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NavCom SF-2050 Rev.D User Manual

Page 62

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SF-2050 User Guide - Rev. D

Proprietary commands those messages sent to and
received from

GPS

equipment produced by NavCom

Technology, Inc. own copyrighted binary language.

pseudo-random noise (

prn

) a sequence of data that

appears to be randomly distributed but can be exactly
reproduced. Each

GPS

satellite transmits a unique

PRN

in its signals.

GPS

receivers use

PRN

s to identify and

lock onto satellites and to compute their pseudoranges.

Pseudorange the apparent distance from the

reference

station

’s antenna to a satellite, calculated by multiplying

the time the signal takes to reach the antenna by the
speed of light (radio waves travel at the speed of light).
The actual distance, or

range

, is not exactly the same

because various factors cause errors in the
measurement.

PVT

GPS

information depicting Position, Velocity, Time

in the NCT proprietary message format.

Radio Technical Commission for Maritime Services

see

RTCM

.


range the distance between a satellite and a

GPS

receiver’s antenna. The

range

is approximately equal to

the

pseudorange

. However, errors can be introduced by

atmospheric conditions which slow down the radio
waves, clock errors, irregularities in the satellite’s orbit,
and other factors. A

GPS

receiver’s location can be

determined if you know the ranges from the receiver to
at least four

GPS

satellites. Geometrically, there can only

be one point in space, which is the correct distance
from each of four known points.

RCP a NavCom Technology, Inc. proprietary processing
technique in which carrier phase measurements, free of

Glossary-60

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