Comes from 30 odd years of designing COMMS systems for naval vessels, including submarines.
Did several surveys of submarines for refit designs.
At 6'2" I'm not built for working on subs, kept bangin' me 'ead! 💥😭🤕
whales have the advantage that they are transmitting directly into water, where sound travels about 4 times faster than in air at sea level. And they can do this mechanically, process still not fully understood, at very low frequencies from around 2Hz to 100Hz mostly. Hence the long ranges achieved.
Up to maybe 24kHz for short range echolocation - nosh hunting!😜
Interestingly, spectrum analysis of Humpback whale sounds shows an FM type structure with pulsed modulation. Just like our FM RC transmitters
We have to transmit first through the air, for several thousand kilometres in some cases, and then have enough energy left to penetrate down a hundred metres or so.
We have to do this electrically, hence long antennas. Wavelength = Speed of light / frequency in Hertz! Do the math - it's a long chunka wire!😮 Halfwave at 8kHz ~18.75km.
Happy whale listening folks,😎
PS; JB, you can always use the antenna for a spot of fly fishing - while waiting for your sub to come up again!😮