JPH07128436A - Sensor equipment of low detectability - Google Patents

Abstract

PURPOSE:To hold down the probability of detection by the other party, to be low, by measuring distance information on the other party by using an angle and distance-measuring sensor of an electromagnetic radiation type at the minimum, while using mainly an angle-measuring sensor which is not accompanied by the radiation of an electromagnetic wave. CONSTITUTION:An angle-measuring sensor 1 executes angular tracking of a target aircraft 3 and outputs measured angle data (e) on the target to a control computer 4. A distance-measuring angle-measuring sensor 2 is controlled directionally in the target direction by a directional control signal (f) from the computer 4, while it radiates a radio wave for distance measurement intermittently at a proper timing according to a radiation signal (g) from the computer 4, with a necessary minimum output corresponding to a radar cross section and the target distance of the aircraft 3, and outputs a signal (h) to the computer 4. The signal (h) is used by a tracking filter for updating a target position. Since electromagnetic radiation can be minimized according to this constitution, the probability of detection by the other party can be held down to be low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low detectability sensor device capable of reducing detectability from the other side,
For example, it applies to police systems, crime prevention and defense systems.

[0002]

2. Description of the Related Art In a conventional sensor system, a sensor centering on a radar and emitting electromagnetic waves is generally used.

For example, as shown in FIG. 4, for example, from the control computer 01 to the radar (active sensor) 02,
When the direction control command f and the radiation command g are output, the radar 02 radiates an electromagnetic wave to the flying body 03 and at the same time, the flying body 03.
And the reflected wave is received, and the distance measurement and angle measurement data h up to the flying body 03 are output to the control computer 01.

[0004]

The conventional sensor system uses a positive sensor that emits electromagnetic waves, as is found in, for example, a radar warning device for a vehicle. Therefore, the presence of the sensor is detected by the other party. However, there is a drawback that the concealment effect, which is an advantage of defense and defense, is diminished.
Therefore, the other party can detect our existence and intention.

Here, in order to eliminate the detectability from the other party, it is conceivable to use a passive sensor such as an infrared (IR) sensor and a visible light (TV) sensor which only receive without electromagnetic wave radiation. Since the passive sensor is basically an angle measuring sensor, it has a drawback that the distance to the other party cannot be directly measured.

Further, when one of the self and the other party is moving, it may be possible to measure the distance by trigonometry, but in many cases, a long observation time is required for the distance measurement. However, it was not practical because the measurement accuracy was poor. In particular, the velocity obtained by the first derivative of the distance and the acceleration obtained by the second derivative cannot be measured.

The present invention has been made in view of the above prior art, and an object of the present invention is to provide a low detectability sensor device in which the electromagnetic wave radiation is minimized and the detectability from the other party is reduced. And

[0008]

The structure of the present invention which achieves such an object is mainly used with an angle measuring sensor (passive sensor) which does not emit electromagnetic waves such as an infrared sensor and a visible light sensor, while using a radar. , The electromagnetic radiation type angle measuring / distance measuring sensor (active sensor) capable of measuring the distance such as laser range finder is used to the minimum to measure the distance information of the other party, and the electromagnetic radiation is suppressed to the minimum. This reduces the detectability from the.

[0009]

Function The tracking of the target is continued mainly by the angle measuring sensor. Therefore, the target side cannot detect us by electromagnetic radiation. The angle-measuring / distance-measuring sensor is oriented in the same direction as the angle-measuring sensor and intermittently emits electromagnetic waves for a very short time to measure the distance to the target.

The data of the angle measuring sensor and the data of the angle measuring / distance measuring sensor are judged by the correlation circuit whether they have the same target or not, and are combined as one target data by the data combining circuit. In order to enable intermittent use of active sensors, a tracking filter is constructed based on the target motion norm, and data is complemented during the ranging cycle.

Further, in order to reduce our detection possibility from the target side as much as possible, the timing of electromagnetic wave radiation for distance measurement is randomized, and when radio waves are used,
The radio wave output is limited to the minimum output required for target distance measurement, and the peak power is reduced by a method such as spread spectrum.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 shows an embodiment of the present invention. In the embodiment shown in the figure, an optical sensor (distance measuring sensor) 1
And a radar (distance measuring / angle measuring sensor) 2 are used to
It tracks and locates the position.

That is, the optical sensor 1 tracks the angle of the flying object 3 which is the target, and obtains the target angle measurement data e from the control computer 4.
Output to. The radar 2 is directed to the target direction by the pointing control signal h from the control computer 4, and the radiation signal g from the control computer 4 intermittently transmits radio waves for distance measurement at appropriate timing to the radar of the air vehicle 3. It radiates with the minimum required output corresponding to the cross-sectional area and the target distance, and outputs the target distance measurement data h to the control computer 4. The distance measurement data h is used for updating the target position by the tracking filter.

FIG. 2 shows an example of the internal configuration of the control computer 4. The control computer 4 shown in the figure comprises a sensor control circuit 5, a data alignment circuit 6, a correlation circuit 7, an estimation circuit 8 and a data fusion circuit 9. The data alignment circuit 6 performs common standardization of coordinates and time and complements missing data. This is because the distance measurement by the radar 2 is performed randomly in order to reduce the detection probability on the target side.

The correlation circuit 7 takes the correlation between the data from the optical sensor 1 and the data from the laser 2, and when it determines that they are the same target, it gives an identification number for identifying them. Although this correlation equation depends on the characteristics of the optical sensor 1 and the laser 2, for example, the Nearest-Neighbour method or the like can be considered. The data fusion circuit 9 fuses the angle measurement data e from the optical sensor 1 and the distance measurement data h from the laser 2 having the same identification number as one target data.

The estimation circuit 8 forms a tracking filter based on the target motion norm, complements target data between distance measurement cycles, and estimates the future position of the target for each calculation cycle.

The sensor control circuit 5 directs the optical sensor 1 and the laser 2 in the direction of the target estimated position output from the estimation circuit 8 to continue tracking, and at the same time calculates the target covariance matrix calculated by the estimation circuit 8. Based on this, an error in data is determined and the distance measurement timing is controlled. For the control of this part, it is possible to adopt a expert system by extracting a control rule for minimizing the indirect detection probability on the target side based on the characteristics of the target side radio wave reception sensor.

Further, in order to reduce our detectability from the target side as much as possible, the timing of the electromagnetic wave emission for distance measurement is randomized, and when radio waves are used,
It is desirable to limit the radio wave output to the minimum output necessary for the target distance measurement and reduce the peak power by a method such as spread spectrum.

FIG. 3 shows the results of the aerial target tracking simulation of the low detectability sensor system when an infrared sensor and a laser are used. That is, after detecting a target by D / L (data link) for 74 seconds, data of an infrared sensor and an intermittently used laser (2 seconds ON, 24 seconds OFF) were fused (data fusion) to track a 76 seconds target. After that, the target was tracked by fusing the data of the infrared sensor and the laser of continuous use (data fusion). Here, the ratio e (%) of the error between the estimated position of the target and the true position of the target is expressed by the following equation.

[0020]

[Equation 1]

However, (x ', y', z '): estimated position of target (x, y, z): estimated position of target R: slant range

As is clear from the results shown in FIG. 3, high target position accuracy is obtained and low detectability is achieved even though the laser radio wave emission is suppressed to a low frequency of about once every 20 seconds. It turns out that it is sufficiently secured.

[0023]

As described above in detail with reference to the embodiments, the present invention mainly uses an angle measuring sensor that does not emit electromagnetic waves, and uses an electromagnetic radiation type angle measuring and distance measuring sensor. By using the lowest limit and measuring the distance information of the other party, the electromagnetic radiation can be minimized, so that the detection probability from the other party can be kept low.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a low detectability sensor device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a control computer according to an embodiment of the present invention.

FIG. 3 is a graph showing an aeronautical target tracking simulation result of a low detectability sensor system when an infrared sensor and a laser are used.

FIG. 4 is a block diagram of a conventional sensor system.

[Explanation of symbols]

 1 Optical Sensor 2 Radar 3 Air Vehicle 4 Control Computer 5 Sensor Control Circuit 6 Data Alignment Circuit 7 Correlation Circuit 8 Estimating Circuit 9 Data Fusion Circuit e Target Angle Measurement Data f Direction Control Command g Radiation Indication h Target Distance Measurement Data

Claims (1)

[Claims] 1. An angle-measuring sensor for continuously angle-tracking a target without electromagnetic radiation, an angle-measuring / distance-measuring sensor for intermittently radiating electromagnetic waves to measure the distance to the target, And a control computer for fusing the angle measurement data from the angle sensor and the distance measurement data from the angle measurement / distance measurement sensor to create one target data and controlling the direction of the angle measurement / distance measurement sensor. A low detectability sensor device characterized by the above.