From: WPL::INTRIERI 28-JAN-1993 19:32:54.52 To: LOLSEN CC: Subj: FIRE II Archive info FIRE CENTRAL ARCHIVE CATALOG INFORMATION INSTRUCTIONS: Complete a separate catalog for EACH DATA SET to be archived. A brief example has been included for each item listed below. Please complete each item with as much detail as possible. DATA BASE INFORMATION --------------------- Check the appropriate data set name. X__FIRE-CI2 (CIRRUS) __FIRE-ASTEX Check the type of data included in this data set. __AIRCRAFT __RADAR __SONDES __BUOYS __RAD_SURF __SURFACE X__LIDAR __SATELLITE __WIND-PROF __MODEL __SHIPS __OTHER, Please Specify Fill in the volume of this data set. _____ KB _____ MB _____ GB _____ TB Is this an ancillary/correlative data set? X__YES __NO If YES, identify the principal data set. Doppler Lidar wind speeds ______________________________________________________________________ DETAILED CATALOG INFORMATION ---------------------------- 1. TYPE OF DATA 1.1 Check ALL parameters included in this data set. Choose from the following list of current, valid NCDS parameter names to make your selections. __AEROSOLS __LANDMASK (Sea/Land Mask) __SALINITY __ALBEDO __LIQUID_WATER __SNOW __ALTITUDE __MET_CONDITIONS __SOI (S. Oscil. Index) __BACKSCATTER __NITRIC ACID __SOILS __CH4 __NO2 __SOLAR_FLUX __CLOUDS __OPTICAL_DEPTH __SOLAR_PLAGE __CO2 __OZONE __SST (Sea Surf. Temp.) __DENSITY (Air) __PHYTOPLANKTON __STABILITY __DEPTH_MIX __PRECIP_VAP __SUNSPOT __EXTINCTION __PRECIP_WATER __TEMPERATURE __HEAT_FLUX __PRECIPITATION __TMP-PROF X__HEIGHT __PRESSURE __VEGETATION __HEIGHT_GEOP __RADIANCE __WAVES __HUMIDITY __RADIATION_BUDGET X_WIND __HYDROGRAPHY __REFLECTANCE __OTHER, Please Specify __ICE __RIVER_FLOWRATE [Max: 15 Char]______________________________________________________ 1.2 List the measurement units for the above named parameters. (Example: deg K; mb; km; m/s; w/m**2; etc.) height: km (agl) wind speed: m/s wind direction: degrees from true North (clockwise) time: UTC 1.3 Check the Data Source from the following list of current, valid NCDS data source names. __AEM-2 __GOES-7 __NOAA-4 __AIRCRAFT __INSAT-1A __NOAA-5 __BALLOON __INSAT-1B __NOAA-6 __BUOYS __INSAT-1C __NOAA-7 __DMSP-F6 __INSAT-1D __NOAA-8 __DMSP-F7 __ITOS-1 __NOAA-9 __DMSP-F8 __LANDSAT __NOAA-10 __ERBS __METEOSAT __NOAA-11 X__FIELD-OBS __METEOSAT-2 __NOAA-12 __GEOS-3 __METEOSAT-3 __OBSERVATORY __GEOSAT __METEOSAT-4 __SEASAT __GMS-1 __MODEL __SEASAT-1A __GMS-2 __NAVY/NOAA __SHIPS __GMS-3 __NESDIS __SME __GMS-4 __NIMBUS-4 __SMM __GOES-1 __NIMBUS-5 __SMS-1 __GOES-2 __NIMBUS-6 __SMS-2 __GOES-3 __NIMBUS-7 __STATION __GOES-4 __NOAA-1 __SYNOPTIC __GOES-5 __NOAA-2 __TIROS-N __GOES-6 __NOAA-3 __OTHER, Please Specify [Max: 15 Char]______________________________________________________ 1.4 Check the Sensor that corresponds to the above Data Sources from the following list of current, valid NCDS data sensor names. __207-PROBE __MIR __SCR-A __ACRIM __MSS __SCR-B __ALTIMETER __NAVIGATION __SMMR __ANALYSES __NONSCANNER __SODAR __AVHRR __OZONESONDE __SPECTROMETER __BAROMETER __PMS-PROBE __SR __BUV __PRT-4/5 __SSM/T __CEILOMETER __PT-RESISTANCE __SUN PHOTOMETER __CH4-ANALYZER __PYANOMETER __TELESCOPE __CO2-ANALYZER __PYRGEOMETER __THIR __CURRENT-METERS __PYRHELIOMETER __TM __CZCS __RADAR __TOMS X__DOPPLER LIDAR __RADIOMETER __TOVS __DOPPLER RADAR __RADIOMETER4.3UM __TOVS/HIRS2 __ER-2 LIDAR __RADIOSONDE __TOVS/MSU __ERB __RAWINSONDE __TOVS/SSU __ESMR __ROSEM-PRES __UMKEHR __HIS __ROSEM-TMP __VAS __HSRL __SAGEI __VHRR __HYGROMETER __SAGEII __VIL __IN SITU __SAM-II __VIRR __JW-HOTWIRE __SAR __VISSR __LIMS __SBUV __WIND-PROFILER __MICROWAVE_RAD __SCANNER __WIND-SENSOR __MCR __SCATTEROMETER __OTHER, Please Specify [Max: 15 Char]_______________________________________________________ 2. Describe the SPATIAL CHARACTERISTICS of the data set. Vertical profiles (approx. 1.5 - 20.0 km agl) vs. time (approx. 1 profile per 1/2 hour) 2.1 What is the spatial coverage? (Example: 80 deg N to 80 deg S; global; point, etc.) Vertical column (see above) 2.2 What is the spatial resolution (horizontal and vertical)? (Example: 250 km x 250 km, 1 level; station, 10 levels; etc.) Vertical - 75 m range gates Horizontal - negligible - collimated laser beam 3. Describe the TEMPORAL CHARACTERISTICS of the data set. Variable - approximately 1 profile per 1/2 hour during intensive mode, and 1 profile per 2 hours during monitoring mode 3.1 What is the temporal coverage? (Example: 07/01/87 - 07/19/87; etc.) 11/13/91 - 12/07/91 3.2 Check the temporal resolution from the following list? __ 1_second __ daily __ annual __ 5_second __ 3_day __ 10_year __ minute __ 5_day __ 30_year __ 10_minute __ weekly __ monthly_climatology __ 30_minute __ 2_week __ seasonal_climatology __ hourly __ 3_week __ annual_climatology __ 3_hourly __ monthly __ climatology __ 6_hourly __ seasonal X__ Other, Please Specify [Max: 15 Char]___________variable____________________________________ 4. Give a complete INSTRUMENT/MODEL DESCRIPTION by providing information in 4.1 - 4.4. 4.1 Mission Objectives. (Example: The mission objectives of the SAGE II are to determine the spatial distribution and to map vertical profiles of water vapor. Specific objectives are ..., etc.) The mission objective was to obtain lidar measurements of relative backscatter signal intensity and radial velocity from cirrus clouds to study their microphysical and radiative properties. 4.2 Key Satellite/Aircraft/Model Parameters. (Example: Nominal orbit parameters for ERBS are listed below: Launch date, Planned Duration, Actual Duration, etc.) Key parameters provided by the Doppler lidar include relative backscatter (m-1 sr-1), radial velocity (m/s), and height (km above ground level). This data set only includes wind profiles derived by the VAD method for the FIRE II top 5 priority days. 4.3 Principles of Operation. (Example: SAGE II is a seven-channel solar photometer with spectral bands at 0.385, 0.448, 0.454, 0.525, 0.600, 0.940, and 1.109 micrometers.) The Doppler lidar is a pulsed, CO2, coherent, mobile laser radar system. Although the principal wavelength of operation is 10.6 micrometers, any wavelength between approximately 9 and 11 micrometers may be used. A laser pulse is released from the TEA cavity and is frequency monitored before exiting the lidar trailer via a computer controlled scanner. The return signal follows the reverse path of the outgoing pulse until it is diverted by a T/R switch onto a detector. A local oscillator held 20 MHz below the CO2 laser is mixed with the returned pulse to compare the amount of frequency off-set to determine the Doppler velocities. All of the scanning and frequency information is recorded onto tape in the trailer. A real-time color display aids in experimental guidance and scanning strategies. 4.4 Instrument Measurement/Model Geometry. (Example: SAGE II uses the sun as a constant radiant source and measures the radiation that reaches the spacecraft after penetrating the Earth's atmosphere during spacecraft sunrise and sunset.) The lidar system scanning capability includes elevation angles ranging from -5 through 90 degrees and full azimuth sweeps of 0 through 360 degrees. 5. Describe the PROCESSING SEQUENCE by providing descriptions in 5.1 - 5.4. 5.1 Processing Steps and Data Sets. (Example: Data from three sources are combined at Langley Research Center (LaRC) to produce the SAGE II MERDAT data set. They include: (1)..., etc.) Field tapes are converted to Universal Format in the laboratory. Visual images of the velocity field can then be perused to assess cases of interest. There are many lidar specific programs used to assess data quality, retrieve profiles of winds, color images, time-height sequences, Cartesian coordinate mapping, etc. 5.2 Derivation Techniques/Algorithms. (Example: Occultation radiometry is the technique used to derive the water vapor profiles.) Vertical profiles of the horizontal wind speed and direction are acquired by the lidar using a classic method commonly referred to as the VAD technique, where VAD stands for Velocity-Azimuth Display. L. Battan (Radar Observations of the Atmosphere, Univ. of Chicago Press, 1973) and other texts that discuss Doppler radar describe the general method. A field comparison of our lidar with other methods is given in "Wind measurement accuracy of the NOAA pulsed infrared Doppler lidar," Appl. Optics., 23, 1984, by F.F Hall, et al. The lidar scans in azimuth at constant elevation angle (typically 60 degrees) to sweep out a cone, whose tip is at the lidar. The lidar measures the radial velocity (wind component parallel to the beam) within gates typically 150 m in length using a three pulse average to form a measurement at typically 1 degree increments in azimuth. Aerosol particles or hydrometeors are the target, which are assumed to move with the air motions. For a horizontally uniform wind, the radial velocity at each range gate gives a sinusiodal behavior as a function of azimuth. The maximum occurs at the azimuth pointed into the wind, and the minimum when pointed downwind. The phase of the sinusoid thus gives the wind direction, and the peak-to peak magnitude and cosine of the elevation angle give the speed. (The method can also measure a combination of vertical motion and divergence, but no attempt has been made to extract those parameters from FIRE II data.) Data are processed to obtain the wind speed and direction at the height of each range gate. The Doppler data have noise caused by turbulence and random inaccuracies in the Doppler estimates, even when scatterers are sufficient for high signal-to-noise ratio. When signal becomes weak because of few scatterers, large range, and extinction of radiation by gaseous absorption and clouds, the uncertainty of individual radial velocity estimates increases. Our processing uses an iterative procedure to find and discard outliers. A sinusoid is fit by least squares to all data at a range gate, and data points falling at least 15 m/s away are discarded. The fit is repeated, and points more than 5 m/s are discarded, followed by a final least squares fit of a sinusoid. The percentage of good (i.e. retained) points is an excellent indicator of the accuracy in the wind speed and direction; we nominally used a value of 50 good points for the FIRE II data. 5.3 Special Corrections/Adjustments. (Example: During the processing of SAGE I and SAGE II data, corrections are made for solar limb darkening, atmospheric refraction, and Rayleigh scattering to derive the parameter data sets.) A time-height plot of wind barbs was examined by staff. Any obvious outliers were then edited from the data set. Accuracy is typically within 1 m/s vector component. 5.4 Processing Changes. (Example: As a result of published corrections to the NOAA temperature data at 5 millibars and above, and the desire to compare SAGE I and SAGE II data for long-term trend studies, the SAGE I data have been reprocessed using improved retrieval techniques employed for SAGE II.) 6. Give a QUALITY ASSESSMENT of the data set by providing descriptions in 6.1 - 6.3. 6.1 Data Validation. (Example: SAGE I and SAGE II results have been validated by comparison with those obtained from a wide range of sensors including an airborne LIDAR and a balloon-borne optical particle counter.) 6.1.1 What is the minimum allowable value for each variable? See above section for details. 6.1.2 What is the maximum allowable value for each variable? See above section for details. 6.2 Confidence Level/Accuracy Judgment. (Example: The accuracy of the measurements is estimated to be 15% based on uncertainties in the absorption cross-sections and their temperature dependence.) See above section for details. 6.2.1 What is the precision/error of each parameter? See above section for details. 6.3 Usage Guidance. (Example: SAGE I MERDAT data are regarded as useful only for deriving extinction coefficients and particle densities by an inversion technique, as was done for the Level 2 data sets.) ASCII formatted files first list all profiles by profile number, time, VAD elevation angle, begin azimuth, end azimuth, sweep #, sweep direction (1=clockwise, -1=counter), quality (99=good, 0=bad), site (18=Coffeyville), begin and end record. Following this master listing, individual profile data follows for each profile. 7. List the Contact(s) for Data Production Information. Name: Janet Intrieri Address: NOAA/ERL/WPL R/E/WP2 325 Broadway Boulder, CO 80303 Telephone: (303) 497-6594 FTS: 320-6594 FAX: (303) 497-5318 Internet: jintrieri@wpl.erl.gov 8. Describe OUTPUT PRODUCTS and AVAILABILITY in 8.1-8.3. Time-height profiles of wind speed and direction derived by the VAD method using Doppler lidar radial wind velocities. All profiles are available for priority days, other days will be processed on a request basis. 8.1 Tape Products. Medium/Specification: (Example: 8mm Exabyte; 9-track, 6250-bpi computer tape; etc.) Format and Content: (Example: CDF, HDF, SDF, netCDF, etc; Gridded (4 x 5) global meteorological data derived from TOVS HIRS/2 and MSU sound data) Data Quantity/Rate: (Example: Each tape contains 1 year of data.) The floppy contains the FIRE II experiment 5 priority days wind profiles. Status: (Example: Available.) Available Plans/Schedule: (Example: Additional data will be integrated periodically as they are received.) 8.2 Film Products. Medium/Specification: Format and Content: Data Quantity/Rate: Status: Plans/Schedule: 8.3 Other Products. Medium/Specification: (Example: floppy disk; online file] Format and Content: (Example: ASCII file) Data Quantity/Rate: Status: Plans/Schedule: 9. DATA ACCESS (NCDS/Goddard DAAC will complete Item 9) 9.1 Archive Identification. 9.2 Procedures for Obtaining Data. 9.3 NCDS/Goddard DAAC Status/Plans. 10. CONTACTS FOR ARCHIVE/DATA ACCESS INFORMATION (Complete if contact should be other than, or in addition to, the NCDS/Goddard DAAC.) Name: Address: Telephone: FTS: FAX: Internet: 11. REFERENCES 11.1 Data Set References 11.2 Journal Articles and Study Reports Post, M.J. and R.E Cupp, 1990: Optimizing a pulsed Dopller lidar, Appl. Opt., Vol. 29, pp 4145-4148. 11.3 Satellite/Instrument/Data Processing/Archive/DBMS Documentation Last revised: 04/30/92