Aerosol Research Branch (ARB) 48 inch Lidar Data

The ARB_48_IN_LIDAR data set contains data collected from a 48-inch lidar system located at NASA Langley Research Center. Each granule consists of one year of data. The days of data are different in each granule. Each measurement consists of four parameters: stratospheric integrated backscatter over altitude, altitude levels, scattering ratio at each altitude level, and aerosol backscattering coefficient at each altitude level. An image was produced to represent the data collected for each granule.The Aerosol Research Branch (ARB) Light Detection and Ranging (LIDAR) project has been taking ground based LIDAR measurements from Langley Research Center in Hampton, Virginia since May 1974. These LIDAR measurements provide high resolution vertical profiles of the upper tropospheric and stratospheric aerosols. The LIDAR system has evolved over the years and provides a valuable long-term history of the middle-latitude stratospheric aerosol.The measurements for ARB were made using a LIDAR system. This system uses a ruby laser that emits one joule per pulse with a repeat rate of 0.15 hertz (Hz) at a wavelength of 0.6943 micrometers. This system also uses a 48-inch cassegrainian configured telescope mounted on a movable platform. The transmitter laser beam has a divergence of about 1.0 mrad, and the maximum receiver field of view is 4.0 mrad. The LIDAR has a signal bandwidth of 1 MHz, and this is equal to a 150 meter vertical resolution. Three photomultiplier tubes are used to enhance the dynamic range. These tubes are electronically switched on at specific times after the laser has been fired. The photomultiplier tube output signals are processed by 12-bit Computer Automated Measurement and Control (CAMAC) based digitizers and acquired by a personal computer. The data are archived on optical discs.