Rtcm Sc-104 - Leica GR30 Online Help Manual

RTCM SC-104

The special committee of the Radio Technical Commission for Maritime Services that developed recommended standards for DGPS.
Selective Availability (SA)
The policy and procedure of denying to most nonmilitary GPS users the full accuracy of the system. SA is achieved by dithering the
satellite clock (delta-process) and degrading the navigation message ephemeris (epsilon-process). Currently SA primarily uses the
delta-process. The effects can be removed with encryption keys or through DGPS techniques.
Signal-to-noise ratio (SNR)
The ratio of incoming signal strength to the amount of interfering noise as measured in decibels on a logarithmic scale.
SMTP
Simple Mail Transfer Protocol: normal e-mail transfer protocol.
SSID
The SSID (service set identification) is the ID of a wireless LAN profile, needed for identifying a wireless network. Only if the configured
SSID matches, can a connection to an access point (infrastructure mode) or another wireless device (ad hoc mode) be established.
Time Zone
Time zone = Local Time - Greenwich Mean Time (GMT). Note that Greenwich Mean Time is approximately equal to GPS time.
UTC (Coordinated Universal Time)
The time scale based on the atomic second but occasionally corrected, by the insertion of leap seconds, to keep it approximately
synchronized with Earths rotation. The leap second adjustments keep UTC within 0.9 seconds of UT1.
UT1
A time scale based on Earth's axial spin. UT1 is a measure of the true angular orientation of Earth in space. Because Earth does not
spin at exactly a constant rate, UT1 is not a uniform time scale.
WGS84
WGS 1984 is the global geocentric datum to which all GPS positioning information is referred to.
Wide Area Augmentation System (WAAS)
A system that enhances the GPS SPS and is available over a wide geographical area. The WAAS being developed by the Federal
Aviation Administration, in concert with other agencies, will provide WADGPS corrections, additional ranging signals from geostationary
(GEO) satellites, and integrity data on the GPS and GEO satellites.
World Geodetic System 1984 (WGS 84)
p for mixed GNSS navigation files
m for meteo files
a for auxilliary files (proprietary, no official part of RINEX standard)
Appendix J: Glossary
295