[amsat-bb] Re: Transit Satellites
morsesat at optonline.net
Tue Aug 31 05:37:18 PDT 2010
The SATNAV system is no longer operational. It takes an earth station
to upload the correct data for a 24hr period(?) to be sent from the
satellite to enable SATNAV units to correctly locate themselves. I
worked on this system for many years on commercial ships as well as
I bought through ebay a Magnavox SATNAV that still hears the satellites
that are operational and it doesn't calculate any position. The
purchase was to give a demo of SATNAV vs. GPS and what was available to
a generation prior to GPS.
They were the original "hurry up and wait" to see if the sat pass was
going to calculate your position or not. All were polar orbits.
Brings back memories. . .
On Tue, Aug 31, 2010 at 12:04 AM, Glenn Little WB4UIV wrote:
> It is my understanding that the transit system is inactive.
> This was a Navy navigation system that used the approx 150 MHz and 400
> MHZ signals for determination of location.
> I used this system while active duty in the USN submarine service.
> I listened to the 149.985 MHz signal at home for many years, but, have
> not heard it for at least 10 years.
> The birds were known as OSCAR (for operational) by the Navy.
> Here are some links to some information indicating that at least one
> bird was transmitting in 1996.
> If you do hear a Transit satellite, and the satellite is operating
> properly, you will hear a data burst, known as a Barker word.
> This data burst occurs at every even 2 minute mark.
> It can be used as an accurate time hack.
> The assumption was that the unit using the system would have time that
> was at least accurate to a minute and this could be used as a time
> Hope this helps
> At 06:49 PM 8/30/2010, Dave Marthouse wrote:
>> With all this talk of the Transit satellites on 149.985MHZ, how are
>> they listed in the keps. I checked for other satellites of interest
>> on the kelso webpage and found navy navigation satellites. There are
>> a few named transit. What Transit birds are we talking about. I
>> want to see how strong their signals are on my scanner. Any
>> information would be appreciated.
>> Dave Marthouse N2AAM
>> dmarthouse at gmail.com
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