C-Nav IALA Hardware Reference Manual page 90

C-Nav Hardware Reference Guide
deviations from the mean. The deviations are not squared like they are for the standard
deviation; the absolute values of the deviations are used.
Azimuth the azimuth of a line is its direction as given by the angle between the meridian and
the line measured in a clockwise direction from the north branch of the meridian.
Bad Packets refer to the number of bad C-Nav Corrections Service packets received since the
unit was turned on.
Bandwidth is a measure of the width of the frequency spectrum of a signal expressed in Hertz.
Baseline is the resultant three-dimensional vector (V) between any two stations from which
simultaneous GPS data have been collected and processed. Generally given in earth-centered
Cartesian coordinates where: V=(Δx, Δy, Δz)
Base station see reference station.
Baud Rate (bits per second) is the number of bits sent or received each second. For example,
a baud rate of 9600 means there is a data flow of 9600 bits each second. One character roughly
equals 10 bits.
Beat Frequency is either of the two additional frequencies obtained when two signals of two
frequencies are mixed, equal to the sum or difference of the original frequencies.
Binary Biphase Modulation is a phase change on a constant frequency carrier of either 0 or
180 degrees. These represent the binary digits 0 and 1, respectively.
Binary Code is a system used in communication where selected strings of 0's and 1's are
assigned definite meanings.
Binary Pulse Code Modulation is a two-state phase modulation using a string of binary
numbers or codes. The coding is generally represented by 1 and 0 with definite meanings
attached to each.
Bits per second see baud rate.
Broadcast Ephemeris is the ephemeris broadcast by the GPS satellites.
British Standard Whitworth (BSW) is a type of coarse screw thread. A 5/8" diameter BSW is
the standard mount for survey instruments. (1" Mount included).
C/A code see Coarse Acquisition code.
CAN BUS is a balanced (differential) 2-wire interface that uses an asynchronous transmission
scheme. Often used for communications in vehicular applications.
Carrier is a high-frequency radio wave having at least one characteristic (frequency, amplitude,
or phase), which may be varied by modulation from an accepted value. In general, the carrier
wavelength is much shorter than the wavelength of the codes.
Carrier Beat Phase is the difference between the phase of the incoming Doppler shifted
satellite carrier signal and the phase of the nominally constant reference frequency generated in
the receiver.
Channel a channel of a GPS receiver consists of the circuitry necessary to receive the signal
for a single GPS satellite.
Chip a. The minimum transition time interval for individual bits of either a 0 or 1 in a binary pulse
code usually transmitted in a pseudo-random sequence. b. A tiny square piece of thin
semiconductor material on which an integrated circuit is formed or is to be formed.
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