37 results about "Differential absorption" patented technology

The invention relates to the technical field of gas detection, in particular to a dual-wavelength-based adaptive methane detection method and system, and the method comprises the following steps: collecting environmental interference characteristics of a to-be-detected gas environment in real time; synchronously emitting a first laser beam and a second laser beam to a to-be-detected gas environment according to the tunable laser source; receiving optical signals of the first laser beam and the second laser beam and converting the optical signals into electric signals; calculating a light intensity difference value of the first laser beam and the second laser beam based on the electric signal to generate a differential absorption signal; performing optical differential compensation on the differential absorption signal, outputting a methane concentration value, and performing environmental drift compensation on the methane concentration value based on environmental interference characteristics; and performing real-time threshold value judgment on the methane concentration value, and if the methane concentration value exceeds a preset threshold value, triggering a local early warning signal. According to the invention, the problem that the detection precision is reduced due to the fact that methane absorption signal common-mode noise and absorption coefficient drift cannot be synchronously inhibited due to dust concentration and temperature and humidity interference in a dynamic complex environment under a mine is effectively solved.

The invention relates to the technical field of water vapor concentration detection, and discloses a water vapor concentration online detection method and system based on a multi-wavelength infrared absorption spectrum, and the method comprises the steps: controlling an infrared light source module to emit pre-modulated light, enabling the pre-modulated light to pass through a gas chamber module, inputting the pre-modulated light into a photoelectric detection module, and converting the pre-modulated light into a sample electric signal; acquiring temperature data and pressure data at a preset position of the air chamber module in real time; calculating to obtain an initial differential absorption signal by using the sample electric signal and combining a Lambert-Beer law; based on the temperature data and the pressure data, performing temperature and pressure dynamic compensation on the initial differential absorption signal by using a pre-stored compensation database to obtain a target differential absorption signal; and determining the water vapor concentration according to the target differential absorption signal. According to the invention, the effects of improving the measurement precision and the measurement stability of the water vapor concentration and measuring the water vapor concentration online in real time can be achieved.

The invention relates to the technical field of laser radars, and discloses an all-solid-state troposphere and stratosphere ozone detection laser radar system, which comprises a pump light generation module used for generating an ultraviolet laser beam; the solid-state ultraviolet laser module is used for dividing the ultraviolet laser beam into four paths of detection laser to respectively form a differential absorption wavelength pair for detecting the ozone in the stratosphere and a differential absorption wavelength pair for detecting the ozone in the troposphere; the wavelength real-time monitoring module monitors the frequency of the four paths of detection laser in real time; the echo optical signal receiving module is used for receiving back scattering echo optical signals of the detection laser at different heights and converting the back scattering echo optical signals into electric signals; and the signal acquisition and storage module acquires the electric signal and stores the electric signal as a digital signal. According to the invention, four narrow-band laser ozone detection wavelengths are generated through an optical parametric oscillation technology, and meanwhile, the all-solid-state design of the system is realized, so that the ozone concentration of the stratosphere and the troposphere can be detected at the same time, and continuous observation in the daytime and at night can be realized.

The invention belongs to the technical field of atmosphere detection remote sensing, and discloses an atmosphere multi-element integrated multi-wavelength coherent differential absorption laser radar system. Lambda on1 wavelength laser generated by the first frequency stabilization seed laser, lambda on2 wavelength laser generated by the second frequency stabilization seed laser and lambda off wavelength laser generated by the third frequency stabilization seed laser are transmitted to the switching module for time domain modulation to obtain an output signal, and the output signal is decomposed into local oscillation light and a main signal by the first coupler. A main signal is modulated by the pulse modulator, amplified by the amplification module and then transmitted to the optical transceiver module, backward scattered light scattered by the atmosphere is transmitted to the second coupler and is subjected to coherent coupling and equalization with local oscillation light, and coherent electric signals are transmitted to the data analysis module through the balance detector to be analyzed. The water vapor concentration, the wind speed and the atmospheric temperature in the propagation path are obtained. Through the coherent detection technology, the signal-to-noise ratio of signals is remarkably improved, and high-precision atmospheric humidity and wind field detection is achieved.

The utility model relates to gas detection technical field, the utility model provides a kind of LNG dual-fuel ship exhaust monitoring device, using ultraviolet differential absorption, non-dispersed infrared absorption and tunable semiconductor laser absorption spectroscopy etc. Optical detection principle realizes the synchronous detection of four kinds of gases SO2 (0~1500ppm), CO2 (0~30%), CH4 (0~1500ppm) and NO (0~1500ppm), error is controlled within ±2%FS, response time is not more than 30s. Realize LNG dual-fuel characteristic gas accurate detection simultaneously, with the advantages of high detection precision, fast response speed, simple operation, relatively low cost and strong gas cross-interference resistance ability under complex working conditions.

The invention relates to the technical field of differential absorption spectrum inversion, and discloses an ozone precursor monitoring method and system based on a two-channel differential absorption spectrum and nonlinear inversion, a terminal and a storage medium, the method comprises the following steps: synchronously obtaining a target spectrum and a reference spectrum of a target area to calculate a multiband atmospheric differential optical thickness; building a combination model based on the difference optical thickness of each wave band, dividing a fitting window, and obtaining the difference inclined column concentration through multi-angle fitting; and inverting a vertical concentration distribution profile of the ozone precursor by using different sensitivities in combination with a radiation transmission model and a logarithmic space iterative inversion algorithm. According to the invention, through a high-performance dual-channel spectrometer observation system and a high-precision nonlinear inversion algorithm, high-spectral-resolution measurement of ultraviolet-visible light full wavebands is realized, logarithmic space processing is introduced in inversion, the inherent problems of strong nonlinearity and large dynamic range of a vertical profile of aerosol and trace gas are effectively solved, and the measurement accuracy is improved. And the measurement precision and stability are improved.

This invention relates to a method for inverting remote sensing data from overlapping strong and weak absorption lines of greenhouse gases, belonging to the field of satellite remote sensing technology. Specifically, it includes the following steps: Step 1: Constructing an optical system, including a satellite platform, camera 1, and camera 2; camera 1 and camera 2 are mounted at the bottom of the satellite platform; camera 1 and camera 2 are mirrored; the imaging spectral band of camera 1 moves from the weak absorption spectral band to the strong absorption spectral band along the positive push-broom direction to the negative push-broom direction; the imaging spectral band of camera 2 is in the opposite direction; the optical system moves horizontally from left to right to achieve horizontal push-brooming of greenhouse gases on the ground, obtaining a dual-camera fused image; the dual-camera differential absorption spectroscopy algorithm is used to invert the dual-camera fused image to obtain the greenhouse gas column concentration; this invention, based on the spectral characteristics of strong and weak absorption lines of greenhouse gases, adopts a detector focal plane segmentation method, and the dual cameras achieve differential absorption and inversion in the same region, which can guide the design of greenhouse gas detection micro / nano satellite payloads.

The application discloses a kind of porous medium combustion internal product in-situ detection device and method, including porous medium combustor, is equipped with combustion chamber, the combustion chamber is filled with ordered structure porous medium material, the two side walls of the combustion chamber are equipped with first penetration layer and second penetration layer, the two outer sides of the first penetration layer and second penetration layer are respectively equipped with first collimating lens and second collimating lens, first lens group between the first collimating lens and first penetration layer is arranged to make that light beam converges into the light beam of extremely small diameter and passes through first penetration layer, second lens group between the second collimating lens and second penetration layer is arranged to make that light beam converges into the light beam of extremely small diameter and is shot into first collimating lens;Light source;Spectrometer, computer.By adjusting the structure design of porous medium, in-situ detection of internal components of porous medium is realized in combination with ultraviolet differential absorption spectrometry.Compared with traditional extraction type, it is faster, lower in cost and stronger in real-time performance.

The application discloses a water body ammonia nitrogen concentration differential absorption detection device based on microwave remote sensing, relates to the technical field of water pollution detection, and comprises a floating platform for floating on a detection water body and a mounting plate arranged on the floating platform. A microwave emission module and a microwave receiving module for microwave remote sensing detection are mounted on the mounting plate. A signal processing and analysis module for information processing and a data storage and display module are arranged on the floating platform. In the detection process, through the cooperation of a swing assembly, a water body depth identification assembly, a lifting assembly and an adjusting assembly, the microwave signal emitted by the microwave emission module on the mounting plate can cover a larger area of the water surface, three-dimensional sampling of the water body can be realized, one-sidedness of single-point detection can be avoided, the detection state can be adaptively adjusted according to the depth of the detection water body during the detection, and flexible detection operation is facilitated.

This invention discloses a data processing method for carbon dioxide column concentration based on a spaceborne lidar, comprising: performing nonlinear correction on the spaceborne integral path differential absorption (IPDA) lidar detection signal; calculating the differential optical thickness based on the IPDA lidar signal; calculating the echo height above sea level and geographic coordinates based on the echo signal location; establishing an absorption cross-section lookup table using differential absorption cross-section data from the High Resolution Transmission Molecular Absorption (HITRAN) database; calculating the pressure at the echo location using the European Centre for Medium-Range Weather Forecasts Reanalysis Dataset (ERA5) and the echo signal height above sea level; calculating the Doppler frequency shift; calculating a weighting function based on pressure profiles, humidity profiles, temperature profiles, and Doppler frequency shift data; and calculating the carbon dioxide column concentration. The key features of this invention are the nonlinear correction of the spaceborne IPDA lidar echo signal, the establishment of a differential absorption cross-section lookup table for carbon dioxide molecules, and the accurate and efficient calculation of the carbon dioxide column concentration using spaceborne IPDA lidar detection data and ERA5 meteorological dataset data.

The invention provides a method and equipment for simultaneously detecting at least two target gases in exhaled gases, and relates to the technical field of gas detection. The method comprises the following steps: constructing a first characteristic space according to a differential absorption spectrum of a first target gas in a standard state, and constructing a second characteristic space according to a differential absorption spectrum of a second target gas in the standard state; obtaining a differential absorption spectrum of the exhaled gas sample; respectively projecting the differential absorption spectrum of the exhaled gas sample to the first characteristic space and the second characteristic space to carry out spectrum decoupling so as to obtain a first differential absorption spectrum and a second differential absorption spectrum; and inputting the first differential absorption spectrum into a first multi-scale convolutional network, inputting the second differential absorption spectrum into a second multi-scale convolutional network, and respectively obtaining the concentration of the first target gas and the concentration of the second target gas in the exhaled gas sample. The problem of spectrum overlapping caused by high noise interference and complex components when multiple target gases in exhaled gases are detected at the same time is solved.

The application discloses a kind of based on laser radar's discharge pollution source analysis method and system, the method includes: according to first pollutant concentration information and second pollutant concentration information, respectively to the various pollutant gases directly obtained from ground monitoring station or satellite and the single pollutant gas monitored by differential absorption module, and the various particulates directly obtained from ground monitoring station or satellite and the multiple particulates monitored by differential absorption module are carried out correlation analysis, and correlation analysis result is obtained;Based on correlation analysis result, identify the composition of discharge pollution source in the discharge area to be measured.The application can carry out high spatial resolution and accurate discharge analysis to discharge pollution source.

The invention belongs to the technical field of gas detection, and particularly relates to a sulfur hexafluoride (SF) concentration detection method and device based on a dual-band tunable diode laser absorption spectrum (TDLAS) and electronic equipment. In order to solve the problems that in an existing SFdetection technology, quantification and positioning functions are separated, the anti-interference capability is poor, and high sensitivity and rapid imaging cannot be synchronously achieved, the invention provides a method combining dual-band differential absorption and TDLAS. According to the scheme, a detection device in which an open type backward reflection path is combined with a built-in White cell (a multi-reflection cell) is adopted, 10.55 microns are selected as a measurement wave band, and 9 microns are selected as a reference wave band; through synchronous or alternate acquisition of dual-band signals, wavelet denoising preprocessing, differential absorption concentration inversion, Kalman filtering gas cloud tracking and Gaussian plume model leakage source inversion, rapid imaging positioning and accurate concentration quantification of an SFleakage point are realized. The system has the advantages of high detection sensitivity, strong anti-interference capability and integrated quantitative positioning function, and is suitable for efficient inspection and accurate diagnosis of the SFleakage of the power equipment.

The invention discloses a laser radar system for synchronously measuring the concentration of C12 and C13 carbon dioxide columns in the atmosphere. The laser radar system comprises a laser emission module, an echo receiving module and a data acquisition and processing module. The laser transmitting module adopts a main oscillation power amplification technology and is integrated with three 2051nm seed lasers, the wavelengths of the seed lasers are respectively locked at a C12 absorption peak, a C13 absorption peak and absorption valleys of the C12 absorption peak and the C13 absorption peak, and high-energy detection pulses are generated by using time division multiplexing and two-stage amplification. The echo receiving module collects back scattering signals through a telescope, and the back scattering signals are received by a detector after being filtered. The system monitors emission energy through an integrating sphere, a data acquisition module synchronously acquires emission and echo signals of each wavelength, and respective column concentrations of two isotopes are obtained through inversion according to a differential absorption algorithm. According to the invention, active, synchronous and high-precision column concentration remote sensing measurement of C12 and C13 carbon dioxide is realized, excellent daytime detection capability of the system is ensured, and real all-day continuous observation is realized.

The present application relates to the technical field of gas detection, and particularly relates to a dual-wavelength adaptive methane detection method and system, which comprises the following steps: collecting the environmental interference characteristics of a to-be-detected gas environment in real time; synchronously emitting a first laser beam and a second laser beam to the to-be-detected gas environment according to a tunable laser source; receiving the optical signals of the first laser beam and the second laser beam and converting them into electrical signals; calculating the light intensity difference value of the first laser beam and the second laser beam based on the electrical signals to generate a differential absorption signal; performing optical differential compensation on the differential absorption signal and outputting a methane concentration value, and performing environmental drift compensation on the methane concentration value based on the environmental interference characteristics; and performing real-time threshold judgment on the methane concentration value, and triggering a local warning signal if the methane concentration value exceeds a preset threshold. Through the present application, the problem of detection precision decline caused by the fact that the dust concentration and temperature and humidity interference cannot synchronously inhibit the common-mode noise of the methane absorption signal and the absorption coefficient drift in the dynamic and complex environment under the mine is effectively solved.

To provide a new LIDAR system attainable by an optical fiber that can execute IPDA (Integrated Path Differential Absorption) and can determine separation distance from an obstacle existing in the background of a measurement region.SOLUTION: A LIDAR system is configured so as to execute differential absorption measurement of a chemical compound between two separate optical frequencies (ν1, ν2) and measure separation distance from an obstacle existing in the background of a measurement region in which absorption occurs. Since the LIDAR system can implement an optical fiber technique while having sufficient light emitting power, a light emitting light power value is changed at a different time interval between radiation light emitting sequences. The LIDAR system can evaluate the amount of chemical compounds included in the measurement region, and separation distance from an obstacle positioned in the background of the measurement region.SELECTED DRAWING: Figure 1a

The present application belongs to the technical field of gas detection, and discloses an acetylene gas detection method, system, device and medium based on laser multiplexing, to solve the problems of low detection precision and poor real-time performance in the prior art. The method comprises: emitting two laser beams with different wavelengths; controlling the two laser beams to be emitted alternately in time sequence and transmitted through the same optical path; generating periodic pressure fluctuations through gas molecule absorption of laser energy to generate an acoustic signal; detecting the intensity and phase of the acoustic signal; converting the acoustic signal into an electric signal and performing low-noise amplification and band-pass filtering processing; performing second harmonic demodulation on the signal with improved signal-to-noise ratio to obtain the amplitude and phase information of the acoustic signal corresponding to the excitation laser beam and the detection laser beam respectively; using differential absorption algorithm analysis to separate the absorption contribution of acetylene gas and water vapor to the absorption signal; and calculating the acetylene concentration according to the separated acetylene net absorption signal by applying Beer-Lambert law.

Disclosed in the present invention is a low-concentration gas measurement method based on direct absorption spectroscopy. In the method, real-time measured spectral data of a gas under test and a database of absorption cross sections of said gas measured in a laboratory are used, the concentration of SO2 is calculated by means of ultraviolet differential absorption spectroscopy, an interference spectrum of SO2 on NO2 is calculated, the influence of SO2 on the absorbance of NO2 is eliminated, the absorbance at a zero absorption position is calculated, the influence of spectral attenuation on measurement is eliminated, and the concentration of NO2 after elimination of cross interference is accurately calculated, thereby greatly improving the measurement accuracy and lowering the measurement limit.

The application discloses a method for identifying flying targets based on coherent differential absorption laser radar, which comprises the following steps: alternately emitting laser pulses with different wavelengths into the atmosphere, obtaining Doppler spectrum information by coherently detecting echo signals; when the speed of the echo signal detection is different from the speed of the background aerosol, the Doppler spectrum shows a double-peak structure; according to the continuity of the speed of the background aerosol, judging the aerosol signal and other target signals in the double-peak signal; calculating the ratio of the echo signal strength of different wavelengths; according to the ratio result, distinguishing the flying target signal and the cloud signal outside the ambiguous distance. The application realizes the identification and distinction of the flying targets within the detection distance and the cloud signals outside the ambiguous distance based on the absorption depth difference of the echo signals by the specific gas, and realizes the detection of the concentration of the specific gas.

The application provides a laser radar-based methane fine concentration field inversion method and system, device and storage medium, and belongs to the technical field of atmospheric remote sensing monitoring, and comprises the following steps: acquiring data of the interference degree of a gas in an atmospheric environment on different wave number lasers and data of the sensitivity of different methane detection wavelengths to the atmospheric environment; determining a target methane detection wavelength based on the acquired data of the interference degree of the gas in the atmospheric environment on different wave number lasers and the data of the sensitivity of different methane detection wavelengths to the atmospheric environment; performing differential absorption laser radar observation according to the determined target methane detection wavelength; and performing methane concentration inversion on an observation signal by using a Chebyshev fitting inversion algorithm to obtain an inversion result. The laser radar-based methane fine concentration field inversion method and system can improve the precision of laser radar inversion of methane concentration and provide effective support for methane emission reduction.

The application relates to the technical field of laser radar, and discloses a full-solid-state troposphere and stratosphere ozone detection laser radar system which comprises a pump light generation module, a solid-state ultraviolet laser module, a wavelength real-time monitoring module, a return light signal receiving module and a signal collection and storage module. The pump light generation module is used for generating an ultraviolet laser beam; the solid-state ultraviolet laser module divides the ultraviolet laser beam into four detection lasers which respectively form a differential absorption wavelength pair for detecting stratosphere ozone and a differential absorption wavelength pair for detecting troposphere ozone; the wavelength real-time monitoring module is used for monitoring the frequencies of the four detection lasers in real time; the return light signal receiving module is used for receiving backscattering return light signals of the detection lasers at different altitudes and converting the backscattering return light signals into electric signals; and the signal collection and storage module is used for collecting the electric signals and storing the electric signals as digital signals. The full-solid-state design of the system is realized through the optical parametric oscillation technology when four narrow-band laser ozone detection wavelengths are generated, the ozone concentrations in the stratosphere and the troposphere can be simultaneously detected, and continuous observation can be realized in the daytime and at night.

The invention discloses a multi-axis differential gas analyzer data real-time transmission system and method, belongs to the technical field of multi-axis differential gas analyzer data real-time processing and transmission systems, and is used for multi-axis differential gas analyzer data real-time processing and transmission. The system comprises a spectrograph, an acquisition card, a storage module, a computer end, a wireless communication module, a core processing unit and a display terminal module, the method comprises the following steps: obtaining initial spectral information by adopting a filtering processing method, obtaining gas concentration data by adopting spectral inversion and a differential absorption algorithm, transmitting the data through the wireless communication plate, and visualizing the data on the display terminal. According to the invention, through a specific transmission mode, the collected original data is transmitted to the core processing unit, the core processing unit processes the original spectral data with a relatively large data volume to obtain the gas concentration data, and the gas concentration data processing speed is improved by a method of performing integration and de-noising processing by using a computer end; and the efficiency of the whole gas analysis data transmission process is improved.

The invention discloses a high-range chlorine dioxide online detection method and system, and relates to the technical field of chlorine dioxide detection. The method comprises the following steps: enabling ultraviolet light to penetrate through a to-be-detected sample containing chlorine dioxide; acquiring a sample spectrum of the ultraviolet light in a preset wave band containing a chlorine dioxide characteristic absorption peak, wherein the preset wave band of the chlorine dioxide characteristic absorption peak is 200-400nm; on the basis of the sample spectrum and the reference spectrum, calculating the concentration of chlorine dioxide by adopting a differential absorption spectrometry, the system comprises a sampling injection device, a spectrum detector and a display device, according to the method and the system disclosed by the invention, online detection of 0-10000 mg / L high-range chlorine dioxide is realized, and the method and the system have the advantages of good anti-interference performance, long service life, simplicity in maintenance, no dependence on chemical reagents, no generation of waste liquid, high response speed, strong reliability and the like.

The invention discloses a wavelength optimization selection method for a three-wavelength differential absorption laser radar, and the method comprises the steps: introducing an intermediate wavelength between an online wavelength and an offline wavelength, and deducing a three-wavelength differential absorption laser radar inversion equation set; then, a gas absorption model is constructed based on a Voigt linear function, the relation between the absorption cross section of molecules and the temperature and the pressure intensity is established, and an equation set is established according to the temperature, the pressure intensity, the concentration, the laser wavelength and the radar signal power; and finally, discretizing the candidate wavelength interval, analyzing candidate wavelengths one by one by adopting a numerical iteration method, determining an optimal third wavelength by taking the minimum temperature inversion deviation as a criterion, and considering error influences such as molecular extinction and wavelength drift, so that high-precision atmospheric temperature and concentration multi-parameter inversion can be realized in a complex atmospheric environment. The system has good monitoring accuracy, high efficiency and practicability, and has important application value and wide market prospect.

This application provides a GaSb single-frequency laser and a dual-wavelength differential multi-gas trace detection system and method based on the GaSb single-frequency laser, belonging to the field of gas detection. It solves the problems of insufficient sensitivity, slow response, susceptibility to environmental interference, and lack of domestically produced core light sources in existing gas detection instruments. The system uses a 1950nm high-power GaSb single-frequency laser as the core light source, adopts a WMS-2f wavelength modulation detection scheme to eliminate low-frequency 1 / f noise, and uses a dual-wavelength differential absorption scheme to achieve rapid switching between the two wavelengths through the unique temperature-tunable characteristics of the GaSb single-frequency laser. Together, these three elements constitute the complete technical solution for achieving ppb-level trace gas detection in this application. This application can perform in-situ, online, and high-precision concentration measurement of the characteristic absorption lines of various gas molecules in industrial processes, new energy equipment, life sciences, and environmental monitoring at the ppb level.

The invention discloses an emission pollution source analysis method and system based on a laser radar, and the method comprises the steps: carrying out the analysis of various pollutant gases directly obtained from a ground monitoring station or a satellite and a single pollutant gas monitored by a differential absorption module according to the first pollutant concentration information and the second pollutant concentration information, performing correlation analysis on various particulate matters directly acquired from a ground monitoring station or a satellite and various particulate matters monitored by the differential absorption module to obtain a correlation analysis result; and identifying the emission pollution source components in the emission area to be detected based on the correlation analysis result. According to the invention, high spatial resolution and accurate emission analysis can be carried out on the emission pollution source.

The application belongs to the technical field of optical detection, and particularly relates to a spectrum detection method based on differential absorption, which can detect and analyze the absorption spectrum of most non-single-element molecules. The application is a tunable semiconductor laser absorption spectrum technology detection method based on the principle of differential absorption, which optimizes the defect of insufficient tunable ability of traditional absorption spectrum technology, can detect and analyze the absorption spectrum of most non-single-element molecules, and provides a new path for the development of tunable semiconductor laser absorption spectrum technology.

The invention discloses a laser radar hydrogen concentration detection system based on a differential detection system, and the system comprises a laser emission unit which is used for generating double-pulse laser which is successively output in time and has wavelengths locked at a hydrogen 2121.8 nm absorption peak online and an absorption valley offset; the echo receiving unit is used for synchronously monitoring emission energy of the double-pulse laser and receiving echo energy reflected by a hard target; and the data processing unit is used for obtaining the hydrogen concentration on the detection path through inversion based on a path integral differential absorption algorithm according to the emission energy and the echo energy. According to the invention, all-day, large-range, high-precision and long-distance hydrogen leakage monitoring can be realized, the device and the method are suitable for places such as hydrogen refueling stations, hydrogen fuel storage tank areas and petrochemical hydrogen-contacting devices, and the safety and reliability of hydrogen leakage detection are remarkably improved.

A system includes illumination and light collection optics configured to illuminate a targeted region of interest and receive backscattered light from the targeted region of interest. The system includes a differential absorption light detection and ranging (“DIAL”) sub-system with a first illuminator configured to emit light, through the illumination and light collection optics at a first wavelength corresponding to a first absorption peak of in an absorption curve of a first analyte of interest, and a second illuminator configured to emit light, through the illumination and light collection optics at a second wavelength corresponding to a first absorption trough in the absorption curve of the first analyte of interest, wherein the second wavelength is adjacent to the first wavelength. The system includes a controller configured to determine a concentration of the first analyte of interest in the targeted region of interest.