private satellites

Well what usually happens is we get the same stupid straw-man argument "GPS does not require satellites". What this has to do with the fact that GPS does in fact use satellites is beyond me. I've compared it in the past to arguing against the existence of boats and planes by saying "Crossing the atlantic does not require boats and planes". I don't see many people swimming across the ocean though.

Quote from: kasroa on March 06, 2007, 09:50:35 AM

Well what usually happens is we get the same stupid straw-man argument "GPS does not require satellites". What this has to do with the fact that GPS does in fact use satellites is beyond me. I've compared it in the past to arguing against the existence of boats and planes by saying "Crossing the atlantic does not require boats and planes". I don't see many people swimming across the ocean though.

Actually, it's more like someone saying, "How can you possibly cross the atlantic without a boat or a plane?"  Well, you can swim it.  Having a boat or a plane is not required to cross the atlantic.  Would it make it easier?  Sure, but it's not required.

Quote from: sokarul on March 06, 2007, 10:11:22 AM

Nope, multiple satellites will allow the spheres to line up at one point.  The error is 3 meters on my bros unit.  Not more not less.  New receivers take into account time dilation and all that good stuff.

You obviously don't understand how integrated systems work.  You don't just have an ephemeris error and that's it.  You also have a clock error, a multipath error, calculation error, and atmospheric errors.  Due to the uncertainty in the calculation, the receiver often won't have spheres that align at only one point, therefore, the unit must calculate a numerically probable location.

The receiver does make the calculations to line up the 4 spheres.  Like I said the accuracy of my brothers receiver is 3 meters.  Thats what it is.  Its not 3 meters plus other error.  All error is accounted for. 
 

Quote from: sokarul on March 06, 2007, 03:42:07 PM

The receiver does make the calculations to line up the 4 spheres.  Like I said the accuracy of my brothers receiver is 3 meters.  Thats what it is.  Its not 3 meters plus other error.  All error is accounted for. 
 

You seem to be confusing 'theoretical land' with the real world.  Theoretically, if you had a perfectly clean, noiseless signal, which contained perfectly clean, noiseless data, obtained from noiseless sensors, theoretically, the GPS unit could calculate your position to three meters due to it's internal calculation and clock errors.  However, in the real world, the signal is not clean.  You can't just wave your hand and say, "all error is taken into account, it's just three meters."  There are at least 12 meters of uncertainty contained within the signal itself.

GPS Accuracy
The accuracy of a position determined with GPS depends on the type of receiver. Most hand-held GPS units have about 10-20 meter accuracy. Other types of receivers use a method called Differential GPS (DGPS) to obtain much higher accuracy. DGPS requires an additional receiver fixed at a known location nearby. Observations made by the stationary receiver are used to correct positions recorded by the roving units, producing an accuracy greater than 1 meter.

Do you agree that the G in GPS stands for global?  And if so, how is GPS global when Cellphones are not?  That act of being global means GPS has to use satellites.  The act that it doesnt take a day to figure out your spot means GPS uses satellites.     

Quote from: sokarul on March 06, 2007, 03:42:07 PM

Do you agree that the G in GPS stands for global?  And if so, how is GPS global when Cellphones are not?  That act of being global means GPS has to use satellites.  The act that it doesnt take a day to figure out your spot means GPS uses satellites.     

Or stratalites. 

Quote from: TheEngineer on March 06, 2007, 07:45:25 PM

Quote from: sokarul on March 06, 2007, 03:42:07 PM

The receiver does make the calculations to line up the 4 spheres.  Like I said the accuracy of my brothers receiver is 3 meters.  Thats what it is.  Its not 3 meters plus other error.  All error is accounted for. 
 

You seem to be confusing 'theoretical land' with the real world.  Theoretically, if you had a perfectly clean, noiseless signal, which contained perfectly clean, noiseless data, obtained from noiseless sensors, theoretically, the GPS unit could calculate your position to three meters due to it's internal calculation and clock errors.  However, in the real world, the signal is not clean.  You can't just wave your hand and say, "all error is taken into account, it's just three meters."  There are at least 12 meters of uncertainty contained within the signal itself.

I see your reading wiki.  Here is some more reading

Quote

GPS Accuracy
The accuracy of a position determined with GPS depends on the type of receiver. Most hand-held GPS units have about 10-20 meter accuracy. Other types of receivers use a method called Differential GPS (DGPS) to obtain much higher accuracy. DGPS requires an additional receiver fixed at a known location nearby. Observations made by the stationary receiver are used to correct positions recorded by the roving units, producing an accuracy greater than 1 meter.

The world is Round. 

GPS Accuracy
The accuracy of a position determined with GPS depends on the type of receiver. Most hand-held GPS units have about 10-20 meter accuracy. Other types of receivers use a method called Differential GPS (DGPS) to obtain much higher accuracy. DGPS requires an additional receiver fixed at a known location nearby. Observations made by the stationary receiver are used to correct positions recorded by the roving units, producing an accuracy greater than 1 meter.

Quote from: EvilToothpaste on March 06, 2007, 08:27:32 PM

Quote from: sokarul on March 06, 2007, 03:42:07 PM

Do you agree that the G in GPS stands for global?  And if so, how is GPS global when Cellphones are not?  That act of being global means GPS has to use satellites.  The act that it doesnt take a day to figure out your spot means GPS uses satellites.     

Or stratalites. 

What are those again? 

Due to their operating altitudes of 12-13 miles from earth, as opposed to satellites that operate from a distant 22,000 miles away, Stratellites™ can provide a superior and fully reclaimable method for operating advanced wireless communications and monitoring services

I stopped reading here

Quote

Due to their operating altitudes of 12-13 miles from earth, as opposed to satellites that operate from a distant 22,000 miles away, Stratellites™ can provide a superior and fully reclaimable method for operating advanced wireless communications and monitoring services

Stratalites couldnt have a known posssiton as it floats around. 

Why is everyone arguing over how GPS would or wouldn't work without satellites when everyone knows it uses satellites whether it needs to or not.

Quote from: sokarul on March 07, 2007, 06:50:31 AM

I stopped reading here

Quote

Due to their operating altitudes of 12-13 miles from earth, as opposed to satellites that operate from a distant 22,000 miles away, Stratellites™ can provide a superior and fully reclaimable method for operating advanced wireless communications and monitoring services

Stratalites couldnt have a known posssiton as it floats around. 

I think your conclusion has nothing to do with that quote.  Why could they not have a known position?

They are floating around.  Air currents and so forth are not 100 percent predicable.  There is no way to know where a balloon is going with any useful accuracy. 

Not to mention floating balloons still don’t cover the Earth to make the Global part still global.   

Quote from: sokarul on March 07, 2007, 09:23:43 AM

They are floating around.  Air currents and so forth are not 100 percent predicable.  There is no way to know where a balloon is going with any useful accuracy. 

I think there is little air current where there is little air. 

Quote from: sokarul on March 07, 2007, 09:23:43 AM

Not to mention floating balloons still don’t cover the Earth to make the Global part still global.   

...on the RE. 

Balloons float on air, where there is a balloon there is air.  Weather ballons dont just sit there, they move. 

Like i said, there is no way to use a balloon in GPS.  I would believe in GPS towers before I believed in GPS balloons.   Yet both are wrong.