Laser ranging application to time transfer using geodetic satellite and to other Japanese space programs

Communications Research Laboratory (CRL) has been developing a laser time transfer system using a satellite laser ranging (SLR) system. We propose Japanese geodetic satellite 'AJISAI', launched in 1986 as a target satellite. The surface is covered not only with corner cube reflectors but also with mirrors. The mirrors are originally designed for observation of flushing solar light reflected by the separate mirrors while the satellite is spinning. In the experiment, synchronized laser pulses are transferred via specified mirror from one station to another while the satellite is up on the horizon to both stations. The system is based on the epoch timing ranging system with 40 ps ranging precision, connected together with UTC(CRL). Simulation study indicates that two stations at thousands of km distance from each other can be linked with signal strength of more than 10 photons and the distributed images of laser beam from AJISAI mirrors give many chances for two stations to link each other during a single AJISAI pass. Retro-reflector In Space for Advanced Earth Observation Satellite (ADEOS) and RendDezVous docking mission of Experimental Technology Satellite-7 (ETS-7) are briefly presented

Ho:YLF Laser Pumped by TM:Fiber Laser

A 2-micron Ho:YLF laser end-pumped by 1.94-micron Tm:fiber laser is described. A ring resonator of 3m length is adopted for the oscillator. The laser is a master oscillator and an amplifier system. It is operated at high repetition rate of 200-5000 Hz in room temperature. The laser outputs were about 9W in CW and more than 6W in Q-switched operation. This laser was developed to be used for wind and CO2 measurements

Ho:YLF Laser Pumped by TM:Fiber Laser

A 2-micron Ho:YLF laser end-pumped by 1.94-micron Tm:fiber laser is described. A ring resonator of 3m length is adopted for the oscillator. The laser is a master oscillator and an amplifier system. It is operated at high repetition rate of 200-5000 Hz in room temperature. The laser outputs were about 9W in CW and more than 6W in Q-switched operation. This laser was developed to be used for wind and CO2 measurements

Indo-Japanese lidar observations of aerosols over a tropical latitude

239-244This paper presents the measurements of atmospheric aerosols observed with Indo-Japanese lidar located at Gadanki (13.5o N, 79.2°E) and preliminary observations on aerosol backscattering cross-section, scattering ratio and turbidity on three days during equinoctial, summer and winter periods. The method of analysis is also discussed

Middle atmospheric temperature measurements using a ground based lidar from low latitude

249-257Lidar measurements of atmospheric density and temperature in the altitude range 30-80 km have been performed during the period March-December 1998, using NMRF-IJL, Gadanki (l3.8°N, 79.2°E). Sample results on temperature structures in the periods of equinoctial, summer and winter nights, results on wave propagation and evidence of mesospheric temperature inversion on an occasion are presented. The data analysis, method of temperature determination and its standard error are also described

Middle atmospheric temperature measurements using ground based lidar from low latitude

Lidar measurements of atmospheric density and temperature in the altitude range 30-80 km have been performed during the period March-December 1998, using NMRF-IJL, Gadanki (13.8 deg N, 79.2 deg E). Sample results on temperature structures in the periods of equinoctial, summer and winter nights, results on wave propagation and evidence of mesospheric temperature inversion on an occasion are presented. The data analysis, method of temperature determination and its standard error are also described