On 7/20/2010 1:41 AM, cavelamb wrote:
Wayne.B wrote:
On Mon, 19 Jul 2010 23:18:19 -0500, cavelamb
wrote:

NOTAM:

Oakland Center (Fremont CA) [ZOA]: April NOTAM #31 issued by Gps
Notam OA [GPS]
Navigation GPS is unreliable and May BE unavailable WITHIN A 375
nautical miles RADIUS of 393101N/1175659W LOVELOCK / LLC / VORTAC
141.25 DEGREE radial at 46.65 nautical miles, at FL400; decreasing in
area with DECREASE in altitude to 290 nautical miles RADIUS at FL250;
220 nautical miles RADIUS at 10000 ft. mean sea level, and 220
nautical miles RADIUS at 4000 ft. above ground level. effective from
April 09th, 2010 at 06:00 AM PST (1004091400) - April 09th, 2010 at
11:30 AM PST (1004091930)

Those ranges quoted are for aircraft thousands of feet above sea
level. The jamming range would be much shorter for boats, probably
10 miles or less.


aSSuming it's a linear relationship, I get 202 mile radius...




Not linear: for a ground level jammer,
The line of sight estimator for distance versus height above sea level
goes something like this:
distance n.m. = 1.2 sqrt (Height ft MSL)