Moon Bounce question
 

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???????

Moon Bounce question
 

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.

Moon Bounce question
 

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.

Moon Bounce question
 

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.

Moon Bounce question
 

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 posed the question above to the nice folks at HAARP and here is the
answer I received:

Billy,

Thanks for the question.

The figure is a chart using real data from the moon bounce experiment
that we previously conducted in late October 2007. The chart shows
signals received at the LWA antenna site in New Mexico. The signal
labeled "HAARP Transmit" was the actual signal level received on the
receiver in New Mexico via sky wave. As you know, the sky wave signal
can be strong or weak depending on ionospheric conditions at the
time. The signal labeled "Lunar Echo" is the actual signal received
directly from the moon. Our observations in October were that the
lunar echo was relatively constant in amplitude during the experiment
while the ionospherically propagated signal from HAARP to New Mexico
varied quite a bit.

I hope this helps.

I.H.

After receiving this reply, I sent him the following response/questions:

Dear I.H.,

Thanks for your prompt reply. However, the following questions beg to
be asked:

What is the estimated round-trip path loss to the moon at 7 MHz?

What power was being transmitted to the moon?

What is the gain of the LWA antenna?

And finally, keeping those numbers in mind, is it reasonable to
expect reception of the echo with a garden variety ham receiver and
40 meter dipole? I believe it would be fair to say that the dipole
would have -significantly- less gain/capture area than the LWA.

Although this is an interesting project (Thanks for getting the
hams/SWLs involved!), realistically speaking, what chances are there
of hearing the echo on a dipole?

Thanks again,
Billy

Moon Bounce question
 

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... :-)

Moon Bounce question
 

In article ,
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???????

You are such a funny guy. Man, I knew you were clueless but you out did
yourself this time. This is to funny.

Hey, Billy it has something to do with the amplifying properties of
green cheese, really, I would not kid you.

--
Telamon
Ventura, California

Moon Bounce question
 

In article ,
Doug Smith W9WI 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???????

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.

No, no Doug it's the moon cheese. Don't confuse Billy.

--
Telamon
Ventura, California

Moon Bounce question
 

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

Moon Bounce question
 

In article ,
Billy Burpelson wrote:

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 posed the question above to the nice folks at HAARP and here is the
answer I received:

They lied about the cheese. You are so gullible.

--
Telamon
Ventura, California