Trimble Outdoors SK8 User Manual

Page 200

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Glossary-2

Lassen-SK8 Embedded GPS Module

Glossary

bandwidth

The range of frequencies occupied by a signal. Also, the information
carrying capability of a communication channel or line.

baud

A measure of the speed of data transmission. Baud and bit rate are the
same for direct equipment interconnections (e.g., via RS-232). Baud and
bit rate are not the same for modulated data links, whether wire or radio.

bit

Binary digit. The smallest unit of information into which digital data can
be subdivided and which a computer can hold. Each bit has only two
values (e.g., on/off, one/zero, true/false).

bit rate

The rate at which bits are transmitted over a communication path.
Normally expressed in bits per second (bps).

byte

A set of contiguous bits that make up a discrete item of information. A
byte usually consists of a series of 8 bits, and represents one character.

C/A code

The Coarse/Acquisition code. This is the civilian code made available by
the Department of Defense. It is subject to selective availability (SA).
Users can reduce the effects of SA by using differential GPS.

carrier

The radio signal on which information is carried. The carrier can be
sensed to determine the presence of a signal.

channel

Either a single frequency or a pair of radio frequencies used as a
communication path.

chip

The length of time to transmit either a zero or a one in a binary pulse
code.

chip rate

Number of chips per second (e.g., C/A code = 1.023 MHz).

configuration

A set of conditions or parameters that define the structure of an item. A
configuration defines the GPS processing and characteristics of the RS-
232 interface ports. The term configuration can also define the hardware
components that comprise a subsystem or system.

data bits

The bits in a byte of data which carry the actual information.

datum

Refers to a mathematical model of the earth. Many local datums model
the earth for a small region: e.g., Tokyo datum, Alaska, NAD-27 (North
America). Others, WGS-84, for example, model the whole earth.

DCE

Data Communications Equipment. The equipment that provides the
functions required to establish, maintain, and terminate a communication
connection. Any equipment that connects to DTE using an RS-232 or
CCITT V.24 standard interface.

default setting

A preset or initial value that is assumed to be the preferred or appropriate
selection for most situations. The Placer GPS sensor is shipped with
factory default configuration settings; the settings were determined by
Trimble Navigation.

DGPS

see differential GPS

2-D

Two Dimensional. A 2-D position is defined as latitude and longitude.
Altitude is assumed to be fixed.

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