GPS Status Screens
CA: Code Acquire. This means the satellite code has been received
and matched to the receiver-generated code.
AS: AGC Set. This means the satellite strength has been assessed and
the Automatic Gain Control has been set.
FA: Frequency Acquire. This means the receiver has correctly locked
onto the satellite data frequency.
BD: Bit Sync Detect. This means the receiver is synchronized with the
satellite's data bit stream.
MD: Message Detect. This means the receiver is synchronized with the
satellite's message stream.
TA: Time Available. This means the satellite is fully locked in and has
sent down UTC time and date information to the receiver.
EA: Ephemeris Acquire. This means the receiver is reading the constel-
lation health status message from the satellite. This usually takes
around two minutes and is a function that is performed in the background
even if the receiver has a fix.
AP: Available for Position. This means the satellite is fully locked in and
tested and can be used for calculating position. A minimum of three
satellites are necessary for a 2D fix.
Key 1 returns to Main Menu. Date, Time, Local Time Offset and Present
Position can be adjusted by selecting one of Keys 2, 3 or 4. Direct
access to Map Mode is available by pressing Key 5.
When using the KMD 150 for the first time (or after it has been relocated
by more than 100 miles since it was last used) setting up the present
position (to within 50 miles or so) and ensuring that UTC and Date are
correct (to within a few minutes) will considerably speed up the TTFF
(time to first fix). It is not absolutely necessary to do this, since given
time, the receiver is quite capable of working out its own position.
Rev 1 Mar/2000
KMD 150 Pilot's Guide