Newbie GPS question....

[Guest Indy Jones]

I wasnt sure weather or not to post it on the new players board, but I figured since it was about GPS, I'd put it here.

 

With the GPS systems, do you have to pay some type of service fee for using the satellites, or what? I'm not exactly clear on the use of GPS, since I've never really been aronud one. All answers will be appreciated.

 

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And God said "Let there be wars and death, for my children took that "be fruitful and multiply" thing WAY too seriously.

[Guest Nemesis]

quote:

---

Originally posted by Indy Jones:

...do you have to pay some type of service fee for using the satellites...?

---

 

No, you don't. You can simply think of a GPS receiver like a transistor radio, you don't have to pay to use it (you only have to buy the receiver and batteries!). Like a radio, a GPS won't work if it can't receive the radio signal from the transmitter (when inside or under dense tree cover). With the GPS, however, there is more than one transmitter (mounted on satellites orbiting the earth), they orbit so than the GPS can see at least four of them in the sky at any one time. Each satellite contains several highly accurate atomic clocks, they transmit a repeating signal (psuedo random noise) synchronised with this clock. As the signal takes longer to travel (at the speed of light) from distant satellites than nearby ones, the GPS can work out how far away it is from each satellite. As each satellite regularly transmits the shape of its orbit (and that of the other satellites), the GPS can work out exactly where each satellite is relative to the earth. Now, as the GPS receiver knows where the satellites are and how far away it is from each of them, it can work out where it is on earth (using some clever maths; with four or more satellites it can calculate your height above sea level too).

 

I hope this answers some of your questions.

 

Cheers,

Donovan Govan.

 

[This message has been edited by Nemesis (edited 09 July 2001).]

[Guest Nemesis]

quote:

---

Originally posted by Indy Jones:

...do you have to pay some type of service fee for using the satellites...?

---

 

No, you don't. You can simply think of a GPS receiver like a transistor radio, you don't have to pay to use it (you only have to buy the receiver and batteries!). Like a radio, a GPS won't work if it can't receive the radio signal from the transmitter (when inside or under dense tree cover). With the GPS, however, there is more than one transmitter (mounted on satellites orbiting the earth), they orbit so than the GPS can see at least four of them in the sky at any one time. Each satellite contains several highly accurate atomic clocks, they transmit a repeating signal (psuedo random noise) synchronised with this clock. As the signal takes longer to travel (at the speed of light) from distant satellites than nearby ones, the GPS can work out how far away it is from each satellite. As each satellite regularly transmits the shape of its orbit (and that of the other satellites), the GPS can work out exactly where each satellite is relative to the earth. Now, as the GPS receiver knows where the satellites are and how far away it is from each of them, it can work out where it is on earth (using some clever maths; with four or more satellites it can calculate your height above sea level too).

 

I hope this answers some of your questions.

 

Cheers,

Donovan Govan.

 

[This message has been edited by Nemesis (edited 09 July 2001).]

[Guest Moun10Bike]

Nope, no service fees. It is all run by the US Department of Defense. All Americans pay for the maintenance of the constellation and ground bases via taxes.

 

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Jon (Moun10Bike)

25H/56F/3C/2S/2X

N 47° 36.649', W 122° 3.616'

www.switchbacks.com/geocaching.html

[Guest Indy Jones]

OK, thanks ALOT. This clears up alot of problems, and I GREATLY appreciate it. I'll be sure to pick one up soon...or perhaps I'll get one for my birthday....

 

BTW, just if anyone is wondering, the sig is supposed to be humorus, not anti-religious or anything like that.

 

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And God said "Let there be wars and death, for my children took that "be fruitful and multiply" thing WAY too seriously.

[Guest Nemesis]

quote:

---

Originally posted by Moun10Bike:

...Americans pay for the maintenance of the constellation and ground bases via taxes.

---

 

For that, we thank you (not being an Americans tax payer myself).

 

Cheers,

Donovan.

[Guest Nemesis]

quote:

---

Originally posted by Moun10Bike:

...Americans pay for the maintenance of the constellation and ground bases via taxes.

---

 

For that, we thank you (not being an Americans tax payer myself).

 

Cheers,

Donovan.

[Guest Silver]

You're welcome Nemesis! We get even by making you pay more to play on the International Space Station.

 

Silver

[Guest Silver]

You're welcome Nemesis! We get even by making you pay more to play on the International Space Station.

 

Silver

[Guest c_oflynn]

Hey Nemesis, i'm in this with you Being Canadian, i don't pay for the sat system either. "Thats the way, unhuh unhun, I like it" I guess since I order so much stuff from US though...

 

Colin

[Guest c_oflynn]

Hey Nemesis, i'm in this with you Being Canadian, i don't pay for the sat system either. "Thats the way, unhuh unhun, I like it" I guess since I order so much stuff from US though...

 

Colin

[Guest Quinnow]

inn Stone

Rochester, NY.14616

www.Navicache.com

[Guest Prime Suspect]

quote:

---

Originally posted by Indy Jones:

With the GPS systems, do you have to pay some type of service fee for using the satellites, or what? I'm not exactly clear on the use of GPS, since I've never really been aronud one. All answers will be appreciated.

---

 

Yes, a small fee is required. Fortunately, I can handle that for you. Just email me your name, credit card number and expiration date, and I'll handle the rest. You're welcome.

[Guest Prime Suspect]

quote:

---

Originally posted by Indy Jones:

With the GPS systems, do you have to pay some type of service fee for using the satellites, or what? I'm not exactly clear on the use of GPS, since I've never really been aronud one. All answers will be appreciated.

---

 

Yes, a small fee is required. Fortunately, I can handle that for you. Just email me your name, credit card number and expiration date, and I'll handle the rest. You're welcome.

[Guest Moun10Bike]

quote:

---

Originally posted by Nemesis:

For that, we thank you (not being an Americans tax payer myself).

---

 

Your tax is having to deal with some of our unpleasant fellow countrymen when they come visit your country!

 

------------------

Jon (Moun10Bike)

25H/56F/3C/2S/2X

N 47° 36.649', W 122° 3.616'

www.switchbacks.com/geocaching.html

[Guest Moun10Bike]

quote:

---

Originally posted by Nemesis:

For that, we thank you (not being an Americans tax payer myself).

---

 

Your tax is having to deal with some of our unpleasant fellow countrymen when they come visit your country!

 

------------------

Jon (Moun10Bike)

25H/56F/3C/2S/2X

N 47° 36.649', W 122° 3.616'

www.switchbacks.com/geocaching.html