A system for monitoring soil composition within a field may have a ground-engaging tool configured to engage soil within a field as an implement moves across the field. The system may further have a sensor configured to generate data indicative of a soil composition within the field, where the sensor is movable relative to the ground-engaging tool while the implement moves across the field such that the sensor generates data indicative of the soil composition at different depths within the field. Additionally, the system may have a controller communicatively coupled to the sensor, with the controller being configured to determine the soil composition at the different depths within the field based at least in part on the data received from the sensor.

There are provided an optical probe and method for analysing a soil located in an underground area. The optical probe includes a probe head insertable into the underground area to contact the soil, the probe head including a waveguide having opposite first and second ends both optically shielded from the soil; a light source configured to generate a multiwavelength interrogating beam and optically coupled to the first end of the waveguide so that the multiwavelength interrogation beam is inputted in the waveguide to propagate towards the second end; and a detector optically coupled to the second end of the waveguide to detect said multiwavelength interrogation beam. The waveguide includes an unshielded interaction zone extending between the first and second ends providing a wavelength-dependent attenuation of the multiwavelength interrogation beam through interaction with the soil.

A method including generating integrated computational element (ICE) models and determining a sensor response as the projection of a convolved spectrum associated with a sample library with a plurality of transmission profiles determined from the ICE models. The method includes determining a regression vector based on a multilinear regression that targets a sample characteristic with the sensor response and the sample library and determine a plurality of regression coefficients in a linear combination of ICE transmission vectors that results in the regression vector. The method further includes determining a difference between the regression vector and an optimal regression vector. The method may also include modifying the ICE models when the difference is greater than a tolerance, and fabricating ICEs based on the ICE models when the difference is within the tolerance. A device and a system for optical analysis including multiple ICEs fabricated as above, are also provided.

A downhole fluid analysis system includes an optical sensor comprising, which includes a light source configured to emit light comprising a plurality of wavelengths, a light detector, and an optical tip through which at least a portion of the light travels and returns to the detector, wherein the incident angle of the light causes total internal reflection within the optical tip. The system further includes a piezoelectric helm resonator that generates a resonance response in response to an applied current, and an electromagnetic spectroscopy sensor positioned symmetrically with respect to the piezoelectric helm resonator in at least one direction. The light may be reflected in the optical tip at one or more reflection points, and each reflection point may generate an evanescent wave in a medium surrounding the optical tip. The light may be internally reflected in the optical tip at a plurality of reflection points.

A sensing system for monitoring a composition of a downhole fluid in a well, where the sensing system includes: a light source, an optical waveguide, an evanescent field sensing element that is indirect contact with a downhole fluid, and a detector. The light source is operable for emitting a beam and includes a frequency comb generator configured to modify at least a portion of the beam into a sensing comb beam. The evanescent field sensing element provides attenuated internal reflection of the sensing comb beam at the interface between the evanescent field sensing element and the downhole fluid, and the portion of the sensing comb beam interacts with the fluid to form at least a portion of an interacted beam. The detector obtains a spectral distribution of the interacted beam.

An in situ near infrared sensing unit includes a housing allowing the sensing unit to be inserted in a variety of media. A transparent window is formed in the sidewall of the housing. A sensing element is mounted inside the housing. The sensing element is configured to emit near infrared light provided from a light source external to the housing, and the sensing element is configured to collect near infrared light transmitted through the transparent window. A mirror is mounted in the housing at an angle with respect to the transparent window and opposite the sensing element. The angle allows the mirror to reflect the near infrared light, emitted by the sensing element, through the transparent window.

Improved devices, systems and methods for measuring in situ saturations of non-aqueous phase liquids and/or petroleum in media such as soil. A clear or otherwise UV-transparent well for detecting fluorescence in a soil column having a transparent casing and an oil sensing device positioned in the well configured to monitor the soil column. A method for real-time estimation of LNAPL saturations in media, including emplacing a UV-transparent well in the media and recording fluorescence in the media via an oil sensing device.

An optical probe and method for analysing a soil located in an underground area are provided. The optical probe includes a probe head insertable into the underground area, the probe head including a transparent wall defining a hollow chamber within the probe head; a light source mounted in the hollow chamber, configured to generate an illumination beam towards the soil, the illumination beam passing through the transparent wall to irradiate the soil, thereby producing a resulting light emanating from the soil, a portion of the resulting light returning towards the probe head and being guided in the transparent wall by total internal reflection along the optical path; a detector configured to receive the portion of the resulting light and outputting an output signal representative of characteristic(s) of the soil; and an optical element guiding the portion of the resulting light from the transparent wall to the detector.

A method for locating human remains in a clandestine or undocumented burial includes providing a spectroscopy assembly including a spectroscopy probe with a distal end to a location that may include human remains, wherein the spectroscopy assembly is configured to identify whether a salt of a fatty acid is present based on overtone wavelengths of the salt of the fatty acid; inserting the distal end of the spectroscopy probe into a testing spot at the location that may include human remains; and analyzing, with the spectroscopy assembly and after the step of inserting, whether the salt of the fatty acid having the overtone wavelengths is present in the location that may include human remains. The step of analyzing may include near-infrared spectroscopy, and the overtone wavelengths may be characterized by an absorption band contour extending from about 1670 nm to about 1800 nm.

A downhole fluid analysis system includes an optical sensor comprising, which includes a light source configured to emit light comprising a plurality of wavelengths, a light detector, and an optical tip through which at least a portion of the light travels and returns to the detector, wherein the incident angle of the light causes total internal reflection within the optical tip. The system further includes a piezoelectric helm resonator that generates a resonance response in response to an applied current, and an electromagnetic spectroscopy sensor positioned symmetrically with respect to the piezoelectric helm resonator in at least one direction. The light may be reflected in the optical tip at one or more reflection points, and each reflection point may generate an evanescent wave in a medium surrounding the optical tip. The light may be internally reflected in the optical tip at a plurality of reflection points.