DE7905866U1 - Device for target location and missile guidance - Google Patents

Description

Device for target location and missile guidance

The invention relates to a device for target location, target tracking and missile guidance by means of a CO. Laser with optical superimposition reception.

- Target location and missile steering arrangements are known in the most varied of embodiments and systems. When using CO_ lasers in these arrangements, there have always been at least two separate lasers for location and guidance required. The known devices had a number of disadvantages, as required they complicated handover measures of the located target direction to the missile control and further an additional IFF transmitter (friend-foe detection). The sensitivity of these arrangements or systems was and is still too low. With two-phase steering, where the In the first phase, the missile is guided by a homing head that detects the thermal radiation of the target the IR seeker head has always been easy to disturb.

The invention is based on the object of creating a locating and steering device of the type mentioned at the beginning, which makes it possible to target moving enemy targets, including missiles, in extremely low proximity to the ground optimally locate, track, identify and combat. This highlights the disadvantages of the systems of the state of the art completely or largely eliminated

³⁰ tigt.

The main problem here lies in the fact that the

purely passive systems - e.g. thermal imaging devices - often

are only able to target one object as a possible

- "to make out, but not to correctly identify this target-

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verify if the object is and is not in front of the sky but in front of a terrain background does not stand out sufficiently from this. This is where the invention intervenes and eliminates it with the laser Doppler lidar the uncertainties, with a CO "laser optical superimposition reception is used. It evaluates the transit time and frequency shift of the laser beam backscattered from a moving target, so that the target can be detected by direction, distance and speed.

The organizational measures of the invention are laid down in the claims and described using an exemplary embodiment and illustrated in the drawings. Show it:

1a shows a structure of the CO ₂ Doppler lidar with homodyne reception in a schematic representation;

1b shows a structure of the CO ₂ Doppler lidar with heterodyne reception in a schematic representation;

2 shows a block diagram for the friend-foe recognition in the laser method according to the invention;

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3 shows a structure of the beacon command systems for overlay reception in a schematic representation;

³ ^ Fig. 4 a structure of the beacon command systems for direct reception in a schematic representation.

By using a powerful CO ₂ laser instead of the Nd: YAG laser previously used in the military sector, an expansion of the wave

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area to the middle IR has become possible and thereby a much better penetration of the atmosphere by the laser radiation as well as the compatibility with the recently used IR thermal imaging devices (FLIR). In addition, it is now due to the larger Wavelength of the superimposition reception feasible, i.e. relative speeds can now be achieved by double _ ler evaluation can be measured.

Optical countermeasures are difficult in this selected wavelength range. Since the CO ₂ laser radiation in the systems presented here is based on a radiation

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density of 0.1 W / cm can be reduced, a hazard to the operating personnel is also completely avoided. The ability to locate and steer the missile is not impaired in any way up to an average range of approx. 5 km with laser powers of approx. 5 W. Since the invention proposes to use a CO_ waveguide laser, it is possible to achieve a substantial reduction in structural volume and weight compared to all known arrangements of the prior art and still achieve the required high mechanical stability. This is a prerequisite for He for superimposition reception required frequency constancy of the emitted radiation. In the case of superimposition reception (10.6 μια wavelength), a reference radiation, which has a fixed frequency spacing from the signal radiation, is superimposed on the receiving detector. This can be done by a partial beam derived from the transmission beam (homodyner reception) or by a separate local oscillator laser beam (heterodyne reception). With homodyne reception, another laser is saved.

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02/28/85, 0403A

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That which occurs at this intermediate frequency at the detector output Signal (electrical) is narrow-band filtered and amplified. When receiving from a moving Radiation scattered back to the target causes an additional frequency shift (Doppler effect).

The device according to the invention now works as follows

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The shooter directs the target device 10 of the launching station 11 roughly in the direction of a suspected or observed target 12 and now switches to active location, with the control unit 20 taking over control of the overall system. The CO ₂ waveguide laser 13 is activated and emits the locating beam 14, to which, through the modulator deflector 18, a spatial modulation suitable for target scanning and tracking, as well as one for distance measurement and IFF detection, but also a target seeker head the target guided missile is impressed with sensitizing, temporal modulation. The light of the locating beam 14 is backscattered by the target 12 and given by a receiving optics 15 to a detector 16 together with the superimposed radiation of a local oscillator 17 (with heterodyne reception) or the frequency shifted radiation of the laser transmitter (13) itself by a modulator (homodyne reception). The position of the difference frequency between transmitted and received radiation 14, 14a - which is determined in a suitable and known manner - provides information about the radial movement of the targeted target. To measure the target distance, the laser beam 14 directed at the target is amplitude-modulated and the phase difference between the transmitted and received modulation from the units 18 and 19 is evaluated. That means: in the evaluation unit

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19 the determined values are sent to the tracking computer 21 and given to the control unit 20.

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It can now be advantageous for special cases if a pulse time-of-flight measurement is carried out as an alternative location method, in which a time or
Distance gate is set, which prevents the transmission of the
Close range of the tracking device allowed.

From the evaluation unit 19 now go the determined
Values for a tracking calculator, which causes the target to be tracked via the modulator / deflector 18.
At the same time, a check is carried out in accordance with the control unit 20 and the IFF unit 22 assigned to it
the well-known friend-foe identification procedure. This IFF unit 22 is composed of an IFF code generator 22a and an IFF detector 22b. The associated IFF response unit 23 of a "friend" target comprises an IFF decoder 23a, an IFF response code generator 23b, a modulator driver 24a and
a modulator 24b to the IFF retroreflector 24c
upstream and is only permeable synchronously with the response code pattern. As a result, the ground station measuring the supposed target automatically receives the IFF response code character, while the retroreflector cannot respond to a possible hostile laser system. The one with an IFF retroreflector
The laser signal that is backscattered from a target equipped with a target can always be unequivocally identified, as it is several orders of magnitude stronger than a diffusely reflected target signal due to the retroreflection. Because of the extremely low divergence of the retroreflected beam (<0.1 mrad), it can only be received by the launching station itself, which makes it easier to keep the IFF response code secret.

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FIGS. 3 and 4 show the expanded application possibilities of the device according to the invention, specifically for the steerable missile 30. The launch station or the location and control center 11 is as described above for the location and guide beam to be transmitted 14 set up. The missile 30 is provided with a beacon receiver 31 on its rearward front Mistake. This can, as shown in FIG. 3, for direct reception or similar to that shown in FIG. 1 Receiver designed for heterodyne reception. However, as shown in FIG. 4, it can only consist of a retroreflector exist if the missile position is then by means of the retroreflected beam or signal is evaluated at the launch station and the necessary steering commands are transmitted separately.

The missile tip has a target guide head 32. According to FIG. 4, the arrangement is shown here as it is for direct reception is suggested in the target head; however, similar to that shown in FIG. 1, heterodyne reception can also be used be performed. The target head is for the signals reflected back from the target a receiving optics 45, a detector 46, the signal evaluation unit 49 and the filing or tracking computer 41, which receives its signals in the second steering phase passes directly to the control organs 33.

The signal evaluation unit 49 only evaluates signals that are applied to the modulator / deflector 18 in accordance with the Modulation voltage are modulated. This ensures that the IR seeker head only points to the now additionally serving as a target illuminator locating and guide beam 14 is sensitized. Through this kind of Target lighting generally becomes geometric

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The center of gravity of the target is marked, i.e. a location that is more favorable in terms of weapons technology than the thermal center of gravity found by conventional IR target seeker heads (e.g. Exhaust jet etc.) of the target. Also be countermeasure took a lot more difficult.

The above information and the comprehensibility of the drawing are to be regarded as unequivocal, which means that further explanations are not necessary.

Thus, a device of the type mentioned at the outset has been created in which the emitted locating beam is further activated after a target has been discovered and this is determined by means of a track mode target automatically tracked and at the same time as friend-foe detection signal, as missile beacon and serves as a target marker. Here, in one embodiment - as described above - the deflects as a guide beam used locating beam the first flight phase, which one can also be referred to as the launch phase of the missile, while the second target-tracking flight phase is directed by the IR seeker head 32, which is sensitized to the modulated laser beams scattered back from the target.

Claims (3)

»4t ·« · »β Γ 02/28/85, 0403A Kre / we 8478 Patent Department G 79 05 866.5 Device for target location and missile guidance Claims for protection 1. Device for target location, target tracking and Missile guidance by means of a CO laser with optical overlay reception, thereby g e k e η η - _{shows that a frequency-stabilized CO 2} waveguide laser (13) serving as a transmitter (I) is assigned a receiver (II) for the laser radiation (14a) reflected back from the target, which is equipped with two beam splitters (13b and 17a) and a modulator (17b) for the frequency-shifted laser light (17c) is provided and connected to an evaluation unit (19). 2. Apparatus according to claim 1, characterized in that a modulator (18), a transmission optics (13a), a control unit (20) and an IFF unit (22) and the CO ₂ waveguide laser (13) of the transmitter (I) is formed. 3. Device according to claims 1 or 2, characterized in that the ejector t unit (19), the IFF unit (22) and the control unit (20) with the tracking computer (21) with a Detector (16) are connected.