Home |
Search |
Today's Posts |
#13
![]() |
|||
|
|||
![]()
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 |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
moon bounce | Policy | |||
moon bounce | CB | |||
moon bounce | Swap | |||
Moon Bounce | Shortwave |