[time-nuts] WAAS.....

[Brian Lloyd]

On 1/9/14 12:20 AM, Joe Leikhim wrote:
>
> GPS jamming, intentional or not is pretty serious, and the FCC takes
> this seriously, but unless you have some pretty hard evidence they may
> not find it.
In my case my most interesting outage was when I lost all GPS while over
the Atlantic ocean between Haiti and the island of Great Inagua in the
Bahamas. It is a bit difficult to stop and look around while flying at
8,500'. I took it for a general GPS outage but now I suspect jamming.

When I was living on my boat in the Virgin Islands (I built a WiFi-based
WISP for marinas and anchorages in the USVI) the US Customs interdiction
boat was only about 4 slips away from me. I often talked with the agents
either going out or coming back from "a run". (You do NOT want to screw
with these guys! They are armed to the teeth!) I now realize that they
would jam GPS so that the druggies couldn't get their drops right. (They
also admitted that, most of the time, they couldn't find the drug
runners' boats anyway and figured they got less than 5% of what they
were after. So much for the "War on Drugs.")

The US Coast Guard had (has?) a base on Great Inagua. They run a fleet
of helicopters out of there for ______________ (redacted - read between
the lines). I got a kick how, when they were coming and going, they
would announce their movements to other aircraft using a civil ID rather
than their military flight ID. At this point I suspect I may have been
shadowed and my GPS jammed. Thank god my airplane still had an LF/MF
automatic direction finder (ADF) aboard. I was able to fall back to
navigating using the non-directional LF beacon on Great Inagua. After
refueling at Great Inagua I continued on sans GPS for nearly 100mi when
>POOF< GPS suddenly came back on.

I wonder what the FCC does if it discovers it is another governmental
agency that is doing the jamming? ;-)

I must admit, I like the idea of multi-system sensors that will track
GPS, GLONASS, and (hopefully) Galileo and the Chinese satellite-based
navigation system that is going up. For that matter, is anyone running
one of the new multi-system receivers? I notice that Garmin is selling
them as a matter of course now. The prevalence of jamming might be the
reason why.

-- 

Brian Lloyd, WB6RQN/J79BPL
706 Flightline Drive
Spring Branch, TX 78070 USA
brian at lloyd.com
+1.916.877.5067