The point of the celestial sphere that is vertically downward from the observer and directly opposite the zenith.  

Nadir-corrected BRDF Adjusted Reflectance (NBAR)

Surface reflectance data that has been corrected to remove the effects of topography and angular variation using bidirectional reflectance modelling. 

National Computational Infrastructure (NCI)

A national facility that provides world-class, high-end computing services to Australian researchers, including those working in the data-intensive areas of climate and Earth system science.

For more information, see NCI.

National Oceanic and Atmospheric Administration (NOAA)

A scientific agency within the US Department of Commerce that focuses on the conditions of the oceans, major waterways and atmosphere.

For more information, see NOAA

Near real time

Time in which reporting on events or recording of events is performed as soon as practicable following an event.