An all fiber pulsed coherent Doppler lidar (CDL) system at 1.54 µm wavelength is developed for wind profiles measurements.This affords 43.0-µJ pulse energy 10-kHz repetition frequency with 500-ns width.The operated in monostatic mode 50-mm diameter telescope.The heterodyne mixing signals are acquired 500 M/s analog to digital converter and 2048 points fast Fourier transform (FFT) implemented.Line of sight speeds measured more than 3.0-km range a horizontal direction about 1.9 km the vertical...

The demand for greenhouse gas measurement has increased dramatically due to global warming. A 1.57-μm airborne double-pulse integrated-path differential absorption (IPDA) light detection and ranging (LIDAR) system CO2 concentration was developed. field experiments of this IPDA LIDAR were conducted at a flight altitude approximately 7 km, the weak echo signal ocean area successfully received. matched filter algorithm applied retrieval signals, pulse integration method used improve...

Spaceborne high spectral resolution lidar (HSRL) provides a wide range of observations, e.g., measurements aerosol backscattering and extinction coefficients depolarization ratio with accuracy, which are great significance to the study air pollution monitoring climate change. With different cells finger temperatures, transmittance absorption lines iodine vapor filter at 532 nm wavelength was measured. The 1064 fundamental frequency pulse energy frequency-doubled output seeder laser...

In this study, a 1.57-µm airborne double-pulse integrated-path differential absorption (IPDA) light detection and ranging (LIDAR) system was developed for CO2 measurements. This IPDA LIDAR is integrated with real-time frequency monitoring system, an sensor temperature, pressure, humidity, inertial navigation global positioning system. The random errors of the which are caused by signal noise, background detector among other factors, analyzed different target reflectivities at flight altitude...

A ground-based double-pulse integrated path differential absorption (IPDA) instrument for carbon dioxide (CO2) concentration measurements at 1572 nm has been developed. ground experiment was implemented under different conditions with a known wall located about 1.17 km away acting as the scattering hard target. Off-/offline testing of laser transmitter conducted to estimate systematic and random errors. Results showed optical depth (DAOD) offset 0.0046 existing in instrument. On-/offline...

This paper presents a method for measuring atmosphere temperature profile using single iodine filter as frequency discriminator. high spectral resolution lidar (HSRL) is system reconfigured with the transmitter of mobile Doppler wind and receiving subsystem redesigned to pass backscattering optical signal through cell twice out aerosol scattering allow analysis molecular spectrum, thus temperatures. We report what are believed be first results vertical profiling from ground 16 km altitude by...

A 1 064-nm pulsed coherent Doppler lidar (CDL) prototype is developed to measure short range wind speed in the lower altitude troposphere layer.The CDL system adopts an injection-seeded Nd:YAG laser with pulse duration of 80 ns, single energy 0.5 mJ, and repetition rate 200 Hz.Speed calibration experiments are implemented obtain a accuracy 0.3 m/s using hard target.Data analysis results show that can line-of-sight velocity at 30 500 m resolution 40 38 pulses accumulation.

A frequency-stabilized laser system at 1572 nm for space-borne carbon dioxide (CO2) detection LIDAR to realize the precise measurement of global atmospheric CO2 concentration is presented in this Letter. distributed-feedback diode serves as master (ML) and wavelength locked line center 1572.0179 nm using external frequency modulation technique. The root mean square drift suppressed about 50 kHz an average time 0.1 s over 8 h. Based on optical phase-locked loops, online seeder offline are...

The influence of molecular scattering models on aerosol optical properties measured by high spectral resolution lidar (HSRL) is experimentally investigated and theoretically evaluated. measurements analyzed in this study were made during three field campaigns the German Aerospace Center airborne HSRL. respective theoretical model spaceborne HSRL retrievals also estimated. Generally, extinction coefficient can be neglected for both HSRLs. However, backscatter depends concentration larger than...

An all-fiber airborne pulsed coherent Doppler lidar (CDL) prototype at 1.54μm is developed to measure wind profiles in the lower troposphere layer. The single frequency laser operated with pulse energy of 300μJ, width 400ns and repetition rate 10kHz. To best our knowledge, it highest eye-safe that used lidar. telescope optical diameter monostatic 100 mm. Velocity-Azimuth-Display (VAD) scanning implemented 20 degrees elevation angle 8 different azimuths. Real-time signal processing board...

The Key Laboratory of Ocean Remote Sensing the Ministry Education China, University has developed first mobile Doppler wind lidar in China. As an important component meteorological services for Good Luck Beijing 2007 Qingdao International Regatta, was used to measure sea surface (SSW) with 100 m*100 m spatial and 10-min temporal resolution from 15 23 August 2007. We present results two aspects this campaign. First, operated fixed-direction mode compared SSW simultaneously measured by a...

The high spectral resolution lidar (HSRL) technique employs a narrow filter to separate the aerosol and molecular scattering components from echo signals therefore can retrieve optical properties ratio (i.e., extinction-to-backscatter ratio) profiles directly, which is different traditional Mie with assumed ratio. Accurate measurement are useful for air quality monitoring. In this paper, spaceborne HSRL system simulation model based iodine vapor cell was presented. According three atmosphere...

Airborne integrated path differential absorption (IPDA) lidar system is an important instrument to verify the performance and data inversion methods of future space-borne systems for atmospheric CO₂ measurement. A ground vertical validation experiment measurement by airborne double-pulsed 1.57-μm IPDA has been implemented. The was carried out temperature, pressure humidity profiles Local Meteorological Station at almost same time are adopted. Backscattering signals from clouds...

An all-fiber pulsed coherent Doppler lidar (CDL) prototype is developed to measure wind profiles in the lower atmosphere layer. The single frequency laser operated with pulse energy of 50μJ, width 500ns and repetition rate 10kHz. AOM heterodyne about 55MHz. diameter telescope 100mm. mixing signal acquired 500M/s AD card. Several experiments are implemented validate performance system. With 3000 pulses accumulated, maximum horizontal measurement range speed 4.2km clear day, vertical near 2km....

Based on the time-domain simulation model of coherent wind measurement, it is deduced that detected atmospheric backscattered spectrum a two-dimensional convolution real information, and instrument point spread function. The spatial resolution can be improved by applying image deconvolution algorithm to inversion Coherent Wind Lidar (CWL) signal. effect in improving compared experiment. results show effectively using when transmitted pulse waveform known.

A focused laser light sheet was used to illuminate the capillary tube filled with liquid and fringe patterns can be seen. The formed by rays directly passing through or reflected one time two times by walls of then transmitted again. The transmission lie before the capillary bell-shaped, steep almost parallel, which strongly depend on position tube. bell shaped pattern qualitatively explained addition diffraction multi-slits is relative aberration cylindrical lens. This is also relative...

Coherent Doppler lidar (CDL) has been a powerful instrument to measure atmospheric wind velocity. In this work, an 1.5 μm all-fiber pulsed CDL developed and deployed profiles in campaign experiment 2018. The 0.1-5 km detection range with resolution of 30 m, temporal 16 s at Velocity-Azimuth-Display (VAD) mode. Field experiments were implemented the vector retrieved. As compared sounding balloon, discrepancy speed direction are nearly 0.7 m/s 5 degrees, respectively. It shows that is tool for...

A ground-based double-pulse 1572 nm integrated path differential absorption (IPDA) lidar was developed for carbon dioxide (CO 2 ) column concentrations measurement. The measured the CO continuously by receiving scattered echo signal from a building about 1300 m away. other two instruments of TDLAS and in-situ analyzer on same time. concentration measurement 430 ppm with 1.637 standard error achieved.

Most of the existing hyperspectral image change detection methods based on deep learning utilize convolutional neural networks (CNN), recurrent (RNN), and long-short-term memory (LSTM). However, CNNs primarily focus extracting spatial information from images, thereby failing to fully channel temporal information. In this paper, we propose a network called STSTNet that can jointly extract spatial, spectral, feature To achieve richer representation space, employ attention module maps, spectral...

Abstract In this paper, we report a diode side-pumped injection-seeded single-frequency Tm,Ho:YLF laser, which operated at lasing threshold and emitted 2051.2 nm. The assistance of Fabry-Pérot (FP) etalons to seed injection via mode selection was investigated. An acouto-optic Q-swiched output 6.7 mJ achieved 5 Hz. A temporal pulse duration 310 ns with spectral linewidth 2.0 MHz frequency stability 0.8 rms detected. beam profile high quality Guassian TEM 00 M 2 x/y = ~ 1.15/1.14. application...