[Amps] 10dB and propagation

[David G4FTC]

Hi Ken

>
>G4FTC worte:
>
>"HAARP was orginally conceived to generate ELF signals - if I recall 
>correctly for communications with
>submarines while submerged."
>
>"and it only requires a relatively small amount of power (but in the MW 
>range) to effectively modulate the electrojet."
>
>*******So it's the modulation of the electrojet that allows the military to 
>communicate with submarines while submerged?
>

I've just had to watch "Masters of the Ionosphere" to make sure I got the 
correct story. It had been sometime since I last watched it and I wasn't too 
clear on some detail.

The communications with submarines was one of the very initial ideas 
proposed for HAARP when project Sangine ran into the public objections. 
However, what sold it to the US Government was the ionospheric heater 
concept as part of the Strategic Defense Initiative (SDI) or better known as 
"Star Wars" under Ronald Regan.

Apparantly the ionospheric heater does exactly as it's name implies - it 
does heat the ionosphere, or more correctly the electrojet, and the 
temperatures can reach many thousands of degrees C.  The sales pitch was 
basically that any incoming IBM would have to pass through the region of 
elevated temperature plasma which in theory might be able to disable the IBM 
in flight.

The BBC programme was made approximately two weeks after HAARP went live - 
and the first experiments were to produce ELF waves - not for submarine 
communications - but as ground penetrating radar and they were managing to 
image abandoned underground mine workings in Fairbanks Alaska.

As far as I know, here in the UK the Royal Navy no longer uses LF for 
submarine communications. The main 19.2kHz GBR transmitter at Rubgy was 
decommissioned about 18 months ago as was the standby transmitter at 
Criggion. I believe all submarine communications are now via satellite.

BTW - the price of HAARP given in the programme (in 1992) was $58 million - 
very cheap.

Regards

David