Filter
Top Products
GPS TIME:
GPS time in hours, minutes and seconds. The advisory time is dis-
played when at least one satellite is being tracked, other-wise the
time field displays dashes.
NOTE: GPS TIME may vary several seconds from GMT due to leap
second input of UTC.
STATE: The GPS receiver state can be one of the following:
Dashes: Idle or no mode data.
INITIALIZE: The receiver is updated with initial position and time
information.
SKY SEARCH: No almanac is available. The system searches for
any satellite in the visible table based on the internal
or external time, data, and position and then assigns
channels in order received.
ACQUISITION: Constellation selection and channel assignments are
being done. Carrier and code lock are in progress.
TRANSITION: The receiver is transitioning from one state, such as
ACQUISITION, to another state, such as NAVIGA-
TION.
NAVIGATION: The GPS receiver is in navigation mode and has at
least a two dimensional position fix.
DR: The system is in dead reckon mode. When the posi-
tion is valid and sufficient satellite measurements are
unavailable, the receiver will continue to output valid
position for a maximum of 30 seconds while using
the last known velocity and track information. The
position is invalid after 30 seconds.
MODE:
Possible receiver modes are ENROUTE, OCEANIC/REMOTE, TER-
MINAL, and APPROACH. These modes are used to determine what
accuracy parameters should be used for a particular phase of flight.
ALT AIDED?:
Indicates the GPS receiver is using an externally supplied altitude
input for position calculation.
Page Display Definitions
2-30
GNS-XL Flight Management System
Rev. 0
Oct/96