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RADIANT TEMPERATURE GROUND DATA (FIFE)
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Radiant Temperature Ground Data (FIFE)

Summary:

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.

Table of Contents:

  1. Data Set Overview
  2. Investigator(s)
  3. Theory of Measurements
  4. Equipment
  5. Data Acquisition Methods
  6. Observations
  7. Data Description
  8. Data Organization
  9. Data Manipulations
  10. Errors
  11. Notes
  12. Application of the Data Set
  13. Future Modifications and Plans
  14. Software
  15. Data Access
  16. Output Products and Availability
  17. References
  18. Glossary of Terms
  19. List of Acronyms
  20. Document Information

1. Data Set Overview:

Data Set Identification:

Radiant Temperature Ground Data (FIFE)
(Surface Temperatures from UNL).

Data Set Introduction:

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.

Objective/Purpose:

Determine the variability of emitted fluxes as a function of topography, vegetative community and management practice.

Summary of Parameters:

Surface temperatures and associated viewing angles.

Discussion:

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.

Related Data Sets:

FIS Data Base Table Name:

RADIANT_TEMP_GROUND_DATA.

2. Investigator(s):

Investigator(s) Name and Title:

Blaine L. Blad, Professor and Department Head
Elizabeth A. Walter-Shea, Asst. Professor
Department of Agricultural Meteorology

Title of Investigation:

Measuring and Modeling Near-Surface Reflected and Emitted Radiation Fluxes at the FIFE Site.

Contact Information:

Contact 1:
Cynthia J. Hays
Lincoln, NE
(402)472-6701

Contact 2:
Mark A. Mesarch
Lincoln, NE
(402)472-5904
AGME012@129.93.200.1

Contact 3:
Elizabeth A. Walter-Shea
Lincoln, NE
(402)472-1553
AGME012@129.93.200.1

Requested Form of Acknowledgment.

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.

3. Theory of Measurements:

Definitions:

Thermal radiant energy (Rb) is composed of an emitted component (e * a * Ts**4) and a reflected component (1 - e) ILWY:

Rb = a * Tirt**4 = e * a * Ts**4 + (1 - e) ILW

where:

e = surface emissivity (unitless)
Ts = surface temperature (K)
ILW = incoming longwave radiation (W/m**2)
a = Stefan-Boltzmann constant (W/m**2/K**4)
Tirt = temperature measurement from infrared thermometer (K)

4. Equipment:

Sensor/Instrument Description:

The Everest infrared thermometer multiplexed Model 4000 measures a temperature that is equal to:

T = (a * Rb)**0.25 (Fuchs and Tanner, 1966)

where:

a = Stefan-Boltzmann constant
Rb = emitted and reflected radiation
T = temperature measured by IRT

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.

Collection Environment:

Ground-based.

Source/Platform:

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.

Source/Platform Mission Objectives:

Not applicable.

Key Variables:

Surface temperatures at different view zenith and azimuth angles, collected at different times of the day.

Principles of Operation:

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.

Sensor/Instrument Measurement Geometry:

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.

Manufacturer of Sensor/Instrument:

The Eppley Laboratory, Inc.
12 Sheffield Ave.
Newport, R. I. 02840
(401) 847-1020

Calibration:

A mid-season calibration was performed on the Everest multiplexed infrared thermometer (IRT) Model 4000. The procedure is described in Blad et al., 1990.

Specifications:

Not available.

Tolerance:

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.

Frequency of Calibration:

1988:

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.

1989:

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.

Other Calibration Information:

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 %.

Calibration Coefficients

1988:

Everest multiplexed infrared thermometer Model 4000 SN 1031
a = -3.3036 degree C
b = 1.0726

5. Data Acquisition Methods:

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.

6. Observations:

Data Notes:

Not available.

Field Notes:

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.

  • June 15 Site 966(2437-EVN) Few cumulus clouds near sun for first measurement period then clear skies, measurement periods: 1500- 1600, 1730-1930, and 2100-2230 GMT.
  • July 14 Site 966(2437-EVN) Clear skies for first measurement period, cumulus aborted second measurement period, measurement periods: 1430-1530 and 1600-1620 GMT.
  • July 26 Site 916(4439-EVN) Few clouds on horizon, measurement periods: 1400-1425 and 1425-1455 GMT.
  • July 27 Site 916(4439-EVN) Cumulus clouds, measurement period 1430-1530 GMT.
  • July 28 Site 916(4439-EVN) Clear skies except for cumulus during last measurement period, measurement periods: 1400-1430, 1500-1530, 1630-1715, 1800-1900 GMT.
  • Aug. 4 Site 916(4439-EVN) Clear skies measurement periods: 1400-1500, 1700-1800, 1930-2000 GMT.
  • Aug. 6 Site 906(2133-EVN) Clear skies, measurement periods: 1430-1500, 1600-1630, 1800-1840, 1930-2000 and 2045-2100 GMT.
  • Aug. 7 Site 906(2133-EVN) Cumulus during first measurement period, the clear skies, measurement periods: 1730-1800 and 1930-2000 GMT.
  • Aug. 8 Site 916(4439-EVN) Clear skies, measurement periods: 1415-1510, 1620-1745, 2010-2030 and 2110-2135 GMT.
  • Aug. 9 Site 966(2437-EVN) Clear skies for first measurement period, then cumulus, measurement periods: 1530-1630 and 1730-1840 GMT.
  • Aug. 11 Site 916(4439-EVN) Lots of cumulus clouds, measurement period 2150-2230 GMT.
  • 7. Data Description:

    Spatial Characteristics:

    All view-zenith angles were measured with respect to gravity not in relation to the slope of the plot.

    Spatial Coverage:

    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.

    Spatial Coverage Map:

    Not available.

    Spatial Resolution:

    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.

    Projection:

    Not available.

    Grid Description:

    Not available.

    Temporal Characteristics:

    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.

    Temporal Coverage:

    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.

    Temporal Coverage Map:

    Not available.

    Temporal Resolution:

    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.

    Data Characteristics:

    The SQL definition for this table is found in the IRT_GRND.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 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).

    Footnote:

    Valid levels

    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.

    Sample Data Record:

         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
    

    8. Data Organization:

    Data Granularity:

    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.

    Data Format:

    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.

    9. Data Manipulations:

    Formulae:

    Tirtc = a + b*Tirt (1)

    where:

    Tirtc = calibration corrected temperature measurement (C)
    a= calibration coefficient (C)
    b = calibration coefficient (unitless)
    Tirt = temperature measurement from one of the three instruments (C)

    Ts = {a * (Tirtc + 273.16)**4 + (1 - e) * ILWY / (e * a)}**.25 - 273.16 (2)

    where: e = surface emissivity (unitless)
    a = Stefan-Boltzmann constant (W/m**2/K**4)
    ILW = incoming longwave radiation (W/m**2)
    TS = surface temperature (C)

    Derivation Techniques and Algorithms:

    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.

    ILW=(((air**6) * 5.31E-14) * 10.) - ((0.035) * (elev / 1000.) * (a * air**r)))

    where:

    a = Stefan-Boltzmann constant (W/m**2/K**4)
    air = MMR chopper or detector temperature (K) (see the document Surface Reflectance Measured with a Mast-borne MMR for details)
    ILW = incoming longwave (W/m**2)
    elev = elevation of each site (m)

    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:

    ILW = (a * (t + 273.16)**4 - ep * a * (Tp + 273.16)**4) / (1.0 - ep)

    where:

    a = Stefan-Boltzmann constant (W/m**2/K**4)

    Tu, or Ta, or T = a + b * Te

    where:

    Te = temperature measurement from the IRT (C) of the appropriate surface
    a,b = calibration coefficients (the Other Calibration Information Section)

    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:

    e = (a * (Tu + 273.16)**4 - ILW) / (a * (Ta + 273.16)**4 - ILW)

    where:

    e = surface emissivity (unitless) (used in eq. 9Y)
    a = Stefan-Boltzmann constant (W/m**2/K**4)

    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.

  • Site 5(2123-SAM): An average emissivity of 0.98 for IFC-2 was used for all dates in which data were taken (IFC-1 and IFC-2).
  • Site 8(3129-BRK): No emissivity values were measured, an assigned value of 0.98 was used.
  • Site 18(4439-BRV): an average emissivity of 0.97 from data taken during IFC-2 was used for IFC-1 and IFC-2 data; average emissivities of 0.98 and 0.97 were used for IFC-3 and IFC-4 data, respectively. Bare soil emissivity was 0.96.
  • Site 26(8739-ECB): An average emissivity of 0.96 from data taken during IFC-2 was used for IFC-1 and IFC-2 data; average emissivities of 0.99 and 0.97 were used for IFC-3 and IFC-4 respectively.
  • Site 28(6943-ECW): An average emissivity of 0.98 from data taken during IFC-3 was used for IFC-1, IFC-2, and IFC-3; average emissivity of 0.98 was used for IFC-4 data.
  • Site 29(0847-SDC): An average emissivity of 0.98 was used for IFC-3 and IFC-4.
  • Site 32(4268-BRK): An average emissivity of 0.97 from data taken during IFC-2 was used for IFC-1 and IFC-2; average emissivity of 0.98 was used for IFC-3 and IFC-4 data.
  • Site 40(1246-BRL): An average emissivity of 0.98 from data taken during IFC-3 was used for IFC-1, IFC-2, and IFC-3; average emissivity of 0.96 was used for IFC-4 data.
  • Site 42(1445-BRL): An average emissivity of 0.99 from data taken during IFC-4 was used for IFC-2, IFC-3, IFC-4.
  • Site 170(0939-BBM): Emissivity data was taken between IFC-2 and IFC-3 and averaged according to the mowing treatment. Average emissivities of 0.97, 0.98, 0.98, and 0.98 were used for the mowing plots of 5 cm height, 10 cm height, 20 cm height or no mowing.
  • 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.

  • May 24, 25, 27, June 28, and July 12 and 13 average emissivity of 0.991 August 11 average emissivity of 0.983
  • 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:

  • Site 916(4439-EVN), all days, average canopy emissivity of 0.964
  • Site 916(4439-EVN), all days, average bare soil emissivity of 0.960
  • Site 906(2133-EVN), all days, average canopy emissivity of 0.980
  • Site 906(2133-EVN), all days, average bare soil emissivity of 0.980
  • Site 966(2437-EVN), all days average bare soil emissivity of 0.960
  • Site 966(2437-EVN), June 15 and July 14, average canopy emissivity of 0.990
  • Site 966(2437-EVN), August 9, average canopy emissivity of 0.980
  • Data Processing Sequence:

    Processing Steps:

    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).

    Processing Changes:

    Not applicable.

    Calculations:

    Special Corrections/Adjustments:

    Not applicable.

    Calculated Variables:

    Graphs and Plots:

    None.

    10. Errors:

    Sources of Error:

    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.

    Quality Assessment:

    Data Validation by Source:

    Not available at this revision.

    Confidence Level/Accuracy Judgment:

    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.

    Measurement Error for Parameters:

    Not available at this revision.

    Additional Quality Assessments:

    Not available at this revision.

    Data Verification by Data Center:

    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.

    11. Notes:

    Limitations of the Data:

    Not available.

    Known Problems with the Data:

    The following data is erroneous or questionable for the Everest infrared thermometer (IRT) Model 4000 and should be used with caution.

    1. Occasionally the instrument malfunctioned. When this occurred the SURFACE_TEMP was assigned the value 99.99.
    2. On June 15 at 1850 GMT for plot 2, the view zenith angles of -50 and 50 are incorrect.
    3. On August 4 at 1938 GMT for plot 999 the view zenith angle of -50 is incorrect.
    4. On June 15 between 1434 and 1545 GMT all values are questionable.

    Usage Guidance:

    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.

    Any Other Relevant Information about the Study:

    Not available at this revision.

    12. Application of the Data Set:

    This data set can be utilized to determine the variability of emitted fluxes as a function of topography, vegetative community and management practice.

    13. Future Modifications and Plans:

    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.

    14. Software:

    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.

    15. Data Access:

    Contact Information:

    ORNL DAAC User Services
    Oak Ridge National Laboratory

    Telephone: (865) 241-3952
    FAX: (865) 574-4665

    Email: ornldaac@ornl.gov

    Data Center Identification:

    ORNL Distributed Active Archive Center
    Oak Ridge National Laboratory
    USA

    Telephone: (865) 241-3952
    FAX: (865) 574-4665

    Email: ornldaac@ornl.gov

    Procedures for Obtaining Data:

    Users may place requests by telephone, electronic mail, or FAX. Data is also available via the World Wide Web at http://daac.ornl.gov.

    Data Center Status/Plans:

    FIFE data are available from the ORNL DAAC. Please contact the ORNL DAAC User Services Office for the most current information about these data.

    16. Output Products and Availability:

    Surface Temperatures from UNL are available on FIFE CD-ROM Volume 1. The CD-ROM filename is as follows:

    DATA\SUR_REFL\IRT_GRND\GRIDxxxx\YyyMmm\ydddgrid.Inn

    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.

    17. References:

    Satellite/Instrument/Data Processing Documentation.

    Multiplexed Model 4000 Infrared Temperature transducers operating manual. Everest Interscience. Inc. Fullerton, CA (1986).

    Journal Articles and Study Reports.

    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.

    Archive/DBMS Usage Documentation.

    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.

    18. Glossary of Terms:

    A general glossary for the DAAC is located at Glossary.

    19. List of Acronyms:

    DAAC Distributed Active Archive Center EOSDIS Earth Observing System Data and Information System FIFE First ISLSCP Field Experiment FIS FIFE Information System IRT Infrared Thermometer ISLSCP International Satellite Land Surface Climatology Project ORNL Oak Ridge National Laboratory MMR Modular Multiband Radiometer UNL University of Nebraska - Lincoln URL Uniform Resource Locator UTM Universal Transverse Mercator

    A general list of acronyms for the DAAC is available at Acronyms.

    20. Document Information:

    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.

    Document Review Date:

    July 8, 1996.

    Document ID:

    ORNL-FIFE_IRT_GRND.

    Citation:

    Cite this data set as follows:

    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).

    Document Curator:

    DAAC Staff

    Document URL:

    http://daac.ornl.gov