Reply With QuoteGPS satellites are in a geostationary orbit just like Pay TV sat's
Adobe.
GPS satellites
Satellites orbit the earth with us but are always in the same position when pointing a dish at them..
Is it any different with GPS satellites …??
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GPS satellites are in a geostationary orbit just like Pay TV sat's
Adobe.
Are you sure? I thought GPS satellites orbited the Earth twice every 24 hours.Originally Posted by Adobe
i also thought they moved
"The GPS satellites circle the earth twice a day, 10,900 miles above the earth. There are 24 satellites in the GPS constellation. Twenty-one satellites can be called on at any time; the other three are spares in case one of the others becomes unhealthy.
Five or six satellites are above and visible (by radio wave) to any spot on the earth at any one time. Buildings, hills, trees, and other ground features may block one or more at one time, or one or two of the satellites may not be at their best. These problems will reduce the number of useful satellites above a position to two, and maybe even one, but three or four are commonly available. Often as many as five and six are visible.
The location in space of each satellite is known. The orbits are carefully planned and constantly updated so that actual location is never off by much from the intended location. Each satellite constantly announces its number, and the time that signal was sent.
The distance from each satellite to the receiver is calculated by comparing the time the signal says it was sent with the time the receiver picks up the signal. The time difference is multiplied by the speed of light to get the distance from satellite to receiver. This is done for each satellite the receiver can "see".
The US Government has just 'switched off' Selective Availability for public users of GPS. This means that the errors that were previously deliberately put into the GPS signals have now been removed and even small hand-held units can achieve an accuracy of about 10 metres in position.
Nice little animation at....
.... and way too much information.
The gps system consists of three pieces. There are the satellites that transmit the position information, there are the ground stations that are used to control the satellites and update the information, and finally there is the receiver that you purchased. It is the receiver that collects data from the satellites and computes its location anywhere in the world based on information it gets from the satellites. There is a popular misconception that a gps receiver somehow sends information to the satellites but this is not true, it only receives data.
When using auto steer in the tractor usually have 8 or 9 sats being used in the solution. The receiver is normally detecting a few more. I think with the Afghan and Iraq conflicts they have extra satellites in this section of the globe.
go here: to see most satellites that are up there and where they are right now. click on any satellite to get further info on it such as use, payload, date launched, from where and on what type of rocket, expected lifespan etc etc etc very interesting. enjoy.
ps. make sure you allow popups from that site as the program opens in a new window.
Did you know there are over eight thousand artificial objects orbiting Earth? Over 2,500 are satellites, operative and inoperative. The remaining objects are orbital debris: parts such as nosecone shrouds, lens, hatch covers, rocket bodies, payloads that have disintegrated or exploded, and even objects that "escape" from manned spacecraft during operations.
J-Track 3D is one of the most popular Java applets on our web site. It shows 900 satellites, out of thousands, swarming about our earth. You can rotate the display and modify all kinds of settings. The display will also zoom in and out.
Last edited by bs_ink; 14-09-08 at 10:37 PM. Reason: allow popups from site to view.
Yes, dax is right. GPS satellites orbited the Earth twice every 24 hours.
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