355-nm direct-detection Doppler wind lidar for vertical atmospheric motion measurement.

A compact and simple 355-nm direct-detection Doppler wind lidar (DDDWL) was developed to measure the line-of-sight (LOS) wind speed of the background atmosphere from atmospheric molecule return signals with and without aerosols and clouds. A receiver design with a Fabry-Perot etalon interferometer (FPEI) without an inside deposited step coating or fiber coupling is considered for the DDDWL using the double-edge technique. The receiver with the double-edge technique uses a FPEI and wedge prism to form a double-edge filter. The development of the double-edge filter in this combination is, to the best of our knowledge, an improvement at 355-nm wavelength. Considerations for the DDDWL receiver with a FPEI revealed that a full-angle light beam divergence into the FPEI and a working FPEI aperture are significant factors for the receiver design. Preliminary experimental evaluation demonstrated that the DDDWL had the potential of LOS wind speed measurements with a random error of less than 1 m/s when the signal-to-noise ratio was approximately 300. The DDDWL-measured vertical LOS wind speed profile was consistent with that of a 2-µm coherent Doppler wind lidar within the measurement error range. The preliminary experimental LOS wind measurement results demonstrated the capability of the DDDWL to measure low LOS wind speeds.

Demonstration of aerosol profile measurement with a dual-wavelength high-spectral-resolution lidar using a scanning interferometer.

Simple dual-wavelength high-spectral-resolution lidar at 355 and 532 nm with a scanning interferometer was developed for continuous observations of aerosol profiles. Scanning the interferometer periodically over a range of one fringe at 532 nm (1.5 fringes at 355 nm) enabled recording of range-resolved interference signals at these two wavelengths. Reference signals taken from the transmitted laser were used to correct the interference phase shift due to laser frequency variation for every scan. Profiles of aerosol backscatter and extinction coefficients were retrieved from range-resolved interference data. One month of continuous measurements demonstrated the robustness of the system.

Possible use of fluorescence from iodine blocking filter in high-spectral-resolution lidar to detect Mie scattering signals.

The detection of atmospheric backscattering signals using fluorescence from an iodine blocking filter in high-spectral-resolution lidar was studied experimentally. The efficiency of detection is determined by the fluorescence quantum efficiency and the optical efficiency of collecting fluorescence. The quantum efficiency was estimated to be ${\sim}{0.08}$ from the measured fluorescence lifetime of 0.18 µs and the radiative lifetime of 2.3 µs estimated from the literature. The efficiency of collecting fluorescence was low (${\sim}{0.008}$) in the current system. Measurements of atmospheric backscattering were performed, and it was confirmed that the method actually detected the Mie scattering component of the signal.

Development of a 355-nm high-spectral-resolution lidar using a scanning Michelson interferometer for aerosol profile measurement.

A simple 355-nm high-spectral-resolution lidar (HSRL) is developed for continuous observation of aerosol profiles. A scanning Michelson interferometer is used to separate the Rayleigh and Mie scattering components. The interferometer is periodically scanned in the range of one fringe. Interference contrast, which contains aerosol backscatter information, is estimated at each height through fitting analysis of the scan data. The interference contrast and fringe position are calibrated with the reference signals taken from the transmitted laser. Furthermore, the 1-day continuous measurement of aerosol backscatter and extinction coefficients is demonstrated. Comparison with a nighttime Raman lidar indicates a good performance of the scanning method.

Measurement of water mist particle size generated by rocket launch using a two-wavelength multi-static lidar.

Water mist generated during a rocket launch is thought to protect the rocket and payloads from acoustic noise. The size of mist particles is essential to understanding the effect on noise reduction. A two-wavelength multi-static lidar was developed for measuring water mist size at the launch site. The lidar determines particle size from signals at three scattering angles at two wavelengths. The method was tested with artificial mist and applied to the Japan Aerospace Exploration Agency's H-IIA/B large-scale rocket launches. The measured particle size near the outside edge of the mist cloud was 3.5-5 µm in diameter. The extinction coefficient at 532 nm derived using the Klett backward inversion method was 100-200 km-1. The estimated liquid water content (LWC) was ∼0.3 g/m3. The extinction coefficient was high, but the LWC was comparable to that of the water clouds.

Measurement method of high spectral resolution lidar with a multimode laser and a scanning Mach-Zehnder interferometer.

A simple high spectral resolution lidar technique using a multi-longitudinal mode laser is proposed for measuring aerosol extinction and backscattering coefficients. A scanning interferometer having the same free spectral range as the mode spacing of the laser is used to separate Rayleigh from Mie scattering. Scanning the interferometer in the span of one fringe, the lidar signals at the minimum and maximum Mie-scattering transmission are measured. The Rayleigh scattering signal is analyzed from these signals, and the aerosol extinction coefficient is derived. The interferometer transmittance for Mie scattering is calibrated with the reference signals taken with a portion of the transmitted laser beam.

Development of a multiple-field-of-view multiple-scattering polarization lidar: comparison with cloud radar.

We developed a multiple-field-of-view multiple-scattering polarization lidar (MFMSPL) to study the microphysics of optically thick clouds. Designed to measure enhanced backscattering and depolarization ratio comparable to space-borne lidar, the system consists of four sets of parallel and perpendicular channels mounted with different zenith angles. Depolarization ratios from water clouds were large as observed by MFMSPL compared to those observed by conventional lidar. Cloud top heights and depolarization ratios tended to be larger for outer MFMSPL channels than for vertically pointing channels. Co-located 95 GHz cloud radar and MFMSPL observations showed reasonable agreement at the observed cloud top height.

Pharmacokinetics, tissue distribution, and excretion of sitafloxacin, a new fluoroquinolone antibiotic, in rats, dogs, and monkeys.

The pharmacokinetics, tissue distribution and excretion of sitafloxacin (CAS 127254-12-0, DU-6859a) were investigated in rats, dogs, and monkeys following single intravenous or single oral administration of 14C-labelled sitafloxacin at a dose of 4.69 mg/kg. Following single administration of the oral dose, serum concentrations of radioactivity peaked at 0.5 h in rats, 2.3 h in dogs, and 2.5 h in monkeys. The apparent absorption ratios of 14C-sitafloxacin based on the AUC0-infinity were 31%, 51%, and 93% in rats, dogs, and monkeys, respectively. In rats, the drug-related radioactivity had been distributed to most organs and tissues 30 min after oral dosing, and had been essentially eliminated after 24 h. The highest levels of radioactivity were observed in the kidneys and liver, whereas the concentrations in the cerebrum and spinal cord were much lower than the serum value. The urinary recoveries of radioactivity after intravenous dosing were 45.5 % in rats, 32.3 % in dogs, and 77.8 % in monkeys. In bile duct-cannulated rats, 57.8 % of the orally administered radioactivity was excreted in the bile within 48 h, and at least 45 % of the sitafloxacin-related material secreted in the bile was re-absorbed from the gastrointestinal tract. These results indicate that sitafloxacin is rapidly absorbed and widely distributed into various tissues. Sitafloxacin-related material is eliminated primarily through both renal and biliary excretion in rats, and possibly in dogs, whereas renal excretion is the major route of elimination in monkeys.