Dataset Edition

General information
Dataset namePATHFINDER - AVHRR - Fraction Absorbed Photosynthetically Active Radiation - Atlantic and Africa- 0.25
Data typeBIOSPHERE
Created on2016-11-28
Useful in the framework ofOPERATIONAL-DATA > Satellite products
Dataset Contact(s)
Data access Original dataset as provided by the Principal Investigator
History

ISSUE2016-11-29

PurposeThese products are derived from the PATHFINDER AVHRR Land (PAL) data set collected from July, 1981 to May, 2001. They have been generated at the Boston University and available to download on the site ftp://crsa.bu.edu/pub/rmyneni/myneniproducts/AVHRR_DATASETS/PATHFINDER/.

NDVI is the Normalized Difference Vegetation Index computed from the atmospherically-corrected visible (580-680nm) and NIR (730-1100nm) reflectances. It is indicative of the abundance and energy absorption by leaf pigments such as chlorophyll. The processing of the PAL NDVI is described in Buermann et al. (2002).

LAI (m²/m²) is defined as half the total foliage area per unit ground surface area. The FAPAR is the daily fraction of photosynthetically active radiation (PAR: [0.4-0.7µm]) absorbed by vegetation. FAPAR is dimensionless. The LAI and FAPAR are derived from atmospherically corrected monthly NDVI using relationships based on simulations of a 3D radiative model ran for 6 major continental biomes (Myneni et al., 1997). The analysis of the multiyear PAL LAI is presented in Buermann et al. (2002).

Projection: The original AVHRR PATHFINDER products are presented in Goode projection at 16km of spatial resolution. They have been put in the geographical lat/lon projection (“plate-carrée”) with a grid step equal to 0.25°. The pixels of the grid are located by the coordinates of their center. The “Atlantique-Afrique” area covers the zone from 59.88° West to 39.88° East, and from 34.88° South to 34.88° North.

Any details about the AVHRR PATHFINDER NDVI, LAI and FAPAR products and the retrieval algorithms are available on the Boston University website : http://cybele.bu.edu.
Instrument
SatellitePATHFINDER
InstrumentAVHRR
Instrument type
Parameters
Parameter nameFraction Absorbed Photosynthetically Active Radiation
Parameter keywordBiosphere > Vegetation
Unit
Coverage
Temporal Coverage
Date begin1981-07-01Date end2001-05-31
Geographic Coverage
Area nameAtlantique-Afrique
West bounding coordinate (°)-59.88East bounding coordinate (°)39.88
North bounding coordinate (°)34.88South bounding coordinate (°)-34.88
Data resolution
Temporal resolution0000-01-00 00:00:00
Latitude resolution0.25
Longitude resolution0.25
Data use information
Use constraintsPublic data
Data policyAMMA data policy
Data format(s)NetCDF