User`s guide

Appendix
Motorola GPS Products - M12+ User's Guide Revision 6.X 09FEB05
198
Almanac
Data transmitted by a GPS satellite which includes orbital information on all the satellites,
clock correction, and atmospheric delay parameters. These data are used to facilitate
rapid satellite acquisition. The orbital information in the almanac is less accurate than the
ephemeris, but valid for a longer time (one to two years).
Ambiguity
The unknown integer number of cycles of the reconstructed carrier phase contained in an
unbroken set of measurements from a single satellite pass at a single receiver.
Argument of Latitude
The sum of the true anomaly and the argument of perigee.
Argument of Perigee
The angle or arc from the ascending node to the closest approach of the orbiting body to
the focus or perigee point, as measured at the focus of an elliptical orbit, in the orbital
plane in the direction of motion of the orbiting body.
Ascending Node
The point at which an object's orbit crosses the reference plane (i.e., the equatorial
plane) from south to north.
Azimuth
A horizontal direction expressed as the angular distance between a fixed direction, such
as north, and the direction of the object.
Bandwidth
A measure of the information-carrying capacity of a signal, expressed as the width of the
spectrum of that signal (frequency domain representation) in Hertz (Hz).
Baseline
The three-dimensional (3D) vector distance between a pair of stations for which
simultaneous GPS data has been collected and processed with differential techniques.
Beat Frequency
Either of two additional frequencies obtained when signals of two frequencies are mixed.
The beat frequencies are equal to the sum or difference of the original frequencies.
Bias
See Integer Bias Terms.
Binary Bi-phase Modulation
Phase changes of either zero or 180 degrees (representing a binary zero or one,
respectively) on a constant frequency carrier. GPS signals are bi-phase modulated.