Abstract: An optimal position analysis unit 24 specifies an optimal installation position for a photodetector 6 by using spectra which by a spectrum and wind speed computing unit 23 calculated by analyzing output data of a photodetector 6 installed at different installation positions, controls a position adjustment made by an optical unit adjustment driving unit 7, and optimizes the installation position of the photodetector 6.

Abstract: A laser radar device includes a multi-wavelength light oscillator to generate a plurality of light beams with different wavelengths, a plurality of modulation units to modulate each of the plurality of light beams with a modulation frequency altered according to a corresponding line of sight of emission, a transmitting/receiving optical system to emit each of the light beams modulated by the modulation units in a corresponding line of sight, and receive reflected light beams, an optical receiver to perform heterodyne detection by using the generated light beams and the received light beams corresponding to the generated light beams, and detect beat signals in the respective lines of sight, and a signal analyzing unit to calculate a value of Doppler wind speed in the respective lines of sight from the respective beat signals, and calculate a value of three-dimensional wind speed using the values of Doppler wind speed.

Abstract: An S/N calculation circuit 12 to calculate the S/N ratio of a received signal, and an S/N comparison circuit 13 to compare the S/N calculated by the S/N calculation circuit 12 with a threshold Th are disposed, and a parameter setting circuit 14 controls the radiation state of a beam radiated from a transmission optical system 5 according to the result of the comparison performed by the S/N comparison circuit 13. As a result, even if the state of the propagation environment gets worse, degradation in the communication quality can be prevented and communicative stabilization can be achieved.

Abstract: There is provided a coherence length measurement device (10) that calculates a coherence length Lc based on a spectrum v calculated by an FFT device (9) and performs, in case where the coherence length Lc is shorter than an FFT gate width Gw, a setting change to shorten the FFT gate width Gw and a pulse width Pw, and the FFT device (9) performs frequency analysis on a received signal outputted from an A/D converter (8) by a unit of an FFT gate following the setting change to calculate the spectrum v of the received signal.

Abstract: A noise spectral differential unit records a noise spectrum in a state without any received signal, and subtracts the noise spectrum from a received signal spectrum. An offset corrector performs offset correction of the signal spectrum obtained by subtracting the noise spectrum by the noise spectral differential unit with respect to the noise level at a frequency separated from the frequency peak position of the received signal by a prescribed value. A frequency shift analyzer executes signal processing of the signal spectrum resulting after the offset correction and measures a frequency shift. A wind velocity converter makes wind velocity detection from the frequency shift measured by the frequency shift analyzer.

Abstract: A wind measurement lidar includes: an output unit to output a laser beam; a transmitter-receiver to emit the laser beam produced by the output unit into the air, and to receive a scattered beam of the laser beam; a received signal acquiring unit to obtain a received signal through heterodyne detection of the laser beam and the beam acquired via the transmitter-receiver; a controller to control the transmitter-receiver; a storage to store as a noise signal the received signal obtained when the laser beam is controlled so as to be produced, but not to be emitted into the air; a frequency difference unit to subtract the noise signal from the received signal obtained when the laser beam is controlled so as to be emitted into the air; and a wind speed measurer to measure a wind speed from the subtraction result.

Abstract: A system controller 16 determines whether the quality of either a distance image or a light intensity image satisfies reference quality, and, when the quality of either the distance image or the light intensity image dos not satisfy the reference quality, outputs a speed change command to lower a speed, an altitude change command to change a submarine altitude (depth), or the like to a navigation control unit 2, thereby changing a physical relative relation between a measurement plane 3 and a device in question. As an alternative, the system controller changes a beam scanning rate f, a beam divergence ?, or the like within limits at which the amount of variation in a spatial resolution does not exceed a permissible amount.

Abstract: An S/N calculation circuit 12 to calculate the S/N ratio of a received signal, and an S/N comparison circuit 13 to compare the S/N calculated by the S/N calculation circuit 12 with a threshold Th are disposed, and a parameter setting circuit 14 controls the radiation state of a beam radiated from a transmission optical system 5 according to the result of the comparison performed by the S/N comparison circuit 13. As a result, even if the state of the propagation environment gets worse, degradation in the communication quality can be prevented and communicative stabilization can be achieved.

Abstract: A laser radar device includes a searchable distance calculation device 2 to calculate an amount of attenuation at a time of propagation of a light wave from a temporal change in scattered light intensity measured by a marine snow measurement device 1, and calculate a searchable distance in a target search device 4 from the amount of attenuation.

Abstract: A noise spectral differential unit records a noise spectrum in a state without any received signal, and subtracts the noise spectrum from a received signal spectrum. An offset corrector performs offset correction of the signal spectrum obtained by subtracting the noise spectrum by the noise spectral differential unit with respect to the noise level at a frequency separated from the frequency peak position of the received signal by a prescribed value. A frequency shift analyzer executes signal processing of the signal spectrum resulting after the offset correction and measures a frequency shift. A wind velocity converter makes wind velocity detection from the frequency shift measured by the frequency shift analyzer.

Abstract: There is provided a coherence length measurement device (10) that calculates a coherence length Lc based on a spectrum v calculated by an FFT device (9) and performs, in case where the coherence length Lc is shorter than an FFT gate width Gw, a setting change to shorten the FFT gate width Gw and a pulse width Pw, and the FFT device (9) performs frequency analysis on a received signal outputted from an A/D converter (8) by a unit of an FFT gate following the setting change to calculate the spectrum v of the received signal.

Abstract: A speed calculator 16 selects a speed calculation method corresponding to a peak value of an SNR which is detected by a peak SNR detector 15 from among a plurality of speed calculation methods of calculating the speed (wind speed) of an aerosol to calculate the speed (wind speed) of the aerosol according to the speed calculation method. As a result, there is provided an advantage of being able to calculate the speed (wind speed) of the aerosol in a short time with a high degree of accuracy.

Abstract: An optimal position analysis unit 24 specifies an optimal installation position for a photodetector 6 by using spectra which by a spectrum and wind speed computing unit 23 calculated by analyzing output data of a photodetector 6 installed at different installation positions, controls a position adjustment made by an optical unit adjustment driving unit 7, and optimizes the installation position of the photodetector 6.

Abstract: A laser radar device includes: a pulse laser that outputs transmission light to a target; an transmission optical system that makes the transmission light at a predetermined beam spread angle; a light-receiving element array that receives scattered light from the target and converts the light to an electric signal; an electric circuit array that detects a reception intensity and a reception time from the electric signal; a range/three-dimensional shape output unit that measures a range to the target or a three-dimensional shape of the target on the basis of the reception time; a determination unit that determines whether the beam spread angle is changed or not on the basis of the reception intensity and the reception time; and a control unit that changes the beam spread angle on the basis of a determination result.

Abstract: A laser radar device includes: a pulse laser that outputs transmission light to a target; an transmission optical system that makes the transmission light at a predetermined beam spread angle; a light-receiving element array that receives scattered light from the target and converts the light to an electric signal; an electric circuit array that detects a reception intensity and a reception time from the electric signal; a range/three-dimensional shape output unit that measures a range to the target or a three-dimensional shape of the target on the basis of the reception time; a determination unit that determines whether the beam spread angle is changed or not on the basis of the reception intensity and the reception time; and a control unit that changes the beam spread angle on the basis of a determination result.