The Multi-angle Imaging SpectroRadiometer (MISR) Validation team was deployed to Sua Pan, a salt playa in the Magkadigkadi region of Botswana, from August 18 to September 4, 2000, during the SAFARI 2000 Dry Season Aircraft Campaign. The experiment was designed to collect data necessary for multi-angle top-of-atmosphere radiance predictions in order to provide a vicarious calibration of the MISR instrument aboard the Terra satellite. Reported here are ground-based reflectance measurements collected using an Analytical Spectral Devices (ASD) spectroradiometer at Sua Pan and adjacent grassland targets. The grasslands provided large homogeneous areas for comparison of scale between ground measurements and remote-sensing results.
Data files contain numeric values that represent mean reflectance over space (grassland) or wavelength range (pan), stored as ASCII files, one file per site, in comma-separated-value (.csv) format, with column headers. The Sua Pan data, collected over a 1 km x 2 km area, are presented as rows of mean reflectance (every 10 nm) for 20 points, where the mean represents the average local reflectance spectra collected within 150 m of the given latitude and longitude. The grassland data cover a 1 km2 area and are provided every nm from 1 to 2500. Each row of data contains a mean and standard deviation at a given wavelength, where the mean represents the average of 570 measurements taken over the 1 km2 area.
Related data sets from Sua Pan provide ground measurements of BRDF, and LAI and FPAR (Helmlinger et al., 2004 and Buermann and Helmlinger, 2004, respectively). Coincident aircraft overflights collected aerial photographs, in-situ aerosol, and BRDF data on the 27th of August and on the 3rd of September. See Myers (2004), Hobbs (2004), and Piketh et al. (2004a and 2004b).
Cite this data set as follows:
Helmlinger, M., W. Buermann, and F. Eckardt. 2005. SAFARI 2000 Surface Spectral Reflectance at Sua Pan, Botswana, Dry Season 2000. Data set. Available on-line [http://daac.ornl.gov/] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/780.
Buermann, W. and M. Helmlinger. 2005. SAFARI 2000 LAI and FPAR Measurements at Sua Pan, Botswana, Dry Season 2000. Data set. Available on-line [http://daac.ornl.gov/] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
Helmlinger, M., W. Buermann, and F. Eckardt. 2005. SAFARI 2000 BRDF Measurements at Sua Pan and Skukuza, Dry Season 2000. Data set. Available on-line [http://daac.ornl.gov/] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
Myers, J. S. 2004. SAFARI 2000 ER-2 Color-IR Aerial Photography, Dry Season 2000. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
Hobbs, P. V. 2004. SAFARI 2000 CV-580 Aerosol and Cloud Data, Dry Season 2000 (CARG). Data set. Available on-line [www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
Piketh, S. J., T. Elias, and D. C. Stein. 2004a. SAFARI 2000 JRA Aerocommander Trace Gas, Aerosol, and CCN Data, Dry Season 2000. 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.
Piketh, S. J., T. Elias, and D. C. Stein. 2004b. SAFARI 2000 JRB Aerocommander Trace Gas and Aerosol Data, Dry Season 2000. 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.
The data files contain numeric values that represent mean reflectance over space (grassland) or wavelength range (pan). The data files are stored as ASCII table files, one file per site, in comma-separated-value (.csv) format, with column headers. The Sua Pan data, collected over a 1 km x 2 km area, are presented as rows of mean reflectance (every 10 nm) for 20 points, where the mean represents the average local reflectance spectra collected within 150 m of the given latitude and longitude. The Sua Pan grassland data, on the other hand, cover a 1 km2 area and are provided every nm from 1 to 2500. Each row of data contains a mean and standard deviation at a given wavelength, where the mean represents the average of 570 measurements taken over the 1 km2 area. The files are:
Sua_Pan_ASD_spectra.csv
Sua_Grass_ASD_refl.csv
Sua Pan Data file description:
| Column Name | Definition | Units |
|---|---|---|
| Latitude | Latitude of sample location | decimal degrees |
| Longitude | Longitude of sample location | decimal degrees |
| Number of Spectra | Number of Spectra | numeric |
| Mean Standard Deviation | Average (over wavelength range) standard deviation of each spectrum | fraction |
| 350 nm | Percent reflectance, Mean of N spectra at 350 nm | percent |
| 360 nm | Percent reflectance, Mean of N spectra at 360 nm | percent |
| .... | and so on, every 10 nm... | .... |
| 2490 nm | Percent reflectance, Mean of N spectra at 2490 nm | percent |
| 2500 nm | Percent reflectance, Mean of N spectra at 2500 nm | percent |
Sua Pan Grassland Data file description:
| Column Name | Definition | Units |
|---|---|---|
| Wavelength | Wavelength of measurement (every nm from 1 to 2500) | nm |
| Reflectance | Mean reflectance at given wavelength | dimensionless |
| Standrard Deviation | Standard deviation of reflectance at given wavelength (n=570) | dimensionless |
Additional information about the data format, site conditions, instrument descriptions, and sampling and data acquisition methods is found in the companion file: http://daac.ornl.gov/daacdata/safari2k/field_campaign/sua_pan_surface_spectra/comp/sua_pan_surface_spectra_readme.pdf.
2004/10/25
2004/10/25
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