How lowrance gps works – Lowrance electronic 540c Baja User Manual

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NOTE:

The above memory capacities refer only to the GlobalMap's on-board

memory. The amount of GPS data you can record and save for recall

later is limited only by the number of MMC cards you have.

How Lowrance GPS Works

You'll navigate faster and easier if you understand how the GlobalMap

540c BAJA scans the sky to tell you where you are and where you're

going. (But if you already have a working understanding of GPS receiv-
ers and the GPS navigation system, skip to Section 2, Installation &
Accessories on page 11. If you're new to GPS, read on, and you can later

impress your friends with your new-found knowledge.)
First, think of your unit as a small but powerful computer. (But don't

worry — we made it easy to use, so you don't need to be a computer ex-

pert to find your way!) The GlobalMap 540c BAJA includes a keypad

and a screen with menus so you can tell it what to do. The screen also

lets the unit show your location on a moving map, as well as point the

way to your destination.
This gimbal-mounted GlobalMap 540c uses a LGC-BAJA module,

which makes the whole system work something like your car radio. But

instead of your favorite dance tunes, this receiver tunes in to a couple

of dozen GPS satellites circling the earth. (It will also listen in to the

WAAS satellites in orbit, but more about that in the upcoming segment

introducing you to GPS and WAAS.)
Your unit listens to signals from as many satellites as it can see above

the horizon, eliminates the weakest signals, then computes its location

in relation to those satellites. Once the GlobalMap 540c figures its lati-

tude and longitude, it plots that position on the moving map shown on

the screen. The whole process takes place several times a second!
The performance doesn't stop there. Stored in the permanent memory
of each unit is a basic background map of the entire world. We lock it in

here at the factory — you can't change or erase this map.
The background map is suitable for many navigation chores, but for

maximum accuracy and much more detail, you need our optional map-
making software, MapCreate

™ 6. Some unit features — such as search-

ing for businesses and addresses — won't work without a custom Map-

Create map. There is so much detail in our background map (and even

more in MapCreate) that we'll describe their contents and differences
in Section 3, Basic GPS Operations, on page 36.
Another portion of your GlobalMap’s onboard memory is devoted to re-
cording GPS navigation information, which includes waypoints, event