What is course over ground?

Course Over Ground (COG) – Actual Compass direction that the boat is moving over the surface of the earth.

What does course of ground mean?

Course Over Ground is the actual direction of progress of a vessel, between two points, with respect to the surface of the earth. The vessel's Heading may differ from the Course over ground due to the effects of wind, Tide and currents.

What is the difference between course over ground and heading?

Course Over Ground (COG) is the actual direction of motion (the intended direction of travel). While heading is the direction in which a vehicle/vessel is pointing at any given moment (https://www.applanix.com/news/blog-course-heading-bearing/).

What is GPS course over ground?

With a modern GPS and chart plotter, reading a Course Over Ground (COG) number tells you what the COG is. As the name suggests, it's the direction the boat is traveling over the bottom, including any side slipping, current and drifting. It can differ from your compass heading, and it's important to know why.

What is SOG and COG?

SOG = Speed over Ground - includes current forecast. COG = Course over Ground to the next waypoint.

Course Over Ground

How is SOG measured?

To get SOG we measure from the origin to the arced line where it crosses the ground track. Students get confused with working out the SOG on course to steer plots but is really quite simple.

What is AIS DB?

The AIS database is a PostgreSQL/PostGIS database that contains Automatic Identification System (AIS) data from the east coast of the U.S. for November 2008 to the present.

What does speed over ground mean?

Speed Over the Ground (SOG) is the speed of the vessel relative to the surface of the earth. Speed Through Water (STW) is the speed of the vessel relative to the water. It is possible for the STW to be zero while the SOG is 5 knots, for example if the boat was drifting in a 5 knot current.

What is the difference between bearing and course?

Bearing is the angle between any two points, whereas course is your intended path of travel to your destination.

What does SOG stand for in boating?

SOG. Speed Over Ground. This differs from boat speed- so for example if your boat is stationary in the water, it may still be moving in relation to the land due to current and wind etc.

What is a nautical course?

Nautical Science is a three years course that results in an undergraduate degree or diploma after which the student joins a ship as a trainee cadet officer (commonly referred to as a deck cadet).

What is difference between bearing and heading?

Heading is the direction the aircraft is pointing. The aircraft may be drifting a little or a lot due to a crosswind. Bearing is the angle in degrees (clockwise) between North and the direction to the destination or nav aid.

What is true course in aviation?

True Course: The aircraft's course over the ground relative to true north. True course is measured with a navigation plotter and a sectional map. True Heading: True course corrected for wind.

What is the course of a ship?

In navigation, the course of a watercraft or aircraft is the cardinal direction in which the craft is to be steered. The course is to be distinguished from the heading, which is the compass direction in which the craft's bow or nose is pointed.

What is a course line?

[′kȯrs ‚līn] (navigation) A line of position plotted on a chart, parallel or substantially parallel to the intended course of a craft, showing whether the craft is to the right or the left of its course.

What is the difference between course and track?

"A track is a line on a chart or across the terrain that an airplane is following or intending to follow. It is a vector, which means it is given as a starting point and a heading. A course is a line between two points on earth. Usually given by stating the names of the starting and ending points."

What is compass course?

Definition of compass course

: the course with respect to true north in which a ship or an aircraft is intended to travel.

Is north 0 or 360?

A magnetic compass points towards the [magnetic] North Pole, because of the way the Earth's magnetic field is oriented, which makes it very convenient to use north as a starting point when it comes to compass directions. North is the starting point, and is equal to 0 (or 360) degrees.

What is the difference between speed and speed over ground?

The vessel's speed is either measured with respect to water or ground. Speed over Ground (SOG) is the speed of the vessel in one hour with respect to the land or any other fixed object such as buoys.

What is STW in radar?

Speed through the water (STW) is the speed of the vessel referenced to the water in which it is navigating. In general, STW is used for radar collision avoidance to provide a more accurate indication of the target's aspect and SOG is used for navigation.

What is speed over ground and speed over water?

Speed over ground is the speed of the ship with respect to the ground or any other fixed object such as fixed buoy or island. Speed through water is the speed of the ship with respect to the water such as anything floating on water.

What is the range of AIS?

The AIS signals have a horizontal range of about 40 nautical miles (74 km), meaning that AIS traffic information is only available around coastal zones or in a ship-to-ship zone.

Why do ships turn off AIS?

A ship's crew may turn off its AIS broadcast for a variety of legitimate reasons, but this behavior may indicate that a vessel is hiding its location and identity to conceal illegal activities like fishing in no-take protected areas or entering another country's waters without authorization.

How many types of AIS are there?

Types of AIS equipment.

For a shipboard fitting there are three types of AIS equipment, Class A, Class B and receive only. Class A is intended for vessels where the fit is mandatory. Class A transmits more information, more frequently and at higher power than Class B.