military takes control of GPS?

[desertratz]

Hi everyone,

I'm an absolute newbie and non-techie so please excuse if I am posting this topic in the wrong place or if it has already been addressed? I just read a link, on another forum (earthquake),that the military has taken back control of the GPS system and that co-ordinates will now be off? Also this is supposed to have some effect on atomic clocks? I assume this is related to the military build-up? Is this true, and if so, will the GPS units still be accurate enough for geocaching? I have not yet bought a unit, but want to clear this up before I spend money for something that might not now work as I expect it? Replies in basic plain English please, since I'm not knowledgeable about this stuff. Thx, Sue

[+MaxEntropy]

The military has always controlled the GPS system. They can at any time flick the switch and degrade everyone's accuracy except for theirs. However, with so many units out there and somy people and companies dependent on it, it's decision that they won't take lightly.

 

As a practical test, I went outside, got five sattelites and 20ft. accuracy. It doesn't look like they've messed with it lately.

[k2dave]

Just to add that WAAS units can correct for the selective availability that the military used (also true dGPS).

 

----(sig line)---> Did you ever do any trail maintainence? - if so you will know that all but the most worn trails need continuous maintenance to prevent mother nature from reclaiming it. herd paths are quickly reclaimed - k2dave

[+ApK]

quote:

---

Originally posted by k2dave:

Just to add that WAAS units can correct for the selective availability that the military used (also true dGPS).

 

---

 

As I understand, the reason they agreed to turn off SA was that they adaopted different technologies for local degredation and denial of service. I'm guessing that they have a way to deny the service to others in an area whether they use differential or not.

 

ApK

[+brdad]

quote:

---

Originally posted by ApK:

I'm guessing that they have a way to deny the service to others in an area whether they use differential or not.

---

 

That's what I am to understand as well - If the gov't feels the need to, they can now block the GPS signals from reaching a particular area on demand.

 

Using that information, if you ever lose all GPS satellite contact for no apparant reason, you might want to be getting out of the area as something BIG may be about to happen there!

 

There's 3 kinds of people in this world, those that can count and those that can't.

[+Desert_Warrior]

quote:

---

Originally posted by MaxEntropy:

The military has always controlled the GPS system. As a practical test, I went outside, got five sattelites and 20ft. accuracy. It doesn't look like they've messed with it lately.

---

 

Your test is invalid. If the SA were on, you would still see the same accuracy you think you are getting, but the actual data would be false by a random amount. For example. If you see a 20 foot accuracy, and the SA is set for a maximum of 100 feet degradation, you could be off by as much as 120 feet, but your GPS would still indicate 20 feet of accuracy. In simpler terms, your GPS tells you its expected accuracy with the data it is given. It doesn't know that that data might be deliberately skewed.

 

quote:

---

Originally posted by brdad:

If you ever lose all GPS satellite contact for no apparant reason, you might want to be getting out of the area as something BIG may be about to happen there!

---

 

I totally agree with this one! BUT, where do you run to? If you are in the desert 20 miles from town, you might just look for a shielded area to hunker down in and wait. If you are downtown in a big city, you might want to head for the desert and hunker down. Being retired military, I am pretty aware of what makes a good target in my area. It wouldn't hurt if everyone gave that some thought in your own town.

 

The terrorist threat has been around for many many years. Most countries have been very lucky so far. But do not believe for one minute you will not be a target. One of the things that makes terror work is the random chance factor. And if all the more desireable targets are well defended, and you are not, you just may be a better choice I am not trying to scare anyone, I am more concerned about auto accidents, lightning, and the lotto. But knowledge is power.

 

Last note. This is standard military info. To win, the attacker need only get lucky once. But the defended must be lucky every time.

 

Y-all have a great weekend geocaching. My son and I are leaving for the mountain in one hour.

 

Mike. KD9KC.

El Paso, Texas.

 

Seventeen minutes after her FIRST call for help, police officers arrived to find Ronyale White dead.

 

Prohibiting self defense is the ultimate crime. Police carry guns to protect themselves. What protects YOU ???

[+st_richardson]

quote:

---

Originally posted by brdad:

...Using that information, if you ever lose all GPS satellite contact for no apparant reason, you might want to be getting out of the area as something BIG may be about to happen there!

---

 

Agreed!

Time to forget the metal can and get the H*** out of the area. I'd only expect signal to be shut off for a target zone.

[+st_richardson]

quote:

---

Originally posted by brdad:

...Using that information, if you ever lose all GPS satellite contact for no apparant reason, you might want to be getting out of the area as something BIG may be about to happen there!

---

 

Agreed!

Time to forget the metal can and get the H*** out of the area. I'd only expect signal to be shut off for a target zone.

[azog]

quote:

---

Originally posted by KD9KC:

I totally agree with this one! BUT, where do you run to? If you are in the desert 20 miles from town, you might just look for a shielded area to hunker down in and wait. If you are downtown in a big city, you might want to head for the desert and hunker down. Being retired military, I am pretty aware of what makes a good target in my area. It wouldn't hurt if everyone gave that some thought in your own town.

---

 

I used to live within walking distance of Picatinny Arsenal (in NJ). It's no longer a munitions dump, now it's mainly research. But back in the 80's it was a different story.

 

I remember in 1983, one of the local gas mains had a leak, and several establishments were leveled by the blast. Waking up at 6am in the morning by three enormous explosions (the first woke me up, and I saw the glow outside the window from the rest), standing on the porch in my undies wondering if "this is it".

 

Yes, I am good for going totally off topic

 

----------

I will prepare food with my iron fist!

Then I will work my way up to ruling you all with my fist!

[azog]

quote:

---

Originally posted by KD9KC:

I totally agree with this one! BUT, where do you run to? If you are in the desert 20 miles from town, you might just look for a shielded area to hunker down in and wait. If you are downtown in a big city, you might want to head for the desert and hunker down. Being retired military, I am pretty aware of what makes a good target in my area. It wouldn't hurt if everyone gave that some thought in your own town.

---

 

I used to live within walking distance of Picatinny Arsenal (in NJ). It's no longer a munitions dump, now it's mainly research. But back in the 80's it was a different story.

 

I remember in 1983, one of the local gas mains had a leak, and several establishments were leveled by the blast. Waking up at 6am in the morning by three enormous explosions (the first woke me up, and I saw the glow outside the window from the rest), standing on the porch in my undies wondering if "this is it".

 

Yes, I am good for going totally off topic

 

----------

I will prepare food with my iron fist!

Then I will work my way up to ruling you all with my fist!

[+GEO*Trailblazer 1]

What would you think of the ability to control the enemy right to where you want them? These are Military tools that we are playing with!We will (OUR NATION)always have the upper hand because of the fact that it is our system.Be aware of where you are,lets always keep the upper hand,Teaching our families of this technology,and furthering our knowledge as well. This is one of the Greatest web sites that I have had the opportunity to share on.September is National Volunteer Month, Lets all volunteer to keep AMERICA SAFE!!!!!!!

[Kerry.]

The DoD has always and will always have control of the GPS and that's nothing new and the best way anyway.

 

By the very nature of Selective Availability (which is still there but simply set to zero) being on or off certainly has a direct affect on the displayed EPE. Because how SA works/worked and being individually unique to each satellite the EPE is based (apart from a few other things) on the data being received and since that data creates a greater circle of error since the measured ranges are directly affected in a random way the determined/displayed error will definately change also. Selective Deniability is a little different again.

 

WAAS has a "Military Emergency Mode" which is invoked at the prerogative of the US Air Force. Similar with any systems like DGPS in dire circumstances they would loose functionality as well.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[Kerry.]

The DoD has always and will always have control of the GPS and that's nothing new and the best way anyway.

 

By the very nature of Selective Availability (which is still there but simply set to zero) being on or off certainly has a direct affect on the displayed EPE. Because how SA works/worked and being individually unique to each satellite the EPE is based (apart from a few other things) on the data being received and since that data creates a greater circle of error since the measured ranges are directly affected in a random way the determined/displayed error will definately change also. Selective Deniability is a little different again.

 

WAAS has a "Military Emergency Mode" which is invoked at the prerogative of the US Air Force. Similar with any systems like DGPS in dire circumstances they would loose functionality as well.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[ManaUser]

Of crouse the EU is going to be launching their own GPS satilites. The US military won't directly control those. Of course they could still jam the signal and can probably expect operation if they need it shut down somewhere.

[+Greenjeens]

quote:

---

Originally posted by desertratz:

I just read a link, on another forum (earthquake),that the military has taken back control of the GPS system and that co-ordinates will now be off? I assume this is related to the military build-up? Is this true, and if so, will the GPS units still be accurate enough for geocaching?

---

 

Thanks for asking this question. Lately it seems that some of the points I have entered in my GPS and visit often, are suddenly off by 30 feet or so. It's easy to blame the military, but the fault may be in my GPS unit (E-MAP). I wonder if temperature, battery strength or some other factors are causing this deviation to show up?

 

Geocaching is still a "horseshoes and handgrenades" accuracy sport, definitely more towards the handgrenade end of the spectrum. I'm continually surprised how much looking around is involved with Geocaching, despite all the fancy electronic equipment.

 

Still harboring this FANTASY.... if I got a new GPS unit with a better antenna (quadrafiler?) like the Garmin 76 or the Garmin V, would I get more repeatable and higher accuracy AND better coverage under trees? Overhead foilage often is the biggest problem in getting a good satellite signal. I could try a GPSgeek.com antenna, but the thought of trying to deal with a long wire attached to my GPS sounds way too cumbersome. Any ideas?

----------

Greenjeens

[+GEO*Trailblazer 1]

The signal strength is pretty constant. I have one of the earliest Magellans made and still prefer it over the newer ones. Mine receives well in all conditions,there are those times in thick cover that get us all!, I've just learned how to compensate. After several years of using mine the total accuracy still amazes me.I found it not to be worth all that big money(unless you have it)to invest or want to pursue a career in the Surveying fields. I have found that by using the Triagulation stations for the internal waypoint control will help the satellites to better define your position. (CONTROL) The benchmarks on the ground are the control for the satellites.ARE WE THERE YET !