What is ELECTROMAGNETIC SPECTRUM?
ELECTROMAGNETIC SPECTRUM meaning in Aerospace terms is The entire range of the different types of electromagnetic radiation, or waves. It goes from the very long wave, low frequency, radio waves through infrared waves and visible light waves to the very high frequency and short waves of the gamma-rays and X-rays. Those wavelengths in the visible light range have a specific color associated with them when they pass through a prism. The lower frequency, longer wavelengths produce a red while those with higher frequency, shorter wavelengths produce a violet. Those wavelengths which fall somewhere in between these two points produce the orange, yellow, green, and blue also found in a spectrum.
reference: StarChild: Glossary