Technical data

Tables
RF Radio frequency
RFI Radio Frequency Interference
RMS Root Mean Square
RS232 Serial communication hardware standard (+/- 12v nom.)
RS422 A serial communication hardware standard (differential)
RTCM Radio Technical Committee for Maritime Services
RTC Real-time Clock (maintaining approximate time when unit is
off)
RTS Request to Send (serial communication handshaking)
RXD Receive Data (serial communication to Data Terminal or ‘DTE’
from Data Communication Equipment or DCE’)
S/A Selective Availability -imposed by the DoD to limit the GPS
performance available to civil users.
SEP Spherical Error Probability
SMA Miniature threaded coaxial connector.
SPS Standard precision Service
SSR Solid State Recorder
SV Satellite Vehicle
TNC A standard threaded coaxial connector
TSPI Time Space Position Information
TTL Transistor-transistor Logic (family of digital electronic
components)
TTFF Time to First Fix
GPS Timing Receiver Installation and Operation Manual
E-6