To whom it may concern: Version 1.1 is the first calibrated data release for the NASA/GSFC Scanning Raman Lidar. The data are split into four datasets that will cover the periods of 8/6-19, 8/20-9/9, 9/12-20, and all the YAG data which includes daytime and nighttime data. If some days are missing, its because more analysis is needed. The data presented were done by merging the angle (10° off the horizon) with the vertical data between a range of 400-600 m, where the data were merged using a linear interpolation based on altitude. For the nights of 8/9-8/12, the data were merged between 600-800 m due to a different system configuration. Below this minimum altitude, the data are all angle data, and above the maximum altitude, the data are all from the vertical. Data from the night of 9/14/98 UTC (which is part of dataset #3) are included here because that was the calibration/validation night. The rest of dataset #3 will be delivered next week. Note that 24 UTC on 9/14/98 is actually 0 UTC. Data collection started on late on 9/13/98 and continued on into 9/14/98 UTC. The times are presented in this manner for ease of data analysis. These data were calibrated using the Vaisala radiosondes launched by the Univ of Wisconsin crew. For each dataset, the coincident radiosonde-lidar calibration is averaged into a single number calibration for the whole dataset. There is some stippling in the data. This is due to clouds attenuating the laser signal, such that, the data above the cloud (the stipled regime) is noisy and not considered good data. Ground data (10 m above sea level) are included in these datasets for comparison and precipitable water calculations. For 8/6-12, the ground data used were the AUTEC surface data which is 1 mile off shore. For the rest of the datasets, the U of Wisconsin chilled mirror data were used for the ground point. On 8/20/98, we took data 80° and 85° from the horizontal. Therefore the start altitude is different for this day the rest of the days. The 85° data was merged into the 80° between 700-800 m. Data for 8/22/98 through 25/98, 8/31/98, 9/7/98 and 9/8/98 UTC are vertical only data. Therefore the start altitude is different on these days than on days when we collected angle data as well. On 8/31/98 we took 10 second time resolution (versus 1 minute) data from 0130-0300 UTC. On 9/1/98, we took 10 second data from 0800-1000 UTC, and on 9/7/98 all the data is 10 second data from 0300-1000 UTC. These data were integrated into 1 minute profiles to be consistent with the rest of the datasets. If you are interested in the 10 second data, please contact us (see below). Data for 9/10/98 and 9/11/98 will be delivered at a later time. If you are interested in this data, please contact us (see below). BEWARE: Of the data later than 0630 UTC on 8/16/98, the calibration is suspect. There seemed to be dew on the window which transmitted the outgoing and incoming signals. This applies also to the data later than 0645 UTC on 8/18/98 due to water on the window because of the rain. Analysis is ongoing to retrieve the best data from these days. If you happen to be interested in these time periods, let us know so we change prioritize it properly. WARNING: If you downloaded data for 8/16-19, or 9/14/98, before 7/30/99 6pm EST, then you should get these data again. There was an error in adding the ground data for these days, although it may not make much difference. BEWARE: Of the data later than 0730 UTC on 9/16/98, the calibration is suspect. There seemed to be dew on the window which transmitted the outgoing and incoming signals. Analysis is ongoing to retrieve the best data from these days. If you happen to be interested in these time periods, let us know so we change prioritize it properly. -------------------------------------------------------------------------------------------------- This rest of this file describes the format of the NASA/GSFC Scanning Raman Lidar data. These are ascii files. Here is a sample of the beginning of one of the file: 160 = number of files 0 3.2044 = file,time 2 106 = number of header, data lines dummy line Range(km) height(km) w (g/kg) err (g/kg) res (km) 0 2.3115e-001 2.3115e-001 1.1870e+000 3.1799e-004 2.3115e-001 1 2.9198e-001 2.9198e-001 1.1908e+000 5.5582e-004 6.0830e-002 2 3.5281e-001 3.5281e-001 1.2360e+000 4.0816e-004 6.0830e-002 The first line contains the number of profiles (160) contained in this data file. This line occurs only once. The next 4 lines occur for every profile. The second line (first of 4) contains the profile number (0), then the time in UTC (3.2044). The times will increment by 1 or 2 minutes, approximately. The third line (second of 4) contains the number of header lines (2) to follow and the number of altitude lines (106) following the header lines. The fourth line (third of 4) is a dummy line. This exists to maintain compatiblity with the current version of the software we are using. The fifth line (fourth of 4) is a header line that describes the data columns. The first column, is the bin number and there is no heading for this line. The next 106 lines are the data in 6 columns. Column 1 is the bin number, 2-range in km from the lidar, 3-altitude in km (this would be the same as the range if the angle is 0.00), the 4th column is the water vapor mixing ratio in g/kg, the 5th column is the error in the water vapor mixing ratio in g/kg, and the last column is the vertical resolution of the data in km. The error is calculated using Poisson statistics (the error is the square root of the counts) and propagated throught the equations to obtain the given error. Any questions, feel free to contact Keith Evans (301) 614-6282, evans@agnes.gsfc.nasa.gov or Dave Whiteman (301) 614-6703, David.Whiteman@gsfc.nasa.gov.