Abstract: Disclosed is a pressure tolerant seismic source for deep water survey. The seismic source can include an electromagnetic coil for generating an electromagnetic pulse, a piston plate movable by said electromagnetic pulse, and a housing with a first chamber and a second chamber separated by each other via a common bulkhead arrangement. The seismic source can also include that the coil is arranged within the first chamber and the piston plate arranged within the second chamber. The seismic source can also include the second chamber is at least partly filled with a liquid coupled to the plate so that due to movement of the plate at least one pressure pulse is generated traveling through the liquid within said second chamber.

Abstract: A method, system and computer program product for determining soil properties comprising a probe including at least a liquid injection port and a pressure transducer. The probe is pushed into a soil and one or more pumping tests are carried out, wherein during a pumping test infiltration liquid is pumped through the liquid injection port of the probe. By means of the pressure transducer a pressure response in the soil resulting from the injection of liquid through the liquid injection port is measured for each of the one or more pumping tests.

Abstract: A system for measuring the attitude of an object in a fixed frame of reference from a moving frame of reference, comprising a first imaging device for producing image data for the object from a first direction, a second imaging device for producing image data for the object from a second direction having a component perpendicular to the first direction and an attitude sensing arrangement for determining an attitude of the first and second imaging devices with respect to the fixed frame of reference at the time the respective images are taken and for generating attitude data. An image processing system analyses and combines the respective image data and attitude data to determine the attitude of the object. The system is particularly useful for determining attitude of offshore piles during piling operations or for monitoring the departure angles of pipes and cables during laying thereof.

Abstract: An underwater positioning system provides position information for a rover, moveable within a reference frame. The system may comprise: at least one beacon having a light source, located at a fixed position within the reference frame; an underwater imaging device, moveable with the rover in the reference frame to observe the light source from different viewpoints and determine direction data representing a direction or change in direction of the light source with respect to the imaging device; an orientation sensor, associated with the imaging device to determine an orientation of the imaging device with respect to the reference frame and generate orientation data; and a scaling element for providing scaling data representative of a distance between the imaging device and the light source. Various different beacons may be provided. In alternative system implementations, the locations of light source(s) and underwater imaging device are reversed between rover and beacon(s).

Abstract: The invention relates to a pore pressure monitoring device, for use in geotechnical engineering, adapted to be deployed underground for monitoring pore-water pressure in the ground, comprising a pressure sensor cavity (2) and a pressure sensor means (4), for sensing a fluid (6) pressure of a fluid in the sensor cavity (2), further comprising a degassing means (10), comprising a gas discharge means (14) and a gas-water filter means (12), wherein the gas-water filter means (12) is adapted for providing a route for gas (8) to escape from the fluid (6) in the sensor cavity (2), towards the gas discharge means (14) for discharging the filtered gas (8) to the atmosphere. The invention also relates to a method for monitoring pore-water pressure.

Abstract: An unmanned underwater vehicle (UUV) with a hydraulic system (100) for use in cold surroundings and method of controlling such hydraulic system. The hydraulic system (100) comprises a hydraulic circuit (10). One or more tools (21,22) may be hydraulically operable via the hydraulic circuit (10). A pump (32) is configured to pressurize a flow of hydraulic fluid (F) via the hydraulic circuit (10) e.g. for actuating the tools (21,22). A valve system (40) comprises control valves (41,42,43) disposed in the hydraulic circuit (10) for controlling the flow of hydraulic fluid (F) through the hydraulic circuit (10). A controller (50) is configured to control one or more of the control valves (43) as a function of a temperature (T) of the hydraulic fluid (F).

Abstract: A system for measuring the attitude of an object in a fixed frame of reference from a moving frame of reference, comprising a first imaging device for producing image data for the object from a first direction, a second imaging device for producing image data for the object from a second direction having a component perpendicular to the first direction and an attitude sensing arrangement for determining an attitude of the first and second imaging devices with respect to the fixed frame of reference at the time the respective images are taken and for generating attitude data. An image processing system analyses and combines the respective image data and attitude data to determine the attitude of the object. The system is particularly useful for determining attitude of offshore piles during piling operations or for monitoring the departure angles of pipes and cables during laying thereof.

Abstract: A system for surveying the structure beneath the seabed, comprising: a survey vessel; a streamer comprising a cable, a first set of N1 sensor groups positioned at a first end portion of the cable, the sensor groups of the first set being spaced from each other by a group interval, and a second set of N2 sensor groups positioned at a second end portion of the cable, the sensor groups of the second set being spaced from each other by the group interval; a sound source; wherein, when the system is in use, the survey vessel travels at a predetermined speed, towing the streamer and the sound source such that the sound source is positioned adjacent an intermediate portion of the cable between the first and second end portions of the cable; the sound source sends acoustic pulses at a predetermined period between pulses towards the seabed such that reflections are produced towards both the first set of sensor groups and the second set of sensor groups; and the speed of the survey vessel and the predetermined period o

Abstract: A method for authentication of GNSS messages by an authentication transmitter apparatus (20) comprising a reference receiver (22), an authentication server (24) and an authentication transmitter (26). The method comprises: receiving, by the reference receiver, a plurality of navigation messages (50) from a plurality of GNSS satellites (10); hashing, by the authentication server, the navigation messages to create a plurality of hashed messages; creating, by the authentication server, a table comprising the plurality of hashed messages; signing, by the authentication server, the table to create a signed table (70) comprising the hashed messages and a cryptographic signature, and transmitting, by the authentication transmitter, the signed table to an authentication receiver apparatus (40).

Abstract: The present invention relates to a seismic source array for deploying a seismic source array, comprising a housing and a plurality of seismic sources suspending from the housing, each source being configured for generating a pressure pulse signal, wherein the array further comprises a protective structure attached to the housing and defining a protective space near the housing, wherein the seismic sources in a first position relative to the housing suspend from the housing such as to be arranged in the protective space defined by the protective structure, and wherein at least one of the seismic sources suspends from the housing by means of a suspension structure configured for moving the at least one seismic source to a second position relative to the housing, the second position being located outside the protective space.

Abstract: The spatial data analysis system for processing spatial data comprises a statistical analysis module (20) and a convolutional neural network (30). The statistical analysis module (20) calculates a discrete two-dimensional spatial distribution (V(k,l)) of at least one statistical measure derived from said spatial data. The spatial distribution defines a statistical measure value of one or more statistical measure for respective raster elements (R(k,l)) in a two-dimensional raster for the data elements derived from the spatial data in the spatial window associated with the raster element. The convolutional neural network (30) is configured to provide object information of objects based on the statistical data.

Abstract: A method for providing and applying Precise Point Positioning-Integer Ambiguity Resolution (PPP-IAR) corrections for a Global Navigation Satellite System (GNSS). In a GNS signal correction system, PPP-IAR corrections (ambiguities plus receiver and satellite hardware delays) are calculated based on observation data (Pi,a, ?i,a) of n satellites for individual reference stations using a functional model, and these individual PPP-IAR corrections are merged into one single and larger set of PPP-IAR corrections. In a broadcast system, the (merged) PPP-IAR corrections are encoded at a System Control Centre (SCC) and transmitted to mobiles. In a mobile system a similar functional model is used to calculate a correction ?x to an a priori position.

Abstract: An image acquisition unit for obtaining data to generate at least one three-dimensional representation of at least one underwater structure is disclosed. The image acquisition unit includes a unit body, a plurality of cameras, a first laser light device, and a second laser light device. The first laser light device can operate based on a first illumination setting. The second laser light device can operate based a second illumination setting. The first and second cameras can be configured to capture light during the first illumination setting and generate a first set of data representative of the first laser projecting on the at least one underwater structure at a predetermined scan rate. The third and fourth cameras can be configured to capture light during the second illumination setting and generate a second set of data representative of the second laser projecting on the at least one underwater structure at the predetermined scan rate.

Abstract: A monitoring system for monitoring an offshore construction is presented. The offshore construction to be monitored comprises mutually mechanically coupled marine assets. The monitoring system comprises a data storage unit, an intrusion detection service, an input device, and an update service. The data storage unit stores data specifying a spatial range of at least one warning zone pertaining to the offshore construction. The intrusion detection service is provided to detecting an intrusion of the spatial range and for issuing an alert message upon such detection. The input device receives position information for one or more of the marine assets. The update service updates the spatial range of the at least one warning zone based on the received position information. Additionally a monitoring method and a computer program product are provided.

Abstract: The present document describes a method of hauling an equipment unit from the water onto a carrier. The carrier comprises a hauling ramp, which is arranged for being extended from a loading area into the water. The carrier further includes a first winch, and a suspension structure arranged for being extended outside the carrier over the water and over the hauling ramp. The suspension structure comprises a second winch. The method comprising the steps of: releasing, by the equipment unit, a hauling buoy. The hauling buoy is connected to a tow line extending from the equipment unit, and to a lift line extending from a lifting point on the unit. The method comprises a further step of recovering the hauling buoy from the water, connecting the tow line to the first winch and connecting the lift line to the second winch. Then, the equipment unit is hauled by towing it onto the hauling ramp using the first winch, while simultaneously guiding the equipment unit using the second winch.

Abstract: Disclosed is a system for surveying the structure beneath the seabed using a sub-bottom profiler. The system can include a survey vessel and a sub-bottom profiler mounted to travel with the survey vessel. The sub-bottom profiler can comprise a transmitter for transmitting pulses at a predetermined period between pulses towards the seabed, and a first receiver and a second receiver for receiving reflections from the seabed of each transmitted pulse. The system can also include that the transmitter and the first and second receivers are mounted along an axis in the direction of travel of the survey vessel and the transmitter is disposed between the first and second receivers and spaced from each of them by a predetermined separation.

Abstract: X-band and P-band synthetic aperture radars are used to simultaneously gather swaths of reflected radar data over a specific area simultaneously. The P-band is used to penetrate surface clutter that may be on the top of an ice formation as well as to penetrate an ice mass. X-band is used to map surface clutter on the top of an ice formation as well as to map the top of snow that may appear on an ice formation. Digital elevation maps of the top of the snow or ice clutter, the top of the ice, and the bottom of the ice and or ice thickness are constructed. By summing these various digital elevation maps a measurement of the thickness of sea ice can be determined. Further analysis of DEM, MAG and CRV layers provides an indication of the quality of the ice, for example cracks and pressure ridges, and its weak points.

Abstract: GNS signal correction system and method for calculating GNSS corrections, and complementary mobile and mobile position determination method based on these GNSS corrections. The methods employ satellite-single-differenced mixed code-and-phase system hardware delays in modelling carrier phase system observables. These system hardware delays are dynamically estimated by the signal correction system using a dynamic system state model. The estimated system hardware delays are transmitted to the mobile, which applies these delays to a dynamic mobile state model, in order to improve the accuracy and/or convergence time of mobile position estimations.

Abstract: Method for precise GNSS positioning system with improved ambiguity estimation. The method is based on the realization that, especially during convergence, the estimated float ambiguities are biased when estimated simultaneously with the ionosphere parameters. The “ionosphere-like” biases can be separated from the actual float ambiguities by using the fixed wide-lane (or extra wide-lane) integer ambiguities. The original real-valued ambiguities (e.g., one of L1, L2 and L5 in the GPS case) are corrected using the corresponding biases, resulting in reliable float ambiguities that are taken as input in the next processing step.

Abstract: A marine seismic data acquisition system, comprising: a seismic source arrangement comprising: a first seismic source adapted to be towed at a first predetermined depth and a second seismic source adapted to be towed at a second predetermined depth, which is deeper than the first predetermined depth, wherein, in use, the first seismic source transmits pulses, each pulse comprising an upwardly-travelling pressure wavefield, which is reflected at the sea/air interface to become a downwardly-travelling ghost pressure wavefield, and a downwardly-travelling primary pressure wavefield, and the second seismic source transmits pulses, each pulse comprising an upwardly-travelling pressure wavefield, which is reflected at the sea/air interface to become a downwardly-travelling ghost pressure wavefield, and a downwardly-travelling primary pressure wavefield, and wherein the first predetermined depth and the magnitude of the peak pressure of the upwardly-travelling pressure wavefield produced by the first seismic source