Apparatus and associated methods relate to an alignment system including an alignment source module (ASM) and an alignment indicator module (AIM) configured to be releasably coupled to a first unit and a second unit, respectively, of a pair of optoelectronic arrays. In an illustrative example, the ASM may be oriented, when coupled, to emit an optical beam in substantial alignment with a first optical axis of the first unit. The AIM may, for example, be configured, when coupled, to provide a visible indication when the optical beam is within a predetermined near-alignment orientation range relative to a second optical axis of the second unit. Each of the AIM and the ASM may, for example, be configured to axially couple along respective longitudinal axes of the first unit and the second. Various embodiments may advantageously facilitate manipulation of the pair of optoelectronic arrays into near alignment with each other.

Apparatus and associated methods relate to an alignment system including an alignment source module (ASM) and an alignment indicator module (AIM) configured to be releasably coupled to a first unit and a second unit, respectively, of a pair of optoelectronic arrays. In an illustrative example, the ASM may be oriented, when coupled, to emit an optical beam in substantial alignment with a first optical axis of the first unit. The AIM may, for example, be configured, when coupled, to provide a visible indication when the optical beam is within a predetermined near-alignment orientation range relative to a second optical axis of the second unit. Each of the AIM and the ASM may, for example, be configured to axially couple along respective longitudinal axes of the first unit and the second. Various embodiments may advantageously facilitate manipulation of the pair of optoelectronic arrays into near alignment with each other.

A laser photopeak location system comprises a gamma-ray spectrometer and a processor. The processor computes a plurality of correlation coefficients based on a comparison of a pulse-height spectrum of the gamma-ray spectrometer with an array of values. The processor locates one or more photopeaks of the pulse-height spectrum based on at least one of the plurality of correlation coefficients. Additional apparatus, methods, and systems are disclosed.

A laser photopeak location system comprises a gamma-ray spectrometer and a processor. The processor computes a plurality of correlation coefficients based on a comparison of a pulse-height spectrum of the gamma-ray spectrometer with an array of values. The processor locates one or more photopeaks of the pulse-height spectrum based on at least one of the plurality of correlation coefficients. Additional apparatus, methods, and systems are disclosed.

An embodiment of a method of performing aspects of a downhole operation includes receiving a measurement value from a first sensor configured to measure a parameter related to the downhole operation, receiving measurement data from a different sensor, the measurement data related to the downhole operation, and performing, by a sensor evaluation module, an evaluation of the first sensor. The evaluation includes determining a condition of the first sensor based on the measurement data from the different sensor, selecting a rule that prescribes a set of one or more measurement values of the parameter that are plausible if the condition is met, and determining whether the measurement value from the first sensor is plausible based on comparing the measurement value to the prescribed set of one or more measurement values.

A method for calculating a tension (T) in a towed antenna. The method includes towing the antenna in water, wherein the antenna includes plural particle motion sensors distributed along the antenna; measuring with the plural particle motion sensors vibrations that propagate along the antenna; calculating a value of a phase velocity (vp) of the vibrations that propagate along the antenna based on (1) an offset between two particle motion sensors and (2) a time delay of the vibrations that propagate from one of the two particle motion sensors to another one of the two particle motion sensors; selecting a relation that links the phase velocity (vp) to the tension (T); and using the value of the phase velocity and the relation to determine the tension (T) at various locations of the plural particle motion sensors along the antenna.

A multi-axis acceleration sensor comprises a frame, a central mass disposed within the frame, and a plurality of transducers mechanically coupled between the frame and the central mass. At least a first set of the transducers are arranged between the frame and the central mass in a manner configured to measure translational and rotational motion with respect to a first predefined axis.

A multi-axis acceleration sensor comprises a frame, a central mass disposed within the frame, and a plurality of transducers mechanically coupled between the frame and the central mass. At least a first set of the transducers are arranged between the frame and the central mass in a manner configured to measure translational and rotational motion with respect to a first predefined axis.

Magnetic field measurement by a set of magnetometers which are linked to a same moveable support and which have different orientations of eigendirections with respect to this support A processor determines, during a measurement in a given position and orientation of the support and of the set of magnetometers, for each magnetometer, of the orientation deviation between the eigendirections of the magnetometer and a candidate magnetic field, the magnetometer for which this deviation is minimal, the magnetic field measured by this sensor being selected as the magnetic field measured by the set of magnetometers. The magnetometers are distributed in space in order to cover a maximum of different orientations.

A multi-axis acceleration sensor comprises a frame, a central mass disposed within the frame, and a plurality of transducers mechanically coupled between the frame and the central mass. At least a first set of the transducers are arranged between the frame and the central mass in a manner configured to measure translational and rotational motion with respect to a first predefined axis.