Answer: • Visible Light, Radio Waves
• Radio - 305-m , at Arecibo, Puerto Rico
Visible Light - 10.4m Mirror, Canary Island
Explanation:
The spectral window is simply the range of frequencies that are correctly measured. It should be noted that the signals that are outside the spectral window are folded when they show up in spectrum.
The two spectral windows through which electromagnetic radiation easily reaches the surface of earth are the visible light and the radio waves.
I don’t know what book you’re talking about so I can’t help but have a look online, you may be able to find it if you search up the book name and look around a few websites
