Abstract: A method for processing waveform data for determining a characteristic inside an object includes receiving raw waveform data collected with waveform sensors over a given object; pretraining a first neural network with the raw waveform data so that structural information within the raw waveform data is extracted; receiving a first task to be performed with regard to the object, based on the raw waveform data; fine-tuning a second neural network, based on (1) pretrained parameters from the first neural network, and (2) the first task; and generating an image of the object using the second neural network with refined parameters.

Abstract: A method for waveform inversion, the method including receiving observed data d, wherein the observed data d is recorded with sensors and is indicative of a subsurface of the earth; calculating estimated data p, based on a model m of the subsurface; calculating, using a trained neural network, a misfit function JML; and calculating an updated model mt+1 of the subsurface, based on an application of the misfit function JML to the observed data d and the estimated data p.

Abstract: A method for partial differential equation inversion, the method including receiving measured data do; selecting an objective function having first and second measures N1 and N2, wherein the objective function depends on three independent variables V, u, and f, V being a perturbation of a wave equation operator L from a background operator L0, u being a wavefield that satisfies the wave equation operator L, and f being a source function that describes the source of the waves; optimizing with a processor the objective function by finding a minimum or a maximum using the inversion; calculating with the processor solutions V*, u*, and f* of the three independent variables V, u, and f; and generating with the processor an image of an object based on the solutions V*, u*, and f*.

Abstract: A method for partial differential equation inversion, the method including receiving measured data do; selecting an objective function having first and second measures N1 and N2, wherein the objective function depends on three independent variables V, u, and f, V being a perturbation of a wave equation operator L from a background operator L0, u being a wavefield that satisfies the wave equation operator L, and f being a source function that describes the source of the waves; optimizing with a processor the objective function by finding a minimum or a maximum using the inversion; calculating with the processor solutions V*, u*, and f* of the three independent variables V, u, and f; and generating with the processor an image of an object based on the solutions V*, u*, and f*.

Abstract: An apparatus and system for acquiring seismic data over a loose surface is disclosed. The apparatus includes a housing capable of moving on the loose surface with an opening configured at a bottom surface of the housing. The apparatus further includes a seismic sensing unit configured within the housing at an angle with respect to a horizontal plane. The horizontal plane may be the bottom surface of the housing. The seismic sensing unit is operable to retractably move within the housing towards and away from the opening. In response to the seismic sensing unit moving towards the opening, the seismic sensing unit establishes contact with the loose surface for acquiring the seismic data.

Abstract: A system for acquiring seismic data over sand dune surfaces is provided. The system includes a seismic wave generator for emitting a plurality of seismic signals into the Earth in an area covered by sand dunes. The system also includes a sand streamer for acquiring seismic data over the sand dune surfaces, such that the sand streamer includes a plurality of geophones. The plurality of geophones receive a plurality of wave signals transmitted from a subsurface corresponding to the sand dune surface, in response to emission of the plurality of seismic signals to the area of the sand dune surface by the seismic wave generator. Each geophone of the plurality of geophones is mounted on a panel wherein, one or more sides of the panel are coupled loosely to one or more rigid plates. The one or more rigid plates provide stability and mobility to assembly of panels and the plurality of geophones, thereby enabling the sand streamer to move efficiently over the surface of the sand dune.

Abstract: A method and apparatus for measuring distance on a loose surface is disclosed. The apparatus includes a frame and a wheel operatively coupled to the frame. The wheel rotates relative to the frame. Further, the wheel includes a hub for operatively coupling the wheel with the frame. The hub rotates relative to the frame in response to one of pushing and pulling of the frame. To increase traction between the wheel and the loose surface, a plurality of spikes is provided on a peripheral surface of the wheel, projecting outwardly away from the hub. As the peripheral surface rolls on the surface, the distance traversed by the wheel is measured by calculating the number of rotations made by the wheel. A counter is operatively coupled to the wheel for tracking the number of rotations made by the wheel as the peripheral surface of the wheel rolls on the loose surface.

Abstract: An apparatus and system for acquiring seismic data over a loose surface is disclosed. The apparatus includes a housing capable of moving on the loose surface with an opening configured at a bottom surface of the housing. The apparatus further includes a seismic sensing unit configured within the housing at an angle with respect to a horizontal plane. The horizontal plane may be the bottom surface of the housing. The seismic sensing unit is operable to retractably move within the housing towards and away from the opening. In response to the seismic sensing unit moving towards the opening, the seismic sensing unit establishes contact with the loose surface for acquiring the seismic data.

Abstract: A method and apparatus for measuring distance on a loose surface is disclosed. The apparatus includes a frame and a wheel operatively coupled to the frame. The wheel rotates relative to the frame. Further, the wheel includes a hub for operatively coupling the wheel with the frame. The hub rotates relative to the frame in response to one of pushing and pulling of the frame. To increase traction between the wheel and the loose surface, a plurality of spikes is provided on a peripheral surface of the wheel, projecting outwardly away from the hub. As the peripheral surface rolls on the surface, the distance traversed by the wheel is measured by calculating the number of rotations made by the wheel. A counter is operatively coupled to the wheel for tracking the number of rotations made by the wheel as the peripheral surface of the wheel rolls on the loose surface.

Abstract: A system for acquiring seismic data over sand dune surfaces is provided. The system includes a seismic wave generator for emitting a plurality of seismic signals into the Earth in an area covered by sand dunes. The system also includes a sand streamer for acquiring seismic data over the sand dune surfaces, such that the sand streamer includes a plurality of geophones. The plurality of geophones receive a plurality of wave signals transmitted from a subsurface corresponding to the sand dune surface, in response to emission of the plurality of seismic signals to the area of the sand dune surface by the seismic wave generator. Each geophone of the plurality of geophones is mounted on a panel wherein, one or more sides of the panel are coupled loosely to one or more rigid plates. The one or more rigid plates provide stability and mobility to assembly of panels and the plurality of geophones, thereby enabling the sand streamer to move efficiently over the surface of the sand dune.