Where do you get daily NDVI?
To produce an NDVI time-series that updates daily, Streambatch fuses data from Sentinel-2, Landsat and MODIS. The methodology entails interpolating Landsat data to the Sentinel-2 grid to create a Sentinel-2/Landsat baseline. Spatially disaggregated MODIS data is used to infer NDVI on days when no Sentinel/Landsat information is available. Daily NDVI data is available at 10m resolution for any location on Earth. See ndvi.streambatch
Streambatch also offers single source NDVI data. (Landsat , Sentinel-2, MODIS)
How do you validate your NDVI calculations?
We validate against a sample of locations and dates for which we have authoritative NDVI measurements obtained for ground sensors.
How do you calculate NDVI?
NDVI is a simple mathematical function of red and infrared sensor outputs. NDVI is explained comprehensively here.
Do you have other variables available?
Yes. We offer EVI. Also, users can specify any custom formula they wish to use.
What order should my coordinates be in for point queries?
Coordinates should be in longitude/latitude (lon,lat) format.
How do I deal with clouds and other atmospheric interference?
Streambatch flags any NDVI output that may have been impacted by clouds or other factors. See the variable you are using to understand how to identify valid observations.