[aprssig] GPS possible disruption SE US Jan 20 - Feb 22

[Gregg Wonderly]

On 1/20/2011 11:58 AM, Gregg Wonderly wrote:
> What is the modulation of the GPS signal? Is it something that a larger power
> transmitter could blanket an area and override the sats as in the FM capture
> effect? I'd guess that "moving things around" could be a good reason for this
> test. It implies that once a target is "guessed", that a high speed interceptor
> could arrive overhead and direct GPS guided weapons away to somewhere else.
>
> I'd guess that smart weapons would be designed to "integrate over time"
> correction of their trajectory and might not be vastly redirect-able at the last
> minute. But dealing with wind changes and other things might make them much more
> nimble and this could allow them to be "flown over" for a long amount of time
> and directed to someplace else, completely.
>
> The recent noise about North Korea being ready to deliver long range nukes might
> be a stimulus for this kind of activity.

Also, given the location of this activity, it would not surprise me to see an 
empty vehicle launched out of NASA out over the sea as a proof of effectiveness 
if this is indeed what might be happening.

> Gregg Wonderly
> W5GGW
>
> On 1/20/2011 11:20 AM, mwbesemer at cox.net wrote:
>> That is possible, and could probably be implemented via the WAAS system, in
>> areas that are augmented by WAAS.
>>
>> However, keep in mind that either jamming or offsetting GPS for aviation or
>> maritime customers would be relatively ineffective due to the fact that those
>> platforms are required to have redundancy in their navigation systems via
>> another source. (GPS backed by INS, DNS, Omega, LORAN, etc.) Also, when near or
>> over land, VORTACs are available for aircraft use (although they could be shut
>> off in case of emergency).
>>
>> Consider, however, the case of smart-munitions. Those that are GPS-guided (are
>> likely to) go into a fail-safe mode if GPS guidance was completly disrupted
>> (jammed). This mode might result in the self-destruction of the weapon or in the
>> safeing of the weapon (rendering it non-explosive, although you still would not
>> want it landing on your house).
>>
>> I'm only speculating on all of this (of course) but I did spend the majority of
>> the past 30 years doing RT&E/DT&E with the military. Most likely, we will NOT
>> hear anything specific regarding the results/purpose of this test (unless
>> Wikileaks gets a hold of it!) for the next 25 years or so. There are some things
>> that the public really doesn't need (or want) to know about.
>>
>> 73,
>>
>> Mike
>> WM4B
>>
>>
>>
>>
>> On Thu, Jan 20, 2011 at 12:03 PM, Lynn W. Deffenbaugh (Mr) wrote:
>>
>>> But with a jammer, the receiver knows they don't have a fix and something's
>>> up. I'm more thinking an experimental scrambler/offsetter that allows GPS
>>> receivers within the cone of influence to arrive at a solution based on the
>>> received signals and generate fix, but they really aren't at the location the
>>> fix describes. And the GPS consumer won't know that they're being mis-lead
>>> (literally!).
>>>
>>> Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32
>>>
>>> mwbesemer at cox.net wrote:
>>>> Nope... you're thinking about it from the wrong angle.
>>>>
>>>> Ever heard of a GPS Jammer?
>>>>
>>>> Mike
>>>> WM4B
>>>>
>>>>
>>>> On Thu, Jan 20, 2011 at 11:36 AM, Gregg Wonderly wrote:
>>>>
>>>>> It sounds like a transmitter at 40,000ft that might be a "relay" of existing
>>>>> GPS data. Perhaps they are trying to figure out how to make GPS work on the
>>>>> ground in cities with tall buildings?
>>>>>
>>>>> Gregg
>>>>> w5GGW
>>>>>
>>>>> On 1/20/2011 9:15 AM, Earl Needham wrote:
>>>>>> I'm just wondering what they're doing that might disrupt GPS...
>>>>>>
>>>>>> Vy 7 3
>>>>>> Earl
>>>>>> KD5XB
>>>>>>
>>>>>> KD5XB -- Earl Needham http://groups.yahoo.com/group/cw_bugs Quoting from
>>>>>> the Coast Guard: ZUT Posted via Blackberry
>>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Steve Noskowicz<noskosteve at yahoo.com>
>>>>>> Sender: aprssig-bounces at tapr.org
>>>>>> Date: Thu, 20 Jan 2011 07:12:37
>>>>>> To: TAPR APRS Mailing List<aprssig at tapr.org>
>>>>>> Reply-To: TAPR APRS Mailing List<aprssig at tapr.org>
>>>>>> Subject: Re: [aprssig] GPS possible disruption SE US Jan 20 - Feb 22
>>>>>>
>>>>>>
>>>>>> --- On Lynn W. Deffenbaugh (Mr) wrote:
>>>>>>> ... I was looking for the coordinates that I could understand ...
>>>>>>> Lynn (D) - KJ4ERJ -
>>>>>>
>>>>>> - - - - - -
>>>>>>
>>>>>> I often say that... "Can you explain that in terms I know?" (;-)
>>>>>>
>>>>>> 304906N = 30.4906 Deg North
>>>>>>
>>>>>> 0802811W = 80.2811 Deg West
>>>>>>
>>>>>> Google maps finds it A-OK.
>>>>>>
>>>>>> If you'd like it, I have an Excel spreadsheet that does conversions between
>>>>>> all forms of these. That is:
>>>>>> 1 - Degrees.decimal (As shown above)
>>>>>> 2 - Degrees, Minutes.decimal
>>>>>> 3 - Degrees, Minutes, Seconds.decimal
>>>>>>
>>>>>> Contact via my web site or MYCALL at arrl.net
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> aprssig mailing list
>>>>> aprssig at tapr.org
>>>>> https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig
>>>>
>>>> _______________________________________________
>>>> aprssig mailing list
>>>> aprssig at tapr.org
>>>> https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig
>>>>
>>>
>>>
>>> _______________________________________________
>>> aprssig mailing list
>>> aprssig at tapr.org
>>> https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig
>>
>> _______________________________________________
>> aprssig mailing list
>> aprssig at tapr.org
>> https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig
>>
>
>
> _______________________________________________
> aprssig mailing list
> aprssig at tapr.org
> https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig
>