[asifrahat]

How does a GPS works? Or how can I use GPS in my PC?

[Credendovidis]

Click here to find out how it does !

It seems not very useful to do that with your computer, unless it is a laptop that you move around with you.
Click here for info on GPS and laptops

Success !

:)

[chuckhole]

The Global Positioning System (GPS) uses satellites that send signals. Your GPS is a receiver. The signals are sent from each receiver with a timing signal. Your receiver gets each signal with the timing to know how far it is away from the satellite. It uses multiple signals to get an intersection point. A minimun of three signals are required to "triangulate" your position in three dimensions. They also calculate height above sea level. In the Continental US and waters, there is an additional calculation that is performed to further enhance accuracy. The units that are sold for navigation can achieve accuracy of an average of 15 feet or better. The commercial units used for survey can achieve accuracy as close to 1/2".

As far as connecting it to a PC, that used to be a big thing when GPS units did not have the processing or storage to hold the vast amount of information required to display accurate maps. This is no longer the case. Now the PC is used to update the Firmware levels of the GPS and to load new map data onto memory cards located in the GPS. This has been the biggest change in GPS over the past 10 years... the ability to display and store map data. You can even purchase GPS antennas and programs for smarphones such as the Treo.

Just a thought. I have used the GPS to map out the boundaries of my 36.5 acre country place along with the roads, creek bed and such. I then downloaded the track data and superimposed it over the satellite images from Google Earth. Now I have an accrate map with height above sea level information of my property. The initial survey that I paid over $2K for does not have all that.

Now, marine GPS has been incorporated into a single display that includes national weather data, depth sounder, radar and NOAA chart display. It is simply amazing how far it has come. My sailboat is 12' wide and 38' long. The GPS is accurate enough to tell me what part of the boat I am on. I am quite happy with that since I remember what it was like to navigate with the Loran C. You were doing well to get better than 1,000 feet accuracy.