An optical turbulence measurement system may include a camera assembly, a first optics assembly, a second optics assembly, and processing circuitry. The first optics assembly and the second optics assembly may be configured to magnify and direct a portion of a source beam received by a respective aperture to the camera assembly to be received as a two portions of a received beam. The processing circuitry may be configured to receive, from the camera assembly, a data representation of a first received beam from the first optics assembly and a second received beam from the second optics assembly, determine a focal spot displacement variance based on motion of a first focal spot corresponding to the first received beam relative to a second focal spot corresponding to the second received beam, and measure optical turbulence along a path of the source beam based on the focal spot displacement variance.

An optical turbulence measurement system may include a camera assembly, a first optics assembly, a second optics assembly, and processing circuitry. The first optics assembly and the second optics assembly may be configured to magnify and direct a portion of a source beam received by a respective aperture to the camera assembly to be received as a two portions of a received beam. The processing circuitry may be configured to receive, from the camera assembly, a data representation of a first received beam from the first optics assembly and a second received beam from the second optics assembly, determine a focal spot displacement variance based on motion of a first focal spot corresponding to the first received beam relative to a second focal spot corresponding to the second received beam, and measure optical turbulence along a path of the source beam based on the focal spot displacement variance.

An optical refraction barometer measures pressure based on refractivity changes and includes: an optical light source; an optical frequency controller; a first optical phase controller; a first polarization controller; an electronic reference arm in optical communication with the first polarization controller; a second optical phase controller in optical communication with the optical frequency controller; a second polarization controller in optical communication with the second optical phase controller; an electronic sample arm in optical communication with the second polarization controller and in electrical communication with the second optical phase controller; a second sideband frequency generator; a mixer in electrical communication with the detector and the second sideband frequency generator; and a first sideband frequency generator in electrical communication with the mixer; and a dual fixed length optical cavity refractometer.

An optical measuring device that measures one or more parameters indicating a state of a measured liquid, includes: a light source that irradiates light to the measured liquid; a light receiver that detects a measured light based on the light irradiated to the measured liquid; an optical component that is disposed on an optical path between the light source and the light receiver; and a heat source on the optical component and that has optical transparency and electrical conductivity.

Apparatus, systems, and methods associated with remote phase and amplitude spectroscopy in frequency, time, and position with correlated frequency combs are applicable in a variety of applications. Multiple beams can be generated from a single laser source, where, in the frequency domain, the multiple beams are frequency combs with equal repetition rates and shifted in frequency from each other. One or more of the multiple beams can be directed to interact with a sample with another one of the multiple beams used as a reference beam. The interaction can include transmission of one of the multiple beams as a signal beam through the sample, reflection of one of the multiple beams as a signal beam from the sample, or backscattering from the sample. Results from the interaction can be analyzed.

A passive thermal imaging system includes multiple detector arrays, imaging optics, and processing electronics. Each of the detector arrays include pixels and detect thermal electromagnetic radiation (EMR) within a band around a desired EMR wavelength. The imaging optics receive thermal EMR within the band from an object and image the received thermal EMR from a same region of the object onto pixels of each of the detector arrays. The processing electronics receive a detected signal from each of the pixels of the detector arrays, calculate a correlation value based on a multi-correlation of the received detected signals of corresponding pixels of different detector arrays, and compare the correlation value with a threshold correlation value to determine that a detection event has occurred in response to the correlation value exceeding the threshold correlation value, the threshold correlation value being equal to or between 0.8 and 0.85.

A system and method are provided for receiving light that has traveled from an optical source through an atmosphere along a distance. The system includes: a receiver lens system having an aperture and being arranged to receive the light from the optical source; a beam splitter; an imaging lens; an image processing component; a photodetector system; and a refractive index structure parameter component. The photodetector system outputs data associated with averaged scintillation data of the aperture. The image processing component generates a normalized covariance curve based on a first portion of the received light. The refractive index structure parameter component generates a refractive index structure parameter, C.sub.n.sup.2, of the atmosphere along the distance based on the data associated with averaged scintillation data of the aperture and the normalized covariance curve.

A system includes a detector and a computing device communicatively coupled to the detector. The detector detects spatial or temporal spectral features of a light beam after transmission of the light beam through a turbulent or aberrated medium and generate a measurement signal indicative of the spectral feature. The computing device receives the measurement signal and a comparative signal indicative of a spectral feature of the light beam prior to or after transmission of the light beam through the medium. The computing device compares the measurement signal and the comparative signal and determines, based on the comparison of the measurement signal and the comparative signal, one or more values related to variations in refractive indices of the medium.

An optical refraction barometer measures pressure based on refractivity changes and includes: an optical light source; an optical frequency controller; a first optical phase controller; a first polarization controller; an electronic reference arm in optical communication with the first polarization controller; a second optical phase controller in optical communication with the optical frequency controller; a second polarization controller in optical communication with the second optical phase controller; an electronic sample arm in optical communication with the second polarization controller and in electrical communication with the second optical phase controller; a second sideband frequency generator; a mixer in electrical communication with the detector and the second sideband frequency generator; and a first sideband frequency generator in electrical communication with the mixer; and a dual fixed length optical cavity refractometer.

A passive thermal imaging system is described. The system includes at least one detector array configured to detect thermal electromagnetic radiation (EMR), imaging optics, and processing electronics. The imaging optics are configured to receive thermal EMR from an object, and to image the received thermal EMR onto pixels of each of the at least one detector array. The processing electronics are configured to receive a detected signal from each of the pixels of the at least one detector array, to calculate a correlation value based on a correlation between the received detected signals from the pixels, and to compare the correlation value with a threshold correlation value to determine whether a detection event has occurred.