CHAPTER ONE
1.6.4 DYNAMIC CAPABILITY
The following specifications are operational dynamic limits for GPS Timing Unit operation.
A. VELOCITY
The velocity of the user is limited to 515 m/sec for proper GPS Receiver operation.
B. ACCELERATION
User acceleration cannot exceed four 4g (39.2 m/sec
2
).
C. JERK
The rate of change of acceleration is not to exceed 5 m/sec
3
.
1.6.5 RF JAMMING RESISTANCE AND BURN-OUT PROTECTION
The GPS RPU provides resistance to all forms of jamming whose effect results in jamming to signal
power ratios of twenty-four dB or less as measured at the antenna/preamplifier interface when the
input signal is at -163 dBm. The GPS RPU/antenna set provides burn-out protection to prevent
damage at RF power densities up to one watt (CW) at the antenna, provided the signal is 100MHz
out of the GPS frequency band.
1.6.6 SYSTEM STATUS AND DIAGNOSTICS
All digital circuitry is tested to the greatest extent possible at power-up. This includes testing the
memory systems, and processor, as well as monitoring the performance of the channel processors.
Should a failure occur in any of these areas, it will be available as status on the RS-232 I/O and will
be displayed on the LCD Display as an error.
1.6.7 GPS POSITION SOLUTION MODES
The user may select either the Auto Mode or the Dynamic Mode for position solutions. (In the
Stationary Mode, the position is already predetermined.) See SELECT MODE in Chapter Three for
front panel LCD and keyboard selection. See Chapter Four for MODE SELECTION using the RS-
232 I/O.
The AUTO mode is actually a combination of the DYNAMIC and the STATIONARY modes.
When powered up in the AUTO mode, the unit will acquire some number of positions in the
DYNAMIC mode calculating an average latitude, longitude, and altitude when there are at least
four satellites in view. The factory set default number of averages is 200. These position averages
are loaded into battery backed memory for future use.
1-16 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc
To Next Page
Loading...
Need help?
General
