Trimble Outdoors SK8 - Manual (Page 206)

Glossary-8 Lassen-SK8 Embedded GPS Module
Glossary
serial communication A system of sending bits of data on a single channel one after the other,
rather than simultaneously.
serial port A port in which each bit of information is brought in/out on a single
channel. Serial ports are designed for devices that receive data one bit at
a time.
signal to noise level GPS signals with SNRs that do not meet the mask criteria are considered
unusable.
signal to noise ratio A measure of the relative power levels of a communication signal and
noise on a data line. SNR is expressed in decibels (dB).
SNR Signal to Noise Ratio.
spread spectrum The received GPS signal is a wide bandwidth, low-power signal (-
160dBW). This property results from modulating the L-band signal with
a PRN code in order to spread the signal energy over a bandwidth which
is much greater than the signal information bandwidth. This is done to
provide the ability to receive all satellites unambiguously and to provide
some resistance to noise and multipath.
SPS Standard Positioning Service. Refers to the GPS as available to the
authorized user.
start bit In asynchronous transmission, the start bit is appended to the beginning
of a character so that the bit sync and character sync can occur at the
receiver equipment.
stop bit In asynchronous transmission, the stop bit is appended to the end of each
character. It sets the receiving hardware to a condition where it looks for
the start bit of a new character.
SV Space Vehicle (GPS satellite).
synchronous
communication A method of sending digital data in which the bits come at fixed, rather
than random, times and are synchronized to a clock.
TAIP Trimble ASCII Interface Protocol. Designed originally for vehicle
tracking applications, TAIP uses printable uppercase ASCII characters in
16 message types for easy integration with mobile data modems,
terminals, and personal computers. The TAIP protocol is defined in full
in Appendix C.
TANS Trimble Advanced Navigation Sensor. Also refers to a Trimble-specified
interface protocol for digital packet communication to/from the GPS
receiver. Data output includes time-tagged position and velocity, satellite
status, dilution of precision factors and diagnostics of GPS receiver
operational status.
Also see TSIP
TNL 4000RL Trimble Navigation, Ltd. Reference Locator (4000RL). Product name for
the Differential GPS Reference Station.
2-D Two Dimensional. A 2-D position is defined as latitude and longitude.
Altitude is assumed to be fixed.