
What is Visible and Near Infrared (VNIR) Imagery?
VNIR refers to visible light (the "V" in VNIR), which is the light we all can see with our eyes. Technically speaking these are light waves that fall between 390 and 700 nanometers (nm). Near infrared imagery (the "NIR" in VNIR) is just beyond the capabilities of our eyes and it represents the light waves that fall between 750 and 950 nanometers. Even though we can’t see these near infrared waves they behave just like visible light and reflect off objects all around us. For example, near infrared imagery is ideal for conducting vegetative analyses that can reveal plant type, age, health, and diversity in much greater detail than visible imagery alone. Four-band VNIR high-resolution satellite imagery has been available since the launch of IKONOS in 1999. Eight-band very-high-resolution VNIR satellite imagery is unique to WorldView-2 and WorldView-3. [caption id="attachment_4081" align="aligncenter" width="700"]
What is Shortwave Infrared (SWIR) Imagery?
SWIR refers to a non-visible range of light falling between about 1400 and 3000 nanometers in wavelength, outside of the visible range. Due to the unique properties of minerals, man-made material, and other features, SWIR imagery can “see” objects in a way that is invisible to the naked eye and VNIR sensors. [caption id="attachment_4085" align="aligncenter" width="750"]
