An optical parametric amplifier has been developed to generate tunable 1570 nm radiation from a 1064 nm pump at high efficiency. A micropulse Nd:YAG with two amplifiers generating an average power of 2 watts (10 kHz) is used to pump a periodically poled lithium niobate crystal injection seeded by two CW distributed feedback lasers: one at 1570.824 nm and the second at 1570.973 nm. A conversion efficiency of ~28% from the pump into the signal wavelength has been demonstrated. The 1-nanosecond signal has a measured time-averaged jitter of <0.3 pm
Mounting concern regarding global warming and the increasing carbon dioxide (CO<sub>2</sub>) concentration has stimulated
interest in the feasibility of measuring CO<sub>2</sub> mixing ratios from space. Precise satellite observations with adequate spatial
and temporal resolution would substantially increase our knowledge of the atmospheric CO<sub>2</sub>distribution and allow
improved modeling of the CO<sub>2</sub> cycle. Current estimates indicate that a measurement precision of better than 1 part per
million (1 ppm) will be needed in order to improve estimates of carbon uptake by land and ocean reservoirs. A 1-ppm
CO<sub>2</sub> measurement corresponds to approximately 1 in 380 or 0.26% long-term measurement precision. This requirement
imposes stringent long-term precision (stability) requirements on the instrument In this paper we discuss methods and
techniques to achieve the 1-ppm precision for a space-borne lidar.
An optical parametric amplifier has been developed to generate tunable 1570 nm radiation from a 1064 nm pump at high efficiency. A micropulse Nd:YAG operating with an average power of 2 watts (10 kHz) is used to pump a PPLN crystal injection seeded by two CW distributed feedback lasers: one at 1570.824 nm and the second at 1570.973 nm. A two stage amplification process has demonstrated a conversion efficiency of ~28% from the pump into the signal wavelength. The 1-nanosecond signal has a measured time-averaged jitter of <40 MHz.
The NASA Langley Research Center and the NASA Goddard Space Flight Center, have collaborated to design, build and fly a combination backscatter and Differential Absorption Lidar (DIAL) instrument for the measurement of aerosols, temperature and ozone from the NASA DC-8. The AROTAL (Airborne Raman Ozone Temperature and Aerosol Lidar) instrument was flown on two separate Arctic missions to look at ozone loss processes during the late winter-early spring, and to validate measurements made by the SAGE III satellite instrument. Results from this instrument have demonstrated that the SAGE III instrument is in agreement with the lidar retrievals to better than ten per cent.
Local and regional pollution interact at the interface between the Planetary Boundary Layer and the Free Troposphere. The vertical distributions of ozone, aerosols, and winds must be measured with high temporal and vertical resolution to characterize this interchange and ultimately to accurately forecast ozone and aerosol pollution. To address this critical issue, the Regional Atmospheric Profiling Center for Discovery (RAPCD) was built and instrumented in the National Space Science and Technology Center on the UAH campus. The UV DIAL ozone lidar, Nd:YAG aerosol lidar, and 2-micron Doppler wind lidar, along with balloon-borne ECC ozonesondes, form the core of the RAPCD instrumentation for studying this problem. Instrumentation in the associated Mobile Integrated Profiling (MIPS) laboratory includes a 915Mhz profiler, sodar, and ceilometer. The collocated Applied Micro-particle Optics and Radiometry (AμOR) laboratory hosts the FTIR, MOUDI, and optical particle counter. Using MODELS-3 analysis by colleagues, and cooperative ventures with the co-located National Weather Service Forecasting Office in Huntsville, AL, we are developing a unique facility for advancing the state-of-the-science in pollution forecasting.
As a part of the international Network for the Detection of Stratospheric Change, Goddard Space Flight Center has developed a mobile differential absorption lidar capable of making precise and accurate measurements in the stratosphere between 20 and 45 km. We present in this paper a description of the instrument, a discussion of the data analysis,
and some results from an intercomparison held at JPL's Table Mountain Observatory in California during October and November 1988.