Abstract: A method of operating an optical device, the method comprising tuning a first emission wavelength of a first output radiation of a laser device continuously within a first wavelength spectrum by modulating a drive current thereof with a first drive current modulation having a frequency of at least 100 KHz. The first wavelength spectrum comprises a first spectral feature associated with at least part of a gas absorption spectrum of at least one gas. The method comprises the steps of modulating the first output radiation of the laser device with a first output modulation, the first output modulation comprising a first plurality of binary pulses, scanning the first wavelength spectrum at a rate of at least 1 ?m per second, projecting the first output radiation towards a first target area, receiving scattered radiation from the first target area, and processing the scattered radiation.

Abstract: Methods and apparatus for detecting and measuring gas flow are disclosed in which lidar distance information, acquired during the detection of gas using a lidar sensor, is used together with prevailing wind data to determine local wind data for the leak location. This local wind data, which may comprise one or more vectors or a 3D wind model, is used in the determination of flow rate.

Abstract: A method of measuring the concentration of a gas in a target environment using a laser lidar system, comprises directing a laser beam towards an environment containing the gas, tuning the laser wavelength over a wavelength range including the absorption line of the gas, and measuring intensity of laser light returned from the environment containing the gas, as a result of scattering as a function of time. The intensity vs time is then converted into gas absorption vs wavelength, and the gas absorption vs wavelength is used to determine the concentration of the gas in the target environment.

Abstract: A lidar system for detection of a gas comprises an optical transceiver for transmitting and receiving optical radiation. A method of operating the system comprises performing spatially scanned sensing measurements of the gas across a system field of view, and analyzing the sensing measurements to determine the presence and location of excess of the gas in the system field of view. Based on the determined location, an adjusted system field of view is determined and spatially scanned sensing measurements of the gas are performed across the adjusted system field of view to obtain sensing measurements at higher spatial resolution.

Abstract: A lidar system for detection of a gas comprises an optical transceiver for transmitting and receiving optical radiation. A method of operating the system comprises performing spatially scanned sensing measurements of the gas across a system field of view, and analyzing the sensing measurements to determine the presence and location of excess of the gas in the system field of view. Based on the determined location, an adjusted system field of view is determined and spatially scanned sensing measurements of the gas are performed across the adjusted system field of view to obtain sensing measurements at higher spatial resolution.

Abstract: A hybridization method of Sinocyclocheilus grahami and carp, which comprises parent fish cultivation, artificial insemination, fish egg incubating and fry feeding, strictly controls environmental parameters and feed types of parent fish cultivation, simulates good living conditions for S. grahami and carp, is beneficial for wild S. grahami and carp to adapt to the artificial breeding environment quickly, realizes natural spermatogenesis and oviposition in artificial environment without using the oxytocin, and provides sperm and eggs both in quality and quantity for artificial hybridization. At the same time, the key parameters during incubation (including incubating water level, water temperature, water flow velocity, pH, dissolved oxygen and sterilization of fertilized eggs, etc.) are also defined to provide suitable environmental conditions for the successful incubation of fertilized eggs.

Abstract: A lidar system for detection of a gas comprises an optical transceiver for transmitting and receiving optical radiation. A method of operating the system comprises performing spatially scanned sensing measurements of the gas across a system field of view, and analyzing the sensing measurements to determine the presence and location of excess of the gas in the system field of view. Based on the determined location, an adjusted system field of view is determined and spatially scanned sensing measurements of the gas are performed across the adjusted system field of view to obtain sensing measurements at higher spatial resolution.

Abstract: A method of measuring the concentration of a gas in a target environment using a laser lidar system, comprises directing a laser beam towards an environment containing the gas, tuning the laser wavelength over a wavelength range including the absorption line of the gas, and measuring intensity of laser light returned from the environment containing the gas, as a result of scattering as a function of time. The intensity vs time is then converted into gas absorption vs wavelength, and the gas absorption vs wavelength is used to determine the concentration of the gas in the target environment.

Abstract: An optical assembly for a laser projection and return laser light detection device comprises a housing; a first series of components arranged in the housing to define an exit path for laser radiation entering from a laser source and then exiting from the housing; a second series of components arranged in the housing to define a return path for scattered returns of the laser radiation entering the housing and passing to a detector; a polarising beam splitter/combiner common to the exit path and the return path arranged to polarise laser light exiting from the housing and to separate scattered laser light returned to the assembly, that is orthogonally polarised to the exiting laser radiation. The polarising beam splitter/combiner forms a window to the housing.

Abstract: A method of measuring the concentration of a gas in a target environment using a laser lidar system, comprises directing a laser beam towards an environment containing the gas, tuning the laser wavelength over a wavelength range including the absorption line of the gas, and measuring intensity of laser light returned from the environment containing the gas, as a result of scattering as a function of time.

Abstract: A method of gas detection comprises emitting radiation of different wavelengths across the absorption spectrum of a gas towards a target area; and analysing the spectrum of returned laser light from the target area to identify the gas in the target area using the time correlation of the emitted radiation and the returning radiation. The radiation is modulated using respective orthogonal modulation codes for the different wavelengths and the modulation codes are modified by the insertion of a gap between each bit of the modulation code, the gap having a duration of at least n-1 bits where n is the number of different wavelengths.

Abstract: A method of operating an optical device, the method comprising tuning a first emission wavelength of a first output radiation of a laser device continuously within a first wavelength spectrum by modulating a drive current thereof with a first drive current modulation having a frequency of at least 100 kHz. The first wavelength spectrum comprises a first spectral feature associated with at least part of a gas absorption spectrum of at least one gas. The method comprises the steps of modulating the first output radiation of the laser device with a first output modulation, the first output modulation comprising a first plurality of binary pulses, scanning the first wavelength spectrum at a rate of at least 1 ?m per second, projecting the first output radiation towards a first target area, receiving scattered radiation from the first target area, and processing the scattered radiation.

Abstract: A hybridization method of Sinocyclocheilus grahami and carp, which comprises parent fish cultivation, artificial insemination, fish egg incubating and fry feeding, strictly controls environmental parameters and feed types of parent fish cultivation, simulates good living conditions for S. grahami and carp, is beneficial for wild S. grahami and carp to adapt to the artificial breeding environment quickly, realizes natural spermatogenesis and oviposition in artificial environment without using the oxytocin, and provides sperm and eggs both in quality and quantity for artificial hybridization. At the same time, the key parameters during incubation (including incubating water level, water temperature, water flow velocity, pH, dissolved oxygen and sterilization of fertilized eggs, etc.) are also defined to provide suitable environmental conditions for the successful incubation of fertilized eggs.

Abstract: An artificial propagation method of Sinocyclocheilus rhinocerous, comprising placing female and male parent fish in a sterilized culture container in which a black cave simulant is placed in advance, strictly controlling the environmental parameters of the parent fish culture. The method realizes natural spawning and sperm production of S. rhinocerous under artificial conditions without using oxytocin. There is no oxytocin used in the artificial propagation, thus not only obtaining a higher fertilization rate and incubating rate, but also reducing the aquaculture cost. The operation is simpler and faster. At the same time, different feeds are fed in different growth stages according to the different growth characteristics of each stage of S. rhinocerous fry, thereby increasing the survival rate and reducing the deformity rate of fries. Therefore, the method provided by the present disclosure realizes efficient artificial propagation method of S. rhinocerous.