Review of Space Laser in orbit

January 24, 2017 · Posted in Uncategorised · Comment 

Review of Space Laser in orbit Since the early 1990s, NASA used semiconductor-pumped quasi- continuous solid-state lasers as the light source in all of its spaceborne lidar systems. The laser satellite altimeter was launched in 1996 using a semiconductor laser-pumped zig-zagNd: YAG slab, with a wavelength of 1064 nm, a pulse energy of 40 mJ, a pulse width of 10 ns, a repetitive The rate was 10 Hz. Mars satellite laser altimeter secondary scientific goal is to get the whole Mars surface tracing data, tracing the accuracy of the data to meet the geological and geophysical research necessary. Since the launch in November 1996 to June 2001 mission end, Mars laser altimeter launched a total of 670000000 laser pulses, access to 640000000 Mars profiles and atmospheric measurement data. These data volumes are more than ten times the sum of all previous LIDAR data, and the performance and life expectancy of the Mars laser altimeter are better than expected. Shuttle Laser Altimeter (SLA) I \u0026 II is a copy of the Mars Laser Altimeter, which was launched in 1996 and 1997 to generate a total of 6 million laser pulses for the Earth’s profile mill drill machine. The laser of the Geoscience Laser Altimeter System (GLAS) was designed for the first time using a passive Q-switched, primary-power amplifier. The laser altimeter system was launched in 2003, the beginning of 2011 to complete the established mission, in the mission period, the three transmitters were fired nearly 2000000000 laser pulses, the system is the next generation of space laser proximity sensor Representatives of lasers. The laser performance of the laser altimetry system is one order higher than that of the laser laser altimeter in terms of power, beam quality, pulse width, and repetition frequency. Specifically, the total energy of the laser pulse is 110 mJ, where the 1.06 μm wavelength pulse Energy of 75mJ, 0.532μm wavelength pulse energy of 35mJ, beam quality of 110μrad, pulse width <6ns, repetition frequency of 40Hz. Mercury profiles, space conditions, geochemistry, and the rangefinder mission (MESSENGER) in the laser altimeter can be necessary to change the distance from the high temperature and the frequent changes in the case things. The satellite reached the reserved orbit with March 2011 and started the network data, the track’s near address is 200km, far address is 15,200km, the cycle is 12 hours best mill drill machine. Laser altimeter from the Mercury profile of the recent 0.5 hours, requiring measurement of distance resolution of less than 40 cm, is expected throughout the mission period of total radiation dose of 30krad, 0.1cm equivalent thickness of the aluminum plate for the barrier straightening machine. In the laser altimeter, the pulse energy of the laser is more than 18mJ, the pulse width is 6ns, the repetition frequency is 8Hz, and the beam quality is near the diffraction limit.

 

Laser temperature range of 15 to 25 degrees Celsius, the rate of change of 0.4 degrees Celsius / minute. Tool application The first in-orbit laser radar was a laser altimeter mounted on Apollo 15, 16, and 17, and was used to perform measurements of the lunar profile. The laser for the ruby ​​laser, using a xenon lamp pump, Q switch machine for the United States Radio Company. More than 40 years later, the United States launched a return to the moon plan, the intention of the lunar profile laser altimeter (LOLA) is the first space multi-beam laser height system. The altimeter has a diffractive optical element (DOE) at the exit pupil of the telescope. After the element, five light beams illuminate the lunar profile. Each beam can measure the flight time (distance), pulse broadening ) And transmit / receive energy (profile reflectance), the altimeter has two sources of laser oscillation, one of which is used as a cold backup. NASA CALIPSO’s cloud-aerosol orthorhombic polarized laser radar, launched in 2006, uses a diode laser-pumped Nd: YAG to produce 1064 nm and 532 nm wavelengths at 20 Hz, with automatic Q switch to obtain the pulse width of 20ns, each laser in the 1064nm 220mJ pulse energy occurred, after the frequency of 110MJ pulse energy.