 The NDVI 3G time series is an improved 8 km normalized difference vegetation index, NDVI, data set produced from advanced very high-resolution radiometer, AVHRR, instruments that extends from 1981 to the present. It is comprised of data from two different sensors, the AVHRR-2 instrument that spans July 1981 to November 2000 and the AVHRR-3 instrument that continues these measurements from November 2000 to the present. To overcome among instrument AVHRR calibration difficulties, we used Bayesian methods with high-quality well-calibrated CWIFS NDVI data for deriving AVHRR NDVI calibration parameters. Our resulting NDVI values have an error of plus or minus 0.005 NDVI units for our 1981 to present data set, which is independent of time within our AVHRR NDVI continuum and has resulted in a non-stationary climate data set. This article was authored by Jorge Ipenzone and Compton J. Tucker. We are article.tv, links in the description below.