Abstract: A seismic source includes a base plate having a bottom surface contacting a surface of the ground. The coupler is connectable to the bottom surface of the base plate and projects downward from the base plate. The coupler contain soil under the base plate during operation. Another seismic source includes a base plate and at least one contact member. The base plate has an upper surface engaging the seismic source, a lower surface configured to contact a soil surface. The contact member projects from the lower surface and has a planar bottom surface with a surface area less than a surface area of the base plate lower surface.

Abstract: A wheel suspension, having a wheel mount, on which at least one wheel is to be rotatably mounted, having at least one upper suspension arm flexibly coupled with the wheel mount for guiding the wheel, having at least one lower suspension arm flexibly coupled with the wheel mount for guiding the wheel, and having at least one strut, which has at least one bearing point to be arranged fixed on the vehicle body, via which the strut is to be articulated at least indirectly on the vehicle body of the motor vehicle, wherein one of the suspension arms is flexibly coupled with the strut, and wherein the one suspension arm is free of a bearing point to be arranged fixed on the vehicle body, via which the one suspension arm is to be mounted on the vehicle body.

Abstract: Disclosed are devices and methods for marine geophysical surveying. An example device may comprise a shell, a base plate, wherein the base plate is coupled to the shell, a driver disposed within the shell, an inner spring element disposed within the shell, wherein the inner spring element is coupled to the driver, wherein outer ends of the inner spring element are coupled to outer ends of the inner spring element at spring element junctions, an outer spring element disposed within the shell, wherein outer ends of the outer spring element are coupled to the spring element junctions, and a back mass disposed on the outer spring element.

Abstract: Apparatus for generating shear waves usable in determining shear waves usable in determining distribution and orientation of geologic features in the subsurface among other uses, having a hammer bar with a rod connected to a center position of the hammer bar and having a coil spring therewith and two magnets on each side of the rod to hold the hammer bar in a position to strike the anvil bar.

Abstract: A vibration motor includes a fixed member, a vibration unit, and an elastic member. The fixed member includes a housing having a receiving space and a coil received in the receiving space and assembled with the housing. The vibration unit includes a first weight, a second weight, and a magnet sandwiched by the first and second weights. The motor further includes a positioning guiding member including a first weight guiding rail, a second weight guiding rail, a first base guiding rail formed on the bottom wall, a second base guiding rail formed on the bottom wall, a first movement rail formed by the first weight guiding rail and the first base guiding rail, a second movement rail formed by the second weight guiding rail and the second base guiding rail, and a plurality of rolling members accommodated in the first movement rail and the second movement rail.

Abstract: A seismic land vibrator, comprising a baseplate comprising a substantially flat, rigid member; at least one driven member that is connected with the baseplate and extends in a direction that is substantially perpendicular to baseplate; a rotation sensor that is coupled to the baseplate and adapted to provide a signal that is indicative of rotational movement of at least a portion of the baseplate.

Abstract: Aspects described herein relate to an electromagnetic seismic vibrator (EMSV) architecture that provide wide frequency range operation, ground force application with high fidelity, and low environmental impact. The EMSV architecture can include a base member that can support a force coil and mitigate electrical heating due, at least in part, to spurious currents. The EMSV architecture can include means for restricting movement of a reaction member included in the EMSV architecture relative to the base member. Such means can permit mitigation of damage of the EMSV architecture in scenarios in which control of the EMSV architecture may fail.

Abstract: A sound source for geophysical studies of the earth for oil, gas and other natural resource exploration and more specifically a streamlined design of a hydraulically controlled impulsive sound source that may be inserted into oil wells and bore holes and a system and method for obtaining high quality seismic records from the impulsive sound source by adjusting and maintaining pressures within the well or bore hole.

Abstract: A seismic land vibrator, comprising a baseplate comprising a substantially flat, rigid member; at least one driven member that is connected with the baseplate and extends in a direction that is substantially perpendicular to baseplate; a rotation sensor that is coupled to the baseplate and adapted to provide a signal that is indicative of rotational movement of at least a portion of the baseplate.

Abstract: Method for seismic prospecting using counter-rotating (207-208) eccentric-mass (201, 202) vibrator (CREMV) technology adapted as vibrator sources for seismic prospecting to produce controlled sweeps, as in the manner used in modern seismic prospecting, but with large forces at low frequencies, e.g. forces >275 kN at frequencies between 1 and 5 Hz. This is achieved by adapting the CREMV to enable rotational frequency and the eccentricity (205, 206) of the masses relative to their rotation axes (203-204) to be varied independently and simultaneously, and by designing the CREMV such that the radius of rotation of the center of mass of each rotating mass is on the order of 50 cm or more.

Abstract: An impulse sound source for geophysical studies of the earth for oil, gas and other natural resource exploration and more specifically a streamlined design of a hydraulically controlled sound source that may be inserted into oil wells and bore holes for analysis of geological formations deep beneath the earth's surface.

Abstract: The invention is an electric sweep type seismic vibrator source of the type used in seismic prospecting for hydrocarbons. The source uses an engine and generator combination to create electric power for all systems on the source such as driving a frame of linear electric motors that direct a rod or piston to contact the ground in a recurring fashion along with driving the source from location to location through a survey area. Preferably, a foot is arranged on the bottom end of the rod or piston for contact with the ground and by engaging the grid of motors to push down against the ground in a rapid progression, acoustic energy is created and delivered into the ground for geophones to sense and record.

Abstract: An apparatus for generating seismic waves includes a housing, a strike surface within the housing, and a hammer movably disposed within the housing. An actuator induces a striking motion in the hammer such that the hammer impacts the strike surface as part of the striking motion. The actuator is selectively adjustable to change characteristics of the striking motion and characteristics of seismic waves generated by the impact. The hammer may be modified to change the physical characteristics of the hammer, thereby changing characteristics of seismic waves generated by the hammer. The hammer may be disposed within a removable shock cavity, and the apparatus may include two hammers and two shock cavities positioned symmetrically about a center of the apparatus.

Abstract: Method, source array and source element that generate seismic waves. The source element includes an enclosure having an opening covered by a piston; a local supply accumulator fluidly communicating with an interior of the enclosure, a pressure of the fluid inside the local supply accumulator being larger than a pressure of the fluid inside the enclosure; a local supply valve located between the local supply accumulator and the enclosure and configured to control a flow of the fluid from the local supply accumulator to the interior of the enclosure; and a controller configured to control the local supply valve such that the pressure inside the enclosure does not fall below a first preset value based upon an ambient pressure of the enclosure while seismic waves are generated.

Abstract: An apparatus for generating seismic waves includes a housing, a strike surface within the housing, and a hammer movably disposed within the housing. An actuator induces a striking motion in the hammer such that the hammer impacts the strike surface as part of the striking motion. The actuator is selectively adjustable to change characteristics of the striking motion and characteristics of seismic waves generated by the impact. The hammer may be modified to change the physical characteristics of the hammer, thereby changing characteristics of seismic waves generated by the hammer. The hammer may be disposed within a removable shock cavity, and the apparatus may include two hammers and two shock cavities positioned symmetrically about a center of the apparatus.

Abstract: A marine seismic source comprises a housing having a central axis, an open end, and a closed end opposite the open end. In addition, the source comprises a piston coaxially disposed within the housing. In addition, the source comprises a flywheel disposed within the housing and axially positioned between the closed end and the piston. The flywheel is configured to rotate about a rotational axis. Further, the source comprises a connecting rod moveably coupling the piston to the flywheel. The connecting rod has a first end pivotally coupled to the piston and a second end pivotally coupled to the flywheel. The second end of the connecting rod has a first position at a first distance measured radially from the rotational axis, and a second position at a second distance measured radially from the rotational axis. The first distance is less than the second distance.

Abstract: An impulse sound source for geophysical studies of the earth for oil, gas and other natural resource exploration and more specifically a streamlined design of a hydraulically controlled sound source that may be inserted into oil wells and bore holes for analysis of geological formations deep beneath the earth's surface.

Abstract: An electromagnetic system having a reaction mass with a field winding embedded therein, a base plate having an inner annular surface and an outer annular surface, and an armature winding coupled to at least a portion of the inner annular surface and at least a portion of the outer annular surface of an upper end portion of the base plate. In operation, directing an electric current in at least one of the field winding and the armature winding causes at least one of the base plate and the reaction mass to move relative to each other. The electromagnetic system can be used for seismic exploration and vibroseis applications, among other uses.

Abstract: An excitation device for downhole seismic testing, includes an excitation hammer, a holding arm connected at one end thereof to the excitation hammer to allow the excitation hammer to rotate about the other end thereof, a support post having the other end of the holding arm rotatably coupled to an upper end thereof to support the excitation hammer and the holding arm at a certain height, and an excitation source configured to allow the support post to stand upright on the upper side thereof and which generates a seismic wave when struck by the rotated excitation hammer. The support post is formed at a lower end thereof with a securing section detachably inserted into a groove for the support post formed on the upper side of the excitation source such that the support post, the holding arm, the excitation hammer and the excitation source can be separated from each other.

Abstract: A seismic vibrator includes a baseplate having a surface configured to couple to a ground surface. A driver is coupled to the baseplate and is configured to move the baseplate in a vibratory manner. A decoupling system is coupled to a part of the baseplate other than the ground-contacting surface. The decoupling system includes a first layer having a Young's modulus greater than that of a second layer coupled to the first layer. The second layer is coupled to the baseplate. The Young's moduli, thicknesses and masses of the first and second layer are selected to provide the decoupling system with a resonant frequency of at most, a spatial aliasing frequency of seismic sensors deployed on the ground surface or a lowest seismic frequency of interest.

Abstract: The invention relates to delivering seismic energy with rotating eccentrics where the eccentrics are driven at relatively high, but different rotational rates create a heterodyned frequency of seismic energy into the earth. The rotating eccentrics may be rotated in opposite directions to deliver pressure waves or in the same direction to create a shear component to the seismic impulses.

Abstract: The invention relates to a sweep-type vibratory seismic source where a baseplate is put to the ground and a series of impulses are applied through the baseplate into the ground and where the baseplate may periodically de-couple from the ground during the delivery of the impulses. A de-coupling baseplate tends to undertake a very high frequency flexing while high frequency energy is being delivered to the ground. The high frequency flexing may be picked up by the vibrator control system and interpreted as an unintended signal being delivered into the ground. While there are already issues getting high frequency data in the return wave field, allowing the vibrator electronics to alter the actual signal in a manner intended to squelch the high pitched ringing of the baseplate is apt to reduce the high frequency data in the data record. One solution for reducing the de-coupling and the ringing of the baseplate is a dampening pad positioned between the baseplate and the ground.

Abstract: A seismic vibrator includes a baseplate having a surface configured to couple to a ground surface. A driver is coupled to the baseplate and is configured to move the baseplate in a vibratory manner. A decoupling system is coupled to a part of the baseplate other than the ground-contacting surface. The decoupling system includes a first layer having a Young's modulus greater than that of a second layer coupled to the first layer. The second layer is coupled to the baseplate. The Young's moduli, thicknesses and masses of the first and second layer are selected to provide the decoupling system with a resonant frequency of at most, a spatial aliasing frequency of seismic sensors deployed on the ground surface or a lowest seismic frequency of interest.

Abstract: A coupling structure for a resonant microgyroscope produced on a substrate, wherein the coupling structure enables a vibratory movement provided by an excitation mechanism to be detected along a first axis, and enables it to be transmitted to seismic masses lying in a plane containing the first axis. The coupling structure includes a closed assembly of beams connected to the seismic masses so as to be anchored only to the seismic masses, wherein the assembly is positioned to detect the vibratory movement provided by the excitation mechanism, and to transmit it to the seismic masses along at least a second axis contained in the plane, wherein the coupling structure has no point of anchorage to the substrate.

Abstract: An apparatus disclosed herein includes a shell movably coupled to a base. The shell defines a chamber, and a counterweight is disposed in the chamber. A first spring is coupled to the shell and a first end of the counterweight, and a second spring is coupled to the shell and a second end of the counterweight. The first spring is oriented at a first angle, and the second spring is oriented at a second angle different than the first angle. The example apparatus further includes an actuator coupled to the first spring or the second spring. The actuator is to oscillate the counterweight to enable the shell to provide an acoustic signal.

Abstract: A marine source sub-array and method for generating a pressure wave in a body of water. The marine source sub-array includes a float configured to float in the body of water; base plates connected to the float through cables; plural individual source elements connected to the base plates and configured to generate pressure waves underwater; and a coverage plate located between the plural individual source elements and the float. The coverage plate has a surface area larger than a surface area of the float.

Abstract: The invention relates to maintaining constant holddown force on the vibrator baseplate during actuation. The invention described measures the weight on the point of locomotion verses the baseplate and dynamically adjusts the forces required to keep the holddown force on the baseplate constant.

Abstract: Methods and systems are provided for induc ing seismic energy waves in a subterranean formation. More particularly, improved seismic transducers are provided that comprise enhanced baseplates. Baseplates are provided that comprise an intermediate plate and a plurality of contact plates secured to the underside of the intermediate plate. The contact plates provide a surface area for engagement with the ground surface that is more limited than the lower surface area of the intermediate plate. Advantages of such baseplate enhancements include, but are not limited to, a reduction of baseplate harmonics or ringing and enhanced baseplate strength so as to reduce baseplate fatigue or failure, a reduction of baseplate flexure. These advantages ultimately translate to improved seismic surveys, having higher resolution of the formations surveyed and resulting in surveys reaching greater depths.

Abstract: An excitation device for downhole seismic testing, includes an excitation hammer, a holding arm connected at one end thereof to the excitation hammer to allow the excitation hammer to rotate about the other end thereof, a support post having the other end of the holding arm rotatably coupled to an upper end thereof to support the excitation hammer and the holding arm at a certain height, and an excitation source configured to allow the support post to stand upright on the upper side thereof and which generates a seismic wave when struck by the rotated excitation hammer. The support post is formed at a lower end thereof with a securing section detachably inserted into a groove for the support post formed on the upper side of the excitation source such that the support post, the holding arm, the excitation hammer and the excitation source can be separated from each other.

Abstract: Methods and systems are provided for inducing seismic vibrations into subterranean formations. Seismic transducers may comprise a frame, a reaction mass, a driver, and a baseplate. The driver actuates the reaction mass, imparting a vibratory energy to the baseplate. This vibratory energy is then imparted directly to the ground surface to propagate seismic waves into the formation. These seismic waves are then reflected by subsurface geological features. The reflected seismic waves may then be detected and interpreted by seismic detectors to reveal seismic information representative of the surveyed region. An external dampener may be secured to the baseplate, which provide, among other benefits, a damping effect to the baseplate. Advantages include, reduced undesirable baseplate harmonic distortion or “ringing,” reduced baseplate decoupling, and reduced seismic noise due to flexure reduction and more uniform baseplate-to-ground conformance.

Abstract: A seismic energy source includes a base plate and a block fixedly coupled in a frame. The base plate is configured for contact with a part of the Earth's subsurface to be seismically energized. The frame has a first electromagnet associated therewith. A second electromagnet is disposed in a travelling reaction mass, which is movably disposed in the frame between the first electromagnet assembly and the top block. The reaction mass includes at least a third electromagnet associated therewith. The source has circuits for selectively energizing the first, second and at least a third electromagnets, and which are configured to energize the first and second electromagnets to repel each other such that the traveling reaction mass is lifted from the first electromagnet, and configured to energize the at least a third electromagnet after a selected delay time to cause attraction between the traveling reaction mass and the top block.

Abstract: A seismic source of the present disclosure includes a first rotation member and a second rotation member having a common axis of rotation and rotated at a same rotational rate in mutually opposite directions. In addition, the seismic source may include a first mass that is eccentrically coupled to the first rotation member and rotates along with the first rotation member. A second mass may be eccentrically coupled to the second rotation member and configured to rotate along with that member. The second mass may be configured such that the center of gravity of the second mass is located radially external to the center of gravity of the first mass relative to the common axis of rotation. The center of gravities of the first and second mass may be located at the same location along a length of the common axis of rotation.

Abstract: Methods and systems are provided for inducing seismic energy waves in a subterranean formation. More specifically, seismic transducers are provided that incorporate enhanced seismic baseplates. In certain embodiments, baseplates comprise certain enhancements such as having a perimeter in the shape of a polygon, such as, a hexagon or an octagon. In other embodiments, the perimeter of the baseplate may take the form of a polygon having n sides, where n is any integer greater than 4. Advantages of such baseplate enhancements include, but are not limited to, a reduction of baseplate harmonics or ringing, enhanced baseplate strength so as to reduce baseplate fatigue or failure, a reduction of baseplate flexure, and a consequent reduction of baseplate weight resulting in a more responsive baseplate. These advantages ultimately translate to improved seismic surveys, having higher resolution of the formations surveyed and resulting in surveys reaching greater depths.

Abstract: A coupling structure for a resonant microgyroscope produced on a substrate, wherein the coupling structure enables a vibratory movement provided by an excitation mechanism to be detected along a first axis, and enables it to be transmitted to seismic masses lying in a plane containing the first axis. The coupling structure includes a closed assembly of beams connected to the seismic masses so as to be anchored only to the seismic masses, wherein the assembly is positioned to detect the vibratory movement provided by the excitation mechanism, and to transmit it to the seismic masses along at least a second axis contained in the plane, wherein the coupling structure has no point of anchorage to the substrate.

Abstract: A seismic wave generating device and methods for generating seismic waves having a relatively strong longitudinal energy and a relatively weak transverse energy are disclosed. A device may have a hollow casing and a striking member passing through the hollow casing, the striking member or the hollow casing bearing a spacing member. A method may drive the hollow casing into the earth, then remove earth from within the hollow casing. The method may place a striking member through the hollow casing and may drive the striking member further into the earth to create seismic waves with a relatively strong longitudinal energy and a relatively weak transverse energy.

Abstract: An adapted seismic vibrator for obtaining a true ground force comprising: a baseplate pad; a baseplate drive system, wherein the drive system is connected to the baseplate pad and moves the baseplate pad up and down; a vibrator controller electronics, wherein the electronics are connected to the drive system and causes the drive system to move the baseplate pad up and down; and a plurality of load cell sensors disposed between the baseplate pad and ground, wherein the sensors measure the vibrator output force during a sweep. A method of obtaining a true ground force sweep comprising the steps of: using the load cell sensors to measure an actual output force of a seismic vibrator and electronics to obtain an actual ground force data; using inversion to invert the actual ground force data and desired original pilot sweep to obtain a revised pilot sweep that produces a true ground force sweep; and entering the true ground force sweep into the electronics.

Abstract: This invention relates to operating a seismic vibrator to produce a uniform displacement sweep wherein the baseplate drive is connected to the baseplate and the baseplate is moved in an up and down or reciprocating pattern creating displacement of the earth. The reciprocating pattern and physical displacement of the baseplate and the ground in contact with the baseplate is maintained at a relatively constant distance over at least most of the frequencies that are delivered into the earth although a constant displacement of the baseplate at higher frequencies will require greater power. The high frequency energy is more significantly present in the data traces of the recorded return wavefield and shows that Q attenuation is not fully to blame for the relative absence of high frequency data but rather in failing to effectively deliver high frequency energy into the earth in the first place.

Abstract: A technique or mechanism for use with a vibrator to be employed for subterranean surveying includes receiving, from a sensor, a unipolar indication of movement of an actuator mass of the vibrator. According to the indication from the sensor, a correlation is determined between the movement of the actuator mass and a reference signal provided to cause movement of the actuator mass.

Abstract: A marine seismic source comprises a housing having a central axis, an open end, and a closed end opposite the open end. In addition, the source comprises a piston coaxially disposed within the housing. In addition, the source comprises a flywheel disposed within the housing and axially positioned between the closed end and the piston. The flywheel is configured to rotate about a rotational axis. Further, the source comprises a connecting rod moveably coupling the piston to the flywheel. The connecting rod has a first end pivotally coupled to the piston and a second end pivotally coupled to the flywheel. The second end of the connecting rod has a first position at a first distance measured radially from the rotational axis, and a second position at a second distance measured radially from the rotational axis. The first distance is less than the second distance.

Abstract: A seismic vibrator has a base plate with at least four isolators isolating a frame from the base plate. Each of these isolators is offset from the plate's footprint on shelves to free up area on the plate's top surface. An accelerometer disposed directly on the base plate detects the acceleration imparted to the plate. To reduce flexing and bending, the plate has an increased stiffness and approximately the same mass of a plate for a comparably rated vibrator. The accelerometer disposes at a particular location of the plate that experiences transition between longitudinal flexing along the plate's length. This transition location better represents the actual acceleration of the plate during vibration and avoids overly increased and decreased acceleration readings that would be obtained from other locations on the plate.

Abstract: Methods and systems are provided for inducing seismic vibrations into subterranean formations. Seismic transducers may comprise a frame, a reaction mass, a driver, and a baseplate. The driver actuates the reaction mass, imparting a vibratory energy to the baseplate. This vibratory energy is then imparted directly to the ground surface to propagate seismic waves into the formation. These seismic waves are then reflected by subsurface geological features. The reflected seismic waves may then be detected and interpreted by seismic detectors to reveal seismic information representative of the surveyed region. An external dampener may be secured to the baseplate, which provide, among other benefits, a damping effect to the baseplate. Advantages include, reduced undesirable baseplate harmonic distortion or “ringing,” reduced baseplate decoupling, and reduced seismic noise due to flexure reduction and more uniform baseplate-to-ground conformance.

Abstract: A seismic source signal generator includes a mass, a primary accumulator and a secondary accumulator, the secondary accumulator having an internal volume smaller than an internal volume of the primary accumulator. A method for generating a signal using a seismic vibrator includes operating the seismic vibrator using hydraulic fluid, damping hydraulic pressure deviations in the hydraulic fluid using a first accumulator in hydraulic communication with the hydraulic fluid, and damping pressure deviations in the hydraulic fluid using a second accumulator in hydraulic communication with the hydraulic fluid, the second accumulator having an internal volume smaller than an internal volume of the first accumulator.

Abstract: A technique or mechanism for use with a vibrator to be employed for subterranean surveying includes receiving, from a sensor, a unipolar indication of movement of an actuator mass of the vibrator. According to the indication from the sensor, a correlation is determined between the movement of the actuator mass and a reference signal provided to cause movement of the actuator mass.

Abstract: A seismic energy source includes a base plate having a first electromagnet thereon. A reaction mass has a second electromagnet thereon. A switchable current source is connected to the first and second electromagnets such that the first electromagnet repels the second electromagnet. At least one damper is functionally connected between the reaction mass and the base plate. The damper is configured to enable faster movement of the reaction mass away from the base plate than toward the base plate.

Abstract: A marine seismic streamer includes a jacket substantially covering an exterior of the streamer. At least one strength member is disposed along the length of the jacket. A sensor mount is coupled to the strength member. At least one particle motion sensor is suspended within the sensor mount at a selected location along the jacket. The at least one particle motion sensor is suspended in the jacket by at least one biasing device. A mass of the particle motion sensor and a force rate of the biasing device are selected such that a resonant frequency of the particle motion sensor within the sensor jacket is within a predetermined range. The sensor mount is configured such that motion of the jacket, the sensor mount and the strength member is substantially isolated from the particle motion sensor.

Abstract: The present invention provides an accelerated weight drop for use as a seismic energy source, a method for operating an accelerated weight drop for use as a seismic energy source, and a seismic survey system including the accelerated weight drop. The accelerated weight drop, among other elements, may include a striker positionable over a surface, a compressed gas spring configured to drive the striker toward the surface thus creating seismic waves within the surface, and a cushioning means positioned proximate the compressed gas spring for dissipating reflected energy. In this embodiment the striker is slidably coupled to the compressed gas spring.

Abstract: One example of a seismic vibrator system includes a baseplate having a bottom surface and a coupling mechanism, the coupling mechanism being operable to a deployed position; a hold-down mass connected to the baseplate; a lifting mechanism in operational connection with the hold-down mass and the baseplate to apply a selected hold-down weight to the baseplate; and a driving mechanism functionally connected to the baseplate to transmit seismic energy through the baseplate into a ground surface to which the baseplate is coupled, wherein the coupling mechanism is urged outward from the bottom surface and into physical contact with the ground surface when operated to the deployed position.

Abstract: A seismic vibrator has a base plate with at least four isolators isolating a frame from the base plate. Each of these isolators is offset from the plate's footprint on shelves to free up area on the plate's top surface. An accelerometer disposed directly on the base plate detects the acceleration imparted to the plate. To reduce flexing and bending, the plate has an increased stiffness and approximately the same mass of a plate for a comparably rated vibrator. The accelerometer disposes at a particular location of the plate that experiences transition between longitudinal flexing along the plate's length. This transition location better represents the actual acceleration of the plate during vibration and avoids overly increased and decreased acceleration readings that would be obtained from other locations on the plate.

Abstract: Systems and methods are implemented for evaluating underground structures and objects, particularly relatively shallow underground structures and objects, using a seismic or acoustic source signal and a resulting seismic or acoustic wave. A discrete or unitary apparatus incorporates both a seismic source transducer and a receiver transducer within a common housing or frame. A unitary seismic probe includes a ground engaging member and a seismic source mechanically coupled to the ground engaging member. The probe further includes a sensor assembly mechanically coupled to the ground engaging member and configured to sense ground vibrations resulting from an impact to the ground engaging member by the seismic source.

Abstract: A seismic source signal generator includes a mass, a primary accumulator and a secondary accumulator, the secondary accumulator having an internal volume smaller than an internal volume of the primary accumulator. A method for generating a signal using a seismic vibrator includes operating the seismic vibrator using hydraulic fluid, damping hydraulic pressure deviations in the hydraulic fluid using a first accumulator in hydraulic communication with the hydraulic fluid, and damping pressure deviations in the hydraulic fluid using a second accumulator in hydraulic communication with the hydraulic fluid, the second accumulator having an internal volume smaller than an internal volume of the first accumulator.