Question about Cell Phone Signals

[Hilarion]

Is cell phone coverage diminished near, say, a lake or an ocean? If so, is there a specific explanation for this? My thanks and +rep to anyone who can help!

[Elfdude]

The signals from a cell phone tower travel outwardly in a sphere. Lakes and oceans if anything should make it easier for cell signals to travel further because there's no mountains to interrupt the signal. I don't know this for fact or anything but I would say no they do not.

[Tiwaz]

They do not affect the signal, as they are not between tower and phone. But if we imagine that you had waterproof phone and went diving, water would radically weaken the signal.

This is why during heavy rain your phone signal gets bit weaker.

[Hilarion]

Ah, okay, thanks for the replies. Why would the signal be radically weakened under water? Is it reflected off or absorbed?

[Tiwaz]

Ah, okay, thanks for the replies. Why would the signal be radically weakened under water? Is it reflected off or absorbed?

Absorb mainly.

Bit same as with microwaves. They get absorbed by water easily as well.

Some other wavelengths are less efficiently absorbed.

[Elfdude]

I would think underwater the signal would simply diffuse rather than be absorbed. Rain water is a lot more difficult to travel through (because it's constantly deflecting the electromagnetic signal) than calm bodies of water I would think; however microwaves are a good point.

[Nik]

Ah, okay, thanks for the replies. Why would the signal be radically weakened under water? Is it reflected off or absorbed?

If a electromagnetic wave hits an area with other physical properties (be it an entierly different material, different density or temperature), a port will be reflected away, the rest will pass into the material and will be absorbed gradually. Even Air absorbs electromagnetic waves.
Absorption of electromagnetic waves for a given material is (mainly) a function of wavelength.
Everyday example: if you have a low hanging cloud cover, the radio signal will actually improve in mounteous terrain, as the signals will by reflected down from the clouds into the valleys.

I would think underwater the signal would simply diffuse rather than be absorbed. Rain water is a lot more difficult to travel through (because it's constantly deflecting the electromagnetic signal) than calm bodies of water I would think; however microwaves are a good point.

Water (in liquid form) has comperatively high absorption rates, which drops radically if the water turns to ice.
Raindrops will markledy decrease the intensitiy of electromagnetic waves (think aforementioned radio signals), but that does not hold a candle to the absorption rates of water. Submarines could (for a long time) not use wireless while submerged. In order to communicate, the sub head either to go to the surface or use a snorkel or periscope with integrated antennas. Rain will decrease your range by a factor of 2, not a 100 like water.