Canadian Coast Guard
www.ccg-gcc.gc.ca
Common menu bar links
Differential Global Positioning System (DGPS)
GPS / DGPS Made Easy
Practical application
- Initialization
- Satellite Status
- Position
- Map
- Navigation Page
- Menu
- Waypoint
- Go To
- Backtrack or Traceback Navigation
- Man Overboard
- Routes
- So remember...
* In this practical application portion, only the basic functions are covered. For more detailed functions please refer to your user's manual.
** Please note that the snap-shots were taken from the GPS screens of one model. The information found on other models might be displayed differently but the information remains the same.
When a GPS receiver is turned on, it searches, acquires and tracks the coded satellite signals and computes a position fix, all automatically.
A new receiver right out of the box will have a completely clear memory; it won't know what time it is, what its position is or where any of the GPS satellites are.
Initialization
Before you start doing anything you must first initialize your receiver. There are various ways of doing this, so please refer to your user's manual.
When the unit is turned on it will immediately start searching for coded satellite signals. It will ask you for intialization information such as an approximate position by selecting a country and/or province from the internal list.
Don't forget also to enter the "time" for the area of operation and for Standard and Daylight Savings Time.
One more thing to keep in mind...
If your receiver has traveled more than 500 miles from where it was last powered up, a re-initialization is required.
Satellite Status
The satellite status provides you with a visual reference of satellite acquisition, signal strength and position.
Position
Once you've acquired sufficient signals, the position page will show up. This shows you where you are, what direction you're heading and how fast you're going, and it's particularly helpful when you do not have an active destination selected.
Map
The map displays allows you to view your position and provides a real time graphic "bread-crumb" display of the path you have traveled over and nearby waypoints that you have entered (see waypoint screen).
Navigation Page
(Compass or Highway)
When going to a waypoint, the navigation page provides graphic steering guidance.
The highway page provides the same information as the compass page.
Menu
This provides access to additional pages (sub-menus) that are used to select and customize operation and navigation setup (access to the waypoint management, route, track log and setup features).
Waypoint
Waypoints serve as electronic markers that let you keep track of starting points, destinations, navaids and other important positions (e.g. good fishing spot). A waypoint position can be entered by taking an instant electronic fix or by manually entering a coordinate or range and bearing in reference to an existing waypoint.
Go To
A Go To is nothing more than the receiver providing a pointer and drawing a straight-line course from your present position to the destination you've selected.
Backtrack or Traceback Navigation
The backtrack or traceback function allows you to quickly and easily retrace your path.
Man Overboard
The man overboard function (MOB) lets you simultaneously mark and set a course to a position for quick response to passing positions (like the spot where your hat blew overboard)
Routes
The route navigation lets you plan and navigate a course from one place to another using a set of pre-defined waypoints.
So remember...
- Setup the Chart Datum correctly and check when changing charts
- Always check your course to "go to" on the chart
SOME COMMON SENSE...
- Read your GPS receiver manual. Most manuals have a good description of the GPS/DGPS system, as well as how to enter waypoints and routes.
- GPS is a tool. Add it to your toolbox of navigation techniques, but remember:
-
It only tells you where you are, and the range and bearing to where you told it you want to go. You've still got to plan the route.
- Due to the risk of collision with the aid, or grounding on the danger the aid is marking, mariners are cautioned not to use an aid to navigation as a waypoint.
