NavCom SF-3050 Rev.I - Manual (Page 195)

SF-3050 GNSS Product User Guide – Rev I
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reference station a reference station collects GNSS data for a fixed, known location.
Some of the errors in the GNSS positions for this location can be applied to positions
recorded at the same time by roving receivers which are relatively close to the reference
station. A reference station is used to improve the quality and accuracy of GNSS data
collected by roving receivers.
RHCP Right Hand Circular Polarization used to discriminate satellite signals. GNSS
signals are RHCP.
RINEX (Receiver Independent Exchange) is a file set of standard definitions
and formats designed to be receiver or software manufacturer independent and to
promote the free exchange of GNSS data. The RINEX file format consists of separate
files, the three most commonly used are:
the observation (.YYo) file,
the navigation (.YYn) file,
meteorological (.YYm) files; where YY indicates the last two digits of the year the data
was collected.
rover any mobile GNSS receiver and field computer collecting data in the field. A roving
receiver’s position can be differentially corrected relative to a stationary reference GNSS
receiver or by using GNSS orbit and clock corrections from a SBAS such as StarFire.
roving receiver see rover.
RTCM (Radio Technical Commission for Maritime Services) a standard format for
Differential GNSS 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) is the deliberate degradation of the GPS signal by encrypting
the P-code and dithering the satellite clock. 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) is a measure of a satellite’s signal strength.
SNR see signal-to-noise Ratio.
StarFire a set of real-time global orbit and clock corrections for GPS satellites. StarFire
equipped receivers are capable of real-time decimeter positioning
(see Appendix C).