Nadir
Point on the ground directly in line with the remote sensing system and the center of the earth.

Nadir view
Vertical view of a scene (where the viewing angle is 0º from the vertical).

NASA
National Aeronautical and Space Administration.

Near infrared (NIR)
The shorter wavelength range of the infrared region of the EM spectrum, from 0.7 to 2.5 µm. It is often divided into very-near infrared (VNIR) covering the range accessible to photographic emulsions (0.7 to 1.0m), and the short-wavelength infrared (SWIR) covering the remainder of the NOR atmospheric window from 1.0 to 2.5m.

Near Range
Refers to the portion of a radar image closest to the aircraft or satellite flight path.

Negative photograph
Photograph on film or paper in which the relationship between bright and dark tones
is the reverse of that of the features on the terrain.

NOAA
National Oceanic and Atmospheric Administration.

Noise
Random or repetitive events that obscure or interfere with the desired information.

Nondirectional filter
Mathematical filter that treats all orientations of linear features equally.

Non-selective scattering
The scattering of EM energy by particles in the atmosphere which are much larger than the
wavelengths of the energy, and which causes all wavelengths to be scattered equally.

Non-spectral hue
A hue which is not present in the spectrum of colours produced by the analysis of white
light by a prism of diffraction grating. Examples are brown, magenta, and pastel shades.

Nonsystematic distortion
Geometric irregularities on images that are not constant and cannot be predicted from
the characteristics of the imaging system.