exceeds a threshold value and then becomes the maximum value, and an identification unit that determines a target trend by the output of the maximum value maintenance time measuring unit. It is composed of and.

Further, the image target detecting apparatus of the present invention has a RAM for storing the maximum brightness, the average brightness, the area, etc. of the tracking target for a plurality of frames, and the product of the average brightness and the area per minute time of the RAM. , A time measuring unit from the maximum value to the steady value, which measures the time from the time when the increase rate of the maximum brightness exceeds the threshold to the maximum and reaches the steady state, and the steady value from the maximum value It is composed of an identification unit that judges the trend of the target based on the output of the time measurement unit until it becomes.

The image target detecting apparatus of the present invention is a RAM for storing the maximum brightness, average brightness, area, etc. of the tracking target for a plurality of frames, and the product of the average brightness and area per minute time of the RAM, or the maximum brightness. The ratio measurement unit that measures the ratio of the value when the increase rate of the maximum value exceeds the threshold value and the maximum value after that, and the target trend by the output of the ratio measurement unit. It is composed of a discriminating section for judging.

Further, the image target detecting apparatus of the present invention has a RAM for storing the maximum brightness, the average brightness, the area, etc. of the tracking target for a plurality of frames, and the product of the average brightness and the area per minute time of the RAM, or , The half-width measuring unit that measures the half-width of the waveform when the increase rate of the maximum brightness becomes equal to or greater than the threshold and reaches the maximum, and then the steady state is reached. It is composed of an identification unit for judging trends.

The image target detecting device of the present invention is an infrared region.
A calculating unit that calculates the ratio of the maximum brightness or the average brightness of the tracking target of a plurality of image signals with different detection wavelengths in the range, A / B use of the aviation target from the output of the calculating unit, and missile launch
And an identification section for identifying

The image target detecting apparatus according to the present invention is provided with a comprehensive discriminating unit which receives the outputs of the discriminating unit and weights the respective outputs so as to comprehensively judge the trend of the target.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. FIG. 1 is a block diagram showing an embodiment of the present invention. Reference numeral 1 is an infrared imaging unit, 2 is a brightness normalization unit, 3 is a target determination unit, and 4 is a spectral brightness data unit.

In the embodiment shown in FIG. 1, the image signal output from the infrared image pickup unit 1 which outputs infrared image signals a and b in a plurality of different wavelength bands for the same target is transmitted to a plurality of brightness normalization units 2. It is input and the brightness is normalized.
The plurality of normalized image signals are input to the target determination unit 3. The spectral brightness data unit 4 holds data of various objects (target and non-target clutter, etc.) as an area of a multi-dimensional brightness coordinate system having orthogonal brightness axes of the normalized brightness signals for each of the different wavelength bands. is doing. The target determination unit 3 compares the plurality of normalized image signals with the output of the spectral luminance data unit 4 and determines a significant target based on whether it is included in the target region.

The operation will be described below. Image signals in a plurality of different wavelength bands need to be normalized in order to match the luminance scale of the spectral luminance data section 4 stored in advance. Here, the reference value fin (α,
The brightness normalization unit 2 uses β) to perform normalization by the operation of “Equation 2”.

[0021]

[Equation 2]

As an example of a plurality of image signals input to the brightness normalization section 2, a case where there are two images of a mid-infrared region and a far-infrared region will be described. First, FIG. 2 shows an example of the contents of the spectral luminance data section 4. The vertical axis represents the far-infrared region brightness and the horizontal axis represents the mid-infrared region brightness. In the figure, the aircraft target region, cloud clutter region, and exhaust gas region are shown. The cloud data in this figure is approximately 30 in the daytime.
It is the figure simply shown based on the data of the high cumulus clouds and the cirrus clouds captured by the imager sensitive to mid-infrared rays and the imager sensitive to far-infrared rays from 00 [m] and the ground. Further, the data of the aircraft in the figure is a value calculated on the assumption that the temperature of the cruising aircraft is increased by aerodynamic heating. Further, the exhaust gas data in the figure is a value calculated from the temperature of the exhaust gas and its components.

Next, the target determination section 3 will be described. The target determination unit 3 creates a brightness map as shown in FIG. 3 from the output of the brightness normalization unit 2. This figure shows the infrared imaging unit
The brightness of the same position (pixels at the same coordinates) in the images of 1a and the infrared imaging unit 1b is plotted on the brightness map, and the result is obtained by performing this operation for all pixels.
The significant target is detected by comparing FIG. 3 with the target area of the spectral luminance data section 2. FIG. 4 is an example of determining a significant target by superposing FIG. 2 on FIG. The plot surrounded by the ellipse of the aircraft target in FIG. 4 is determined as the target.

As described above, by using a plurality of image signals having different wavelength bands, only a significant target can be determined with a low false alarm.

Second Embodiment FIG. 5 is a block diagram showing a second embodiment of the present invention. In the figure, 5 is an optical system, 6 is a filter rotator, 7 is a filter rotator controller,
Reference numeral 8 is an infrared detector, 9 is an amplifier section, and 10 is a timing section.

An example of the configuration of the optical system 5, the filter rotator 6 and the infrared detector 8 will be described below. Optical system 5
Is assumed to transmit near infrared rays to far infrared rays, and the infrared detector 8 is an infrared detector having sensitivity from near infrared rays to far infrared rays. FIG. 6 shows an example of the filter rotator 6, which is a near-infrared bandpass filter 11 that transmits only infrared rays in the near-infrared region, a mid-infrared bandpass filter 12, and a far-infrared bandpass filter 1.
3 is shown.

Next, the operation will be described. The filter rotating body control unit 7 controls the filter rotating body 6 by the timing unit 10.
And the state of the filter rotator 6 (which filter is inserted between the optical system 5 and the infrared detector 8) is detected. The filter rotator 6 is controlled by the filter rotator control unit 7 to control the angular velocity ω.
Suppose it is spinning at.

FIG. 7 shows the spectral radiance characteristic of the object. When the near-infrared band-pass filter 11 is passing between the optical system 5 and the infrared detector 8 at a certain timing, infrared rays in the near-infrared region of FIG. 7 enter the infrared detector 8. The infrared detector 8 outputs a signal according to the incident infrared energy to the amplifier unit 9. The amplifier unit 9 amplifies the output signal of the infrared detector 8 and outputs a near infrared image signal. When a bandpass filter for mid-infrared rays or far-infrared rays is passing between the optical system 5 and the infrared detector 8 at the next timing, the output of the amplifier unit 9 outputs the image signal of far-infrared rays or far-infrared rays. The image signal is output.

As described above, by using the same infrared detector in a time division manner, it is possible to obtain a plurality of image signals having different detection wavelengths with a single infrared detector.

Third Embodiment FIG. 8 is a block diagram showing a third embodiment of the present invention, showing a method of providing a reference value for adjusting the brightness scale in the infrared imaging section 1 shown in the first embodiment. It is a thing. In the figure, 1 is an infrared imaging unit, 5 is an optical system, 8 is an infrared detector, 9 is an amplifier unit, and 14 is an infrared reference light generation unit.

An infrared reference light generator 14 is provided so as to form a reference light for normalization on a part of the image pickup surface of the infrared detector 8. Regarding the operation, the brightness normalization unit 2 normalizes the light generated by the infrared reference light generation unit 14. Subsequent processing is the same as that in the first embodiment.

With such a method, a significant target can be determined with a low false alarm by using a plurality of image signals having different wavelength bands.

Fourth Embodiment FIG. 9 is a block diagram showing a fourth embodiment of the present invention, which is an embodiment not using the technique as shown in the third embodiment. In the figure, 1 is an infrared imaging unit, 2 is a brightness normalization unit, 3 is a target determination unit, 4
Is a spectral luminance data section, and 15 is a reference value determination section.

In order to match the brightness scale of the spectral brightness data section 4 as shown in the first embodiment, it is necessary to normalize the image signal. In general, the sky temperature can be assumed to be a black body and absolute zero. When detecting an aerial target, it is generally considered that the whole or part of the image has the sky. Therefore, in the present embodiment, a case will be described where normalization is performed using the sky as a reference value.

In the embodiment shown in FIG. 9, the image signals in a plurality of wavelength bands are input to the reference value determination unit 15 to search for the sky part of the image, and the reference data is added to a part of the plurality of image signals to be output. . Subsequent processing is the same as that in the first embodiment.

The operation of the reference value judging section 15 will be described below. Among a plurality of image signals having different detection wavelength bands input to the reference value determination unit 15, the portion having the lowest brightness in common among the respective image signals is assumed to be the sky temperature being a black body and having an absolute zero degree. Judge as the sky. Then, the brightness value at that position is used as the reference value position fin (α,
Write in β). The plurality of image signals to which the reference value is added in this way are output toward the plurality of luminance normalization units 2.

As described above, by using the brightness of the sky as the reference brightness, even if the image signal does not have a reference value for adjusting the brightness scale, the significant target is lowered by using a plurality of image signals having different wavelength bands. It can be judged by a false alarm.

Embodiment 5. FIG. 10 is a block diagram showing a fifth embodiment of the present invention, in which there is no reference value for adjusting the luminance scale to a part of the image signal as shown in the third embodiment, and it is shown in the fourth embodiment. This is an embodiment in which normalization is not performed in such a sky part. Reference numeral 1 is an infrared imaging unit, 3 is a target determination unit, and 16 is a threshold value calculation unit.

In the embodiment shown in FIG. 10, a plurality of image signals having different detection wavelength bands are input to the target determination section 3 and the threshold value calculation section 16. The threshold calculation unit 16 calculates the target area based on the plurality of image signals. Subsequent processing is the same as in the above embodiment.

The operation of the threshold calculator 16 will be described below. As an example of the operation of the threshold value calculation unit 16, it is assumed that there are two input image signals. The respective threshold values are calculated from the two input image signals having different detection wavelength bands by using, for example, "Equation 1". This results in two thresholds t1
And t2 are calculated. From this value, the threshold region is calculated using "Equation 3". As a result, the same effects as those shown in the third and fourth embodiments are obtained.

[0041]

[Equation 3]

Sixth Embodiment 11 is a block diagram showing a sixth embodiment of the present invention. 17 is a binarization unit, 1
Reference numeral 8 is a feature amount calculation unit, and 19 is a target direction determination unit.

In the embodiment shown in FIG. 11, a plurality of image signals having different detection wavelength bands are sent to a plurality of binarizing units 17 provided in a one-to-one correspondence with the image signals together with the position data of the significant target. Is entered. A plurality of binarization units 17
Then, the significant target portion of the image signal is binarized.
The plurality of binarized image signals binarized by the plurality of binarization units 17 are output to the plurality of feature amount calculation units 18 provided in one-to-one correspondence with the plurality of binarization units 17. To be done. In the plurality of feature amount calculation units 18, the significant target area, the vertical center of gravity, the horizontal center of gravity, the overall center of gravity, the vertical length, the horizontal length,
A feature amount such as a ratio of length to width or brightness information before binarization is calculated. The feature amount data of the plurality of feature amount calculation units 18 are output to the target direction determination unit 19. The target direction determination unit 19 calculates and outputs the target traveling direction.

The operation will be described below. Where 2
The images input to the binarization unit 17 are, for example, an image captured in the mid-infrared region and an image captured in the far-infrared region. Also, assume that the target is an aircraft. FIG. 12 is an image in which the side surface of the aviation target is captured in each wavelength range. Further, FIG. 13 is an image in which the front of the aviation target is captured in each wavelength range. The mid-infrared region is more sensitive to hot objects than the far-infrared region. Therefore, as shown in the figure, the mid-infrared image clearly shows the exhaust gas (plume) emitted from the airframe. On the other hand, in the far infrared image, the plume is projected smaller than the former. Therefore, the lateral center of gravity P1 of the mid-infrared image is on the plume side (rear side) of the center of gravity P2 of the far-infrared image. In FIG. 13, since the plume is not visible, the mid-infrared image and the far-infrared image have the same horizontal center of gravity. From the above, by comparing the lateral center of gravity of the mid-infrared image with the lateral center of gravity of the far-infrared image, it is possible to know whether the target is moving left or right on the image monitor. An example of a specific judgment is "Equation 4"
Shown in. Further, by comparing the center of gravity in the vertical direction, it is possible to know whether the image is moving up or down on the image monitor. Further, in the case of head-on, the far-infrared image has a higher brightness than that in the medium-infrared image, and in the case of tail-on, the middle-infrared image has a higher brightness than the former case. This allows the depth direction to be known when the image is displayed on the monitor.

[0045]

[Equation 4]

As described above, by using a plurality of image signals having different wavelength bands, it is possible to instantly determine in which direction the image monitor is progressing. This makes it possible to select a target with a high threat level.

Embodiment 7. FIG. 14 is a block diagram showing a seventh embodiment of the present invention, which is an embodiment in which the target identifying function is added by further advancing the sixth embodiment.
Up to the target direction determination unit 19 is the same as in the sixth embodiment, 20 is a target identification unit, 21 is a target data unit, and 22 is a servo mechanism.

In this embodiment, it is assumed that the target is a ship. In the target data section 21, the height of the hull, the height of the center of gravity of the stack,
Information such as total length and width is stored in advance. The target identifying unit 20 identifies the target based on the data of the target data unit 21 and the target depression angle information and range information of the servo mechanism 22 with respect to itself. It is assumed that the image signals input to the binarization unit 17 are mid-infrared rays and far-infrared rays, as in the fifth embodiment. In the case of a ship, what is different from the case of an aircraft is that the exhaust gas of the ship is exhausted from the chimney portion and that the ship is considered to have almost no vertical movement. Figure 1
5 shows a medium infrared image and a far infrared image. In the mid-infrared ray, the exhaust gas part looks better than in the far-infrared ray as before.
The traveling direction can be determined by comparing these.

The operation of the target direction determining section 19 and thereafter will be described below. As shown in FIG. 16, by optimizing the binarization processing, it is possible to selectively display only the chimney portion with mid-infrared rays. FIG. 17 shows the center of gravity P1 of the hull part of the ship and the center of gravity P2 of the chimney part of the ship advancing in the depression angle θ direction with respect to the ship at the aspect ξ. If the point on the draft surface on the side opposite to the traveling direction is (0, 0), P1 (X1, Y1), P2
(X2, Y2) can be calculated by "Equation 5". The scale ratio m of the ship on the screen can be calculated by "Equation 6" from the range information d of the servo mechanism 22. Since the depression angle information θ is known from the servo mechanism 22, there are five unknowns and four formulas, so the ratio of the height of the hull, the height of the chimney center of gravity, the total length, and the full width can be known. As a result, the target can be identified.

[0050]

[Equation 5]

[0051]

[Equation 6]

Embodiment 8. 18 is a block diagram showing an eighth embodiment of the present invention. Reference numeral 23 is a RAM, 24 is a rise time measurement unit, and 25 is an identification unit.

In the following, as an example, the tracking target is an aircraft, and attention is paid to its maximum brightness to distinguish between A / B use and missile launch. First, FIG. 19 shows the maximum luminance-time characteristics when the A / B is used and when the missile is launched. In FIG. 19, a time t1 (hereinafter, a rising time) from when the increase rate of the maximum brightness is equal to or higher than a threshold value to a maximum value thereof, and a time t2 (hereinafter, a maximum brightness maintenance time) maintained by the maximum value are shown. , The time t3 from the maximum value to the steady state (hereinafter, the time from the maximum value to the steady value), the ratio of the maximum value NM to the steady luminance value NK (hereinafter the maximum / steady ratio), Luminance from steady state to steady state −
The half width t4 of the time characteristic is shown.

The operation will be described below. RAM23
Stores the maximum luminance, average luminance, area, etc. of the tracking target for a plurality of frames. The rising time measuring unit 24 of this example monitors the rate of change of the maximum luminance per Δt time, and when the rate of change exceeds the rate of change caused by shaking of the optical system 5 or the like, the rising from that time point is started. Measure time t1. The discrimination unit 25 discriminates the rise time t1 from the use of A / B and the launch of the missile by using, for example, "Equation 7", and outputs the result.

[0055]

[Equation 7]

By measuring the rise time as described above, it is possible to monitor the A / B use of the tracking target and the missile launch.

Ninth Embodiment 20 is a block diagram showing a ninth embodiment of the present invention. Reference numeral 26 is a maximum value maintenance time measuring unit, and is otherwise similar to that of the eighth embodiment.

In this embodiment, a maximum sustaining time measuring unit 26 is provided instead of the rising time measuring unit 24 of the eighth embodiment. The operation is performed by measuring the maximum maintenance time t2 shown in FIG.
B Use is distinguished from missile launch and the result is output. This makes it possible to monitor A / B usage of tracking targets and missile launches.

[0059]

[Equation 8]

Embodiment 10. 21 is a block diagram showing a tenth embodiment of the present invention. Reference numeral 27 denotes a time measuring unit from the maximum value to the steady value, which is the same as that of the eighth embodiment.

In this embodiment, a time measuring unit 27 from the maximum value to a steady value is provided instead of the rising time measuring unit 24 of the eighth embodiment. In the operation, the time t3 from the maximum value to the steady value shown in FIG. 19 is measured, A / B use and missile launch are discriminated using, for example, "Equation 9", and the result is output. This makes it possible to monitor A / B usage of tracking targets and missile launches.

[0062]

[Equation 9]

Eleventh Embodiment 22 is a block diagram showing an eleventh embodiment of the present invention. Reference numeral 28 denotes a ratio measuring unit, which is otherwise the same as that of the eighth embodiment.

In this embodiment, a ratio measuring unit 28 is provided instead of the rise time measuring unit 24 of the eighth embodiment. In the operation, the maximum / steady ratio shown in FIG. 19 is measured, the A / B use and the missile launch are discriminated using, for example, "Equation 10", and the result is output. This makes it possible to monitor A / B usage of tracking targets and missile launches.

[0065]

[Equation 10]

Twelfth Embodiment 23 is a block diagram showing a twelfth embodiment of the present invention. Reference numeral 29 denotes a half-width measuring unit, and the other parts are the same as those in the eighth embodiment.

In this embodiment, a half value width measuring section 29 is provided instead of the rise time measuring section 24 of the eighth embodiment. The operation is to measure the full width at half maximum shown in FIG. 19 and to distinguish between A / B use and missile launch using, for example, "Equation 11" and output the result. This allows
It is possible to monitor A / B usage of tracking targets and missile launches.

[0068]

[Equation 11]

Thirteenth Embodiment 24 is a block diagram showing a thirteenth embodiment of the present invention. 25 is an identification part,
Reference numeral 30 is a calculation unit.

In the following, an example will be distinguished between A / B use of aviation targets and missile launch. First, in FIG.
An example of the spectral brightness of smoke emitted from A / B and a missile is shown. As shown in this figure, the smoke emitted from both the A / B and the missile has peaks in the wavelength bands A and B, but their areas (luminance) SA and S
The ratio with B is different.

The operation will be described below. A plurality of tracking target image signals having different wavelength bands are input to the arithmetic unit 30. Here, as an example, it is assumed that the tracking target image signal is one captured in the wavelength band A and the wavelength band B. The calculation unit 30 calculates the ratio of SA and SB and outputs the result to the identification unit 25.

The identifying unit 25 identifies the use of A / B and the launch of a missile according to "Equation 12" and outputs the result. This makes it possible to monitor A / B usage of tracking targets and missile launches.

[0073]

[Equation 12]

Fourteenth Embodiment 26 is a block diagram showing a fourteenth embodiment of the present invention. Reference numeral 31 is a comprehensive identification unit.

The operation will be described below. A plurality of identification results of A / B use and missile launch as an example of the eighth to thirteenth embodiments are input to the comprehensive identification unit 31. Comprehensive identification section 31
Then, as shown in "Equation 13", weights are applied to the outputs of the respective identification units to perform comprehensive identification, and the results are output. This makes it possible to comprehensively distinguish between A / B use and missile launch.

[0076]

[Equation 13]

[0077]

According to the present invention, the time from the product of the average brightness of the tracking target and the area or the rate of increase of the maximum brightness or the like to a threshold value or more until the value reaches the maximum value is measured. By doing so, it is possible to selectively warn targets with high threat levels.

Further, according to the present invention, after the product of the average luminance of the tracking target and the area or the increasing rate of the maximum luminance becomes equal to or more than the threshold value, the value becomes the maximum value, and the maximum value is maintained. By measuring the time taken, it is possible to selectively warn targets with high threat levels.

According to this invention, after the product of the average luminance of the tracking target and the area or the increase rate of the maximum luminance or the like becomes equal to or greater than the threshold value, the value becomes the maximum value, and the maximum value becomes the steady value. By measuring the time until it becomes possible, it is possible to selectively warn targets with high threat levels.

Further, according to the present invention, after the product of the average luminance of the tracking target and the area or the increasing rate of the maximum luminance becomes equal to or more than the threshold value, the value becomes the maximum value and then becomes the steady value. By measuring the ratio between the maximum value and the steady-state value when the target is high, it is possible to selectively warn targets with high threat levels.

According to the present invention, the luminance-time characteristic from the product of the average luminance of the tracking target and the area, or the increase rate of the maximum luminance, etc., from the threshold value or more to the maximum value and then to the steady value By measuring the full width at half maximum of, the target with high threat level can be selectively warned.

Further, according to the present invention, it is possible to selectively warn a target having a high threat level by measuring the spectral brightness of the tracking target.

[Brief description of drawings]

FIG. 1 is a block diagram showing an image target detecting apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of contents of a spectral luminance data section.

FIG. 3 is a diagram showing an example of creating a luminance map.

FIG. 4 is a diagram showing an example of determining a significant target.

FIG. 5 is a block diagram showing an image target detecting device according to a second embodiment of the present invention.

FIG. 6 is a diagram showing an example of a filter rotating body.

FIG. 7 is a diagram showing wavelength and spectral luminance.

FIG. 8 is a block diagram showing an image target detecting device according to a third embodiment of the present invention.

FIG. 9 is a block diagram showing an image target detecting device according to a fourth embodiment of the present invention.

FIG. 10 is a block diagram showing an image target detecting device according to a fifth embodiment of the present invention.

FIG. 11 is a block diagram showing an image target detecting device according to a sixth embodiment of the present invention.

FIG. 12 is a diagram showing image centroids of mid-infrared rays and far-infrared rays on the side surface of an aircraft.

FIG. 13 is a diagram showing image centroids of mid-infrared rays and far-infrared rays in front of an aircraft.

FIG. 14 is a block diagram showing an image target detecting device according to a seventh embodiment of the present invention.

FIG. 15 is a view showing image centroids of mid-infrared rays and far-infrared rays on the side surface of a ship.

FIG. 16 is a selection view of a chimney portion.

FIG. 17 is a diagram showing the center of gravity of the ship and the center of gravity of the chimney.

FIG. 18 is a block diagram showing an image target detecting device according to an eighth embodiment of the present invention.

[Fig. 19] Maximum brightness during A / B use and missile launch-
It is a figure which shows a time characteristic.

FIG. 20 is a block diagram showing an image target detecting device according to a ninth embodiment of the present invention.

FIG. 21 is a block diagram showing an image target detecting device according to a tenth embodiment of the present invention.

FIG. 22 is a block diagram showing an image target detecting device according to an eleventh embodiment of the present invention.

FIG. 23 is a block diagram showing an image target detecting device according to a twelfth embodiment of the present invention.

FIG. 24 is a block diagram showing an image target detecting device according to a thirteenth embodiment of the present invention.

FIG. 25 is a diagram showing spectral brightness characteristics of A / B and a missile.

FIG. 26 is a block diagram showing an image target detecting device according to a fourteenth embodiment of the present invention.

FIG. 27 is a block diagram showing a conventional image target detecting apparatus.

FIG. 28 is a diagram showing an image signal of far infrared rays and a binarized image.

FIG. 29 is a diagram showing a mid-infrared image signal and a binarized image.

FIG. 30 is a diagram showing an example of atmospheric transmittance in summer and winter.

FIG. 31 is a block diagram showing a conventional image target detecting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 infrared imaging part, 2 brightness normalization part, 3 target determination part, 4 spectral brightness data part, 5 optical system, 6 filter rotator, 7 filter rotator control part, 8 infrared detector, 9 amplifier part, 10 timing part ,
11 near-infrared bandpass filter, 12 mid-infrared bandpass filter, 13 far-infrared bandpass filter, 14 infrared reference value generation unit, 15 reference value determination unit, 16 threshold value calculation unit, 17 binarization unit, 18 feature amount calculation unit, 19 target direction determination unit,
20 target discriminating unit, 21 target data unit, 22 servo mechanism, 23 RAM, 24 rising time measuring unit, 25 discriminating unit, 26 maximum value maintaining time measuring unit,
27 Time measurement unit from the maximum value to the steady value, 2
8 ratio measuring unit, 29 half-value width measuring unit, 30 arithmetic unit, 31 comprehensive identifying unit, 32 photodetection element, 33
Scan conversion means, 34 target detection means, 35 level comparison means, 36 determination means

Continuation of the front page (56) Reference JP-A-4-184283 (JP, A) JP-A-6-174822 (JP, A) JP-A-5-142324 (JP, A) JP-A-5-157824 (JP , A) JP-A-5-207372 (JP, A) JP-A-6-273505 (JP, A) Actual development 3-110385 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G01S 3/76-3/789 G01S 7/48-7/50 G01S 17/00-17/88 F42B 15/08

Claims (7)

(57) [Claims] 1. A RAM for storing a maximum luminance, an average luminance, an area, etc. of a tracking target for a plurality of frames and a product of the average luminance and the area per minute time of the RAM, or an increase rate of the maximum luminance, etc. A rising time measuring unit for measuring a time from when the value is equal to or higher than a threshold value to when the value becomes maximum, and an identifying unit for judging a target trend by an output of the rising time measuring unit. Image target detection device. 2. A RAM for storing a maximum luminance, an average luminance, an area, etc. of a tracking target for a plurality of frames, and a product of the average luminance and the area per minute time of the RAM, or an increase rate of the maximum luminance, etc. A maximum value maintenance time measuring unit that measures a time period that exceeds a threshold value and becomes maximum thereafter and maintains the maximum value, and an identification unit that determines a target trend by the output of the maximum value maintenance time measuring unit. Image target detecting device. 3. A RAM for storing a maximum luminance, an average luminance, an area, etc. of a tracking target for a plurality of frames, and a product of the average luminance and the area per minute time of the RAM, or an increase rate of the maximum luminance, etc. The time from the maximum value to the steady value, which measures the time from when the maximum value exceeds the threshold value to the steady state, and the output from the time measurement section from the maximum value to the steady value are output. An image target detecting apparatus, comprising: an identification unit that determines a trend of a target. 4. A RAM for storing a maximum luminance, an average luminance, an area, etc. of a tracking target for a plurality of frames and a product of the average luminance and the area per minute time of the RAM, or an increase rate of the maximum luminance, etc. A ratio measurement unit that measures the ratio between the value when the threshold value is exceeded and the maximum value and the value when the steady state is reached, and an identification unit that determines the target trend by the output of the ratio measurement unit. An image target detecting device comprising: 5. A RAM for storing a maximum luminance, an average luminance, an area, etc. of a tracking target for a plurality of frames and a product of the average luminance and the area per minute time of the RAM, or an increase rate of the maximum luminance, etc. A full width at half maximum measuring unit for measuring the full width at half maximum of the waveform when the maximum value is taken after the threshold value or more and then a steady state is obtained, and an identifying unit for judging the target trend by the output of the full width at half maximum measuring unit. An image target detecting device characterized by the above. 6. A calculation unit for calculating a ratio of maximum brightness or average brightness of tracking targets of a plurality of image signals having different detection wavelengths in an infrared region, and A / A of aviation targets output from the calculation unit.
B. An image target detecting device, comprising : an identification unit for distinguishing between use and missile launch . 7. A comprehensive discriminating unit that receives the outputs of the discriminating units according to claims 1 to 6 and applies a weight to each output to comprehensively judge the trend of the target. Image target detection device.