Discriminating between a cable locating signal and a false cable locating signal is described. A reference signal, which contains a locating signal frequency impressed on it, is transmitted in a way which provides for detection of a phase shift between the locating signal and the false locating signal. Based on the phase shift, a receiver is used to distinguish the locating signal from the false locating signal.

An electromagnetic locate device configured for removable attachment to a handheld paint marking device includes an elongated element extending substantially a length of the handheld paint marking device, a channel extending longitudinally along the elongated element, the channel configured for accepting at least a portion of the handheld paint marking device, fasteners located on the elongated element, the fasteners configured to fasten the handheld paint marking device to the elongated element, electromagnetic antennas located along a length of the elongated element, the electromagnetic antennas configured for producing electromagnetic data responsive to an electromagnetic field emanating from a buried asset, and a housing coupled to a top of the elongated element, the housing including a processor communicably coupled to the electromagnetic antennas and configured to process the electromagnetic data from the electromagnetic antennas, so as to produce buried asset data, and a display for displaying said buried asset data.

Numerical and/or semi-analytical methods are leveraged to decouple a complete set of nonzero electromagnetic field tensor components (118) from detected signal data (119). Nine nonzero components can serve as inputs for a three-dimensional inversion process to determine formation properties. A resistivity tool (100) containing at least one transmitter (111) and at least one receiver (108, 109) at tilted angles receives an electromagnetic signal throughout a rotation. A difference in the azimuthal positions of the transmitter(s) and receiver(s) during rotation of the resistivity tool can result in an azimuthal offset between resistivity tool subs. The components (118) are decoupled from the detected signal data (119) numerically or semi-analytically according to whether the azimuthal offset angle is known. If the azimuthal offset angle is known, the nine components are determined numerically through curve fitting. If the azimuthal offset angle is unknown, a semi-analytical process is used to solve for the nine components.

Numerical and/or semi-analytical methods are leveraged to decouple a complete set of nonzero electromagnetic field tensor components (118) from detected signal data (119). Nine nonzero components can serve as inputs for a three-dimensional inversion process to determine formation properties. A resistivity tool (100) containing at least one transmitter (111) and at least one receiver (108, 109) at tilted angles receives an electromagnetic signal throughout a rotation. A difference in the azimuthal positions of the transmitter(s) and receiver(s) during rotation of the resistivity tool can result in an azimuthal offset between resistivity tool subs. The components (118) are decoupled from the detected signal data (119) numerically or semi-analytically according to whether the azimuthal offset angle is known. If the azimuthal offset angle is known, the nine components are determined numerically through curve fitting. If the azimuthal offset angle is unknown, a semi-analytical process is used to solve for the nine components.

Buried object locators including an omnidirectional antenna array and a gradient antenna array are disclosed. A locator display may include information associated with a buried object determined based on processing of both omnidirectional antenna array signals and gradient antenna array signals.

A long-offset acquisition system includes a source vessel; a signal source coupled to the source vessel; and a long-offset streamer coupled to a survey vessel and including an aft-most receiver, an offset of the aft-most receiver being at least 12 km. A long-offset acquisition method includes towing a signal source with a source vessel; towing a first long-offset streamer with a survey vessel; and acquiring data with receivers of the first long-offset streamer. A long-offset acquisition method includes towing a signal source with a first survey vessel; towing a long-offset streamer with a second survey vessel, the long-offset streamer having a plurality of receivers; actuating the signal source while an offset between the signal source and at least one of the plurality of receivers is at least 15 km; and acquiring data with receivers of the long-offset streamer.

A long-offset acquisition system includes a source vessel; a signal source coupled to the source vessel; and a long-offset streamer coupled to a survey vessel and including an aft-most receiver, an offset of the aft-most receiver being at least 12 km. A long-offset acquisition method includes towing a signal source with a source vessel; towing a first long-offset streamer with a survey vessel; and acquiring data with receivers of the first long-offset streamer. A long-offset acquisition method includes towing a signal source with a first survey vessel; towing a long-offset streamer with a second survey vessel, the long-offset streamer having a plurality of receivers; actuating the signal source while an offset between the signal source and at least one of the plurality of receivers is at least 15 km; and acquiring data with receivers of the long-offset streamer.

The present disclosure provides a foldable portable metal detector including: a detection coil disk; a waterproof circuit protection compartment; a circuit component; a folding and fixing component; a fastening component; and an extension rod; the circuit component is inserted into the waterproof circuit protection compartment; the extension rod is fixedly connected to the waterproof circuit protection compartment; the circuit component is electrically coupled to the detection coil disk; the detection coil disk is provided with a bracket provided with a first through-hole and a second through-hole; the fastening component is provided with a bolt and a fixing column; the waterproof circuit protection compartment is provided with a connector provided with a connection hole; the bolt penetrates the connection hole and the first through-hole in sequence, the fixing column penetrates the second through-hole; and the waterproof circuit protection compartment is selectively rotated around the bolt.

A foldable metal detector includes a detection coil disk, a waterproof circuit protecting chamber, a circuit component fixedly disposed in the waterproof circuit protecting chamber, folding fixing components, fastening components, an extending rod fixedly connected to a tail end of the waterproof circuit protecting chamber, and a BLUETOOTH remote control component configured to control the foldable metal detector. The extending rod is manually detachable from the waterproof circuit protecting chamber. The circuit component is electrically connected with the detection coil disk. Brackets are disposed on the detection coil disk. Each bracket includes a first through hole and a second through hole. The fastening components include bolts and fixing columns. Connecting heads with connecting holes are disposed on the waterproof circuit protecting chamber. Each bolt passes through each connecting hole and each first through hole. The bolts are movably connected to the folding fixing components.

A foldable metal detector includes a detection coil disk, a waterproof circuit protecting chamber, a circuit component fixedly disposed in the waterproof circuit protecting chamber, folding fixing components, fastening components, an extending rod fixedly connected to a tail end of the waterproof circuit protecting chamber, and a BLUETOOTH remote control component configured to control the foldable metal detector. The extending rod is manually detachable from the waterproof circuit protecting chamber. The circuit component is electrically connected with the detection coil disk. Brackets are disposed on the detection coil disk. Each bracket includes a first through hole and a second through hole. The fastening components include bolts and fixing columns. Connecting heads with connecting holes are disposed on the waterproof circuit protecting chamber. Each bolt passes through each connecting hole and each first through hole. The bolts are movably connected to the folding fixing components.