Rohde & Schwarz EVSF1000, User Manual

Page: 117 / 295

GBAS/SCAT-I Mode (Options R&S EVSG-K4/-K5)
R&S
®
EVSF1000
117 User Manual 1178.6410.02 ─ 05
8.1.4 Time Slot Synchronization via PPS
The GBAS/SCAT signal is synchronous to the PPS signal of the GPS system. With the
help of this synchronization, the GBAS/SCAT-I signal is assigned to eight time slots
(twice a second).
The R&S EVSF1000 requires a valid PPS signal for the analysis of a GBAS/SCAT-I
signal and for detection of the individual time slots. If the R&S EVSF1000 finds a valid
PPS signal at its selected trigger connector, the status line of the display indicates
"PPS Locked". Only in this case GBAS/SCAT-I signal analysis is possible.
8.2 GBAS/SCAT-I Status Display
The basic measurement information is displayed in the mini display directly on the
R&S
EVSF1000 (see also Chapter 3.4.1, "Basic Configuration and Status Display" ,
on page 22).
For GBAS/SCAT-I mode, the following measurement information is displayed:
●
"F" : The channel frequency that determines the carrier frequency at which the
measurement is performed. See "Frequency (Freq)" on page 118.
●
"Tref" : Time reference; indicates the status of the PPS signal from an external
GPS device (see "Time reference status (Time Ref.)" on page 119)
– "PPS" :
A GPS receiver or a valid signal is available at the PPS-In,Trigger-In, or
RS232-GPS connector.
– "Unlk" :
No valid signal available at the PPS-In or Trigger-In connector. GBAS/SCAT-I
signals cannot be detected correctly.
●
The burst status is indicated by the color of the slot cell (see also "Status"
on page 121):
–
Green : The status is "OK". The received burst passed the cyclic redundancy
check (CRC).
– Red : An error occured. The received burst did not pass the cyclic redundancy
check (CRC).
– Gray : No burst received.
GBAS/SCAT-I Status Display