AusENDVI: A long-term NDVI dataset for Australia

AusENDVI (Australian Emprical NDVI) is a monthly, 5-km gridded estimate of NDVI across Australia from 1982-2022. It is built by calibrating and harmonising NOAA's Climate Data Record AVHRR NDVI data to MODIS MCD43A4 NDVI using a gradient boosting ensemble decision tree method.  Additionally, the datasets are gapfilled using a synthetic NDVI dataset.  The methods are extensively described in an Earth System Science Data pre-publication.

AusENDVI consists of several datasets, each dataset has a description in the attributes of the NetCDF file that describes its provenance.  The naming convention is "AusENDVI_<model_type>_<year_range>_<version>.nc". 

1. AusENDVI-clim_1982_2013. Calibrated and harmonised NOAA's Climate Data Record AVHRR NDVI data from Jan. 1982 to Dec. 2013. This version of the dataset used climate data in the calibration and harmonisation process. The dataset has not been gap filled, and extra data has been filtered/removed beyond the typical QA filtering using methods described in the publication.
2. AusENDVI-noclim_1982_2013. Calibrated and harmonised NOAA's Climate Data Record AVHRR NDVI data from Jan. 1982 to Dec. 2013. This version of the dataset did not use climate data in the calibration and harmonisation process. The dataset has not been gap filled, and extra data has been filtered/removed beyond the typical QA filtering using methods described in the publication. 
3. AusENDVI-synthetic_1982_2022. This dataset consists of synthetic NDVI data that was built by training a model on the joined _AusENDVI-clim_ and _MODIS-MCD43A4 NDVI_ timeseries using climate, woody-cover-fraction, and atmospheric CO2 as predictors.
4. AusENDVI-clim_gapfilled_MCD43A4_1982_2022. This dataset consists of calibrated and harmonised NOAA's Climate Data Record AVHRR NDVI data from Jan. 1982 to Feb. 2000, joined with MODIS-MCD43A4 NDVI data from Mar. 2000 to Dec. 2022. This version of the dataset _used climate data_ in the calibration and harmonisation process. The dataset has been gap filled using _AusENDVI-synthetic_
5.  AusENDVI-noclim_MCD43A4_1982_2022. This dataset consists of calibrated and harmonised NOAA's Climate Data Record AVHRR NDVI data from Jan. 1982 to Feb. 2000, and MODIS-MCD43A4 NDVI data from Mar. 2000 to Dec. 2022. This version of the dataset _did not use climate data_ in the calibration and harmonisation process. The dataset has not been gap filled.

All datasets are in "EPSG:4326" projection, and have a spatial resolution of 0.05 degrees. Geographic coordinate information is contained in the "spatial_ref" variable.

A Jupyter Notebook is also provided that shows how to load, plot, QC mask, reproject, and gap-fill AusENDVI datasets. The notebook is effectively a 'readme' file.

• The notebook is also available to view/download here

An open-source github repository details the methods used to create these datasets

• https://github.com/cbur24/AusENDVI