Background noise generation simulator

Abstract

A seismic simulator on a carrier platform for generating simulated seismic signals is presented, comprising: a) a signaling unit programmed to dynamically vary the intensity, frequency and duration of the emitted background noise signals to simulate realistic seismic scenarios, b) an output unit which directs the emitted signals into the ground to amplify background noise.

Description

[0001] The invention relates to a simulator for generating background noise to deceive sensors for seismic waves.

[0002] There are four types of seismic waves, which can be classified into two categories: primary and secondary waves are body waves, while Love and Rayleigh waves are surface waves. Body waves originate at the center of, for example, an earthquake and travel through the Earth from there. Love and Rayleigh waves are confined to the Earth's surface.

[0003] Besides the detection of natural seismic waves, for example due to earthquakes, methods for generating and detecting artificial seismic waves are also known.

[0004] The vibroseis method is a modern and efficient technique that uses a vibroseis vehicle to generate seismic signals. Unlike traditional methods that use explosions (gunfire), the vibroseis vehicle creates artificial seismic waves through mechanical vibration. The vibroseis vehicle is equipped with a large, powerful vibrator (vibroseis source) that is pressed into the ground. The vibrator generates controlled vibrations with varying frequencies and amplitudes. These vibrations propagate as seismic waves through the subsurface. The seismic waves penetrate the ground and are reflected by the different rock layers. The reflected waves are recorded by geophones placed on the Earth's surface. The data obtained allows us to create a detailed picture of the structure and composition of the subsurface.

[0005] From German patent application DE 31 03 376 A1, a method for seismic soil investigation is known with at least one detector installed on the surface and at least one vibration source, which is excited by means of a signal formed from a sequence of vibrations and as a result transmits vibrations into the ground, a part of which is received by the detector after refraction and / or diffraction and / or reflection, whereupon the emitted signal and the signal received by the detector are each recorded using the sign-bit method and these recordings are cross-correlated to form a final trace recording, characterized in that a substantially linearly responding vibration source is excited with a pseudo-random code.

[0006] In addition to seismic waves that rise to the Earth's surface from the Earth's interior as a vibration or reflection, it is also known to detect seismic waves that are introduced into the Earth's surface from the air, for example.

[0007] DE 10 2022 002 396 A1 discloses a detector system for flying missiles, hypersonic missiles or stealth flying objects, characterized in that it consists of at least one sensitive vibration / seismic sensor, which is installed under the ground or is placed under the ground with the aid of a drill rod or probe, a computer or evaluation unit that is coupled to the vibration sensor and evaluates the sensor data, software that determines the microseismic waves in the ground from the pressure wave of a rapidly moving source and filters out other vibrations or seismic activity from other sources, a data transmitter that is connected by cable to a monitoring center or is a radio transmitter that sends the determined data to a monitoring center, and a power source that supplies the electrical elements with current.

[0008] US 2010 / 0157729A1 describes a method for detecting the passage of vehicles, which includes the following steps: locating a geophone on the ground at a known location and processing the signals from the geophone to derive a density statistic that corresponds to the number of peaks of the geophone signal above a threshold set above a measured background level, with the number of peaks above the threshold indicating the presence of a vehicle.

[0009] The invention focuses on the unification of geophones and a unique property of the seismic signature of vehicles that is not caused by nearby personnel or other temporary environmental disturbances such as wind.

[0010] Unique properties of a seismic signature, which captures background noise, are described.

[0011] US Patent 3,984,804 A discloses a remote detector for detecting and transmitting acoustic and seismic signals, comprising in combination the following: a canister assembly with a pan and a lid covering the pan to form a first housing; and a second housing within the first housing, connected at one end to the lid and at the other end to the pan near their respective centers, and having a first cavity adjacent to the lid and a second cavity adjacent to the pan; a microphone assembly for detecting acoustic signals, mounted in the first cavity assembly; and a seismometer assembly for detecting seismic signals, mounted in the second cavity assembly.and a transmission device with an antenna mounted on the lid, which is operationally connected to receive the output signals of the microphone device and the seismometer device and simultaneously transmit an acoustic and a seismic signal.

[0012] A remote detector for troop movements, consisting of a common detector assembly or canister containing a microphone and a seismometer, as well as a power supply and a transmitter circuit, and designed to adapt to different operational situations.

[0013] It is called a detection and reception unit for the transmission of seismic signals.

[0014] German patent application DE 252 8 647 A1 discloses a device for generating transverse waves in the ground, comprising a target element with a ground contact surface, a mass intended to strike the target element, and devices that impart a velocity to this mass which has a component parallel to the contact surface, characterized in that these devices have movable actuating elements that are adjustable relative to the target element to keep the mass in a specific plane, as well as control elements to raise the mass relative to the target element and direct its fall towards the target element.

[0015] The invention relates to a movable device for generating acoustic transverse waves with an increased repetition frequency in the ground.

[0016] It is called a carrier platform, which is designed as a movable device for generating acoustic transverse waves for introduction into the ground.

[0017] In military applications, seismic vibrations are used, for example, to detonate mines. The advantage of seismic detonators is that the sensors detect the approach to the mine and trigger it accordingly, without the need for additional mechanical devices such as tripwires or similar, or for the mine to be buried.

[0018] Furthermore, it is known to use seismic sensors for object protection and for detecting excavation activities in the area of ​​border installations.

[0019] The prerequisite for the detection of seismic signals is the identification of a signal attributable to an emission source, which stands out clearly from the ubiquitous background noise or can be selected from background noise.

[0020] Background noise refers to unwanted sounds or signals present in a given system or environment that can interfere with the analysis or perception of relevant information. It can occur in various contexts, such as acoustics, signal processing, communications engineering, and geophysics.

[0021] In acoustics, background noise refers to sounds present in an environment, such as traffic, conversations, or machinery, that can impair the clarity of desired sounds or speech signals. In signal processing, background noise can be considered random disturbances in a signal that reduce the accuracy of measurements or the quality of data analysis.

[0022] In geophysics, particularly when using seismic or acoustic sensors, background noise can impair the ability to detect weak signals, such as those from earthquakes or other geophysical events. Therefore, it is important to minimize or filter background noise to improve the quality of the collected data and perform more precise analyses.

[0023] For the purpose of camouflaging one's own military forces, it is therefore advantageous to increase the background noise in order to make it more difficult to detect the seismic waves generated by one's own vehicles or weapon systems.

[0024] The object of the invention is therefore to present a device that increases the background noise for seismic detectors in order to make it more difficult to detect seismic signals.

[0025] This problem is solved by the characterizing features of the main claim. Advantageous embodiments are described in the dependent claims.

[0026] Mobile seismic simulators have the advantage of being equipped with a chassis, which allows them to be used on roads and, particularly, off-road. These chassis are usually multi-wheeled systems with at least two axles or tracked systems with at least two running gear. Depending on the application, wheeled systems are advantageous for on-road use and faster convoy travel. Experience has shown that tracked systems are more suitable for off-road use.

[0027] In addition to the chassis, the invention also provides a support platform for the seismic simulator according to the invention. The support platform comprises several assemblies, such as drive units, frames, transmissions, sensor devices, and / or control units. Drive units can be electric motors or internal combustion engines, with uniformly rotating drives being preferable to a linearly operating piston engine in order to avoid generating their own easily detectable vibrations. The frame assemblies connect the components of the support platform and create installation space depending on the design principle. For example, an output unit that transmits emitted signals into the ground can be mounted at the front, mid-axle, or rear. Depending on the design, the frame assemblies serve to create the necessary clearances.Gearboxes adjust the rotational speeds of different assemblies, thus generating work speeds adapted to the specific task. Depending on the degree of autonomy of the seismic simulator in its operational state, different sensors are required. For hand-operated vehicles, only display devices indicating the driving status are sufficient, while for autonomously functioning units, sensors for orientation, vehicle monitoring, and signal transmission are known to be necessary. Control devices of the seismic simulator according to the invention include hand-operated actuators such as pedals and steering mechanisms, wired or wireless remote controls, and / or electronic control units for autonomous driving.

[0028] As is well known, seismic waves are introduced into the subsurface for geological investigations to study their propagation behavior, such as propagation speed, adsorption, reflection, etc. This generates a consistently uniform signal, for example, over 10 seconds with increasing frequency and constant amplitude. Such signals can be extracted from the Earth's surface vibration profile using mathematical methods. However, increased background noise with comparable frequencies, varying amplitudes, and uneven temporal profiles complicates detection.

[0029] The seismic detector according to the invention comprises a signaling unit that generates various seismic oscillations based on natural or artificial patterns. For example, to amplify background noise in rural areas, natural oscillations comparable to Love and Rayleigh waves can be generated, indicating an earthquake and thus concealing actual oscillations, for example, from military operations. Oscillations that mimic natural events are suitable for deceiving the sensors of modern military mines when crossing minefields or for concealing tunnel excavation work in border security. Furthermore, artificial oscillations can also be simulated in rural areas, for example, those from agricultural or forestry machinery or herds of animals.

[0030] In urban areas, vibrations can be generated to mimic road or rail traffic, construction site operations, groups of people, or the vibration emissions from infrastructure. Construction site emissions, in particular, are inconspicuous signals that perfectly mask the vibrations of a short- or medium-term deployment of military forces.

[0031] Furthermore, the signaling unit according to the invention is also capable of generating vibration patterns of military wheeled or tracked vehicles or troop movements. With a plurality of seismic simulators according to the invention, signals can be generated that indicate a large number of military vehicles or military units and, if initiated at different locations, can distract and / or divide enemy defense forces.

[0032] The generated vibration patterns are transmitted to the Earth's surface by means of an output unit. A hydraulic vibrator is particularly advantageous for this output unit. Forces of up to 400 kN are possible with vehicle masses of up to 40 t. However, the seismic simulators according to the invention also exhibit lower vehicle masses and thus greater agility and usability, especially in off-road applications.

[0033] For better understanding, the following process is described: The seismic simulator's signal unit generates a vibration pattern. This pattern depends on the circumstances of the planned military operation and the conditions at the deployment site. If a covert military operation is planned, background noise is generated to mask the actual vibrations of the operation, such as crossing a minefield or tunneling activities. If the signals are intended to distract the enemy, the vibration patterns are based on the signature of moving vehicles or troop movements. The conditions at the deployment site allow for the simulation of road or rail traffic, construction site operations, groups of people, or vibrations emitted by infrastructure in urban areas, agricultural or forestry machinery, and natural vibrations caused by earthquakes in rural areas.

[0034] The seismic simulator moves under its own power to the planned deployment location and emits the vibration patterns into the ground using an output unit to amplify background noise.

[0035] It shows Fig. 1 a seismic simulator according to the invention in schematic representation.

[0036] It shows Fig. 1. A support platform 1 with a chassis 2. The support platform 1 includes components not shown, such as a drive unit, a frame, several gearboxes, and sensor devices. A radio-controlled control unit 3 is provided for data transmission. The vibrations are transmitted to the ground 5 via a hydraulic vibrator 4. Reference symbol list 1 carrier platform 2 Chassis 3 radio remote control unit 4 Hydraulic Vibrator 5 Floor

Claims

[1] Seismic simulator on a support platform (1) for generating simulated seismic signals comprising: a) a signaling unit programmed to dynamically vary the intensity, frequency and duration of the emitted background noise signals to simulate realistic seismic scenarios, b) an output unit which introduces the emitted signals into the ground (5) to amplify background noise. [2] Device according to claim 1, wherein the signaling unit simulates background noise reflecting artificial and / or natural environmental conditions. [3] Device according to one of claims 1 and 2, wherein the signaling unit generates seismic signals to enable the avoidance or circumvention of mines. [4] Device according to one of claims 1 and 2, wherein the background noises are configured by the signaling unit to simulate a signature of operated vehicles or troop movements, [5] Device according to one of claims 1 and 2 wherein the signal unit generates seismic signals so that signals resulting from tunnel excavation activities are superimposed.

Images