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JL_HSTRE

The Big Blue Switch

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Was there actually a (presumably symbolic) blue switch flipped in 2000 to disable selective availability? A little searching from news coverage makes no mention of it which makes me think it's apocryphal.

 

The term/story was clearly in use by the 10th anniversary in 2010 though.

 

So if there was no actual blue switch in 2000 how did the story/symbol get started?

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All I know is that there was never an actual blue switch.

I did a couple of searches, and came up with nothing non-related to geocaching.

But now I am wondering the story behind it!

Edited by TmdAndGG
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I could be totally wrong, about this, but I will put forth what I think is the explanation. Long ago in the mists of time (the very late 20th century), I had to study something about the subject of the military use of satellite technology. Aside from the burgeoning field of orbital imagery, the potential for orbital weaponry, and so on,  there was the use of satellites for navigation / guidance. GPS was nothing new to the military, nor its Russian / Soviet equivalent GLONASS.

However, there was also an increasing demand for civilian use for GPS. One of the issues raised was that governments [US/NATO] were worried about the fact that countries other than them might be able to use GPS for their own weapons guidance, getting a sort of "free ride" so to speak. Or non-state actors with rogue weapons and nefarious intentions, and so on. Basically, it was tangentially related to issues surrounding proliferation of nuclear weapons and ballistic or cruise missiles; they were worried about putting accurate orbital-based navigation into the hands of just anybody. 

Their solution, at the time was that GPS for civilians was a "dumbed down" version, maybe 1/10th as accurate as the pure version, and so on. It was controversial, and later as things like GLONASS popped up, promising no dumbing down, it forced the powers controlling GPS to finally relent and allow the truly accurate version for civilian uses. From that day forward it spread like wildfire. Now everybody uses it, more or less all the time - and remember this issue being kicked around was before smartphones put a GPS into basically everyone's hand (and other systems in peoples' cars, and so on).

So, my guess, is that "blue switch day" is commemorating the day the powers-that-be made GPS accurate enough to be useful to civilians.

Did I guess right ?

 

 

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22 minutes ago, mysterion604 said:

Did I guess right ?

What you wrote is basically correct, but I think the question is more around the use of the term "Blue Switch" given that there almost certainly was never a switch, let alone a blue one, and it seems this phrase is only used by Groundspeak, so I think the OP is wondering why "Big Blue Switch".

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4 hours ago, MartyBartfast said:

What you wrote is basically correct, but I think the question is more around the use of the term "Blue Switch" given that there almost certainly was never a switch, let alone a blue one, and it seems this phrase is only used by Groundspeak, so I think the OP is wondering why "Big Blue Switch".

 

If I were to guess, it was more of a software switch rather than a physical blue switch.

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After further review, one article I read suggested that the implementation of selective availability was rather simple. 

 

Each satellite broadcasts a unique signal that tells the receiver the time at the satellite in space. Each satellite also has a unique position in space. The GPS receiver knows where every satellite is supposed to be, knows what time it is on the ground, and hears the signal from each satellite about what time it was in space when the signal was sent. The receiver uses all of this information to calculate the time it took for at least 4 satellite messages to travel to the Earth, and then uses the known position for those 4 (or more) satellites to figure out your latitude, longitude, and elevation.

 

With Selective Availability on, the GPS receiver doesn't know what time it really is at the satellites, because the S.A. makes the satellite send the wrong time. The time the satellite sends is usually pretty close to the real time, but not exact. Without knowing the exact times at the satellites when they create their time message, the receiver cannot tell you the exact location you are trying to measure. This means the GPS receiver gives you a less accurate position because of S.A too!

 

 

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President Bill Clinton removed selective availability in 2000.

 

Selective Availability (SA) was an intentional degradation of public GPS signals implemented for national security reasons.

In May 2000, at the direction of President Bill Clinton, the U.S government discontinued its use of Selective Availability in order to make GPS more responsive to civil and commercial users worldwide.

 

https://www.gps.gov/systems/gps/modernization/sa/#:~:text=In May 2000%2C at the,ever use Selective Availability again.

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I seem to recall an interview somewhere sometime when that questions about why the 'big blue switch' depiction was chosen, but I can't remember where... 

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17 hours ago, NYPaddleCacher said:

 

If I were to guess, it was more of a software switch rather than a physical blue switch.

I took it metaphorically as the Big Blue (Sky) Switch.

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According to this blog post:

Quote

For reasons unknown, this is often referred to as the flipping of the “Big Blue Switch”.

I was honestly hoping for something more exciting. :signalviolin:

Edited by TmdAndGG
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As pointed out above, selective availability was basically a sort of semi-random "fuzz factor" added in for non-military receivers. So, they'd get close, but not TOO close. It could be ajusted as needed, but was typically set at a level that would make accuracy below +/-50 meters horizontally and +/-100m vertically impossible.  Following Clinton's order to turn it off, apparently the GPS software was modified to set the Selective Availability factor to zero.

 

It's cool to think about a big switch being thrown, but as with many things, real life is just a bit more mundane.

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On 1/13/2021 at 8:10 AM, NYPaddleCacher said:

If I were to guess, it was more of a software switch rather than a physical blue switch.

14 hours ago, colleda said:

I took it metaphorically as the Big Blue (Sky) Switch.

6 hours ago, TmdAndGG said:

According to this blog post:

I was honestly hoping for something more exciting. :signalviolin:

 

Got another option...   :D   IIRC, during the election,  Bush v Gore ...

In 1999 VP Al Gore was already looking into a civilian "signal, and said if he became president he'd shut off selective availability of GPS. 
When Bill Clinton did it in 2000 , a large group of folks said that bill gave an
 unfair advantage to his buddy (which didn't pan out for him anyway).

"Blue" switch, as in the democrat party (blue - dems, red - gop) .  :)

 

But (to me) colleda's sounds about right.  ;)

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When I see Big Blue, I think of IBM.  Were they involved in the development of the computers and programming of the GPS satellites and computer systems?

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12 hours ago, Joe_L said:

When I see Big Blue, I think of IBM.  Were they involved in the development of the computers and programming of the GPS satellites and computer systems?

 

I don't think so. Lockheed Martin is responsible for designing and launching most of them.  

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On 1/13/2021 at 11:26 PM, colleda said:

I took it metaphorically as the Big Blue (Sky) Switch.

I thought of the blue switch as a classification term. Green switches often refer to companies becoming economical and carbon neutral. I always thought the "blue" switch refers to the releasing of technology, turning on that technology with regard to the public's eye.

 Why blue? Outside of the matrix trilogy blue seems to be the primary media depicted color of computer based technology, possibly thanks to windows using blue a lot.

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7 hours ago, CheekyBrit said:

I thought of the blue switch as a classification term. Green switches often refer to companies becoming economical and carbon neutral. I always thought the "blue" switch refers to the releasing of technology, turning on that technology with regard to the public's eye.

 Why blue? Outside of the matrix trilogy blue seems to be the primary media depicted color of computer based technology, possibly thanks to windows using blue a lot.

 

 

Also, Big Blue is IBM_logo_logotype_emblem.png

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I remember standing outside with my GPS unit watching the Lat/Long adjust (correct) when the SA was turned off (I was up in Alaska at the time)

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