TBennettcc
- Dec 4, 2010
- 292
- Joined
- Dec 4, 2010
- Messages
- 292
Gamenut,
I'm not sure where you're getting your numbers from. Light and radio waves are both forms of electromagnetic radiation, the speed of which (in a vacuum) is always 3.0 x 10^8 m/s. I don't understand your reasoning between the correlation of the speed of electromagnetic waves and the amount of transmissions able to be made? The amount of information transmitted and the time it takes to transmit that information is dependent on several factors, including frequency, how the information in encoded, bandwidth, encode and decode times, etc.
In order to make a measurement, the measurement has to have a reference point. They have a 'standard meter' and a 'standard kilogram' for reference at the International Bureau of Weights and Measures, to ensure that when someone says '1 kilogram', everyone is referencing the SAME kilogram. So is the problem with your project. Sure, it's easy to measure the length of time a signal was transmitted. But how do you know WHEN that signal was transmitted? Both the source and the target have to reference the SAME time source, not an easy task, especially when you are talking accuracy of +/- 1 mm.
The US GPS satellites #1) have their own atomic clocks on board, and #2) are constantly in contact with ground stations for error corrections and timing of the signals. Check out WAAS for more information. WAAS accuracy is claimed to be about 25 feet, which is pretty darn good considering those satellites are orbiting at an altitude of over 12,000 miles.
This might also be good reading: http://en.wikipedia.org/wiki/Global_Positioning_System#Correcting_a_GPS_receiver.27s_clock
Hope this sheds some light on the subject.
I'm not sure where you're getting your numbers from. Light and radio waves are both forms of electromagnetic radiation, the speed of which (in a vacuum) is always 3.0 x 10^8 m/s. I don't understand your reasoning between the correlation of the speed of electromagnetic waves and the amount of transmissions able to be made? The amount of information transmitted and the time it takes to transmit that information is dependent on several factors, including frequency, how the information in encoded, bandwidth, encode and decode times, etc.
In order to make a measurement, the measurement has to have a reference point. They have a 'standard meter' and a 'standard kilogram' for reference at the International Bureau of Weights and Measures, to ensure that when someone says '1 kilogram', everyone is referencing the SAME kilogram. So is the problem with your project. Sure, it's easy to measure the length of time a signal was transmitted. But how do you know WHEN that signal was transmitted? Both the source and the target have to reference the SAME time source, not an easy task, especially when you are talking accuracy of +/- 1 mm.
The US GPS satellites #1) have their own atomic clocks on board, and #2) are constantly in contact with ground stations for error corrections and timing of the signals. Check out WAAS for more information. WAAS accuracy is claimed to be about 25 feet, which is pretty darn good considering those satellites are orbiting at an altitude of over 12,000 miles.
This might also be good reading: http://en.wikipedia.org/wiki/Global_Positioning_System#Correcting_a_GPS_receiver.27s_clock
Hope this sheds some light on the subject.