designed to measure the time of transit or difference in transit times of electromagnetic waves in the atmosphere.

EPS requires a relay unit on shore which must be equipped with a ____, ______ and an _____.

EPS is a typical system consists essentially of transmitting on a ______ ______, an ______ ______from the ship to the three triangulation stations of known position

The accuracy of any measurement by an electronic positioning system is highly dependent upon the ______, _______, and ______ at the time the measurement is made

Classification of Electric Positioning System

originally developed for blind bombing by military aircraft and aerial photographic reconnaissance.

widely used now often in most offshore measurements and in establishing triangulation stations for horizontal control networks.

SHORAN was often used for ___ ___ in military

SHORAN was usually employed when ____________________ is required even under adverse weather conditions.

SHORAN operates on ___ frequency

range of SHORAN

With Shoran, distances can be determined to __ or even __ of a kilometer

principle employed is similar to Shoran

Principle employed is similar to Shoran except the use and transmission of _____

Loran follows the ____ better than low-frequency waves

What does EPI means?

combines some of the principles and techniques used in long-range and short-range navigation.

Who developed the Electronic Positioning Indicator?

Distance of Electronic Positioning Indicator

used to determine the position of survey vessel

What does RAR stands for?

Advantage of RAR

Method of measuring the depth of water

Instrument used for determining the depth of water by echo-sounding by which has an indicator scale which is graduated to read depths directly instead of time

Instrument used for determining the depth of water by echo-sounding by which has an indicator scale which is graduated to read ____ directly instead of time

Fathometer display the depth visually in _______ form and others produce an _________ or _______ in a roll of specially prepared paper.

Fathometer is designed to

Types of Echo Sounders

mounted on a small boat or suspended over the side.

Portable Fathometers are operated by _______ and can be easily shifted from one boat to another

up to how many depths can be read in a portable fathometer

considered part of the navigation equipment of the or survey sounding vessel

Non portable fathomeresigned to measure sounding to depths of _______ to an accuracy of about ________.

Graphic recording and draw continuous profiles of the sea-bed on a moving strip of paper

For echo sounding, the medium is the ____ and the reflecting surface is the _______

recently copied by echo sounders to provide an intermediate printout of sounding depths and their related positions.

developed to allow interpolation between plotted depths and plotters are utilized to draw the depth (bathymetric) contours automatically just as in automated plotting for topographic surveys

employs lasers, offers high accuracies but is applicable only to depths less than 50m.

Soon expected to replace conventional hydrographic survey methods performed on board sounding vessels.

a pulse-type laser is used to emit a burst of light which is reflected at the water surface and at the bottom of the body of water.

Systems are based on the principle that less energy is returned from deep waters than from shallow waters, calibration of such a system is done by comparing returned energy with known water depths.

Allow remote measurements of water depths.

an aerial camera is used to photograph the water areas using standard techniques of photogrammetry.

New Developments in Electronic Sounding Equipments

First Landsat Satellite was launched by _______ and when?

the spacecraft was equipped with a multispectral scanner which had the capability to view a 185-km wide strip of the Earth’s surface on an 18-day repetitive cycle.

First Landsat Satellites Altitude: Weight: Interval of Circling the Earth: Wide Strip:

In ____ , it was decided to rename ERTS to ____

Landsat emits four bands of the spectrum

unit used in remote sensing to express the wavelength of an electromagnetic spectrum.

water is quite transparent in this band and it tends to enhance features such as sediment with water.

Wavelength range of green band

Penetrates the atmosphere and is suitable for landuse studies.

Wavelength range of red band