NavCom SF-2050 Rev.D - Manual (Page 64)

SF-2050 User Guide - Rev. D
roving receiver see rover .
RTCM
(Radio Technical Commission for Maritime Services)
a standard format for
Differential GPS corrections used
to transmit corrections from a base station to rovers .
RTCM allows both real-time kinematic ( RTK ) data
collection and post-processed differential data
collection. RTCM SC-104 (RTCM Special Committee
104) is the most commonly used version of RTCM
message.
RTK see
Real-time kinematic .
RTG Real Time GIPSY, a processing technique
developed by NASA’s Jet Propulsion Laboratory to
provide a single set of real time global corrections for
the
GPS satellites.
S/A see
Selective availability .
SBAS (Satellite Based Augmentation System) this is
a more general term, which encompasses
WAAS ,
StarFire
™ and
EGNOS type corrections.
Selective Availability (S/A) deliberate degradation of
the
GPS signal by encrypting the P-code . When the US
Department of Defense uses S/A , the signal contains
errors, which can cause positions to be inaccurate by as
much as 100 meters.
Signal-to-Noise Ratio (
SNR ) a measure of a satellite’s
signal strength.
single-frequency a type of receiver that only uses the
L1
GPS signal. There is no compensation for ionospheric
effects.
Glossary-62