Systems and methods for analyzing soil are generally provided. In particular, the disclosure provides systems and methods for determining bulk density of soil using rotational soil penetrometers. In some embodiments, the bulk density is determined by obtaining spectroscopic data and penetration torque data from the rotational soil penetrometer, and determining the bulk density of the soil based at least in part on the spectroscopic data and the penetration torque data. Bulk density may be combined with in situ measurements of elemental composition (e.g., carbon content) of soil in order to calculate total quantities of an element (e.g., carbon) in an area's topsoil. Also disclosed herein are systems and methods for modeling bulk density and/or carbon content of soil, based at least in part on spectroscopic data and penetration torque data. For example, trained statistical models determination are provided herein.

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 downhole fluid analysis system includes an optical sensor that includes a light source configured to emit light, a light detector, and an optical tip optically coupled to the light source and the light detector. At least a portion of the light emitted from the light source travels through the optical tip and returns to the detector, wherein the optical tip has a bi-conical shape. The system further includes a piezoelectric helm resonator, in which the piezoelectric helm resonator 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. In some embodiments, the optical tip includes a first conical portion and a second conical portion.

A downhole fluid analysis system includes an optical sensor that includes a light source configured to emit light, a light detector, and an optical tip optically coupled to the light source and the light detector. At least a portion of the light emitted from the light source travels through the optical tip and returns to the detector, wherein the optical tip has a bi-conical shape. The system further includes a piezoelectric helm resonator, in which the piezoelectric helm resonator 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. In some embodiments, the optical tip includes a first conical portion and a second conical portion.

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.

The present invention generally relates to detecting a root of a plant in soil. An exemplary system comprises a support structure configured to be at least partially disposed in the soil; an LED unit affixed to the support structure, wherein the LED unit comprises an emitter and a detector, wherein the emitter is configured to produce a plurality of outgoing light signals, wherein the detector is configured to receive a plurality of returned light signals corresponding to the plurality of outgoing light signals, and wherein each of the plurality of returned light signals comprises at least a portion of the corresponding outgoing light signal reflected from at least one of the soil and the root; and a microprocessor configured to detect a presence of the root based on the plurality of returned light signals.

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 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.

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 that includes a light source configured to emit light, a light detector, and an optical tip optically coupled to the light source and the light detector. At least a portion of the light emitted from the light source travels through the optical tip and returns to the detector, wherein the optical tip has a bi-conical shape. The system further includes a piezoelectric helm resonator, in which the piezoelectric helm resonator 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. In some embodiments, the optical tip includes a first conical portion and a second conical portion.