The Surface Temperatures from UNL Data Set contains surface temperatures collected between July 15 and August 11, 1989 at three FIFE area sites. These surface temperatures were measured with an Everest multiplexed infrared thermometer (IRT) Model 4000 predominantly in the solar principal plane, with nadir and off-nadir, view-zenith angles (mounted on the portable mast with the Barnes Model 12-1000 Modular Multiband Radiometer (MMR)). The purpose of this study was to determine the variability of emitted fluxes as a function of topography, vegetative community and management practice.
Spatial and temporal sampling at sites 906 (2133-EVN), 916 (4439-EVN), and 966 (2437-EVN) was achieved. Measurements were typically coordinated with aircraft and/or satellite overpasses.
Radiant Temperature Ground Data (FIFE)
(Surface Temperatures from UNL).
The Surface Temperatures from UNL data set contains surface temperatures and associated viewing angles collected between July 15 and August 11, 1989 at three FIFE area sites.
Determine the variability of emitted fluxes as a function of topography, vegetative community and management practice.
Surface temperatures and associated viewing angles.
This data set contains surface temperatures measured with an Everest multiplexed infrared thermometer (IRT) Model 4000 predominantly in the solar principal plane, with nadir and off-nadir, view-zenith angles (mounted on the portable mast with the Barnes Model 12-1000 Modular Multiband Radiometer (MMR)). All data was collected on 12 days between July 15 and August 11, 1989.
Spatial and temporal sampling at sites 906 (2133-EVN), 916 (4439-EVN), and 966 (2437-EVN) was achieved. At sites 906 (2133-EVN) and 916 (4439-EVN), six (6) plots were identified. One of the 6 plots was a bare soil plot prepared with a weed trimmer that removed the surface vegetation but left the root systems intact. On days when measurements were not made the bare soil was covered with a plastic mulch that allowed moisture to penetrate the surface but hindered the regrowth of the vegetation. Measurements were typically coordinated with aircraft and/or satellite overpasses. At site 966 (2437-EVN), sixteen (16) plots were identified. One of these plots was a bare soil plot that was treated in the aforementioned manner.
The Everest multiplexed infrared thermometer (IRT) Model 4000 was mounted on a portable mast that was aligned in the solar principal plane at sites 906 (2133-EVN) and 916 (4439-EVN). At site 966 (2437-EVN) the mast was aligned parallel to the aspect of each plot (i.e., north-south or east-west). View zenith angles at nadir and off nadir were obtained.
Blaine L. Blad, Professor and Department Head
Elizabeth A. Walter-Shea, Asst. Professor
Department of Agricultural Meteorology
Measuring and Modeling Near-Surface Reflected and Emitted Radiation Fluxes at the FIFE Site.
Cynthia J. Hays
Mark A. Mesarch
Elizabeth A. Walter-Shea
The Surface Temperatures from UNL were collected under the direction of B.L. Blad and E.A. Walter-Shea at the University of Nebraska. The dedicated efforts of C.J. Hays and M.A. Mesarch in the collection and preparation of these data is particularly appreciated.
Thermal radiant energy (Rb) is composed of an emitted component (e * a * Ts**4) and a reflected component (1 - e) ILWY:
The Everest infrared thermometer multiplexed Model 4000 measures a temperature that is equal to:
The Everest multiplexed infrared thermometer (IRT) Model 4000 has a spectral band-pass of 8-14 microns. The Model 4000 has two components: a temperature transducer and a multiplexer. The temperature transducer is 89 mm by 114 mm and weighs 0.8 Kg.
The multiplexer is 159 mm by 114 mm by 159 mm and weighs 2.2 Kg. The field-of-view is 15 degrees. In 1988 and 1989 SN 1031 was used.
The Everest multiplexed infrared thermometer (IRT) Model 4000 was mounted 3.4 m above the soil surface on a portable, pointable mast which allowed the IRT to view approximately the same surface area, regardless of the view zenith angle.
Surface temperatures at different view zenith and azimuth angles, collected at different times of the day.
The Everest multiplexed infrared thermometer Model 4000 measures an integrated emitted and reflected radiation value from a target over their specific field-of-view. This radiation is related to the surface temperature by the Stefan-Boltzmann law. For a further description of the basic principles of infrared thermometry see Fuchs and Tanner (1966). For the specifics of the instrument see the appropriate instruction manual.
The Everest multiplexed infrared thermometer (IRT) Model 4000 was mounted on a portable, pointable mast. The mast allowed the IRT to view approximately the same surface area, regardless of the view zenith angle. The IRT was located at 3.4 m above the soil surface with a 15 degree field-of- view and a spot size of approximately 0.75 m diameter at nadir.
The Eppley Laboratory, Inc.
12 Sheffield Ave.
Newport, R. I. 02840
A mid-season calibration was performed on the Everest multiplexed infrared thermometer (IRT) Model 4000. The procedure is described in Blad et al., 1990.
The Everest multiplexed infrared thermometer Model 4000 specifications are an accuracy of +/- 0.5 degree C, a repeatability of +/- 0.1 degree C and a resolution of +/-0.1 degree C.
When the calibration derived coefficients are applied to the calibration data set (i.e., not an independent data set) comparisons of the corrected instrument reading to the blackbody source temperature show that the mean bias errors ranged from 0.0 to - 0.2 degree C and the mean relative errors ranged from -0.8 to 3.9 % over the three years.
A pre-season calibration was performed on the Everest multiplexed infrared thermometer (IRT) Model 4000. Daily stability checks were made using an Everest Model 1000 calibration source.
A mid-season calibration was performed on the Everest multiplexed infrared thermometer (IRT) Model 4000. Daily stability checks were made using an Everest Model 1000 calibration source.
When the calibration derived coefficients for the Everest multiplexed infrared thermometer Model 4000, Model 112C, and Schedular Plant Stress Monitor (see the document for the Surface Temperatures, Reflected and Emitted Radiation, and PAR from UNL data set) are applied to the calibration data set (i.e., not an independent data set) comparisons of the corrected instruments reading to the blackbody source temperature show that the mean bias errors ranged from -0.2 to 0.1 degree C and the mean relative errors ranged from -1.0 to 3.9 % over the three years for the different instruments. When calibration derived coefficients were not applied to the same data set comparisons to the blackbody source show that the mean bias errors ranged from -0.8 to 1.0 degree C and the mean relative errors ranged from -3.2 to 23.0 %.
Everest multiplexed infrared thermometer Model 4000 SN 1031
a = -3.3036 degree C
b = 1.0726
At site 906 (2133-EVN) and 916 (4439-EVN) measurements with the Everest multiplexed infrared thermometer (IRT) Model 4000 were always made in the solar principal plane. Measurements were made at nadir and 20,35 and 50 degrees at each view azimuth angle. Three replications at each view zenith angle were recorded. At site 966 (2437-EVN) the measurements were made parallel to the aspect of the plot (i.e., north-south or east-west). In addition to the view zenith angles measured at sites 906 (2133-EVN) and 916 (4439-EVN) a view zenith angle perpendicular to the slope of the plot was added at the appropriate view azimuth angle. Unless otherwise noted, the same procedure as in 1988 was followed.
During data collection at each site the following notes were taken:
The Everest multiplexed infrared thermometer (IRT) Model 4000 was used on the following dates and approximate times.
All view-zenith angles were measured with respect to gravity not in relation to the slope of the plot.
Measurement were made at the following locations:
SITEGRID STN NORTHING EASTING LATITUDE LONGITUDE ELEV -------- --- -------- ------- -------- --------- ----- 2133-EVN 906 4329726 711604 39 05 34 -96 33 12 443 2437-EVN 966 4329150 712375 39 05 15 -96 32 41 4439-EVN 916 4325193 712773 39 03 06 -96 32 28 443 SITEGRID SLOPE ASPECT -------- ----- ------ 2133-EVN 1 TOP 2437-EVN 4439-EVN 2 N
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, available in the GRAB-BAG 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 surface area viewed by the Everest multiplexed infrared thermometer Model 4000 had a diameter of 0.75 m at nadir and changed with view zenith angle.
In 1989 measurements on all the plot at sites 906 (2133-EVN) and 916 (4439-EVN) required 30 minutes or less and were coordinated with aircraft and satellite overpasses. Measurements of all the plots at site 966 (2437-EVN) required 2 to 3 hours.
The measurement time ranged from 1351 to 2200 GMT. Measurements were not continuously made over this range but were in discrete measurement periods depending on the number of plots in a site and coordination with aircraft and satellite overpasses.
Measurements were made from June 15 through August 11, 1989, on the following 12 days:
OBS_DATE OBS_DATE -------- ---------- 15-JUN-89 06-AUG-89 14-JUL-89 07-AUG-89 26-JUL-89 08-AUG-89 27-JUL-89 09-AUG-89 28-JUL-89 10-AUG-89 04-AUG-89 11-AUG-89
Data were obtained at only one site per day. A maximum of five (5) discrete measurement periods throughout the day were obtained.
The optimum time interval between plot measurements was approximately 5 minutes. The typical time interval between plots was approximately 10 minutes. The time interval depended on the distance between the plots, the terrain, and sky conditions.
The SQL definition for this table is found in the IRT_GRND.TDF file located on FIFE CD-ROM Volume 1.
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 FIS site identifier used to designate this site.
OBS_DATE The date of the observations.
OBS_TIME The time (HHMM) that the [GMT] observation was taken.
PLOT_NUM The plot number at the site where the data was collected.
SLOPE If a hillside plot, the slope of [degrees] the plot
ASPECT If a hillside plot, the aspect [degrees direction of the plot from north]
SOLAR_ZEN_ANG The solar zenith angle, the [degrees] vertical angle of the sun from zenith. Zero degrees is straight up; 90 degrees is on the horizon.
SOLAR_AZIM_ANG The solar azimuth angle, the [degrees horizontal angle of the sun from north]
VIEW_ZEN_ANG The view zenith angle, the angle [degrees] from the surface normal (straight up) to the observing instrument.
VIEW_AZIM_ANG The view azimuth angle, the [degrees horizontal angle of the from north] measurement
SURFACE_TEMP The radiant temperature of the [degrees plot. Celsius]
FIFE_DATA_CRTFCN_CODE * This column contains the FIFE Certification Code for the data, in the following format: CPI (Certified by PI), CPI-??? (CPI - questionable data).
LAST_REVISION_DATE This column contains the last format (DD-MMM-YY).
The primary certification codes are: EXM Example or Test data (not for release) PRE Preliminary (unchecked, use at your own risk) CPI Checked by Principal Investigator (reviewed for quality) CGR Checked by a group and reconciled (data comparisons and cross checks)
The certification code modifiers are: PRE-NFP Preliminary - Not for publication, at the request of investigator. CPI-MRG PAMS data that is "merged" from two separate receiving stations to eliminate transmission errors. CPI-??? Investigator thinks data item may be questionable.
SITEGRID_ID STATION_ID OBS_DATE OBS_TIME PLOT_NUM SLOPE ASPECT ----------- ---------- --------- -------- -------- ----- ------ 4439-EVN 916 26-JUL-89 1404 1 4439-EVN 916 26-JUL-89 1404 1 4439-EVN 916 26-JUL-89 1404 1 4439-EVN 916 26-JUL-89 1404 1 SOLAR_ZEN_ANG SOLAR_AZIM_ANG VIEW_ZEN_ANG VIEW_AZIM_ANG SURFACE_TEMP ------------- -------------- ------------ ------------- ------------ 59.2000 89.2000 50.0000 90.0000 24.97 59.2000 89.2000 50.0000 90.0000 24.98 59.2000 89.2000 50.0000 90.0000 24.94 59.2000 89.2000 35.0000 90.0000 24.83 FIFE_DATA_CRTFCN_CODE LAST_REVISION_DATE --------------------- ------------------ CPI 21-FEB-94 CPI 21-FEB-94 CPI 21-FEB-94 CPI 21-FEB-94
Measurements were not made continuously but were in discrete measurement periods depending on the number of plots in a site and coordination with aircraft and satellite overpasses. Data were obtained at only one site per day.
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: Record 1 Name of this file, its table name, number of records in this file, path and name of the document that describes the data in this file, and name of principal investigator for these data. Record 2 Path and filename of the previous data set, and path and filename of the next data set. (Path and filenames for files that contain another set of data taken at the same site on the same day.) Record 3 Path and filename of the previous site, and path and filename of the next site. (Path and filenames for files of the same data set taken on the same day for the previous and next sites (sequentially numbered by SITEGRID_ID)). Record 4 Path and filename of the previous date, and path and filename of the next date. (Path and filenames for files of the same data set taken at the same site for the previous and next date.) Record 5 Column names for the data within the file, delimited by commas. Record 6 Data records begin.
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.
SURFACE TEMPERATURE CALCULATIONS
The surface temperature was calculated using the calibration corrected temperature measurement, incoming longwave radiation (ILW) and surface emissivity values (eq. 2). Values for incoming longwave radiation were calculated for each Barnes Model 12-1000 Modular Multiband Radiometer (MMR) data record.
The equation is valid for clear daytime conditions (Deacon 1970). These values were averaged over the measurement period at a specific site. The values are in a data set submitted to FIS (UNL longwave).
Surface emissivity measurements were made under completely overcast sky conditions or at night and not in conjunction with the measurements made in this data set. An Everest infrared thermometer (IRT) Model 112C measured the temperature of the surface (Tu) and the temperature of the surface covered by an aluminum tent (Ta). The incoming longwave radiation under these conditions was determined using an IRT temperature measurement of an aluminum plate (t) of known emissivity (ep) and a thermocouple temperature of the plate (Tp).
The incoming longwave at the time of the surface emissivity measurement was calculated as:
Emissivity measurements were made over a sampling of the plots at a specific site during each IFC period in 1987. The emissivity is calculated as:
Emissivity values were averaged per site per IFC for calculations of the true surface temperature The following is a listing of the emissivity values used in 1987.
Emissivity measurements were made over a sampling of plots at site 811(4439-PAM) close to days of measurements for this data set in 1988. The measurements were averaged per site for the specific days listed. The following is a listing of the emissivity values used in 1988.
Emissivity measurements were made over a sampling of plots at Sites 906(2133-ECA), 916(4439-ECV), and 966(2437-EVN) close to days of the measurements for this data set in 1989. The values were averaged per site for specific days for the canopy and bare soil. The following are the emissivity values used in 1989:
The calibration coefficients used in equation 1 are listed in the Other Calibration Information Section.
SURFACE TEMPERATURE CALCULATIONS
The Everest multiplexed infrared thermometer Model 4000 surface temperature measurements used the following reduction method.
Equation 1 is used to correct the temperature measurement of the instrument using calibration-derived coefficients (Blad et al., 1990).
The calibration corrected temperature measurement of the instrument, incoming longwave radiation and surface emissivity values are used to calculate surface temperature using Equation 2 (Blad et al. 1976).
Errors associated with the measurements can occur due to orientation of the platforms. The view zenith angle could only
Shadowing is another source of error.
The pointable mast had other instruments mounted on it besides the Everest infrared thermometer Model 4000. These instrument added to the shadowing error.
Variable cloud cover could be an error source if comparing measurements from the various plots within a measurement period.
Not available at this revision.
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.
The following data is erroneous or questionable for the Everest infrared thermometer (IRT) Model 4000 and should be used with caution.
Before using this data the incoming radiation from the AMS station at the site or nearby site should be checked for possible cloud-induced errors.
Not available at this revision.
This data set can be utilized to determine the variability of emitted fluxes as a function of topography, vegetative community and management practice.
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
ORNL Distributed Active Archive Center
Oak Ridge National Laboratory
Telephone: (865) 241-3952
FAX: (865) 574-4665
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.
Surface Temperatures from UNL are available on FIFE CD-ROM Volume 1. The CD-ROM filename is as follows:
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., Y87 = 1987) and mm is the month of the year (e.g., M12 = December). 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.Inn, 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 (e.g., 061 = sixty-first day of the year), and nn is the plot number where the data were collected. The content of each file is described in the Data Characteristics Section.
Multiplexed Model 4000 Infrared Temperature transducers operating manual. Everest Interscience. Inc. Fullerton, CA (1986).
Blad, B.L. and J.J. Rosenberg. 1976. Measurement of crop temperature by leaf thermocouple, infrared thermometry and remotely sensed thermal imagery. Agronomy Journal. 68:635-641.
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. Department of Agricultural Meteorology. University of Nebraska-Lincoln. Lincoln, Nebraska. 68583-0728.
Conaway, J. and C.H.M. van Bavel. 1966. Remote measurement of surface temperature and its application to energy balance and evaporation studies of bare soil surfaces. U.S. Water Conservation Laboratory. Research Report No. 392. Interim report to USAE Com. Atmos. Sci. Lab. Fort Hauchuca, Ariz. 136 pp.
Deacon, E.L. 1970. The derivation of Swinbank's long-wave radiation formula. Quarterly Journal of the Royal Meteorological Society. 96:313-319.
Fuchs, M. and C.B. Tanner. 1966. Infrared thermometry of vegetation. Agronomy Journal. 58:5976-601.
Iqbal, M. 1983. An introduction to solar Radiation. Academic Press: Toronto, Canada. 390 pp.
Sellers, P.J. and F.G. Hall. 1989. FIFE-89 Experiment Plan. GSFC/NASA, Greenbelt, MD 20771
Tanner, B.D. 1990. Instrumentation of studying vegetation canopies for remote sensing in optical and thermal infrared regions - automated weather stations. Remote Sensing Reviews. 5 (1): 73-98.
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 22, 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.
July 8, 1996.
Blad, B. L., and E. A. Walter-Shea. 1994. Radiant Temperature Ground Data (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. doi:10.3334/ORNLDAAC/72. 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).