Leica Geosystems Leica mojo3D - User Manual - Manual (Page 374)

374 Leica mojo3D, Glossary of Terms
Appendix D Glossary of Terms
Almanac
Almanac data is used to predict which satellites are
visible, and thus shorten search times.
Base
A source of the correction signals for the RTK solu-
tion. May also be referred to as: base station, refer-
ence station and network reference station.
C/A code
The Coarse/Acquisition GPS code modulated on the
GPS L1 signal. This code is a sequence of 1023 pseu-
dorandom binary biphase modulations on the GPS
carrier at a chipping rate of 1.023 MHz, thus having
a code repetition period of one millisecond.
CAN bus
The Controller Area Network bus is a specialized
internal communications network that interconnects
components inside a vehicle.
A network inside a vehicle must meet specific
requirements: these include assurance of message
delivery, no conflict between messages, minimum
time for delivery, low cost, and ability to operate reli-
ably in an electrically noisy environment. Conven-
tional computer network technologies, such as
Ethernet, are rarely used in vehicles.
CDMA
Code-Division Multiple Access. CDMA refers to any of
a number of protocols used in second-generation
(2G) and third-generation (3G) cell phones. CDMA
uses multiplexing, which allows many signals to be
transmitted in a single channel. The frequency of a
signal is varied according to a code (defined pattern),
so that the signal can be picked up only by a receiver
that holds the same code.