The NDVI processing chain is as follows: Ascending GAC orbit data are unpacked and staged. Ancillary data needed in processing are retrieved, this includes ozone data from Nimbus-7 Total Ozone Mapping Spectrometer (TOMS), and surface elevation from the ETOPO5 data set. Pointers to the appropriate satellite ephemeris files are established. Each scan is navigated using an orbital model. Based on the precise navigation, latitudes, longitudes, solar, satellite and relative azimuth angles are calculated and written for each pixel. Counts are converted to radiances which are used to derive reflectance and brightness temperatures. NDVI is calculated as [(CH1 - CH2) / (CH1 + CH2)] and ocean masks are applied. When 10 days of data are composited the NDVI and metadata are quality controlled. The data is resampled to 8 km x 8 km resolution from the nominal 4 x 4 km resolution of the original level-1B data.
Data are available as daily images, and 10-day composites. Both daily and composite images have twelve layers of information, namely, NDVI, CLAVR cloud flags, Quality check flags, scan angle, solar zenith angle, relative azimuth angle, channel-1 and -2 reflectances, and channel-3, -4, -5 brightness temperatures. The data are mapped to a global 8 km x 8 km grid in the Goodes Interupted Homolosine projection. Each image is stored in HDF as scientific data set (essentially BSQ with gain and offset annotation). The image dimension is 5005 pixels by 2170 lines, and each image is approximately 230 MB. A separate ancillary data file, in HDF and approximately 55 MB, includes the latitude, longitude, elevation, and land/sea mask. Distribution will be on 4-mm and 8-mm tapes.
The AVHRR 'Pathfinder' Land data sets are being produced through the cooperation of the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA), in order to facilitate integrated global studies. A Land Science Working Group was chartered to provide recommendations and guidance for generating these land data sets.
Entry_ID: GSFC_DAAC_PATH_AVHRR_LAND (MD Identifier: 3716)
Temporal Coverage:
From: 1987-01-01 TO: 1988-06-01
Geographic Coverage:
Southwest Extent: 90S,180W Northeast Extent: 90N,180E
Source:
NOAA 11
NOAA 7
NOAA 9
NOAA POES>NOAA Polar Orbiting Environmental Satellites
Sensor:
AVHRR>Advanced Very High Resolution Radiometer
Storage Media:
Magnetic Tapes
Optical Disks
Campaign/Project:
PATHFINDER>AVHRR Land Dataset Program
Discipline, Subdiscipline:
EARTH SCIENCE > ATMOSPHERE
EARTH SCIENCE > LAND
Location Keyword:
GLOBAL
Parameter Group, Parameter:
ATMOSPHERIC DYNAMICS > SOLAR RADIATION
EARTH RADIATIVE PROCESSES > ALBEDO
EARTH RADIATIVE PROCESSES > BRIGHTNESS TEMPERATURE
EARTH RADIATIVE PROCESSES > RADIANCE
reflected solar radiation
EARTH RADIATIVE PROCESSES > RADIANCE
diffuse solar radiation
EARTH RADIATIVE PROCESSES > RADIANCE
vegetation index
EARTH RADIATIVE PROCESSES > RADIANCE
direct solar radiation
EARTH RADIATIVE PROCESSES > RADIANCE
albedo
EARTH RADIATIVE PROCESSES > RADIANCE
brightness temperature
GEOGRAPHY AND LAND COVER > SURFACE VEGETATION
RADIANCE AND IMAGERY > INFRARED
RADIANCE AND IMAGERY > VISIBLE
General Keywords:
AVHRR PATHFINDER
DAILY DATA
DAILY IMAGES
EOSDIS
GAC
GLOBAL COVERAGE
GLOBAL LAND
GSFC DAAC
IMAGE DATA
LAND
NDVI
PATHFINDER
RADIATION
TEN-DAY COMPOSITE IMAGES
VEGETATION INDEX
Revision Date: 1993-12-06
Archive:
GSFC_DAAC>Goddard Space Flight Center Distributed ActiveArchive C...
Data Set ID: PATHFINDER AVHRR LAND
Contact: USER SUPPORT OFFICE, GSFC/DAAC
Electronic Mail: INTERNET> DAACUSO@EOSDATA.GSFC.NASA.GOV
Phone: (301) 286-3209
Investigator: TUCKER, COMPTON
Electronic Mail: GSFCMAIL> CTUCKER@GSFCMAIL
NSN> COMPTON@GIMMS835.NASA.GOV
Phone: (301) 286-7122
Tech Contact: JAMES, MARY
Electronic Mail: GSFCMAIL/MJAMES> MJAMES@GSFCMAIL
INTERNET> MARY@UPOLU.GSFC.NASA.GOV
NSI/DECNET> 15548::MJAMES
Phone: (301) 286-2432
Information in this entry provided by GSFC
Goward, S.N., B. Markham, D.G. Dye, W. Dulaney, and J. Yang. 1991. Normalized
difference vegetation index measurements from the Advanced Very High
Resolution Radiometer. Remote Sens. Environ. 35:257-277.
Holben, B.N. 1986. Characteristics of maximum-value composite images from
temporal AVHRR data. International Journal of Remote Sensing, 7:1417-1434.
Justice, C.O., B.L. Markham, J.R.G. Townshend, and R.L. Kennard. 1989. Spatial
degradation of satellite data. International Journal of Remote Sensing,
10:1539-1561.
Kidwell, K. 1991. NOAA Polar Orbiter Data (TIROS-N, NOAA-6, NOAA-7, NOAA-8,
NOAA-9, NOAA-10, NOAA-11 and NOAA-12) User's Guide, NOAA/NESDIS, National
Climatic Data Center, Washington D.C. .
National Aeronautics and Space Administration. 1993. Data set documentation,
product description, and User's Guide for the AVHRR Pathfinder Land data
set. EOSDIS DAAC, GSFC, Greenbelt, Maryland.
Rao. C.N.R. 1993a. Nonlinearity corrections for the thermal channels of the
Advanced Very High Resolution Radiometer: Assessment and recommendations.
NOAA Technical Report NESDIS-69. NOAA/NESDIS. Washington, DC.
Rao, C.N.R. 1993b. Degradation of the visible and near-infrared channels of
the Advanced Very High Resolution Radiometer on the NOAA-9 spacecraft:
Assessment and recommendations for corrections. NOAA Technical Report
NESDIS-70. NOAA/NESDIS. Washington, DC.
Stowe, L.L., E.P. McClain, R. Carey, P. Pellegrino, G.G. Gutman, P. Davis, C.
Long, and S. Hart. 1991. Global distribution of cloud cover derived from
NOAA/AVHRR operational satellite data. Adv. Space Research, 3:51-54.
Tarpley, J.D., S.R. Schneider, and R.L. Money. 1984. Global vegetation indices
from the NOAA-7 meteorological satellite. Journal of Climate and Applied
Meteorology, 23:491-494.
Tucker, C.J. 1989. Comparing SMMR and AVHRR data for drought monitoring.
International Journal of Remote Sensing, 10:1663-1672.
1. Source: NOAA 11
2. Source: NOAA 7
3. Source: NOAA 9
4. Source: NOAA>NOAA Polar Orbiting Environmental Satellites
5. Sensor: ADVANCED VERY HIGH RESOL. RAD.>Advanced Very High Resolution ...