NavCom SF-2040 Rev.F - Manual (Page 87)

SF-2040 User Guide – Rev. F
multipath error a positioning error resulting from
interference between radio waves that has traveled
between the transmitter and the receiver by two paths
of different electrical lengths.
navigation (.YYn) files one of the three file types
that make up the RINEX file format. Where YY
indicates the last two digits of the year the data was
collected. A navigation file contains satellite position
and time information.
observation (.YYo) files one of the three file types
that make up the RINEX file format. Where YY
indicates the last two digits of the year the data was
collected. An observation file contains raw GPS
position information.
P/N Part Number.
P-code the extremely long pseudo-random code
generated by a GPS satellite. It is intended for use
only by the U.S. military, so it can be encrypted to Y-
code deny unauthorized users access.
parity a method of detecting communication errors by
adding an extra parity bit to a group of bits. The parity
bit can be a 0 or 1 value so that every byte will add up
to an odd or even number (depending on whether
odd or even parity is chosen).
PDA Personal Digital Assistant.
PDOP see Position Dilution of Precision.
PDOP mask the highest PDOP value at which a
receiver computes positions.
phase center the point in an antenna where the
GPS signal from the satellites is received. The height
above ground of the phase center must be measured
accurately to ensure accurate GPS readings. The
phase center height can be calculated by adding the
height to an easily measured point, such as the base
Glossary-85