Can anybody tell me what it said below:
A signal is transmitted from each satellite in the direction of the Earth. This signal is
encoded with the “Navigation Message,” which can be read by the user’s GPS receivers.
The Navigation Message includes orbit parameters (often called the “broadcast
ephemeris”), from which the receiver can compute satellite coordinates (X,Y,Z). These are
Cartesian coordinates in a geocentric system, known as WGS-84, which has its origin at the
Earth centre of mass, Zaxis pointing towards the North Pole, X pointing towards the Prime
Meridian (which crosses Greenwich), and Y at right angles to X and Z to form a right-handed
orthogonal coordinate system. The algorithm which transforms the orbit parameters into WGS
-84 satellite coordinates at any specified time is called the “Ephemeris Algorithm,”
which is defined in GPS textbooks [e.g., Leick, 1991]. We discuss the Navigation Message in
more detail later on. For now, we move on to “pseudoranges.”
A signal is transmitted from each satellite in the direction of the Earth. This signal is
encoded with the “Navigation Message,” which can be read by the user’s GPS receivers.
The Navigation Message includes orbit parameters (often called the “broadcast
ephemeris”), from which the receiver can compute satellite coordinates (X,Y,Z). These are
Cartesian coordinates in a geocentric system, known as WGS-84, which has its origin at the
Earth centre of mass, Zaxis pointing towards the North Pole, X pointing towards the Prime
Meridian (which crosses Greenwich), and Y at right angles to X and Z to form a right-handed
orthogonal coordinate system. The algorithm which transforms the orbit parameters into WGS
-84 satellite coordinates at any specified time is called the “Ephemeris Algorithm,”
which is defined in GPS textbooks [e.g., Leick, 1991]. We discuss the Navigation Message in
more detail later on. For now, we move on to “pseudoranges.”
