Evaluation of the NDVI and sensor zenith angle values associated with the Global Land AVHRR 1-km data set

Abstract

This study was initiated to assess the quality of the data available from the Global Land AVHRR 1-km data set. The normalized difference vegetation index (NDVI) and sensor zenith angle (SZ) values associated with the Global Land AVHRR 1-km data set were compared to those values included in the NOAA/NASA Pathfinder AVHRR Land (global, 8-km) data set at coincident spatial and temporal scales. The NDVI and SZ data were averaged within 10 by 10 grid cells and compared for each of the 10-day composite intervals during the 1 April 1992 through 31 March 1993 time period. The results indicate that the sensor zenith angles of the two data sets varied considerably, however, the NDVI values were quite similar.