At the HAARP web site for the moon bounce experiment
(http://www.haarp.alaska.edu/haarp/mbann.html), they display a graph
that shows relative power of the incident and reflected signal versus
time. They show the transmitted signal at ~ -65 dB; they show the
reflected signal at ~ -77 dB.

Are they implying that the round trip path loss to the moon and back is
only ~ 12 dB???????

Billy Burpelson wrote:
At the HAARP web site for the moon bounce experiment
(http://www.haarp.alaska.edu/haarp/mbann.html), they display a graph
that shows relative power of the incident and reflected signal versus
time. They show the transmitted signal at ~ -65 dB; they show the
reflected signal at ~ -77 dB.

Are they implying that the round trip path loss to the moon and back is
only ~ 12 dB???????

It's gotta be closer to 100 dB path loss I would think. BTW, an
absolute level must be in dBm, or something similar. Plain XX dB always
refers to a comparison.

Billy Burpelson wrote:
At the HAARP web site for the moon bounce experiment
(http://www.haarp.alaska.edu/haarp/mbann.html), they display a graph
that shows relative power of the incident and reflected signal versus
time. They show the transmitted signal at ~ -65 dB; they show the
reflected signal at ~ -77 dB.

Are they implying that the round trip path loss to the moon and back is
only ~ 12 dB???????

For comparison purposes, I should have mentioned that the nominal path
loss at 144 MHz (2 meter band) is about 252 dB.

On Sat, 19 Jan 2008 14:30:12 +0000, Billy Burpelson wrote:
At the HAARP web site for the moon bounce experiment
(http://www.haarp.alaska.edu/haarp/mbann.html), they display a graph
that shows relative power of the incident and reflected signal versus
time. They show the transmitted signal at ~ -65 dB; they show the
reflected signal at ~ -77 dB.

Are they implying that the round trip path loss to the moon and back is
only ~ 12 dB???????

I think they're talking about the relative power *as measured at some
distant point*. If you're listening at a point say, 5,000 miles from the
transmitter in Alaska, you might hear the direct terrestrial signal from
Alaska at -65dB, and the lunar reflection at -77dB.

In other words, 12dB is the *difference* in path loss between the
lunar-reflected signal and the terrestrially-propagated signal.

(that difference still seems awfully small to me)

Another way of putting it... if there was a ham 200 miles away doing a
moonbounce transmission on 144MHz... his direct, terrestrially-propagated
signal at my location would be pretty weak... especially since his
antennas would be pointed up, at the moon, not down along the horizon...
so I would not be surprised if the *difference* between his
lunar-reflected signal and his terrestrial signal was a lot less than
252dB.

On Sat, 19 Jan 2008 14:30:12 +0000, Billy Burpelson wrote:
At the HAARP web site for the moon bounce experiment
(http://www.haarp.alaska.edu/haarp/mbann.html), they display a graph
that shows relative power of the incident and reflected signal versus
time. They show the transmitted signal at ~ -65 dB; they show the
reflected signal at ~ -77 dB.

Are they implying that the round trip path loss to the moon and back is
only ~ 12 dB???????

Doug Smith W9WI wrote:

I think they're talking about the relative power *as measured at some
distant point*. If you're listening at a point say, 5,000 miles from the
transmitter in Alaska, you might hear the direct terrestrial signal from
Alaska at -65dB, and the lunar reflection at -77dB.

In other words, 12dB is the *difference* in path loss between the
lunar-reflected signal and the terrestrially-propagated signal.

(that difference still seems awfully small to me)

Good call, Doug...that's exactly what they did (see HAARP response I
posted elsewhere).

Unfortunately, it seems like a rather meaningless comparison, as the
terrestrial signal can be all over the board due to the vagaries of
propagation. Sort of like measuring something with a rubber ruler... :-)

In article ,
Billy Burpelson wrote:

On Sat, 19 Jan 2008 14:30:12 +0000, Billy Burpelson wrote:
At the HAARP web site for the moon bounce experiment
(http://www.haarp.alaska.edu/haarp/mbann.html), they display a graph
that shows relative power of the incident and reflected signal versus
time. They show the transmitted signal at ~ -65 dB; they show the
reflected signal at ~ -77 dB.

Are they implying that the round trip path loss to the moon and back is
only ~ 12 dB???????

Doug Smith W9WI wrote:

I think they're talking about the relative power *as measured at some
distant point*. If you're listening at a point say, 5,000 miles from the
transmitter in Alaska, you might hear the direct terrestrial signal from
Alaska at -65dB, and the lunar reflection at -77dB.

In other words, 12dB is the *difference* in path loss between the
lunar-reflected signal and the terrestrially-propagated signal.

(that difference still seems awfully small to me)

Good call, Doug...that's exactly what they did (see HAARP response I
posted elsewhere).

To late. Billy boy is really confused now.

--
Telamon
Ventura, California

On Sat, 19 Jan 2008 21:36:16 +0000, Billy Burpelson wrote:
Unfortunately, it seems like a rather meaningless comparison, as the
terrestrial signal can be all over the board due to the vagaries of
propagation. Sort of like measuring something with a rubber ruler... :-)

True enough, though I would suggest the same would apply to the lunar
signal. The Moon isn't perfectly flat - and any signals bounced off it
have to pass through the ionosphere (twice). Ham moonbounce VHF
communications are subject to changes in propagation, and I'd bet those
effects would be even more pronounced on HF.

I would suggest the purpose of the graph was to show in general terms how
to identify whether you were hearing the HAARP signal or not, and if you
were, whether it was the terrestrial signal or the lunar signal. (or both)

On Sat, 19 Jan 2008 21:36:16 +0000, Billy Burpelson wrote:
Unfortunately, it seems like a rather meaningless comparison, as the
terrestrial signal can be all over the board due to the vagaries of
propagation. Sort of like measuring something with a rubber ruler... :-)

Doug Smith W9WI wrote:

True enough, though I would suggest the same would apply to the lunar
signal. The Moon isn't perfectly flat - and any signals bounced off it
have to pass through the ionosphere (twice).

No, the moon certainly isn't flat, with a radio reflectivity of about 7%.

Additionally, the effects of libration of the moon can cause the signal
to fluctuate a bit.

I would suggest the purpose of the graph was to show in general terms how
to identify whether you were hearing the HAARP signal or not, and if you
were, whether it was the terrestrial signal or the lunar signal. (or both)

Agreed. They just didn't label it properly; as 'I.H.' (the HAARP
spokesperson) stated in his response to me: "I'll need to add some
clarifying information to the figure, I can see".

Doug Smith W9WI wrote:
On Sat, 19 Jan 2008 21:36:16 +0000, Billy Burpelson wrote:
Unfortunately, it seems like a rather meaningless comparison, as the
terrestrial signal can be all over the board due to the vagaries of
propagation. Sort of like measuring something with a rubber ruler... :-)

True enough, though I would suggest the same would apply to the lunar
signal. The Moon isn't perfectly flat - and any signals bounced off it
have to pass through the ionosphere (twice). Ham moonbounce VHF
communications are subject to changes in propagation, and I'd bet those
effects would be even more pronounced on HF.

I would suggest the purpose of the graph was to show in general terms how
to identify whether you were hearing the HAARP signal or not, and if you
were, whether it was the terrestrial signal or the lunar signal. (or both)


Is there anything left of the ionosphere above the HAARP array, once the
XMTRs fire-up (so to speak)?

On Sun, 20 Jan 2008 05:42:03 -0800, David wrote:
Is there anything left of the ionosphere above the HAARP array, once the
XMTRs fire-up (so to speak)?

Actually, I think the point of HAARP (though not in this particular
experiment) is to artifically energize the ionosphere.