HR: 0800h
AN: B51B-0201    [Abstracts]
TI: Correcting Green Vegetation Fraction for Calibration and Spectral Effects in AVHRR and VIIRS
AU: * Tarpley, D
EM: Dan.Tarpley@noaa.gov
AF: NESDIS/Office of Research, NESDIS/Office of Research World Weather Building 5200 Auth Road, Suitland, MD 20746 United States
AU: Jiang, L
EM: jiangl@imsg.com
AF: I.M. Systems Group, Inc., World Weather Building 5200 Auth Road, Suitland, MD 20746 United States
AB: NESDIS delivers an operational weekly green vegetation fraction (GVF) product for use as a boundary condition in numerical weather prediction. The GVF is derived by regression against a scaled NDVI, called Vegetation Condition Index, which, in turn, is dependent on the current NDVI and a weekly NDVI climatology. The underlying assumption of the process is that the observed NDVI from each AVHRR (or VIIRS) is well-calibrated and is derived from bands that have the same spectral band shape as those that went into the NDVI climatology. This is obviously not the case among the different AVHRRs or between AVHRR and VIIRS. To adjust the GVF from any imager to one comparable to the standard AVHRR, correction methods are being evaluated. The most promising is adjusting the current sensor NDVI to the standard NDVI (climatology) by matching empirical distribution functions between the operational instrument and the standard. If successful, the correction should allow quick delivery of operational GVF products upon the launch of a new AVHRR or from VIIRS. Results of experiments with the procedure will be shown.
DE: 0498 General or miscellaneous
DE: 0499 New fields (not classifiable under other headings)
SC: Biogeosciences [B]
MN: Fall Meeting 2005