 The NDVI 3G time series is an improved 8 km normalized difference vegetation index, NDVI, dataset produced from advanced very high resolution radiometer, AVHRR, instruments that extends from 1981 to the present, with data from two different sensors, AVHRR-2 and AVHRR-3. The main difficulty in processing AVHRR NDVI data is dealing with limitations of the AVHRR instruments, including dual gain introduced in late 2000 on the AVHRR-3 instruments for channels 1 and 2. To overcome calibration difficulties, we use Bayesian methods with high-quality well-calibrated CWIFS NDVI data to derive AVHRR NDVI calibration parameters. The resulting NDVI values have an error of plus or minus 0.005 NDVI units for our 1981 to present dataset, which is independent of time within our AVHRR NDVI continuum and has resulted in a non-stationary climate dataset. This article was authored by Jorge Epenzone and Compton J. Tucker. We are article.tv, links in the description below.