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SAFARI 2000 AVHRR DAILY SITE (1.5 KM) AND 15-DAY REGIONAL (1.5- AND 6-KM) IMAGERY
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SAFARI 2000 AVHRR Daily Site (1.5 km) and 15-Day Regional (1.5- and 6-km) Imagery

Summary:

The Global Inventory Modeling and Mapping (GIMMS) group at NASA/GSFC provided SAFARI 2000 with remotely sensed satellite data products at the site and regional level. These Advanced Very High Resolution Radiometer (AVHRR) data contain two main sets of data: site extracts of SAFARI core sites (Mongu, Etosha, Kasungu, Maun, Skukuza, and Tshane) and regional 15-day composites from sets of single-day images. These AVHRR data contain four main sets of data:

1.5-km daily site extracts of SAFARI core sites (2000)
1.5-km 15-day composites of SAFARI core sites (1998-2000)
1.5-km 15-day composites of the southern African region (March, September 2000)
6-km 15-day composites of the southern African region (1998-2000)

The primary data layers for site extracts and regional composites are fire pixel counts and maximum normalized difference vegetation index (NDVI). The fire product is different for the daily and for the composited products (see readme file) and a fire product is not included in the 1.5-km regional data set. NDVI composite-associated data layers for the regional data sets include land surface temperature, reflectance, solar zenith angle, view zenith angle, and relative azimuth angle. NDVI composite-associated data layers for the site extracts include these same variables as well as brightness temperature, fire mask composite, latitude, and longitude.

The data are stored in binary image format files. There is a metadata file for each site and date/compositing period, in ASCII format.

Data Citation:

Cite this data set as follows:

Tucker, C. J., A. S. Morahan, and J. Kendall. 2005. SAFARI 2000 AVHRR Daily Site (1.5 km) and 15-Day Regional (1.5- and 6-km) Imagery. 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/822.

References:

El Saleous, N. Z., E. F. Vermote, C. O. Justice, J. R. Townshend, C. J. Tucker, and S. N. Goward. 2000. Improvements in the global biospheric record from the Advanced Very High Resolution Radiometer (AVHRR). International Journal of Remote Sensing, 21(6-7): 1251-1277.

Townshend, J. (ed.). 1995. Global data sets for the land from AVHRR. International Journal of Remote Sensing, 15: 3315-3639 (special issue describing several program-generating composite AVHRR image data sets).

Data Format:

The images are all flat binary files, the number of bits per pixel are given in the metadata files, as are the image sizes, also given below. There is a metadata file for each site and date/compositing period, in ASCII format.

6 km Regional Composites

515 image rows
639 image columns

1.5 km Regional Composites

2060 image rows
2556 image columns

Site Extracts, Daily and Composites

150 image rows
150 image columns

The bands contained within each image product are:

6 km and 1.5 km Regional Composites

Primary Data Layers

ID

Description

BITS

UNITS

SCALE

OFFSET

SPECIAL

FIRE

Fire Pixel Count

8

--

1.0

0

X=640 Y=752 *(6 km only)

NDVI

Median 1.5-Km Max NDVI

16

--

0.001

0

 

NDVI Composite-Associated Data Layers

ID

Description

BITS

UNITS

SCALE

OFFSET

LST

Land Surface Temperature

16

Kelvin

0.1

0

R1 Reflectance Channel 1 16 percent 0.01 0
R2 Reflectance Channel 2 16 percent 0.01 0
TS Solar Zenith Angle 16 percent 0.01 0
TV View Zenith Angle 16 percent 0.01 0
PHI Relative Azimuth Angle 16 percent 0.01 0

Site Extract Composites

Primary Data Layers

ID

Description

BITS

UNITS

SCALE

OFFSET

NOTE

FIRE

Fire Pixel Count

8

--

0.1

0

NDVI Maximum NDVI 16 -- 0.001 0
LAT Latitude 32 -- -- -- signed integer
LON Longitude 32 -- -- -- signed integer

NDVI Composite-Associated Data Layers

ID

Description

BITS

UNITS

SCALE

OFFSET

LST

Land Surface Temperature

16

Kelvin

0.1

0

R1 Reflectance Channel 1 16 percent 0.01 0
R2 Reflectance Channel 2 16 percent 0.01 0
TS Solar Zenith Angle 16 percent 0.01 0
TV View Zenith Angle 16 percent 0.01 0
PHI Relative Azimuth Angle 16 percent 0.01 0
DAY Composite Day Index 8 -- -- --

Site Extract Daily

ID

Description

BITS

UNITS

SCALE

OFFSET

NOTE

LST

Land Surface Temperature

16

Kelvin

0.1

0

R1 Reflectance Channel 1 16 percent 0.01 0
R2 Reflectance Channel 2 16 percent 0.01 0
T3 Brightness Temperature Channel 3 16 Kelvin 0.01 0
T4 Brightness Temperature Channel 4 16 Kelvin 0.01 0
T5 Brightness Temperature Channel 5 16 Kelvin 0.01 0
TS Solar Zenith Angle 16 degrees 0.01 0
TV View Zenith Angle 16 degrees 0.01 0
PHI Relative Azimuth Angle 16 degrees 0.01 0
NDVI Maximum NDVI 16 -- 0.001 0
LST Land Surface Temperature 16 Kelvin 0.01 0
FIRE Fire Mask Composite 8 -- -- --
LAT Latitude 32 -- -- -- signed integer
LON Longitude 32 -- -- -- signed integer
Fire Mask Classes:
0 missing
1 water
2 cloud
3 no fire (and not even a potential fire)
4 no fire (but was a potential fire)
5 unknown
6 fire (low confidence)
7 fire (nominal confidence)
8 fire (high confidence)

Additional information about the AVHRR parameters/variables, AVHRR data manipulations, and sensor/instrument description is found in the companion file: http://daac.ornl.gov/daacdata/safari2k/remote_sensing/avhrr/comp/avhrr_site_regional_imagery_readme.pdf.

Document Information:

2005/6/29

Document Review Date:

2005/6/29

Document Curator:

webmaster@www.daac.ornl.gov

Document URL:

http://daac.ornl.gov