Dualbeam Plus Tm Sonar; How Gps And Cartography Work - Humminbird 363 Operation Manual

531448-1_A - 363_Man_Eng.qxd 11/9/2005

How GPS and Cartography Work

Your 300 Series TM Fishing System also supports GPS and chartplotting, and uses GPS and
sonar to determine your position, display it on a grid, and provide detailed underwater
information. The Global Positioning System (GPS) is a satellite navigation system
designed and maintained by the U.S. Department of Defense. GPS was originally
intended for military use; however, civilians may also take advantage of its highly
accurate position capabilities, typically within +/- 10 meters, depending on conditions.
This means that 95% of the time, the GPS receiver will read a location within 10 meters
of your actual position. Your GPS Receiver also uses information from WAAS (the Wide
Area Augmentation System), EGNOS (the European Geostationary Navigation Overlay
Service), and MSAS (the MTSAT Satellite Augmentation System) satellites if they are
available in your area.
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DualBeam PLUS TM Sonar
Your 300 Series TM Fishing System uses a 200/83
kHz DualBeam PLUS TM sonar system with a
wide (60°) area of coverage. DualBeam PLUS TM
sonar has a narrowly focused 20° center beam,
surrounded by a second beam of 60°,
expanding your coverage to an area equal to
your depth. In 20 feet of water, the wider
beam covers an area 20 feet wide. The 20°
center beam is focused on the bottom, to show
you structure, weeds and cover. The 60° wide
beam is hunting for fish in the wide coverage
area. DualBeam PLUS TM sonar returns can be
blended together, viewed separately or
compared side-by-side. DualBeam PLUS TM is
ideal for a wide range of conditions - from
shallow to very deep water in both fresh and
salt water. Depth capability is affected by such
factors as boat speed, wave action, bottom
hardness, water conditions and transducer
installation.
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GPS uses a constellation of 24 satellites that continually
send radio signals to the earth. Your present position is
determined by receiving signals from up to 16 satellites
and measuring the distance from the satellites.
All satellites broadcast a uniquely coded signal once per
second at exactly the same time. The GPS receiver on
your boat receives signals from satellites that are visible
to it. Based on time differences between each received
signal, the GPS receiver determines its distance to each
satellite. With distances known, the GPS receiver
mathematically triangulates its own position. With
once per second updates, the GPS receiver then
calculates its velocity and bearing.
The GPS Receiver included with your 300 Series
combine easy-to-use FishingGPS TM chartplotter and navigation capabilities with
advanced fishfinding. The following GPS functionality is currently supported by the
TM
300 Series Fishing System:
• View current position
• View current track (breadcrumb trail)
• View precision speed and heading from your GPS receiver
• Save tracks, waypoints and routes
• Travel a route and navigate from one waypoint to the next.
Your unit also comes with a built-in Uni-Map
America (Domestic models) or a more detailed map of Europe and Southeast Asia,
including Australia and New Zealand (International models).
Your 300 Series TM uses the GPS Receiver to determine the position of the boat
automatically, and uses the zoom level settings on a particular view to select the best
chart to display. See Viewing Cartography for more information.
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TM Fishing System, allows you to
TM with a more detailed map of North