A mobile base station in an urban environment has a power measurement of 25 µW at 225 m. If the propagation follows an inverse 4th-power law (Section 3.2.2), assuming a distance of 0.9 km from the base station, what would be a reasonable power value, in µW? Express your answer in scientific notation to 2 decimal place

Guest Feb 11, 2021

#2**0 **

**I am curious why the propagation of EM (radio) waves from a mobile base station in an urban (or any) environment would follow an inverse 4th-power law, instead of the inverse square law that is typically associated with EM wave propagation**.

Perhaps “Section 3.2.2” might give some context for its use in this case. Normally, the inverse 4th-power law is used as a baseline for EM waves reflected back to a radar transmitter, or as a baseline to correct errors in __time-domain reflectometry__ measurements. There may be other uses; even so, this hypothetical question appears inconsistent with the physics equations relating energy densities over distance.

At this point, I assume the mathematician who created the text book question was unfamiliar with the correct application of the related physics equations, and chose an ** inconsistent** scenario as an application for a hypothetical question using inverse 4th-power law.

If there is an alternative, I’d really like to know what it is.......

**How many mathematicians does it take to change a light bulb? How many physicists? How many engineers?**

GA

GingerAle Feb 11, 2021