WO2012095080A1

WO2012095080A1 - Method for operating an electronic reconnaissance system in surroundings that are protected by a jammer

Info

Publication number: WO2012095080A1
Application number: PCT/DE2011/002165
Authority: WO
Inventors: Ralf Lorch; Rainer Müller; Askold Meusling
Original assignee: Eads Deutschland Gmbh
Priority date: 2010-12-24
Filing date: 2011-12-21
Publication date: 2012-07-19
Also published as: IL226406A; EP2656528B1; KR20140005158A; KR101918576B1; ES2672394T3; IL226406A0; DE102010056268A1; EP2656528A1

Abstract

The invention relates to a method for operating an electronic reconnaissance system (2) in surroundings that are protected by a jammer (1). Jamming phases (TJ2) for transmitting a jamming signal and monitoring phases (TB) for receiving and analyzing signals to be jammed are carried out in an alternating manner during the operation of the reactive jammer (1), and a signal reception of the electronic reconnaissance system (2) is carried out exclusively during the monitoring phases (TB) of the reactive jammer (1).

Description

A method of operating an electronic reconnaissance system in an environment protected by a jammer

Mobile jammers are used to protect vehicles or vehicle convoys against remote-controlled explosive devices (so-called RCIEDs, remote controlled jmprovised explosive devices). In addition to the operation of the jammer, the operation also requires parallel operation of an electronic reconnaissance system (also known as ESS: Electronic Support Measures) in many operations. Such reconnaissance systems typically include components for modulation type detection, bearing, and, depending on the operational requirement, e.g. also for demodulation and development of the signal content.

The RF interference power radiated by the jammer to protect the vehicle or convoy causes an overload or saturation in the receiving channels of the reconnaissance system and thus makes it useless. Therefore, the reconnaissance mode of the jammer and thus the most consistently desired protection function must be turned off.

From DE 10 2009 006 861 A1 and US 2005/0041728 A1 so-called reactive jammers (English: Responsive Jammer) are known. These are jammers that only perform a fault when they have detected a signal to be disturbed. In order to detect such signals, reactive jammers work with an observation phase connected between two interference phases. During the observation phases, only the signal environment is observed and evaluated, but no interference signal is transmitted. In the following interference phase, RF power is actively radiated only on frequencies that have an occupancy. The observation phase of the reactive jammer is so short that targets (eg bombs) can not trigger during this time. US2006 / 0153280 A1 likewise describes a reactive jamming transmitter which, however, can additionally determine the direction of a signal received in the observation phase. This direction is taken into account in the subsequent disturbing phase, in particular in that the interference signal is emitted only in the corresponding direction.

It is an object of the present invention to provide a method enabling electronic variable quality / reconnaissance intelligence without losing the simultaneously desired protection against RCIEDs by the reactive interferer, i. Both systems should be able to operate in parallel with their individual functions.

This object is achieved by the method according to claim 1. advantageous

Embodiments and a reconnaissance system for use in the method according to the invention are the subject of further claims.

According to the invention, the operation of reactive jammer and reconnaissance system is synchronized such that signal reception of the reconnaissance system occurs only within the observation phases of the reactive jammer. This ensures that the reconnaissance system is not disturbed by the interference radiation. Thus, a high-quality setup operation becomes possible even when the protection function against RCIEDs (executed by the jammer) is activated.

In reconnaissance mode, at least one of the following functions is performed: - Bearing,

Types of modulation recognition,

demodulation

Development of the signal content. In a particularly advantageous embodiment, a reaction of the reconnaissance system to the perturbation cycle of the reactive jammer is possible. In particular, a dynamic adaptation of the system synchronization can take place in such a way that the length of the observation phases and / or the interference phases of the reactive interference transmitter is controlled as a function of the operational requirements of the reconnaissance system. Thus, both the efficiency of disturbance and the depth of explanation can be controlled in a targeted manner.

For example, for more complex functions of the reconnaissance system, such as e.g. Unlocking the signal content, the reconnaissance system a longer

Signal recording time or a shorter distance between two or more signal recordings are granted, in which the observation phase of the jammer extended accordingly or the Störphase is shortened accordingly.

Particularly advantageously, the direction information obtained by the reconnaissance system can be used for direction-selective disruption with a multi-antenna system. The generation of the directional signal can be realized either by appropriate beam shaping in phased array antennas or by antenna switching in the case of multiple directional antennas.

If reactive jammer and reconnaissance system are not generally operated in combination, can be provided in a further embodiment, that the reconnaissance system automatically synchronized to the set in the reactive jammer temporal position of the observation phase as soon as the two units in contact with each other in operational use.

Reactive jammer and reconnaissance system can be used in particular for the protection of vehicles or vehicle convoys. The reconnaissance system and reactive jammer may be located on the same vehicle or different vehicles depending on operational requirements. The invention will be explained in more detail with reference to figures. Show it:

Fig. 1 is a diagram for synchronizing the operation of reactive jammer and reconnaissance system;

Figure 2 is a schematic representation of the overall configuration of reactive jammer and on clarification system.

3 is a circuit diagram of details of the protection circuit of FIG. 2.

Fig. 1 shows a representation of the timing of the individual process steps within the reactive jammer and the reconnaissance system. In this exemplary embodiment, only the function "bearing" is considered for the reconnaissance system. As noted above, the reconnaissance system may have additional functions, e.g. Modulation type detection, be provided. The internal procedure of the jammer is the upper view of FIG. 1, the internal procedure for the direction finder is shown in the lower illustration of FIG.

The procedure in the jammer is as follows:

Time duration T _J2 : emission of an interference signal with the frequency f_old.

Time T _L T: Signal recording to detect potential threats.

Time duration: The signal received during T _LT is subjected to an FFT to obtain spectrum information and to determine therefrom the required new interference frequency f_new. Subsequently, the determination of the new interference signal with the frequency f_neu. Duration T _J2 : Transmission of the new interference signal with the frequency f_new.

Subsequently, the signal recording takes place again within T _L T and the cycle described begins again from the beginning. The durations T _L T and Tj! together form the observation phase T _{B |} which lies between two interference phases T _J2 .

To increase the reconnaissance depth according to the current operational requirements, the observation phase T _B can be adjusted by lengthening T _L T.

Alternatively, to increase the reconnaissance depth in accordance with the current operational requirements, the cycle time between successive observation phases T _B can be adjusted by shortening the disturbance phase T _J2 and / or omitting the time duration Tji.

If a high disturbance efficiency is required from operative field tasks, the disturbance phase T _{J2 can be} extended. Alternatively or additionally, the observation phase TB can be shortened to the time T _LT and the interference phase can be lengthened accordingly, in which an interference signal is also transmitted in the time period Tji.

In general, the interference efficiency Ή _{y of} the jammer is as follows:

T + T

^'J ¹ TJ \ + ^ T ^A J 2 + T LT The sequence in the reconnaissance system example used here, the direction finder is as follows: It carried out there in parallel to the activities of the jammer, the following processing steps:

bearing values, Signal recording,

Spectrum analysis with FFT,

bearing values,

with subsequent repetition of this cycle.

According to the invention, the operation of reconnaissance system and reactive jammer is synchronized such that the signal pickup of the direction finder takes place only within the observation time TB of the reactive jammer, and never during the jamming phase T _J2 , during which the jammer emits spurious energy. The synchronization can be done, for example, with a synchronization line (eg copper or glass fiber) or via an air interface. The air interface has the advantage that several vehicles can work in parallel.

Incidentally, the duration of the individual work phases can be freely selected by the reactive interferer and the reconnaissance system. For example, it is not mandatory that the signal pickup from the jammer and direction finder (as can be seen in the example of FIG. 1) begin or end at the same time.

Fig. 2 shows a schematic representation of the overall configuration of reactive jammer 1 and reconnaissance system 2. The jammer 1 includes the jammer module ECM and the associated antenna A-ECM for emitting the interference signal and for receiving signals. Reconnaissance system 2 comprises the reconnaissance module ESM and the associated antenna A-ESM for receiving signals. The two systems 1 and 2 are, as described in detail above, synchronized with respect to the signal recording of the reconnaissance system 2. The synchronization can be done via a cable connection as shown. This is especially preferred when the two systems 1, 2 are located on the same vehicle. Alternatively, a wireless connection may also be provided, in particular if the two systems 1, 2 are located on different vehicles or platforms. To protect the receiver within the reconnaissance module ESM during the emission of the interference signal by the jammer 1, an antenna protection device P is present, which is explained in more detail in Fig. 3. Fig. 3 shows the structure of the antenna protection device P of Fig. 2 in detail. It is characterized in particular by speed in the switching open / closed and by a high insulation in the open state.

As shown in FIG. 3, several protection components are connected in the output line of the antenna A-ESM of the reconnaissance system. They differ in the speed of their response and in the maximum power they provide effective protection.

The coarse protection GS is intended to derive the essential part of the inflowing energy and may be e.g. consist of a gas gap. The remaining voltage is applied to a fast switch SSC (e.g., a relay, a PIN diode, or even a MEMS switch) which turns off the antenna. To further increase the protective effect, in the embodiment shown, a limiter LT is provided, e.g. consists of diodes.

Depending on the application or expected field strength, all three components mentioned, combinations of two of these components or only one of the components mentioned can be used.

Claims

claims:

1 . Method for operating an electronic Aufkiärungssystems (2) in an environment protected by a jammer (1), wherein in the operation of the reactive jammer (1) alternately interference phases (TJ2) for emitting an interference signal, and observation phases (TB), for receiving and for evaluation to be traversed by interfering signals, characterized in that a signal recording of the electronic reconnaissance system (2) takes place exclusively during the observation phases (TB) of the reactive jammer (1).

2, Method according to claim 1, characterized in that the duration of the observation phases (TB) and / or interference phases of the reactive jammer (1) is variably adapted to operational requirements of the reconnaissance system (2).

3. The method according to claim 1 or 2, characterized in that the by the reconnaissance system (2) obtained reconnaissance information from the reactive jammer (1) are taken into account when disturbing.

4. The method according to any one of the preceding claims, characterized marked, that the reconnaissance system (2) automatically synchronized to the reactive jammer (1) set timing of the observation phase (TB) as soon as the two units mentioned have contact.

5. reconnaissance system for use in a method according to one of the preceding claims, characterized in that it is equipped to protect it against the interference radiation of the reactive Jammers during its interference phases (TJ2) with a Antennensch utzschalter.

6. Reconnaissance system according to claim 5, characterized in that the antenna protection switch has a series connection of a coarse protection, a fast switch and a limiter.