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Re: Radar Pings off ISS



On Wed, 3 Dec 2003, 7351 wrote:

> This past weekend I was listening to the ISS using the Navspasur fence. I
> copied the ISS on my first attempt using a single square loop cut for 217MHz
> into my R8500 receiver....

Great! Ah, but where are you?  Thats the one key element you omitted from
your excellent report...
thanks
Bob

 The IF output of the
R8500 radio goes into an
SDR-14
> receiver. I calculated that the ISS was going to be due east (90) at lake
> Kickapoo, TX at 22:26:17. I copied the reflection 3 seconds early. I have
> some observations taken by WA4NJP that show that the fence might actually be
> tilted a couple of degrees in elevation toward the south. I am able to hear
> reflections from the moon at all 3 frequencies and even at the same time. I
> just got a beam antenna and hope to increase the sensitivity. I will be
> taking some very high resolution FFT captures (sub Hz) in the next couple of
> days using ISS. I hope to capture more detail. You can download a picture of
> my first attempt at copying ISS here:
>
> http://www.rfspace.com/ISS.gif
>
> 73's
>
> Pieter Ibelings
> N4IP
> ----- Original Message -----
> From: "Bob Bruninga" <bruninga@usna.edu>
> To: <amsat-bb@AMSAT.Org>
> Sent: Tuesday, December 02, 2003 7:15 PM
> Subject: [amsat-bb] Radar Pings off ISS
>
>
> > Navy Satellite Radar at 217 MHz:
> >
> > The Navy operates (for the last 30+ years) a 400 Megawatt(?) ERP radar
> > transmitter at 217 MHz that pings off every satellite that flies over the
> > southern USA.  Its called the Navy Space Surivellance Radar (NAVSPASUR).
> >
> > When any object flies through the 0.5 degree wide FAN beam, you should
> > hear a quick 1 or 2 second Doppler ping on 216.98 MHz on an SSB receiver
> > if it is large enough or you have a big enough antenna depending on where
> > you live.  In Maryland we only get one ISS "ping" opportunity per day
> > during working hours from the ISS.
> >
> > On our third attempt we still havent heard anything other than computer
> > birdies...  but we are only just beginning.  To help, I wrote a program
> > called SPASUR.EXE that shows you the geometry of where and when to point
> > your antenna for the ISS and other big objects.
> >
> > See http://www.ew.usna.edu/~bruninga/raft.html
> >
> > This site is primarily for our next CUBESAT, but it also has to show the
> > mids all about the NAVSPASUR radar so they understand the background.  If
> > you want to see the sample output from SPASUR.EXE or download a copy,
> > go about 2/3rds of the way down the page...
> >
> > I know these pings can be heard.  In fact, I have links to WAV files
> > recorded by Dr. Steven Bienvenu, M.D. of not only satellites, but also
> > meteors using only a dipole receive antenna in Louisianna. Lots of fun for
> > anyone interested in listening to things...  10,000 objects a day pass
> > through the fence.  Though maybe only 100 are big enough for amateurs to
> > hear..  My calculations show that his nearness to the transmit site gives
> > him a 15 dB advantage over what we can hear in Maryland.. so we just need
> > a bit more gain...
> >
> > Also, the MOON passes through the fence once or twice a day also for more
> > than a week each month.  Think of it as a 400 MW CW EME transmitter.
> > Compared to a typical EME HAM transmitter of 1 KW, I still compute that
> > someone with only a dipole should hear this too?  We are just entering a 2
> > week phase when the moon goes through the fence...
> >
> > So, no, I have still not been successful.  Still working on it.  But just
> > thought someone else might like a new project...
> >
> > You dont even need any special software.  Just set your OBSERVER
> > coordinates at the main transmitter site 33.5N and 98.7W and whenever the
> > ISS passes within a half degree of the fan beam on a bearing of 091 or 271
> > degrees from that site, then it is in the beam and *if* you can also see
> > the ISS at that same instant no matter where you are, then you should be
> > able to receive the reflected energy for about a second...
> >
> > Or so the theory goes....  still piddling here...
> >
> > P.S.  There are 100 brightest satellites in the CELESTRAK VISUAL.TXT file,
> > but that is too much for my program and I am sure some are bigger than
> > others.  I'd like to filter down the list to the 10 BIGGEST objects and
> > concentrate on those.  Does anyone know what are the 10 biggest objects
> > besides the MOON and ISS (and shuttle when it flies)...
> >
> > de WB4APR@amsat.org, Bob
> >
> >
> > ----
> > Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> > Not an AMSAT member? Join now to support the amateur satellite program!
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> >
>

de WB4APR@amsat.org, Bob

PCsat WEB  page     http://www.ew.usna.edu/~bruninga/pcsat.html
ISS-APRS FAQ:       http://www.ew.usna.edu/~bruninga/iss-faq.html
CUBESAT Designs     http://www.ew.usna.edu/~bruninga/cubesat.html
APRS LIVE pages     http://www.ew.usna.edu/~bruninga/aprs.html
APRS SATELLITES     http://www.ew.usna.edu/~bruninga/astars.html
MIM/Mic-E/Mic-Lite  http://ssdl.stanford.edu/mims/


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