Advisory - GPS 'anomalies' for SE US coast Jan-Feb

JoeD · Jan 20, 2011

Maybe this is the reason?

Notices to Mariners or other sources given.
[FONT=Arial, Helvetica, sans-serif]Hazardous Navy Exercises off North Florida Coast:
THE FOLLOWING AREAS WILL CONTAIN EXERCISES HAZARDOUS TO SURFACE VESSELS FROM 0000-2359 DAILY BETWEEN 17-23 JAN 11 IN THE FOLLOWING AREAS:
GUNEX AREA AREA BOUNDED BY
"BB/CC" 30-45N 080-32W
30-45N 079-40W
30-37.5N 079-40W
30-34N 080-33W
"31J" 29-20N 079-50W
29-20N 079-40W
29-10N 079-40W
29-10N 079-50W
"27C" 30-00N 081-00W
30-00N 080-50W
29-50N 080-50W
29-50N 081-00W
"26C/26D" 30-10N 081-00W
30-10N 079-40W
30-30N 081-00W
30-00N 079-40W (7th District LNM 03)[/FONT]

Bill Roosa · Jan 21, 2011

Why marine interests are not being advised

If you look at the map you will see that as you move farther away from the transmitter off the coast the flight levels (FL) get higher. This is a gps test against interferance not a gps satellite test. Your receiver (if the antenna is high enough) will receive the (ahem) test signal and probably (since it does not have the military anti spoofing receiver) get somewhat confused and report your position either wrong or not at all.
With that said most of us any diatance from the transmitter will not have your antenna 4000'+ in the air. The transmitter is vhf/uhf and is line of sight.
But you should still never use only one source of navigation information.

JoeD's post if for a GUNEX or gunnery exercise. I did not plot the area but at 53 minutes long (E-W) and only 11 minutes wide (N-S) it is not that big a gunnery range. We have bigger ones in the Chesapeake Bay

Advisory - GPS 'anomalies' for SE US coast Jan-Feb

RichH

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JoeD

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Bill Roosa

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