73 results about "Laser remote sensing" patented technology

The invention relates to the field of laser remote sensing technology, in particular to a satellite-borne laser altimeter system solid surface target plane and height accuracy test method. A satellite-borne laser altimeter system is set up to measure solid surface distance accuracy and a height accuracy mathematical model, a complete altimeter system accuracy rapid test method is designed, an echo energy calculation method related to a specific implementation process is derived, and a surface target parameter calculation method is designed. According to the method, ranging accuracy between a satellite laser reference point and a surface target can be tested when known altimeter system hardware parameters and surface target parameters are tested, and plane and height accuracy of a laser altimeter system can also be detected by combining satellite platform attitudes and position data. The plane and height accuracy test method has a high reference significance in laser altimeter system parameter design and accuracy assessment.

The invention provides a double-resonance, wide-tuning and narrow-linewidth all-solid-state nanosecond pulse medium-infrared optical parameter oscillator comprising four parts including single-frequency pump light, a double-resonance resonant cavity, an electrical control part and seed light. A 1.064 <mu>m single-frequency pulse laser pump quasi-phase matching multi-cycle polarized crystal double-resonance parameter oscillator is adopted to acquire dual-band laser output of wide-tuning range near-infrared signal light and medium-infrared idle light. The output central wavelength is tunable within the wide spectral range, and the cavity length is dynamically adjusted through electro-optical crystal by combining a single-frequency continuous semiconductor laser seed injection technology so as to realize narrow-linewidth laser output of the optical parameter oscillator. The oscillator can be widely applied to the field of high-resolution laser spectroscopy, laser radar, laser remote sensing, environmental detection, optical-electro countermeasure and laser medicine.

A laser remote sensing apparatus comprises a laser to provide collimated excitation light at a wavelength; a sensing optic, comprising at least one optical element having a front receiving surface to focus the received excitation light onto a back surface comprising a target sample and wherein the target sample emits a return light signal that is recollimated by the front receiving surface; a telescope for collecting the recollimated return light signal from the sensing optic; and a detector for detecting and spectrally resolving the return light signal. The back surface further can comprise a substrate that absorbs the target sample from an environment. For example the substrate can be a SERS substrate comprising a roughened metal surface. The return light signal can be a surface-enhanced Raman signal or laser-induced fluorescence signal. For fluorescence applications, the return signal can be enhanced by about 10⁵, solely due to recollimation of the fluorescence return signal. For SERS applications, the return signal can be enhanced by 10⁹ or more, due both to recollimation and to structuring of the SERS substrate so that the incident laser and Raman scattered fields are in resonance with the surface plasmons of the SERS substrate.

The invention discloses an underwater acoustic signal sensing method and device through coherent laser remote-sensing detector, which comprises the following steps: dividing the single-frequency laser into detecting light and reference light; transmitting the detected light to the water surface through optical heterodyne; vibrating the water surface through acoustic wave from underwater element; making the frequency and strength of underwater acoustic wave consistent with the vibrating frequency and amplitude; modulating frequency of reflective light of water surface through forced vibrating speed; interfering the reflective light and reference light detected by photoelectric detector; modulating the vibrating speed of water surface through electric heterodyne modulator; obtaining the waveshape of the underwater acoustic wave; realizing the detection of the underwater acoustic signal. The invention has high sensitivity, far distant measurement, flexible optical path and reliable structure, which is easy to modulate.

The invention relates to a laser ceilometer dynamic threshold selecting method based on pulse echo forms, and belongs to the field of laser remote sensing. The laser ceilometer dynamic threshold selecting method based on the pulse echo forms solves the problems that in an existing threshold selecting method, only extreme point positions or fifty-percent peak point positions or dual-threshold positions of pulse echoes are adopted to confirm transition time of laser pulses, the selected thresholds can be only suitable for specific measurement conditions or plane targets of small slopes. According to the laser ceilometer dynamic threshold selecting method based on the pulse echo forms, a mathematic model of the laser ceilometer pulse echo forms, noise standard deviation and threshold rising edge moment variance is regarded as a theoretical basis, the range error minimization of a laser ceilometer serves as a basis, and the optimization selection of the threshold coefficient of the laser ceilometer is achieved through a parameter iterative search method. The influences of noise and pulse widening introduced by gap title effects of the plane targets are fully considered in the threshold value selection method, range errors caused by threshold setting can be reduced, and the satellite-borne laser ceilometer can complete high-precision laser ranging of the plane targets of different slopes under different measurement conditions.

The present invention is a method and apparatus for remotely detecting methane gas in mines by laser remote sensing technologies. The apparatus has at least one light source emitting photons towards mine walls and at least one light detection device accepting photons reflected from mine walls. When methane gas presents at the optical path, these photons experience strong optical attenuation and indicate methane existence. The invention employs tunable laser spectroscopy technology to measure the concentration path length vectors. The invention further uses tomography algorithms to determine existence, concentration and distribution of methane gas from the measured concentration path length vectors. Explosions due to mix of methane mine gas with air can be prevented by sensing methane existence and minimizing its concentrations through methane drainage and ventilation.

The invention provides a laser remote sensing technology based gas leakage unmanned aerial vehicle inspection concentration inversion method which comprises the following steps that a path integral concentration sample is obtained through a laser methane sensor based on a scanning curve of an unmanned aerial vehicle; a lattice concentration inversion based on a gas pipeline coordinate system is obtained; maximum likelihood estimation of a gas leakage diffusion model based on a dot matrix concentration and a wind direction estimation is performed to obtain leakage position and leakage rate estimation values; the gas leakage diffusion model is used for reconstructing a continuous concentration map, and a dangerous zone and an isolation zone are divided according to a danger threshold value;and an intelligent emergency auxiliary decision analysis is performed by adopting a ground terminal or a handheld APP.

This relates to the field of real-time detection of chemical contamination of water in harsh environmental conditions by using laser remote sensing apparatus for detection of oil or oil products. In-time detection and localization of oil pollution in seawater are the measures to minimize potential damages to the marine and coastal environment. A technical solution for remote detection and classification of chemical pollution in water, to optimize operational parameters, weight, size and power consumption of such device, to make possible continuous unattended operation of such device on board of a moving or stationary platform and to provide data processing and reporting the results through communication channels is described.

The invention provides a double-shaft laser remote sensing instrument ground detection and calibration system, which comprises a simulation echo generator, a two-dimensional moving platform, a heavy-caliber long-focus collimator and a light beam quality analyzer. One side of the heavy-caliber long-focus collimator is provided with a beam splitter and a pyramid prism, and the other side of the heavy-caliber long-focus collimator is provided with a total-reflection mirror. The simulation echo generator is composed of a photolectric transducer, a time delay unit, an optical fiber output laser, optical fiber and an electronic control optical attenuator. The optical fiber output laser is connected with one end of the optical fiber, and the other end of the optical fiber is located on the other side of the heavy-caliber long-focus collimator. A port of the other end of the optical fiber is located on a focal plane of the heavy-caliber long-focus collimator and fixed on the two-dimensional moving platform. The detection and calibration system is capable of obtaining far-field light beam quality distribution and detectivity of the detected active and passive laser remote sensing instrument and is capable of obtaining geometric construction factors of the detected active and passive laser remote sensing instrument.

The invention discloses a laser remote sensing detector for natural gas concentration and distance. The detector comprises infrared laser transmitting and receiving components and a control processing component electrically connected with the infrared laser transmitting and receiving components; particularly, the control processing component comprises a transmitting signal control assembly and a receiving signal processing assembly which are electrically connected; the transmitting signal control assembly is used for achieving modulation of output of a laser (7) in the infrared laser transmitting component; the receiving signal processing assembly comprises a distance signal processing unit and a concentration signal processing unit which are electrically connected with a detector (14) in the infrared receiving component, wherein the distance signal processing unit is used for working out the distance between a reflector (12) and the infrared receiving component, and the concentration signal processing unit is used for working out the gas concentration. The detector has the high precision for natural gas concentration detection, and can be widely applied to accurate positioning and detection of natural gas leakage.

The invention relates to a determination method for satellite laser ceilometer pin point geometry positioning errors and belongs to the field of laser remote sensing. The problems that an existing pin point geometry positioning error analysis method neglects position and the angle placement errors between a laser measuring system and a carrying platform sensor, only provides partial instant geometry positioning error molds of laser pin points on the premise that height fluctuations of a measured target are not considered and does not analyze extreme values of laser pin point geometry positioning errors are solved. On the basis of the satellite laser ceilometer pin point geometry laser pin point geometry positioning process and error communication theory, the method for comprehensively determining the satellite laser ceilometer laser pin point geometry positioning errors is provided by comprehensively considering the influence on various error sources and plane target fluctuations; the analysis method with the combination of the instant geometry positioning error and the extreme geometry positioning error can achieve comprehensive analysis and evaluation of performance indexes obtained before and after emission of a satellite laser ceilometer.

The invention discloses an airborne detecting device for laser remote sensing of gas leakage. The airborne detecting device comprises an infrared laser transmitting part, an infrared laser receiving part and a controlling and processing part electrically connected with the infrared laser transmitting part and the infrared laser receiving part; particularly, the airborne detecting device is located on an aircraft and also comprises a spiral detecting track part composed of a rotating reflecting mirror (13) arranged on a shaft of a motor (14), wherein the included angle formed by a normal of the rotating reflecting mirror (13) and an axis of the motor (14) is 1-6 DEG, and an angle formed by the normal of the rotating reflecting mirror (13) and an optical axis (12) of the infrared laser transmitting part is 40-50 DEG; and the controlling and processing part comprises a transmitting signal control assembly and a receiving signal processing assembly which are electrically connected, wherein the transmitting signal control assembly is used for realizing modulation for the output of a laser device (5) in the infrared laser transmitting part, and the receiving signal processing assembly is used for calculating the concentration of leaked gases according to the detected signals carrying leakage gas information. The airborne detecting device can be widely applied to precise location and large-area rapid detection for natural gas leakage.

The invention relates to a portable natural gas laser remote sensing detecting instrument. The portable natural gas laser remote sensing detecting instrument comprises a body, a telescopic mechanism, an angle adjusting mechanism, a central control mechanism, a sensor and a storage battery. The angle adjusting mechanism comprises a fixing seat, an adjusting assembly and a measuring probe, an adjusting assembly comprises a first connecting rod, a first hinge, a second hinge, a second connecting rod, a first driving shaft and a first motor, and the telescopic mechanism comprises a rotating assembly, a movable assembly and a flat plate. The rotating assembly comprises a second motor, a second driving shaft and a connecting unit. In the portable natural gas laser remote sensing detecting instrument, the functions of stretching out and drawing back of the measuring probe are achieved through the telescopic mechanism, thus in remote measuring, natural gas which is within a large range and is usually hard to make contact with can be measured, measuring personnel can be away from a to-be-measured site, and personnel safety is improved; and through the angle adjusting mechanism, when a narrow space is measured, the measuring probe can also extend into the narrow space, so that the measuring effect is improved, and practicability of the measuring instrument is improved.

The invention discloses an atmosphere laser remote sensing method based on polarization modulation and polarization laser radar. According to the invention, by use of specially designed polarization modulation light signals as detection light, back scattering light of a to-be-detected target includes two paths of orthogonal polarization echo signals and respectively carries carriers and positive first-order sideband signals. Thus, a receiving end detects reflection echoes only by use of a detector. By measuring frequency and power of beat frequency electrical signals in the echo signals, real-time measurement can be performed on wind speed information and depolarization ratio information in the atmosphere simultaneously. The invention discloses a polarization laser radar. Compared with theprior art, by ingeniously designing detection of optical signals, it can be achieved that real-time accurate measurement can be performed on wind speed and depolarization effects of to-be-detected atmosphere; only one set of detectors can be required; and the system structure is quite simple and the achieving cost is quite low.

The invention discloses a chlorophyll concentration vertical section inversion method of a satellite-borne single-photon laser radar, belongs to the technical field of laser remote sensing, and is used for acquiring vertical sections of seawater parameters and chlorophyll parameters. Separating and extracting the water surface signal photon point cloud and the water body back scattering signal photon point cloud obtained by the satellite-borne single-photon laser radar; correcting the influence of the residual pulse effect of the single-photon laser radar on the photon signal by using an RL deconvolution algorithm; constructing a probability statistical model of spaceborne single-photon laser radar water surface reflection signal photons and water body back scattering signal photons, and calculating a laser radar system constant by using wind speed data; and constructing a spectrum empirical analysis model, and calculating the vertical section of the chlorophyll of the water body. Compared with the prior art, the method can accurately invert the water chlorophyll vertical section result of the to-be-detected water area, and has important significance in multiple fields of monitoring water pollution, algae outbreak, ocean carbon cycle, global climate change and the like.

The invention discloses a high-accuracy laser remote-sensing numerically-controlled power supply system and a control method. The system comprises a BOOST PFC (power factor correction) module, a chip-isolating power supply module, an MOS (metal oxide semiconductor) driving module, a main circuit voltage reducing module and a control module. The BOOST PFC module is connected with the chip-isolatingpower supply module and the main circuit voltage reducing module. The chip-isolating power supply module is connected with the MOS driving module. The main circuit voltage reducing module is connected with the control module. The control module is connected with the MOS driving module. The MOS driving module is connected with the main circuit voltage reducing module. The high-accuracy laser remote-sensing numerically-controlled power supply system and the control method have the advantages that the problems of low digitization of the laser power sources of semiconductor pumps and low constantcurrent accuracy of low voltage and high currents are solved; the structures of conventional two-stage series circuits are improved, and accordingly, high-accuracy working currents can be provided tolaser remote-sensing semiconductor laser devices; the control method capable of achieving rapid algorithm filtering, high-accuracy control and high-robustness control is provided.

The embodiment of the invention discloses a coal mine gas inspection robot based on laser remote sensing and an inspection method. The coal mine gas inspection robot comprises a laser remote sensing device with a distance measuring function, a longitudinal rotating device for enabling the laser remote sensing device to longitudinally rotate and a central processing unit. The laser remote sensing device synchronously collects gas concentration information and longitudinal distance information of a detection area, monitors the gas concentration information, and screens out top-off distance information from the longitudinal distance information; and the central processing unit obtains relative distance information through trigonometric function relation by using the longitudinal distance information and the top-off distance information, and coordinates of the laser remote sensing device serve as a coordinate starting point, and coordinates of a collection position are obtained through coordinate conversion of a space coordinate system. According to the invention, the space coordinate information of the collection points is obtained based on the coordinates of the collection points inthe space coordinate system and three-axis displacement vectors, perfect fusion of large-range gas monitoring and space coordinate positioning is achieved, and due to the fact that gas mostly floats on the top of a roadway, the technology can be better applied.

The invention relates to a radial plume multi-component gas measurement remote sensing system, which belongs to the field of laser remote sensing measurement, and comprises a reflected laser acquisition unit and a data acquisition unit; the data acquisition unit comprises a data acquisition card and a computer; the reflected laser acquisition unit comprises a plurality of lasers; the light of eachlaser is divided into two paths through a beam splitter, one path is irradiated to a first detector through a reference absorption cell, and the other path of light is irradiated to a beam expander through a beam combiner; a cooperative target reflector, a reflector and a first lens are sequentially arranged along the light paths and are converged to an optical grating, separation of different wavelengths is achieved at the position of the optical grating, light of different wavelengths enters a second detector connected with the data acquisition card through a narrow-band filter and a secondlens, the number of the lasers is two or more, the lasers are modulatable semiconductor lasers, the scanning frequency is larger than 100 Hz, and the modulation frequency is larger than 20 kHz. The system is simple and compact in structure, high in sensitivity and capable of detecting the concentrations of various gases in the air in real time.

The invention relates to a filtering method based on a frequency distribution principle. The filtering method comprises the following steps: acquiring N groups of Raman spectrums, and calculating peak intensity storage arrays Ix of the Raman spectrums; dividing Ix into M sections; grouping the arrays Ix according to the sections, and counting the frequency of the sections; calculating a section K with the maximum frequency, and calculating a medium value Ixm (K) of the section; setting the maximum Raman spectrum intensity fluctuation deviation A, if the Raman spectrum intensity of the (N+1)th group is within a section [Ixm(K)-A, Ixm(K)+A,], judging that the Raman spectrums are effective, preprocessing, and storing in a register, or else judging that the Raman spectrums are ineffective, and abandoning, wherein the lengths of a plurality groups of Ix are fixed, the peak intensity of each group of newly acquired Raman spectrums is put into an array tail, one piece of data at the head of an original array is abandoned, N data is kept the latest, and overlapping is performed after L groups of effective Raman spectrums inside the register are achieved. The filtering method is remarkable in filtration effect and good in instantaneity, instantaneous noise interference can be effectively eliminated, and the interference resistance and the water temperature measurement precision of a Raman scattering ocean temperature laser remote sensing system can be improved.

Disclosed is a 2.9 mu m intermediate infrared solid-state laser based on an automatic Raman pump. The 2.9 mu m intermediate infrared solid-state laser based on the automatic Raman pump comprises a pumping source, a beam shaping device, an input coupling optical lens, an automatic Raman crystal, a Q switch, a first output mirror, a first all-trans mirror, a gain medium, a second all-trans mirror and a second output mirror. The connection relationship of the upper elements is that the pumping source, the beam shaping device, the input coupling optical lens, the automatic Raman crystal, the Q switch, the first output mirror, the gain medium and the first all-trans mirror are arranged in sequence along a pumping optical path, and the second all-trans mirror, the gain medium and the second output mirror are arranged in sequence along a laser optical path. The 2.9 mu m intermediate infrared solid-state laser based on the automatic Raman pump has the advantages of being good in stability, high in beam quality and high in output power and efficiency. The 2.9 mu m intermediate infrared solid-state laser based on the automatic Raman pump can be applied in fields such as laser ranging, laser remote sensing, laser imaging, photoelectricity confrontation, medical diagnosis and treatment, material processing, optical signal processing, data processing and the like.

The invention relates to a water optical parameter inversion method for a satellite-borne single-photon laser radar, and belongs to the technical field of laser remote sensing. The method comprises the steps of firstly, extracting an effective signal when the satellite-borne single-photon laser radar flies above a water surface and carries out measurement, and eliminating a residual pulse effect of the single-photon laser radar through a deconvolution algorithm; establishing a water body backscattering theoretical model, calculating a water body backscattering coefficient and a diffusion attenuation coefficient by using a least square fitting method and the obtained water body backscattering laser pulse point cloud after the residual pulse effect is eliminated, and calculating a water body backscattering coefficient according to a water body parameter backscattering model. According to the invention, the main optical parameters of a seawater subsurface layer of ta local water body can be quickly and accurately calculated through the point cloud data obtained when the satellite-borne single-photon laser radar flies over the ocean, which plays an important role in effectively monitoring the water body pollution, water body eutrophication, water quality decline and the like.

The invention discloses a high-precision laser remote sensing numerical control power supply circuit, which comprises a BOOST PFC module, a chip isolation power supply module, a main circuit step-downmodule, an MOS driving module, a control module and a sampling module. Optimization and improvement are performed on a secondary driving MOS circuit of transformer isolation drive, so that the designof the transformer isolation driving circuit module can achieve low power consumption and no negative voltage and has a driving waveform with a fast rising edge and falling edge. When the system adopts a high switch operating frequency of 100KHz, the transformer isolation driving circuit module can still obtain a high driving MOS capability and acquire an effect of low temperature rise. The circuit adopts a full-isolation circuit design, the damages for a laser are effectively reduced when the power supply breaks down, a wide operating range is outputted, the disturbance of sampled signals iseffectively reduced, safe isolation between high voltage of a main circuit and low power supply voltage of a chip is achieved, the chip is effectively protected, and the miniaturization of the wholemachine is realized.

A laser remote sensing detection system and method are disclosed. First and second detection state triggering signals can be sent alternatively to a signal generator through a trigger so that the system is alternate between a first detection state (a distance measuring state) and a second detection state (a gas concentration measuring state), thus achieving two functions which are distance measuring and gas concentration measuring through a time-shared measurement manner. The distance measuring function is achieved on the basis of not changing the optical frame of a laser gas remote sensing device, thus simplifying the structure and reducing the cost and size of the detection system.

The invention discloses a thulium-doped 2[mu]m laser crystal and a preparation method thereof. The crystal is of a double perovskite structure and belongs to a cubic crystal system, and the composition expression of the crystal is A2MM<III>X6: xTm, wherein A is a monovalent cation, M is a monovalent cation, M<III> is a trivalent cation, X is a halogen anion, and 0< x < = 0.1. The preparationmethod comprises the following steps of: respectively dissolving AX, MX, M<III>2O3 and Tm2O3 in HX acid; mixing the two solutions; reacting the mixed solution in an oven; and after the reaction isfinished, carrying out cooling, filtering and washing. The laser crystal disclosed by the invention can realize 2[mu]m emission by using 808nm laser diode pumping, and can be applied to the fields oflaser ranging, laser remote sensing, laser imaging, photoelectric countermeasure, medical diagnosis and treatment, scientific instruments, material processing, optical signal processing, data processing, environmental monitoring of differential absorption laser radar and the like.