POSITION DISPLAY - FULL DATA MODE
The
position display shows GRI in use,
water
depth (DEPTH), TO's for
all stations in the chain, station status, SNR:
for each station, present
position (in latitude/longitude), automatic or manual mode indicator, pri-
mary
or alternate solution indicator, and fix quality.
tri2: 22222. LOCKED 99
W: 14598.83 LOCKED 95
X:31883.31 LOCKED 79
Brc.fl:
45360.95 LOCKED 99
REE.H: 60866.12 LOCKED 99
I!
I1IiE MODE
SOUl
FIX QUALITY IMmJu1 (9 )
MESSAGE BOX
The GRI in use
and the water
depth
show at the
top
of the screen.
Immediately beneath these is the station data box. The TD (time
difference) for each station shows to the right
of the station's letter. The
stations in use by the bran to calculate the latitude/longitude have a
black box around their
letter. In the example above, the Z-9500 is using
stations M, V, and Z to calculate the
present position. The letters "REC"
to the left of
the station letters show which stations the Z-9500 recom-
mends to use. To the
right of the TD's the
station status shows. This
will be one of five messages: BLINK, SEARCHING, LOW SNR, CYC
ERR,
or LOCKED. Blink is a
message from the station
warning that it is
not usable at this time. Searching means the loran is
trying
to find the
station's
signal. Low SNR means the
signal-to-noise ratio is low. (See
below.) Cyc Err is short for Cycle Error. It means the bran has not
locked onto the correct third
cycle crossing
of the
signal. Locked means
the
unit has locked on to the thrid cycle crossing
and is a usable station.
Navigate only with stations
showing a "LOCKED" message! To the
right of the station
message is the
SNR display. This shows the
signal-
to-noise ratio or
SNR. The lalDer
the
number, the better. The range is
0 to 99. Beneath the station box is the present position display in
latitude/longitude. To the
right of the
position display are the automatic/
manual mode, primary/alternate solution, and fix quality indicators. If
the unit is in the automatic mode, the letters AUTO
appear. If the letters
"MAN" appear, then it's in the manual mode. The primary/alternate
solution
display is similar, If the unit is in the
primary mode,
the letters
A mathematical formula
in
the
loran receiver uses TD's to determine the
latitude/longitude position. Due to the nature of loran, your position in
latitude/longitude can be on either side of a baseline. (The baseline is
an imaginary straight tine connecting the master and each secondary
station.) It's possible for the loran to lock onto the stations, give good fix
qualities and signal strengths, but show the latitude/longitude on the
other side of the baseline from your present position. These two
posi-
tions (your present position and the one on the other side of the
baseline) are
called the primary and alternate solutions. They're usually
far apart, making it easy
to tell if the loran is displaying a position
far
from your actual location. However, if
you're close to the
baseline, the
difference between the alternate and primary solution could be only a
few
miles, or less. For this reason alone, its always important
to know
your approximate position
when initializing or
using
a loran.
To switch from the primary to the alternate solution, first press the
MENU key. Next, press the key adjacent to the "CHANGE SETUP"
label. Now
press
the key
adjacent to the
"Primary
Sol. OFF" label. The
Z-9500 returns to a loran screen after this selection. If you're using a
screen with
the
latitude/longitude displayed, the
lat/long will flash until a
new position displays. If the unit doesn't show the proper tatitude/
longitude position, you may have to change stations, then try switching
the
primary
and alternate solutions.
• The solution
currently
in use by
the Z-9500 is displayed at the
top
of the
position
screen. See the "Position Screen" section for more information.
Check
your position against the loran after it displays a new latitude/
longitude. They should be the same. To switch back from the alternate
to the
primary solution, repeat the above
steps. The
only difference is
the label now reads "Primary Sol. ON".
70 67
PDF compression, OCR, web-optimization with CVISION's PdfCompressor