planned GPS outage on the west coast

[agesilaus]

THe Navy is up to something--secret: POPMech

May not affect you too much on the ground unless you are near the Naval Weapons Station in the SoCal desert.

[joebedford]

China has had a limited GPS system since 2000 and is well on its way to a full system now.

Maybe I'll soon be able to get a cheap "Carmin" (China Garmin) using their sats.

[SCVJeff]

agesilaus wrote:
Since we own the GPS system... That's our right, and duty.
-------------------------------------------------------------

There are two or maybe three gps systems in operation right now, the Europeans have one and the Russians either plan on one or may have already started building the satellite array.

There are two in operation for sure: GPS (USA), and GLONASS (Russia) that is in a suprisingly high number of cellphones. China, India, Japan, and a few others are planning their own.

[SCVJeff]

Gene&Ginny wrote:

SCVJeff wrote:

Gene&Ginny wrote:
One of the online stories (that I can't find at the moment) showed a "side view" of the interference. It was a V shaped directional pattern.

Dont forget that they are reporters trying to demonstrate a point. But look at the plot issued on the NOTAM. The radius of this thing looks to go out possibly 500miles. If that's accurate the verticle view is probably going to look like a mushroom. It'll be interesting to see who and what's affected by this. Even at Goldstone there are GPS sync'd clocks

The story I mentioned had a link to an FAA drawing showing the cone shaped beam. Anything on the ground will not be affected. Virtually every telcom office uses GPS clocks to sync digital switches and transmission equipment so it isn't just places like Goldstone.

im aware of that, but Fort Irwin/ China Lake (or wherever it really coming from) is not within eyesight of any telecom of any kind, gas station, radio or TV station, data center, or comm site (all depending on GPS) not controlled by the military. Other than the onboard electronics in the various weapons on the base, Goldstone is the only other piece of technology anywhere in the area. That was the only reason for the reference. You sound like you may have some RF experience. If true you should also know that 1.5GHz is not 100% line of sight. Not until you get north of ~2.5GHz would I believe anyone that says a conical beam pointing in the air will have no affect on ground devices, especially after looking at their IX plot.

Your last post is no surprise. Look at the area this device will take out if it works.

[Gene_Ginny]

Seems the test has been cancelled. clicky
The U.S. Navy has canceled plans to jam GPS signals in the vicinity of the China Lake, California, Naval Air Weapons Station. AOPA had raised concerns about the impact on civilian air traffic and the size of the affected area. The Navy did not reveal the cause of the cancellation, other than to say the reason was “internal.”

[Gene_Ginny]

SCVJeff wrote:

Gene&Ginny wrote:
One of the online stories (that I can't find at the moment) showed a "side view" of the interference. It was a V shaped directional pattern.

Dont forget that they are reporters trying to demonstrate a point. But look at the plot issued on the NOTAM. The radius of this thing looks to go out possibly 500miles. If that's accurate the verticle view is probably going to look like a mushroom. It'll be interesting to see who and what's affected by this. Even at Goldstone there are GPS sync'd clocks

The story I mentioned had a link to an FAA drawing showing the cone shaped beam. Anything on the ground will not be affected. Virtually every telcom office uses GPS clocks to sync digital switches and transmission equipment so it isn't just places like Goldstone.

[agesilaus]

Since we own the GPS system... That's our right, and duty.
-------------------------------------------------------------

There are two or maybe three gps systems in operation right now, the Europeans have one and the Russians either plan on one or may have already started building the satellite array.

[wa8yxm]

From reading the article the project likely has two objectives.

1: To enable the US Military to confuse and confound enemy flyers

2: To prevent the enemy from doing that to OUR flyers.

Since we own the GPS system... That's our right, and duty.

[SCVJeff]

Gene&Ginny wrote:
One of the online stories (that I can't find at the moment) showed a "side view" of the interference. It was a V shaped directional pattern.

Dont forget that they are reporters trying to demonstrate a point. But look at the plot issued on the NOTAM. The radius of this thing looks to go out possibly 500miles. If that's accurate the verticle view is probably going to look like a mushroom. It'll be interesting to see who and what's affected by this. Even at Goldstone there are GPS sync'd clocks

[Gene_Ginny]

One of the online stories (that I can't find at the moment) showed a "side view" of the interference. It was a V shaped directional pattern.

[SCVJeff]

Gene&Ginny wrote:

Tvov wrote:
I'm curious how you can "block" GPS only in the air, but not on the ground? Wouldn't anything blocking it in the air, prevent the signal from getting to the ground?

It looks like the jamming signal is being transmitted upward so anything on the ground will still be able to see the "birds". Anything in the air above the cone shaped area would have the satellite signal from above blocked by the jamming signal from below.

if you look at the plot it's likely on omni that's terrain blocked. That's likely the only thing that keeps ground based receivers "safe"

[Gene_Ginny]

Tvov wrote:
I'm curious how you can "block" GPS only in the air, but not on the ground? Wouldn't anything blocking it in the air, prevent the signal from getting to the ground?

It looks like the jamming signal is being transmitted upward so anything on the ground will still be able to see the "birds". Anything in the air above the cone shaped area would have the satellite signal from above blocked by the jamming signal from below.

[SCVJeff]

Now that the forum is back up again... I slipped a digit on the coordinates last night, it's actually in or around Ft. Irwin and there are lots of mtns out there. That's where Goldstone is also.

As far as the NOTAM, that doesn't mean it won't affect anything on the ground. Personally I'd like to know why, when the GPS quits working for no reason, even on the ground.

[Homer1]

Why are always looking for something worry about. I don't trust my GPS further than a block from home.

[ccxnola]

Fact Finder: Here is the NOTAM (Notice to AirMen)
https://www.faasafety.gov/files/notices/2016/Jun/CHLK_16-08_GPS_Flight_Advisory.pdf

Clicky

Now...I am no technical specialist, but the NOTAM is specific about the radius and altitude of the outage.
It is my understanding that the GPS reading comes from the co-ordination of two or more (three for a good reading) signals from satellites.

It is important to notice - the lowest altitude is 50 feet above ground level (AGL). It is somewhat strange that the 4000 ft notation is also "AGL" when in fact all aircraft use an altimiter (adjusted for local barometric pressure) and aircraft altitude is always noted as above mean sea level.

So...at the 50 foot level, it is an area from San Diego to Oakland and out in the desert past Lost Wages!!

It will be most interesting to see if the folks that travel in those mountains have any difficulties if they stay below 50 feet.