represent part of the sperical earth on a plane surface. it shows water depth the shoreline of adjacent land, prominent topographic features, aids to navigation, and other navigational information.

Navigators most often use the plane conformal projection

is not perspective, and its parallel can be derived mathematically as well as projected geometrically.

also known as transit

The system accuracy was better than 0.1 nautical mile anywhere in the world, through its availability was somewhat limited.

it was also used in hydrographic surveying and geodetic position determination.

The federal radionavigational plan has designed he navigational system using timing and ranging ( NAVSTAR) global positioning system ( GPS) as the primary navigational system of the US government.

is a spaced-base radio positioning system which provides suitably equipped user with highly accurate position, velocity and time data.

What are the 3 major segments

Consist of 31 GPS satellite with atleast 24 operational 95% of the time. spacing of the satellites in their orbits is arrange so that at least four satellite are in view to a user any time, anywhere on the earth, including north and south poles.

includes a master control station ( MCS ), a number of monitor stations, and ground antennas located throughout the world.

is designed to received and process signal from four or more orbiting satellites either simulataneously or sequentially.

is an earth centered, earth fixed terrestia reference and geodetic datum.

is based on a consistent set of constant and model parameters that describe the earths size, shape and gravity and geomagnetic fields.

one of the most serious impacts of different datums on navigation occurs when a navigation system provides a fix based on a datum different from that used for the nautical chart.

is a common features for mariner GPS units.

is the position of one point relative to another.

navigators express direction as the angular difference in degrees from a reference directions, usually north or the ships head

is the horizontal direction in which a vessel is intended to he steered, expressed as angular distance form north clockwise through 360.

is often designated as true, magnetic, compass, or grid according to the reference direction.

is the direction in which a vessel is pointed at any given moment, expressed as angular distance from 000* clock wise through 360*

Constantly changes as a vessel yaws back and forth acroas the course due to sea, wind, and steering error.

is the direction of one terrestrial point from another, expressed as angular distance from 000* (north) clockwise through 360*

when measured through 90* or 180* from either north and south.

are sometimes used interchangeably, but the latter more accurate referes to the horizontal directions of a point on the celestial sphere from a point in the earth.

determine distance to an object by measuring the time required for a radio signal to travel from a transmitting antenna to the object, reflect off that object, and return as a received echo.

represent part of the sperical earth on a plane surface. it shows water depth the shoreline of adjacent land, prominent topographic features, aids to navigation, and other navigational information.