The SE-590 Spectroradiometer Reflectance Factors from GSFC Data Set contains spectral data collected with the Spectron SE-590 Spectral Radiometer at selected FIFE sites located primarily on the Konza Prairie. These measurements were acquired in conjunction with the Surface Reflectances measured by the PARABOLA bi-directional measurements. Ground SE-590 data were acquired in all four 1987 Intensive Field Campaigns and in the 1989 Intensive Field Campaign. The ground SE-590 data were collected at approximately every 10 degree change in solar zenith angle (SZA) to characterize diurnal variations and/or simultaneous observations acquired by helicopter, airplane, or satellite over flights. The data were collected as wavelength intensity values which were converted to spectral radiances with instrument and campaign-specific calibration coefficients.
SE-590 Ground Data: GSFC (FIFE).
(SE-590 Spectroradiometer Reflectance Factors from GSFC).
The SE-590 Spectroradiometer Reflectance Factors from GSFC Data Set contains surface reflectance, wavelength, and viewing angle data. These data were acquired in all four 1987 Intensive Field Campaigns and in the 1989 Intensive Field Campaign.
The purpose in collecting the ground SE-590 data was to characterize diurnal variations and/or simultaneous observations acquired by helicopter, airplane, or satellite over flights.
Surface reflectance, wavelength, and viewing angle.
The Surface Radiation Measurement Team (SRB-3) collected spectral data with the Spectron SE-590 Spectral Radiometer at selected FIFE sites located primarily on the Konza Prairie. These measurements were acquired in conjunction with the Surface Reflectances Measured by the PARABOLA bi-directional measurements. The ground SE-590 data were collected at approximately every 10 degree change in solar zenith angle (SZA) to characterize diurnal variations and/or simultaneous observations acquired by helicopter, airplane, or satellite over flights. Ground SE-590 data were acquired in all four 1987 Intensive Field Campaigns and in the 1989 Intensive Field Campaign. The data were collected as wavelength intensity values which were converted to spectral radiances with instrument and campaign-specific calibration coefficients.
SE590_GROUND_GSFC_DATA.
Dr. Elizabeth M. Middleton
NASA Goddard Space Flight Center
Quantifying Reflectance Anisotropy of Photosynthetically Active Radiation in Grasslands.
Contact 1:
Dr. Elizabeth Middleton
NASA/Goddard Sp. Fl. Ctr.
Greenbelt, MD
(301) 286-8344
middleton@pldsg3.gsfc.nasa.gov
Contact 2:
K. Fred Huemmrich
NASA/Goddard Sp. Fl. Ctr.
Greenbelt, MD
(301) 286-4862
fred@ltpsun.gsfc.nasa.gov
The SE-590 Spectroradiometer Reflectance Factors from GSFC were collected by Dr. Elizabeth M. Middleton and her colleagues at NASA Goddard Space Flight Center.
Ground spectral radiances were acquired for grassland canopies and spectral irradiances were determined from radiation reflected from a barium sulfate reference panel. Radiances and irradiances were available at 252 wavelength channels that sampled the spectrum between 0.372 - 1.1 micrometers at unequal intervals of 0.002 - 0.003 micrometers. The true spectral resolution was 0.12 (O.10-0.15) micrometers. Due to decreased sensitivity of the instrument at extreme wavelengths, the data were retained for the interval 0.400 - 1.01 micrometers. Spectral reflectance was calculated as the ratio of the grassland radiance to the irradiance per spectral channel.
The SE-590 was fitted with a 15 degree IFOV lens and mounted, along with another instrument (the PARABOLA, D. Deering, Code 923, NASA/GSFC) and a down-looking camera, on a large tripod-supported boom. The boom was elevated to position the instruments approximately 4.5 m above the surface in a relatively large area (50-70 [m^2]) that was judged to be as uniform and representative of the site as possible. The instruments were connected by cables to the respective recording units that were placed on elevated platforms behind the tripod/boom/instrument apparatus.
Ground-based.
The SE-590 was mounted 4.5 m above the surface on a large tripod-supported boom.
To measure surface radiance.
Surface radiances and reflectance factors from 0.372 to 1.1 micrometers at unequal intervals of 0.002 - 0.003 micro-meters.
The SE-590 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 SE-590 was mounted on a tripod/boom apparatus 4.5 m above the ground. The SE-590 was fitted with a 15 degree IFOV lens All data were collected with the boom oriented normal to the solar principal plane (SPP). The azimuth orientation of the boom was adjusted before each sampling period to ensure that the data were acquired in the SPP. Typically 2 - 10 nadir observations were collected aligned in the SPP. These nadir SPP measurements were immediately followed by 2 or more additional nadir observations taken when the boom was rotated slightly to either side of the SPP.
Spectron Engineering, Inc.
255 Yuma Court
Denver, Colorado 80223
(303) 733-1060
During any given data collection time period, multiple observations with the SE-590 were made of the vegetated surface and of the barium sulfate reference panel. The reference scans were taken at the beginning and end of each sampling period since the boom had to be swung around 180 degrees to avoid trampling on the target vegetation surface.
The SE-590 was calibrated in house (GSFC) against several standards:
The true spectral resolution was 0.12 (0.10 - 0.15) micrometers.
Daily stability checks were only performed during the IFC-5 period. A post-season wavelength and radiance calibration were performed at Goddard Space Flight Center.
Not available at this revision.
The ground SE-590 data were collected at approximately every 10 degree change in solar zenith angle (SZA). Each SZA sampling period typically lasted 5 - 20 minutes, averaging 10 minutes duration. During any given data collection time period, multiple observations with the SE-590 were made of the vegetated surface and of the barium sulfate reference panel. The reference scans were taken at the beginning and end of each sampling period since the boom had to be swung around 180 degree to avoid trampling on the target vegetation surface. For the vegetation scans, typically 2 - 10 nadir (view zenith angle = 0) observations of the grassland were collected with the boom realigned in the SPP. These nadir SPP measurements were immediately followed by 2 or more additional nadir observations taken when the boom was rotated slightly to either side of the SPP, increasing spatial sampling (1 m separated each of the three surface sample centers).
Not available.
Not available at this revision.
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.
These data were located at the following locations within the FIFE study area:
SITEGRID STN NORTHING EASTING LATITUDE LONGITUDE ELEV
-------- ---- -------- ------- -------- --------- ----
1916-EMS 2 4330296 708270 39 05 56 -96 35 30 340
2043-EMS 44 4330003 713536 39 05 42 -96 31 51 415
2132-EMS 6 4329774 711336 39 05 36 -96 33 23 405
2655-EMS 36 4328787 716070 39 05 00 -96 30 07 367
2731-EMS 4 4328678 711110 39 05 01 -96 33 34 446
3129-EMS 8 4327702 710711 39 04 30 -96 33 51 430
3414-EMS 10 4327286 707854 39 04 19 -96 35 51 410
4439-EMS 16 4325215 712794 39 03 07 -96 32 28 445
4439-EMS 916 4325193 712773 39 03 06 -96 32 28 443
8739-EMS 926 4316699 712845 38 58 31 -96 32 35 442
SITEGRID SLOPE ASPECT
-------- ----- ------
1916-EMS
2043-EMS
2132-EMS
2655-EMS
2731-EMS
3129-EMS
3414-EMS
4439-EMS
4439-EMS 2 N
8739-EMS 1 TOP
Not available.
The SE-590 was fitted with a 15 degree IFOV lens.
Not available.
Not available.
The data was collected during FIFE's five IFC's, covering the period from June 1, 1987 through August 11, 1989.
OBS_DATE OBS_DATE OBS_DATE
--------- --------- ---------
01-JUN-87 15-AUG-87 27-JUL-89
03-JUN-87 16-AUG-87 28-JUL-89
04-JUN-87 17-AUG-87 01-AUG-89
05-JUN-87 20-AUG-87 04-AUG-89
06-JUN-87 06-OCT-87 06-AUG-89
26-JUN-87 07-OCT-87 07-AUG-89
28-JUN-87 11-OCT-87 08-AUG-89
06-JUL-87 12-OCT-87 09-AUG-89
11-JUL-87 13-OCT-87 10-AUG-89
10-AUG-87 26-JUL-89 11-AUG-89
11-AUG-87
Not available.
Each solar zenith angle sampling period typically lasted 5 - 20 minutes, averaging 10 minutes in duration.
The SQL definition for this table is found in the SE_GSFC.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 (SSEE-III) give the south (SS) and east (EE) 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 [GMT] in GMT. The format is (HHMM).
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]
WAVLEN The wavelength at which the [microns] observation was made.
REFL The average percent reflectance. [percent] These reflectance values take into account the anisotropy of the calibration panel.
REFL_UNCORR The average percent reflectance. [percent] These reflectance values DO NOT take into account the anisotropy of the calibration panel.
REFL_SDEV The standard deviation of the [percent] reported reflectances.
COMMENTS Any comments describing the data.
FIFE_DATA_CRTFCN_CODE The FIFE 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).
Footnote:
Decode the FIFE_DATA_CRTFCN_CODE field as follows:
The primary certification codes are:
The certification code modifiers are:
SITEGRID_ID STATION_ID OBS_DATE OBS_TIME NUM_OBS VIEW_AZIM_ANG
----------- ---------- --------- ---------- ---------- -------------
2133-EMS 906 04-AUG-89 1736 5 0
2133-EMS 906 04-AUG-89 1736 5 0
2133-EMS 906 04-AUG-89 1736 5 0
2133-EMS 906 04-AUG-89 1736 5 0
VIEW_ZEN_ANG SOLAR_AZIM_ANG SOLAR_ZEN_ANG WAVLEN REFL
------------ -------------- ------------- ---------- ----------
0 148.85 24.56 .402 2.55
0 148.85 24.56 .405 2.54
0 148.85 24.56 .407 2.53
0 148.85 24.56 .41 2.53
REFL_UNCORR REFL_SDEV COMMENTS
----------- --------- ---------------------
.11
.09
.05
.02
FIFE_DATA_CRTFCN_CODE LAST_REVISION_DATE
--------------------- ------------------
CPI 08-OCT-92
CPI 08-OCT-92
CPI 08-OCT-92
CPI 08-OCT-92
The ground SE-590 data were collected at approximately every 10 degree change in solar zenith angle (SZA). Each SZA sampling period typically lasted 5 - 20 min, averaging 10 min duration.
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.
Spectral radiances measured over the reference panel were corrected for the known non-lambertian characteristics of the specific panel utilized. These non-Lambertian characteristics were determined by the University of Arizona personnel, in Arizona under clear skies, using a nadir-looking Barnes MMR instrument. The reference panel was rotated (during measurements) to manipulate the solar incidence angles in each MMR band, as compared to the nadir incidence angle. From these, coefficients were generated for each MMR band. The calculated values were found to be similar for all visible bands and the NIR band, and differences were less than the measurements error. Therefore, one anisotropic factor (0>anisotropic factor>1) was chosen to represent the full SE-590 spectrum. The calculated anisotropic factors at the measurement incident angles were linearly interpolated at 1 degree intervals. A look-up table was generated with 2 variables: solar zenith angle and the associated anisotropic factor. A different table was required for each reference panel used in the 1987 and 1989 field campaigns. The solar zenith angle in the SE-590 header was used to determine the appropriate anisotropic factor in the look-up table for use with a SE-590 reference spectrum.
In practice, the spectral irradiance (I(lambda)) was estimated from the measured spectral radiance of the reference panel (P(lambda)), the known solar zenith angle (THETA), and the anisotropic factor at that THETA (F(THETA)) [From the look-up table] as:
This provided and improved estimate of total irradiance which was then utilized in the calculation of percent spectral reflectance for the grassland canopy at each THETA. This was the ratio of the upwelling spectral radiance (L(lambda)) to the downwelling spectral irradiance (I(lambda)), or L(lambda) was directly determined from observations made with the SE-590 over the grassland surface from its position at the end of the tripod-boom.
In 1987, the data were originally recorded on magnetic tape in microcassettes and transferred via computer interface to floppy diskettes. Each scan consisted of a header which included date, time, scan sequence number, etc. and a string of 252 digital count values for each wavelength sampled (0.372 - 1.011 fm). The data were carefully examined scan by scan to evaluate data quality and to validate each one relative to the field data log sheets. Data were processed on a 286 or 386 desk-top computer using SE-590 processing and analysis software developed by Moon Kim (Code 923, NASA/GSFC). Data files were segmented into smaller files corresponding to SZA sampling periods. For "Canopy-Level" data, the processing program followed these steps:
Not available at this revision.
Not available at this revision.
Not available at this revision.
Not available at this revision.
Due to decreased sensitivity of the instrument at extreme wavelengths, the data were retained only for the interval 0.400 - 1.01 nm.
Not available at this revision.
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.
Not available at this revision.
Not available at this revision.
Noot available at this revision
This data set can be utilized to characterize diurnal variations and/or simultaneous observations acquired by helicopter, airplane, or satellite over flights.
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.
The SE-590 Spectroradiometer Reflectance Factors from GSFC are available on FIFE CD-ROM Volume 1. The CD-ROM filename is as follows:
\DATA\SUR_REFL\SE5_GSFC\GRIDxxxx\yyddd\ydddgrid.Gnn
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.Gnn, 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.
Anonymous. Spectron Engineering, Inc. Operating Manual: SE-590 field-portable data-logging spectroradiometer. Spectron Engineering. Denver, CO 80223.
Deering, D.W., and E.M. Middleton. 1990. Spectral bi-directional reflectance and effects on vegetation indices for a prairie grassland. Symposium on FIFE. First ISLSCP Field Experiment. American Meteorological Society. Boston, Mass. pp. 71-76.
Deering, D.W., T.F. Eck, and J. Otterman. 1990. Bi-directional reflectances of selected desert surfaces and their three parameter soil characterization. J. Agric For. Meteorol. 52:71-93.
Deering, D.W., E.M. Middleton, J.R. Irons, B.L. Blad, E.A. Walter-Shea, C.J. Hayes, C.L. Walthall, T.F. Eck, S.P. Ahmad, and B.P. Banerjee. 1992. Prairie grassland bi-directional reflectances measured by different instruments at the FIFE site. J. Geophys. Res. 97:18,887-18,903.
Frouin, R. and E.M. Middleton. 1990. A differential absorption technique to estimate atmospheric total water vapor amounts. Symposium on FIFE. First ISLSCP Field Experiment. American Meteorological Society. Boston, Mass. pp. 135-139.
Mesarch, M.A., E.A. Walter-Shea, B.L. Blad, C.J. Hays, and E.M. Middleton. 1993. Comparing biophysical properties of the Streletskaya steppe reserve and the Konza prairie. Remote Sens. Environ. (submitted 4/93).
Middleton, E.M., D.W. Deering and S.P. Ahmad. 1987. Surface anisotropy and hemispheric reflectance for a semiarid ecosystem. Remote Sens. Environ. 23:193-212.
Middleton, E.M. 1990. Diurnal change in the vegetation index for tallgrass prairie. Proc. IGARSS '90. pp. 1013-1016.
Middleton, E.M. 1991. Solar zenith angle effects on vegetation indicies and estimates of canopy variables in tallgrass prairie. Remote Sens. Environ. 38:45-62.
Middleton, E.M. 1992. Quantifying reflectance anisotropy for photosynthetically active radiation in grasslands. J. Geophys. Res. 97(D17): 18,935-18,946.
Middleton, E.M. 1992. Inferring total canopy APAR from PAR bi-directional reflectances and vegetation indicies in tallgrass prairie. Proc. IGARSS '92. pp. 749-751.
Ranson, K.J., C.S.T. Daughtry, L.L. Biehl, and M.E. Bauer. 1985. Sun-view angel effect on reflectance factors of corn canopies. Remote Sens. Environ. 18:147-161.
Sellers, P.J. 1985. Canopy reflectance, photosynthesis and transpiration. Int. J. Remote Sens. 8(6):1335-1372.
Sellers, P.J. 1987. Canopy reflectance, photosynthesis and transpiration, II. The role of biophysics in the linearity of their interdependence. Remote Sens. Environ. 21,:143-183.
Sellers, P.J., and F.G. Hall, FIFE experiment plan. 1987. International Satellite Land Surface Climatology Project. NASA Goddard Space Flight Cent. Greenbelt, Md. May.
Sellers, P.J., and F.G. Hall. 1989. The FIFE 1989 experiment plan. NASA Goddard Space Flight Cent. Greenbelt, Md. July.
Sellers, P.J., F.G. Hall, G. Asrar, D.E. Strebel, and R.E. Murphy. 1988. The first ISLSCP field experiment (FIFE). Bull. Am. Meteorol. Soc. 69(1):22-27.
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 (Eds.). 1990. FIFE interim report: Experimental execution, results, and analyses. NASA Goddard Space Flight Center. Greenbelt, Md.
Walthall, C.L., and E.M. Middleton. 1992. Assessing spatial and seasonal variations in grasslands with spectral reflectances from a helicopter platform. J. Geophys. Res. 97:18,905-18,912.
Walthall, C.L., J.M. Norman, J.M. Welles, G. Campbell, and B.L. Blad. 1971. Simple equation to approximate the bi-directional reflectance from vegetative canopies and bare soil surfaces. Appl. Plant Physiol. 47:656-662.
Walter-Shea, E.A., B.L. Blad, C.J. Hays, M.A. Mesarch, D.W. Deering, and E.M. Middleton. 1992. Biophysical Properties Affecting Vegetative Canopy Reflectance and Absorbed Photosynthetically Radiation at the FIFE Site. 97(D17):18,887-18,934.
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.
May 4, 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_GSFC.
Middleton, E. M. 1994. SE-590 Ground Data: GSFC (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_Ground_Data_GSFC.html