[BC] Satellite sensitivity...

[Dave Dunsmoor]

    Well, I wasn't referring to an uplink type of situation. There are
"roving" satellites that (perhaps among other duties) listen for errant
emergency locator transmitters (ELTs). These transmitters are very low power
(50mw, I think) and activate upon aircraft crash landings, facilitating
location and recovery of the aircraft (and hopefully, passengers).

Dave



> It's a bit more complicated. Because of the gain of the antenna, the ERP
of
> an uplink is many times in the mega-watt range.  Think about it, a 3.8M
> dish with 40dB of gain has a power gain multiplication of 10,000.  Put 100
> watts into the feed point and you have a 1MW ERP emission.  5 meter dishes
> is easily 5MW when driven with 200 watts.
>
> Even VSAT uplinks found at most BP/Amoco stations is probably on the order
> of 50KW ERP aimed at a VERY sensitive RX in orbit.
>
> MM

> >At 10:00 PM 2/15/2006, you wrote:
> >>     Now if that satellite can hear such a extremely small signal from
> >>however high up they orbit, why doesn't IBUZ use something like 5 watts
and
> >>have the receiver manufacturers come up the rest of the gain and noise
> >>floor? That in itself would be a superb incentive to move over to IBUZ.
> >>Similar (or even better than) to moving to SS from a tube transmitter.
> >>
> >>
> >>Dave Dunsmoor