SETUP
ProMARK X
3-5
The unit collects the current time (UT) from the GPS satellites when it collects
or refreshes its almanac. It is therefore unnecessary to set the date or time
if you want to operate on UT.
If you prefer, the unit can display local time on a 12-hour (AM/PM) clock or
a 24-hour local clock.
Access SETUP 3. The screen displays the current date and time on the UT
clock. Do nothing to use UT.
Press the
RIGHT ARROW
to display local time on a 12-hour clock (AM/
PM). Press
CLEAR
, then key in the current date for your time zone in
month/day/year order. (Date order is changed with SETUP 20.) Press
ENTER
.
Key in the local time (hours, minutes, seconds). Use the
RIGHT ARROW
to select AM or PM. Press
ENTER
.
OR
From the UT display, press the
RIGHT ARROW
twice to display time on
a 24-hour local clock. Enter the local date and time as described above.
SETUP 4 — Choosing a Mask Angle
. The mask angle is the angle above
the horizon below which the unit will not search for satellites. The ProMARK
X has a user-adjustable mask angle.
The default mask angle is 10
°
. The unit will not search for satellites whose
elevation is less than 10
°
and will stop tracking any satellite that sets below
that elevation.
If there are not enough visible satellites above 10
°
, you can extend the search
as low as the horizon. This feature gives the unit more flexibility, but using
the lower elevation satellites may affect the accuracy of the position fixes
computed by the unit. Errors may be induced by humidity, and tropospheric
and ionospheric conditions may also increase the possibility of errors. Always
carefully evaluate the integrity of your fixes when using low elevation
satellites before using the data.
Alternatively, you can also limit the search to 15
°
or 20
°
. Under certain
circumstances, this may prevent the unit from using the best satellite set
among the visible satellites by forcing the unit to consider only satellites with
higher elevations. Remember that the PDOP is generally better when there
is sufficient “spread” between the satellites being used for the position
solution.
Summary of Contents for GPS PROMARK X
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