SNF Site Characterization Validation: Data Set Guide Document Summary: This document is in progress. Please be patient as we continue to update and improve this data set documentation. In the interim, we are providing an abstract of the entire Superior National Forest (SNF) data collection activity from which the SNF Site Characterization Validation data set is a product that we have incorporated into the ORNL DAAC search and order systems. During the summers of 1983 and 1984, the National Aeronautics and Space Administration (NASA) conducted an intensive experiment in a portion of the Superior National Forest (SNF) near Ely, Minnesota, USA. The purpose of the experiment was to investigate the ability of remote sensing to provide estimates of biophysical properties of ecosystems, such as leaf area index (LAI), biomass and net primary productivity (NPP). The study area covered a 50 x 50 km area centered at approximately 48 degrees North latitude and 92 degrees West longitude in northeastern Minnesota at the southern edge of the North American boreal forest. The SNF is mostly covered by boreal forest. Boreal forests were chosen for this project because of their relative taxonomic simplicity, their great extent, and their potential sensitivity to climatic change. Satellite, aircraft, helicopter and ground observations were obtained for the study area. These data comprise a unique dataset for the investigation of the relationships between the radiometric and biophysical properties of vegetated canopies. This is perhaps the most complete dataset of its type ever collected over a forested region. Detailed vegetation data were collected on the ground for about 100 sampled sites. These sites represent a range of stand density and age for spruce and aspen and also include jackpine and mixed stands. At each site, five circular subplots of 16 meters in diameter were sampled within a large plot of 60 meters in diameter. Within the subplots, all woody stems over 2 meters in height were tallied by species, diameter, and height. Within each subplot, coverage by vegetation was determined for the canopy, subcanopy and understory. Thirty each of black spruce and aspen trees from outside the plots were sacrificed and dimension analysis relations developed between diameter at breast height, biomass and leaf area index. Also, above-ground NPP was estimated for each test site. For the aspen sites, bark area and understory leaf area indexes were found. During the spring, measurements of understory leaf extension and canopy coverage were made on several days to describe the phenology of an aspen stand. Measurements of the optical properties of canopy components were made for wavelengths between 0.35 and 2.1 micrometers. Reflectance and transmittance properties of leaves and needles of eight major overstory tree species and three understory shrubs were measured. Multiple measurements of aspen and spruce allow an investigation of the variability of optical properties within a species, spagnum moss and leaf litter. Above-canopy reflectance was observed by a helicopter-mounted Barnes Modular Multiband Radiometer (MMR). The helicopter MMR data have a spatial resolution of approximately 32 meters. In 1983, 10 days of data were collected between May and October, with a total of 105 sites observed. In 1984, 8 days of data were collected between May and September, with a total of 29 sites observed. Several sites have multiple observations, to allow studies of seasonal variation. Thematic Mapper Simulator (TMS) data were collected fron the NASA C-130 flying over the SNF. The flights were in a 'criss-cross' pattern to allow observation of the same location with multiple sun and view angles. The TMS scans out to 50 degrees off nadir; in flights at 5000 feet above ground level, a nadir pixel covers 3.81 meters along the scan. Three days of TMS data are presented; these data have been atmospherically corrected and calibrated to determine surface reflectance. A key goal of the experiment was to use the aircraft measurements to scale up to satellite observations for the remote sensing of biophysical parameters. Tables of Contents: 1. Data Set Overview 2. Investigator(s) 3. Theory of Measurements 4. Equipment 5. Data Acquisistion Methods 6. Observations 7. Data Description 8. Data Manipulations 9. Data Organization 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: SNF Site Characterization Validation Data Set Introduction: Objective/Purpose: Summary of Parameters: Discussion: Related Data Sets: 2. Investigator(s): Investigator(s) Name and Title: Dr. Forrest G. Hall NASA Goddard Space Flight Center Dr. K. Fred Huemmrich NASA Goddard Space Flight Center Dr. Donald E. Strebel Versar, Inc. Dr. Scott J. Goetz Universtity of Maryland Ms. Jaime E. Nickeson NASA Goddard Space Flight Center Dr. Kerry D. Woods Bennington College Dr. Celeste Jarvis NASA Headquarters Title of Investigation: Contact Information: Dr. Forrest G. Hall NASA Goddard Space Flight Center Code 923 Greenbelt, Maryland 20771 USA Fax +1 (301) 286-0239 Telephone +1 (301) 286-2974 Email: fghall@ltpmail.gsfc.nasa.gov Requested Form of Acknowledgememt: Please cite the following NASA Technical Memorandum 104568 in any work or any publication using these data: Hall, F.G., K.F. Huemmrich, D.E. Strebel, S.J. Goetz, J.E. Nickeson, and K.D. Woods, July 1992. Biophysical, Morphological, Canopy Optical Property, and Productivity Data From the Superior National Forest. NASA Technical Memorandum 104568. National Aeronautics and Space Administration, Washington, D.C. 20546. 3. Theory of Measurements: 4. Equipment: Sensor/Instrument Description: Collection Environment: Ground-based. Source/Platform: Source/Platform Mission Objectives: Key Variables: Principles of Operation: Sensor/Instrument Measurement Geometry: Manufacturer of Sensor/Instrument: 5.2 Calibration: Calibration: Specifications: Tolerance: Frequency of Calibration: Other Calibration Information: 5. Data Acquisition Methods: 6. Observations: Data Notes: Not Available. Field Notes: 7. Data Description: Spatial Characteristics: Spatial Coverage: Spatial Coverage Map: Not Available. Spatial Resolution: Projection: Not Available. Grid Description: Not Available. Temporal Characteristics: Temporal Coverage: Temporal Coverage Map: Not Available. Temporal Resolution: Data Characteristics: **************************************************************************** Variable Name/ Long Name SAS Type Generic Type Description ---------------------------------------------------------------------------- 1 grid_id GRID_ID $ 5 CHAR(5) "Grid ID" ---------------------------------------------------------------------------- 2 plot_id PLOT_ID 8 NUMBER(3,0) "Plot ID within the site" ---------------------------------------------------------------------------- 3 photo_id PHOTO_ID 8 NUMBER(4,0) "Photo ID for site location" ---------------------------------------------------------------------------- 4 obs_datc OBS_DATE $ 12 DATE "Observation date in DD-MON-YY format (ex. 01-JAN-90)" ---------------------------------------------------------------------------- 5 pct_rock PCT_ROCK 8 NUMBER(3,0) "Percent of ground cover that is rock" ---------------------------------------------------------------------------- 6 pct_soil PCT_SOIL 8 NUMBER(3,0) "Percent of ground cover that is bare soil" ---------------------------------------------------------------------------- 7 pct_herb PCT_HERB 8 NUMBER(3,0) "Percent of ground cover that is herbaceous matter" ---------------------------------------------------------------------------- 8 pct_shrb PCT_SHRUB 8 NUMBER(3,0) "Percent of ground cover that is low shrubs" ---------------------------------------------------------------------------- 9 pct_othr PCT_OTHER 8 NUMBER(3,0) "Percent of ground cover that is other materials (identified by OTHER_ID)" ---------------------------------------------------------------------------- 10 other_id OTHER_ID $ 12 CHAR(12) "Other ground cover: water, dead matter, etc." ---------------------------------------------------------------------------- 11 shrbspec SHRUB_SPECIES $ 6 CHAR(6) "Shrub species code (see SNF plant species reference file, spec_ref.dat)" ---------------------------------------------------------------------------- 12 shrbcvr SHRUB_COVER 8 NUMBER(3,0) "Percent of coverage of the low shrub layer that is specified by SHRUB_SPECIES for the plot" ---------------------------------------------------------------------------- 13 subcspec SUBCAN_SPECIES $ 6 CHAR(6) "Subcanopy species code (see SNF plant species reference file, spec_ref.dat)" ---------------------------------------------------------------------------- 14 subc_cvr SUBCAN_COVER 8 NUMBER(3,0) "Percent of coverage of the subcanopy layer that is specified by SUBCAN_SPECIES for the plot" ---------------------------------------------------------------------------- 15 subcstem SUBCAN_STEMS 8 NUMBER(3,0) "Number of tree stems of subcanopy species specified by SUBCAN_SPECIES within a 2 meter radius of the plot center" ---------------------------------------------------------------------------- 16 subc_ht SUBCAN_HEIGHT 8 NUMBER(3,0) "Average height of subcanopy species specified by SUBCAN_SPECIES within a 2 meter radius of the plot center" ---------------------------------------------------------------------------- 17 can_spec CANOPY_SPECIES $ 6 CHAR(6) "Canopy species code (see SNF plant species reference file, spec_ref.dat)" ---------------------------------------------------------------------------- 18 prismcnt PRISM_COUNT 8 NUMBER(3,0) "The BAF prism count of all tree stems for the species specified by CANOPY_SPECIES" ---------------------------------------------------------------------------- 19 can_clos CANOPY_CLOSURE 8 NUMBER(4,0) "Percent canopy closure of entire overstory of plot" ---------------------------------------------------------------------------- 20 grid_n 8 "Grid ID (numeric for sorting)" ---------------------------------------------------------------------------- 21 plot_n 8 "Plot ID (numeric for sorting)" **************************************************************************** Parameter/Variable Name Parameter/Variable Description Footnote: Sample Data Record: Not available at this time. 8. Data Organization: Data Granularity: Data Format: The data files associated with this data set consist of numeric and character fields of varying lengths aligned in columns. The first row of each data file contains the 8-character SAS variable name that links to the data format definition file. Character fields are enclosed in double quotes and numeric fields are listed without quotes. Missing data values can be of two varieties: * values that were identified as missing in the original data files Missing numeric values of this type are identified in these data as -999. * those holes that were created as a result of combining files that contained a slightly different variable set. Missing values of this type are identified in these data files as empty double quotes. 9. Data Manipulations: Formulae: Derivation Techniques and Algorithms: Data Processing Sequence: Processing Steps: Processing Changes: None. Calculations: None available at this revision. Special Corrections/Adjustments: None known at this revision. Calculated Variables: Data Processing by Data Center: The Superior National Forest data was received from the Goddard Space Flight Center in three media: * as data dumps from the original Oracle SNF database maintained by GSFC, transferred electronically from the GSFC system to the ORNL system * as ASCII files that mirrored the tables published in the Tech Memo * as hard copy (Tech Memo) Data from both electronic sources were input into SAS by ORNL DAAC data management staff and compared using computer code developed to process the SNF data. In many cases, the data values from both sources were found to be identical. In some cases, however, differences were identified and the providers of the data were consulted to resolve inconsistencies. Additionally, some variable columns were available in one source, but not the other for various reasons. For example, some calculated variables/columns were provided in the ASCII files (reflecting the Tech Memo tables) that were not stored in the Oracle database for purposes of space conservation. For similar reasons, coded values were used for many of the site and species identifier variables. A separate reference table was provided to link the coded variable with its definition, e.g., the SPECIES_REF file and the SITE_REF file. The database produced by the ORNL DAAC is a hybrid product that is a composite of data and information extracted from all three source media. In data sets where coded variables were included, the code definition variables have been added to improve usability of the data set as a stand-alone product. Therefore the ASCII files that are available through the ORNL DAAC on-line search and order systems are output from a data set that is a product of the essential core of numeric data provided by the data source (GSFC), augmented with additional descriptive information provided by GSFC and reorganized by the ORNL DAAC into a data structure consistent with other similar data sets maintained by the ORNL DAAC. Data Center Processing Steps: Graphs and Plots: None available at this revision. 10. Errors: Sources of Error: Quality Assessment: Data Validation by Source: Confidence Level/Accuracy Judgement: Measurement Error for Parameters: Additional Quality Assessments: Data Verification by Data Center: 11: Notes: Limitations of the Data: Not Available. Known Problems with the Data: None known at this revision. Usage Guidance: Any Other Relevant Information about the Study: None. 12. Application of the Data Set: 13. Future Modifications and Plans: None known at this revision. 14. Software: 15. Data Access: ORNL DAAC User Services P.O. Box 2008 Mail Stop 6407 Oak Ridge National Laboratory Oak Ridge, TN 37831-6407 USA Telephone: 423-241-3952 FAX: 423-574-4665 Email: ornldaac@ornl.gov Data Center Identification: EOSDIS Distributed Active Archive Center P.O. Box 2008 Mail Stop 6407 Oak Ridge National Laboratory Oak Ridge, TN 37831-6407 USA Telephone: 423-241-3952 FAX: 423-574-4665 Email: ornldaac@ornl.gov Procedures for Obtaining Data: Users may place requests by letter, telephone, electronic mail, FAX, or personal visit. Data is also available via the World Wide Web at http://www-eosdis.ornl.gov Data Center Status/Plans: The Superior National Forest Data is 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: 17. References: Satellite/Instrument/Data Processing Documentation: Journal Articles and Study Reports: 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 is not available at this revision. 18. Glossary of Terms: A general glossary for the DAAC is located at http://www-eosdis.ornl.gov/glossary.html 19. List of Acronyms: 20. Document Information: date . Document Review Date: Document ID: ORNL-SNF_SITE_86 Citation: Document Author: Merilyn J. Gentry mjg@walden.rmt.utk.edu Document URL: http://www-eosdis.ornl.gov ------------------------------------------------------------------------------ ORNL DAAC User Services Office: 423-241-3952; email ornldaac@ornl.gov Web Document Curator: Sarah Jennings, xqj@ornl.gov Document Editor: Donna Lambert Revision Date: URL: http://www-eosdis.ornl.gov