The SE-590 Reflectance Factors and Radiances Measured from a Helicopter Data Set were collected using the helicopter-borne SE-590 during Intensive Field Campaign 5 (IFC-5) in 1989. These data were collected at 17 different grid locations within the FIFE study area. Data were collected on 6 days from July 28, 1989 through August 8, 1989, when sky conditions were clear.
The helicopter missions were designed to provide a means of spectrally characterizing each FIFE site and provide an intermediate scale of sampling between that of the surface measurements and the higher altitude aircraft and spacecraft multispectral imaging devices. The SE-590 instrumentation was chosen to provide compatibility with surface-based radiometers and TM spacecraft sensors. Off-nadir measurements were made as a means of providing more accurate estimates of hemispherical reflectance and for use with bi-directional reflectance models.
SE-590 Reflectance & Radiances (FIFE).
(SE-590 Reflectance Factors and Radiances Measured from a
Helicopter).
The SE-590 Reflectance Factors and Radiances Measured from a Helicopter Data Set contains wavelength, reflectance, standard deviation of the reflectance data.
The FIFE Staff Science effort covered those activities which were community level activities, or which required uniform data collection procedures across sites and time. Hence, these activities were more appropriate for a team under the direction of a single scientist who would respond to the needs of the Science Steering Group of the experiment. This included the acquisition of the multispectral radiometer data from FIFE sites using a helicopter platform.
Wavelength, reflectance, standard deviation of the reflectance.
The data were collected using the helicopter-borne SE-590 during Intensive Field Campaign 5 (IFC-5) in 1989. There are no data for 1987. These data were collected at 17 different grid locations within the FIFE study area. Data were collected on 6 days from July 28, 1989 through August 8, 1989, when sky conditions were clear.
SE590_HELO_DATA.
Staff Science.
Staff Science Helicopter Data Acquisition Program.
Contact 1:
Charles L. Walthall
Laboratory for Global Remote Sensing Studies
Dept. of Geography, Univ. of MD
College Park, MD
(301) 405-4058
cw7@umail.umd.edu
The SE-590 Reflectance Factors and Radiances Measured from a Helicopter data were collected by a dedicated team of pilots, mechanics, photographers and scientists. The efforts of the following individuals are notable: Helicopter crew: Charles Walthall, mission scientist;
William Dykes, pilot; Charles Smith, mechanic and observer; Ed Bohles, mechanic and observer; Richard Huey, photographer; David Pierce, engineer; Douglas Young, engineer; US Army 82nd Medical Helicopter Unit, Ft. Riley, Kansas for on-site hanger space and helicopter technical support.
The helicopter missions were designed to provide 1) a rapid means of intensively, spectrally characterizing each FIFE site while providing FIFE study area coverage, and 2) to provide an intermediate scale of sampling between that of the surface measurements and the higher altitude aircraft and spacecraft multispectral imaging devices. The SE-590 instrumentation was chosen to provide compatibility with surface-based radiometers and TM spacecraft sensors. Off-nadir measurements were made as a means of providing more accurate estimates of hemispherical reflectance and for use with bi-directional reflectance models.
The Spectron Engineering SE-590 is a portable, battery operated spectro-radiometer consisting of a data analyzer/logger controller, spectral detector head and an external battery charger/power supply. The controller is a self contained microprocessor based unit which processes the signal from the head, amplifying and digitizing it with 12 bit resolution. For each spectral scan, the controller actuates the spectral head shutter, measures and stores the dark current, calculates optimum integration time, acquires the spectrum and automatically subtracts the noise for all 256 spectral elements. A series of scans can be taken and automatically averaged. The spectrum is stored in a double precision register which saves the entire 12-bit binary spectra until it is transmitted through the RS-232C port. The spectral detector head uses a defraction grating as the dispersive element; the spectrum is imaged onto a 256 element photodiode array. Each element integrates simultaneously acquiring the spectrum in a fraction of a second. The interconnect cable from the spectral head to the controller couples the spectral signals to the controller, timing and control signals to the head. A shutter in the head, operated by the controller closes the light path for dark current measurements. For further information consult the SE-590 operating manual or Spectron Engineering, Denver, Colorado.
Airborne.
During 1989 the SE-590 (serial number 1571) was mounted on a pointable mount attached to the starboard side of a NASA Bell UH-1B "Huey" helicopter (NASA 415). The data collection system and methodology were developed for prior experiments over forested areas (Williams et al., 1984).
There were two type of helicopter optical system missions: H-1a and H-1b. The objective of the H-1a missions was to acquire spectral data of specific FIFE sites coincident with surface, atmospheric and satellite measurements. The objective for the H-1b missions was to acquire multispectral data of as many FIFE sites during the available flight time. All regular FIFE sites were measured from a hover. Some special sites were flown in a slow-flight transect mode.
The area for observations within a site differed for the three primary sites (906, 916 and 928) from the other FIFE sites. The "WAB" area was outlined by crews on the surface with flags: the two edges and a center line directly into the wind were marked. Using these lines as guides, slow flight transects with an average of 8 observations per line were flown. Sampling of the other FIFE sites followed the 1987-type pattern of sampling. The sample area for these sites was a doughnut-like ring around the automated weather stations or over areas where surface radiance and biology measurements were being conducted. The ring around the weather stations was 2-3 times the width of the weather station areas (the instruments were normally bounded by fences).
Reflected radiation, emitted radiation, and surface temperature.
The SE590 spectral detector head uses a defraction grating as a spectral discrimination element; the spectrum is imaged onto a 256 element photodiode array. Each element integrates simultaneously acquiring the spectrum in a fraction of a second. Gain is set based on maximum levels recorded by a scan taken before the actual data collection scan.
When mounted on the helicopter, the optical head is equipped with lenses having a 1 degree FOV. Given a nominal data acquisition altitude of 330 m, spectral irradiance from the ground surface area of a circle with an approximate diameter of 5.76 m is recorded. Off-nadir view angles were possible in the backscatter direction using the pointable mount.
Spectron Engineering, Inc.
255 Yuma Court
Denver, Colorado 80223
(303) 733-1060
Calibration of the SE-590 for absolute radiance was carried out by Staff/GSFC using transfer radiometer procedures. The calibration procedures and specifics can be found in Markham 1987; and Markham et al., 1988. Estimates of irradiance were derived from the use of a separate SE-590 located on the surface mounted over a horizontal BaSO4 reflectance panel using a 15 degree field-of-view lens. The calibration panel was operated by University of Nebraska SRB personnel. No corrections were made for the temperature sensitivity (Blad et al., 1990). A post-season wavelength calibration was performed. The post-season radiance and wavelength calibrations were performed at Goddard Space Flight Center.
Each SE-590 has a unique wavelength associated with each of its 252 bands. So that wavelength to wavelength comparisons could be made among SE-590s used at FIFE, a cubic spline interpolation was applied to the 252 bands to standardize the wavelengths to every 5 nm from 400 to 1000 nm.
Results from the temperature dependency data indicated that measurements at wavelength of 1000 nm may result in discrepancies of approximately 50 W/m**2/sr/um if the instrument temperature varies for 16 to 43.5 degree C (Blad et al., 1990).
BaSO4 measurements were made at intervals no longer than 20 minutes apart with the start of daily data collection being 30 minutes prior to the first helicopter mission and ending 30 minutes after the last helicopter mission of the day.
Not available at this revision.
The NASA Bell UH-1B helicopter optical remote sensing system for 1989 supported a data acquisition system consisting of a boresighted SE-590; a color video camera; and one 35 mm flight research camera loaded with color film. Controller units for all the optical devices are rack-mounted inside the helicopter and are wired such that a single switch closure triggers all devices. The switch closure also activates an audible tone which is recorded on one of the two audio tracks of a Beta-format video recording system. The other audio track of the VCR was used to record cabin intercom conversations among the helicopter crew. If one desires to examine site conditions in greater detail, the higher resolution 35 mm still photography can be reviewed. Note that the 35 mm camera was secured in a nadir-looking configuration. The video camera was mounted on the pointable platform with the radiometric instruments.
Not available.
Special targets include Off-nadir data is limited to backscatter measurements, and is limited in quantity. Data quality checks have not been made. No atmospheric corrections have been made.
The FIFE study area with areal extent of 15 km by 15 km, is located south of the Tuttle Reservoir and Kansas River, and about 10 km from Manhattan, Kansas, USA. The northwest corner of the area has UTM coordinates of 4,334,000 Northing and 705,000 Easting in UTM Zone 14.
All view zenith angles were measured with respect to gravity not in relation to the slope of the plot. These measurement plots were located northeast of the Wind Aligned Blob (WAB) site (Sellers et al. 1989). A topography file containing the northing and easting of the plots at each site except for site 966 (2437-BBS), is available in the GRABBAG section of FIFE CD-ROM Volume 1 in the UNL directory, in file UNL_PLOT.T89. This file also includes slope, aspect, soil depth and vegetative height of the plots, for all sites.
The number and spatial distribution of the sites covered on each mission varied according to the specific mission objectives as established by the Science Steering Group. During IFC-5 the three primary sites (906, 916 and 926; sitegrids 2133-HLS, 4439-HLS, 8739-HLS, respectively) were measured on every mission to assure continuity.
Measurements were taken at the following locations:
SITEGRID STN NORTHING EASTING LATITUDE LONGITUDE ELEV SLOPE ASPECT
-------- --- -------- ------- -------- --------- ---- ----- ------
0847-HLS 929 4332344 714439 39 06 57 -96 31 11 418 1 TOP
1478-HLS 938 4331223 720664 39 06 15 -96 26 53 375 2 N
1511-HEL 107 4331080 707287 39 06 22 -96 36 10
1916-HLS 902 4330282 708259 39 05 55 -96 35 30 351 2 N
1942-HLS 944 4330133 713414 39 05 46 -96 31 56 422 1 TOP
2123-HLS 905 4329866 709506 39 05 41 -96 34 39 405 1 TOP
2133-HLS 906 4329726 711604 39 05 34 -96 33 12 443 1 TOP
2330-HLS 908 4329314 711066 39 05 22 -96 33 35 424 5 E
2655-HLS 936 4328787 716070 39 05 00 -96 30 07 367 4 E
3129-HLS 912 4327822 710820 39 04 33 -96 33 47 431 14 E
3317-HLS 910 4327395 708485 39 04 22 -96 35 24 427 15 W
4268-HLS 932 4325633 718582 39 03 16 -96 28 26 420 1 TOP
4439-HLS 916 4325193 712773 39 03 06 -96 32 28 443 2 N
6469-HLS 923 4321189 718752 39 00 51 -96 28 25 440 3 NE
6735-HLS 913 4320652 712073 39 00 40 -96 33 03 385 1 BOTTOM
6912-HLS 924 4320111 707336 39 00 26 -96 36 20 397 2 N
8739-HLS 926 4316699 712845 38 58 31 -96 32 35 442 1 TOP
Not available.
The ground resolution of the data is 26.06 square meters at nadir (0.5 degrees FOV at 330 m AGL) and changed with view zenith angle.
Not available.
Not available.
Missions were dependent on the availability of clear sky conditions.
Every site was not observed on every flight.
Missions were dependent on the availability of clear sky conditions. Every site was not observed on every flight. The overall period of coverage was from July 28, 1989, through August 8, 1989. Measurements were made on the following five dates:
July 28, 1989
August 4, 1989
August 6, 1989
August 7, 1989
August 8, 1989
Not available.
Observation time over each site was 2 to 5 minutes during which an average of 20 measurements were made (maximum of 150).
The SQL definition for this table is found in the SE_HELO.TDF file located on FIFE CD-ROM Volume 1.
Parameter/Variable Name
Parameter/Variable Description Range Units Source
SITEGRID_ID This is a FIS grid location code. Site grid codes (EESS-III) give the east (EE) and south (SS) cell number in a 100 x 100 array of 200 m square cells. The last 3 characters (III) are an instrument identifier.
STATION_ID The station ID designating the location of the observations.
OBS_DATE The date of the observations, in the format (DD-MMM-YY).
OBS_TIME The start time of the observation in GMT. The format is (HHMM).
DURATION The length of time data was [seconds] collected at a site, in seconds.
NUM_OBS The number of observations averaged together.
VIEW_AZIM_ANG The view azimuth angle (With [degrees North=0, East=90). from North]
VIEW_ZEN_ANG The view zenith angle of the [degrees] observations. With a nadir view=0
SOLAR_AZIM_ANG The solar azimuth angle (With [degrees North=0, East=90). from North]
SOLAR_ZEN_ANG The solar zenith angle. [degrees]
ALTITUDE The helicopter altitude above [meters] ground level.
OBS_TYPE A description of the area observed, FULL is the entire site, SRB is the same area as the ground surface radiance observations, WAB is the area upwind of the flux tower, SMT is a transect.
MISSION_ID The mission identification for the helicopter flight.
WAVLEN The wavelength of the observations. [microns]
REFL The average percent reflectance. [percent] Radiance values have been resampled using a cubic spline interpolation then ratioed with calibration panel data.
REFL_SDEV The standard deviation of the [percent] reflectances.
FIFE_DATA_CRTFCN_CODE The FIFE DATA Certification Code * for the data, in the following format: CPI (Certified by PI), CPI-??? (CPI - questionable data).
LAST_REVISION_DATE The last revision date for the data, in the format (DD-MMM-YY).
Note:
Valid levels
The primary certification codes are:
The certification code modifiers are:
SITEGRID_ID STATION_ID OBS_DATE OBS_TIME DURATION NUM_OBS
----------- ---------- --------- --------- --------- ----------
3317-HLS 910 08-AUG-89 2009 126 5
3317-HLS 910 08-AUG-89 2009 126 5
3317-HLS 910 08-AUG-89 2009 126 5
3317-HLS 910 08-AUG-89 2009 126 5
VIEW_AZIM_ANG VIEW_ZEN_ANG SOLAR_AZIM_ANG SOLAR_ZEN_ANG
------------- ------------ -------------- ---------------
0 0 229.62 31.18
0 0 229.62 31.18
0 0 229.62 31.18
0 0 229.62 31.18
ALTITUDE OBS_TYPE MISSION_ID WAVLEN REFL REFL_SDEV
-------- -------- ---------- --------- --------- ----------
305 FULL 890616B .75 24.56 1.38
305 FULL 890616B .48 4.35 .11
305 FULL 890616B .475 4.3 .11
305 FULL 890616B .47 4.26 .18
FIFE_DATA_CRTFCN_CODE LAST_REVISION_DATE
--------------------- ------------------
CPI 27-NOV-90
CPI 27-NOV-90
CPI 27-NOV-90
CPI 27-NOV-90
The number and spatial distribution of the sites covered on each mission varied according to the specific mission objectives as established by the Science Steering Group. The overall period of coverage was from July 28, 1989, through August 8, 1989.
A general description of data granularity as it applies to the IMS appears in the EOSDIS Glossary.
The CD-ROM file format consists of numerical and character fields of varying length separated by commas. The character fields are enclosed with a single apostrophe. There are no spaces between the fields. Each file begins with five header records. Header records contain the following information:
Each field represents one of the attributes listed in the chart in the Data Characteristics Section and described in detail in the TDF file. These fields are in the same order as in the chart.
The algorithms and techniques to calculate the data in this data set are described in detail in Jackson et al., 1987, Markham et al., 1988 and Markham 1989. See these articles for this information.
None known at this revision.
None reported at this revision.
Reflectance.
None.
Errors associated with the measurements can occur due to orientation of the SE-590. The angle of attack of the helicopter varies during flight. The motion of the helicopter cabin beneath the main rotor blades is analogous to a pendulum swinging. Swings resulting in off-nadir views up to 8 degrees off-nadir are possible. There has been no quantitative inquiry into this effect as only very small (estimated at 1 to 2 degrees) off-nadir-induced errors have been estimated in extreme cases. The instrument operator can normally wait for this motion to stop or can anticipate the position of the helicopter before triggering the instruments. The helicopter roll, pitch and yaw are dependent on atmospheric conditions, engine performance and aircrew fatigue. Off-nadir observations are especially questionable under less-than-optimal atmospheric conditions.
The shadowing caused by the SE-590 and the helicopter in measuring the "hot spot" area is another source of error. Variable cloud cover could be an error source with reflectance factors since the incoming radiation measurements were not made simultaneously with the surface measurements. Differences in irradiance between the reference panel location and the site being measured are an additional source of error (spatial distribution of atmospheric properties affecting irradiance).
The lack of correction of the calibration panel for non-Lambertian properties will also induce some errors.
There is also some debate on the amount of atmosphere in the pathlength between the helicopter and the surface. Recent inquiries have revealed absolute reflectance differences of up to 1 percent in the visible bands when at-sensor helicopter MMR radiances were corrected for atmospheric path length (of 300 m AGL) and processed for reflectance when using an atmospheric model. This has not been fully investigated and is still under investigation at the time of this writing.
The heterogeneity of the study site can also affect the measurements. This has been shown to be a potential problem when comparing airborne radiometric measurements to surface radiometric measurements.
There is also some question as to the radiometric fidelity of the data beyond 1000 nm. The use of two different instruments (one for target radiance and one for irradiance measurements) will result in some noise. The spline fit used for wavelength assignments to the sensor array channels is used to deal with some of these differences.
Although silicon detectors have very little temperature effects, there could be some noise induced due to this since there are no means of compensating for this with the SE-590.
The SE-590 instrumentation and data have not been examined as closely as the MMR data. Calibration and characterization procedures for this instrument are still under investigation.
Comparisons have been made with the Surface Reflectances Measured by the PARABOLA, the Surface Reflectance Measured with a Mast-borne MMR data, and the SE-590 Reflectance Factors from GSFC and UNL. Plots of all helicopter SE-590 observations used in calculations of site averages have been made and examined for selected cases. The video tapes for these flights were reviewed as well. No obvious sources of error are indicated other than those listed above.
On days with variable cloud conditions the data should be used with caution. The AMS incoming solar radiation data at the site or nearby site should be consulted. On clear days the measurements fall within the precision of the instrument and errors that were discussed in previous sections.
Not available at this revision.
Not available at this revision.
The data verification performed by the ORNL DAAC deals with the quality of the data format, media, and readability. The ORNL DAAC does not make an assessment of the quality of the data itself except during the course of performing other QA procedures as described below.
The FIFE data were transferred to the ORNL DAAC via CD-ROM. These CD-ROMs are distributed by the ORNL DAAC unmodified as a set or in individual volumes, as requested. In addition, the DAAC has incorporated each of the 98 FIFE tabular datasets from the CD-ROMs into its online data holdings. Incorporation of these data involved the following steps:
Each distinct type of data (i.e. "data set" on the CD-ROM), is accompanied by a documentation file (i.e., .doc file) and a data format/structure definition file (i.e., .tdf file). The data format files on the CD-ROM are Oracle SQL commands (e.g., "create table") that can be used to set up a relational database table structure. This file provides column/variable names, character/numeric type, length, and format, and labels/comments. These SQL commands were converted to SAS code and were used to create SAS data sets and subsequently to input data files directly from the CD-ROM into a SAS dataset. During this process, file names and directory paths were captured and metadata was extracted to the extent possible electronically. No files were found to be corrupted or unreadable during the conversion process.
Additional Quality Assurance procedures were performed as follows:
As errors are discovered in the online tabular data by investigators, users, or DAAC staff, corrections are made in cooperation with the principal investigators. These corrections are then distributed to users. CD-ROM data are corrected when re-mastering occurs for replenishment of CD-ROM stock.
Not available.
Precise locations of the observations used to calculate a site average may not coincide with the exact locations of surface-based measurements.
Before using reflectance factors the incoming radiation from the AMS station at the site or nearby site should be checked for possible cloud-induced error in reflectance factors. The cal panel procedure assumes spatially invariant irradiance conditions for the study area since it is at a fixed location. The data has not been corrected for the effects of the atmosphere beneath aircraft.
Not available.
This data set provides an intermediate scale of sampling between that of the surface measurements and the higher altitude aircraft and spacecraft multispectral imaging devices.
The FIFE field campaigns were held in 1987 and 1989 and there are no plans for new data collection. Field work continues near the FIFE site at the Long-Term Ecological Research (LTER) Network Konza research site (i.e., LTER continues to monitor the site). The FIFE investigators are continuing to analyze and model the data from the field campaigns to produce new data products.
Software to access the data set is available on the all volumes of the FIFE CD-ROM set. For a detailed description of the available software see the Software Description Document.
ORNL DAAC User Services
Oak Ridge National Laboratory
Telephone: (865) 241-3952
FAX: (865) 574-4665
Email: ornldaac@ornl.gov
ORNL Distributed Active Archive Center
Oak Ridge National Laboratory
USA
Telephone: (865) 241-3952
FAX: (865) 574-4665
Email: ornldaac@ornl.gov
Users may place requests by telephone, electronic mail, or FAX. Data is also available via the World Wide Web at http://daac.ornl.gov.
FIFE data are available from the ORNL DAAC. Please contact the ORNL DAAC User Services Office for the most current information about these data.
SE-590 Reflectance Factors and Radiances Measured from a Helicopter are available on FIFE CD-ROM Volume 1. The CD-ROM filename is as follows:
\DATA\SUR_REFL\SE5_HELO\GRIDxxxx\yyddd\ydddgrid.Hnn
Where xxxx is the four digit code for the location within the FIFE site grid, yy is the last two digits of the year (e.g., 87 = 1987), and ddd is the day of the year, (e.g., 061 = sixty-first day in the year). Note: capital letters indicate fixed values that appear on the CD-ROM exactly as shown here, lower case indicates characters (values) that change for each path and file.
The format used for the filenames is: ydddgrid.Hnn, where grid is the four-number code for the location within the FIFE site grid, y is the last digit of the year (e.g., 7 = 1987, and 9 = 1989), ddd is the day of the year, and nn is the number of spectra during a day, when all the spectra are ordered chronologically and all spectra for a minute are in the same file. The content of each file is described in the Data Characteristics Section.
Barnes Engineering. 1982. Calibration and data book: Multispectral 8-channel radiometer. Barnes Engineering Company. Stamford, CT.
Blad, B.L., E.A. Walter Shea, C.J. Hays, and M.A. Mesarch. 1990. Calibration of field reference panel and radiometers used in FIFE 1989. AgMet Progress Report 90-3. Dept. of Agricultural Meteorology. Univ. of Nebraska-Lincoln. Lincoln, Nebraska. 68583-0728.
Jackson, R.D., S.M. Moran, P.N. Slater, and S.F. Biggar. 1987. Field calibration of reference reflectance panels. Remote Sensing of Environment. 17:103-108.
Markham, B.L. 1987. FIFE MMR Calibration Report. GSFC/NASA, Greenbelt, MD 20771.
Markham, B.L., F.M. Wood, and S.P. Ahmad. 1988. Radiometric calibration of the reflective bands of NS001 Thematic Mapper Simulator (TMS) and Modular Multispectral Radiometers (MMR). Society of Photo-Optical Instrumentation Engineers Recent Advances in Sensors, Radiometers, and Data Processing for Remote Sensing. 924:96-108.
Markham, B.L. 1989. MMR Calibration data for FIFE 89 and related studies. GSFC/NASA, Greenbelt, MD 20771.
Sellers, P.J. and F.G. Hall. 1989. FIFE-89 Experiment Plan. GSFC/NASA, Greenbelt, MD 20771.
Sellers, P.J., F.G. Hall, D.E. Strebel, R.D. Kelly, S.B. Verma, B.L. Markham, B.L. Blad, D.S. Schimel, J.R. Wang, and E. Kanemasu. 1990. FIFE Interim Report. GSFC/NASA. Greenbelt, MD 20771.
Walthall, C.L., 1989. The FIFE Helicopter Mission: Summary. Laboratory for Global Remote Sensing Studies. Univ. of Maryland, College Park,
Walthall C.L. and E.M. Middleton. 1992. Assessing spatial and grasslands with the use of a helicopter platform. J. Geophys. Res. FIFE issue. (in press).
Williams, D.L., C.L.Walthall and S.N. Goward, 1984. Collection of in- situ forest canopy spectra using a helicopter: A discussion of methodology and preliminary results. Proced. of 1984 Symp. on Machine Processing of Remotely Sensed Data. Purdue Univ. West Lafayette Indiana. p. 94-106.
Contact the EOS Distributed Active Archive Center (DAAC) at Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee (see the Data Center Identification Section). Documentation about using the archive and/or online access to the data at the ORNL DAAC is not available at this revision.
A general glossary for the DAAC is located at Glossary.
A general list of acronyms for the DAAC is available at Acronyms.
April 25, 1994 (citation revised on October 16, 2002).
Warning: This document has not been checked for technical or editorial accuracy by the FIFE Information Scientist. There may be inconsistencies with other documents, technical or editorial errors that were inadvertently introduced when the document was compiled or references to preliminary data that were not included on the final CD-ROM.
Previous versions of this document have been reviewed by the Principal Investigator, the person who transmitted the data to FIS, a FIS staff member, or a FIFE scientist generally familiar with the data.
August 14, 1996.
ORNL-FIFE_SE_HELO.
Walthall, C. L. 1994. SE-590 Reflectance and Radiances (FIFE). Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Also published in D. E. Strebel, D. R. Landis, K. F. Huemmrich, and B. W. Meeson (eds.), Collected Data of the First ISLSCP Field Experiment, Vol. 1: Surface Observations and Non-Image Data Sets. CD-ROM. National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, Maryland, U.S.A. (available from http://www.daac.ornl.gov).
http://daac.ornl.gov/FIFE/Datasets/Surface_Radiation/SE-590_Refl_Rad.html