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Eng ID Term Definition
4121
protractor: three arm
An instrument consisting essen­tially of a circle graduated in DEGREES, to which is attached one fixed arm and two arms pivoted at the centr... more
An instrument consisting essen­tially of a circle graduated in DEGREES, to which is attached one fixed arm and two arms pivoted at the centre and provided with clamps so that they can be set at any angle to the fixed arm, within the limits of the instrument. It is used for finding a ship's POSITION, when the angles between three fixed and known points are measured. In British terminology, a perspex (or transparent plastic) device used when the MARKS are too close for the use of a STATION POINTER. This instrument has replaced the CUST PROTRACTOR.
4122
province
In OCEANOGRAPHY and in a morphological sense, a region composed of a group of similar physiographic features whose characteris­tics are mark... more
In OCEANOGRAPHY and in a morphological sense, a region composed of a group of similar physiographic features whose characteris­tics are markedly in con­trast with surrounding areas (rarely used in marine CARTOGRAPHY).
4123
psephyte
A coarse fragmen­tal ROCK (conglomerate) or DEPOSIT composed of rounded PEBBLES.
4124
psychrometer
Instrument used to measure the humidity of the ATMOSPHERE. It comprises two identical THERMO­METERS, the bulb of one of which is dry, while ... more
Instrument used to measure the humidity of the ATMOSPHERE. It comprises two identical THERMO­METERS, the bulb of one of which is dry, while that of the other is wet and covered by a film of pure water or ICE.
4125
pseudorange
The time shift required to align (corre­la­te) a replica of the GPS code generated in the recei­ver with the received GPS code, scaled into ... more
The time shift required to align (corre­la­te) a replica of the GPS code generated in the recei­ver with the received GPS code, scaled into distance by the speed of light. This time shift is the diffe­rence between the time of signal reception (measured in the receiver time frame) and the time of emission (measured in the satellite time frame).
4126
puddle
An accumulation on the ICE of melt water, mainly due to melting SNOW, but in the more advanced stages also to the melting of ICE. Initial st... more
An accumulation on the ICE of melt water, mainly due to melting SNOW, but in the more advanced stages also to the melting of ICE. Initial stage con­sists of patches of melted SNOW.
4127
pull
An impression from an individual printing PLATE.
4128
pulsar
A rotating neutron star emitting electromagne­tic radiation in regular pulses related to its rota­tional period.
4129
pulse (or impulse)
A variation of quantity whose value is normally constant (often zero), the variation being characterized by a rise and a decay. A common exa... more
A variation of quantity whose value is normally constant (often zero), the variation being characterized by a rise and a decay. A common example is a very short burst of electromagnetic energy. See WAVE: CONTINUOUS.
4130
pulse length
The time interval during which the ampli­tude of a pulse is at or greater than a specified value, usually stated in terms of a fraction or p... more
The time interval during which the ampli­tude of a pulse is at or greater than a specified value, usually stated in terms of a fraction or per­centage of the maximum value.
4131
pulse modulation
See MODULATION.
4132
pulse radio altimeter
See ALTIMETER: RADIO.
4133
pulse repetition rate
The rate at which recurrent PULSES are transmitted, usually expressed in PULSES per SECOND.
4134
pumice
An excessively cellular, glassy LAVA. It is very light and can float on water until it becomes waterlogged and sinks.
4135
punch register system
System involving the use of prepunched holes in the flat and plate and a set of plastic pins or buttons which are used in registering succee... more
System involving the use of prepunched holes in the flat and plate and a set of plastic pins or buttons which are used in registering succeeding flats, positioning the image on the plate, and positioning the plate on the press. See also REGI­STRATION.
4136
punched (or punch) card equipment
A system whose principal feature is that numbers are recorded on cards by means of holes punched in successive columns of a card, the row of... more
A system whose principal feature is that numbers are recorded on cards by means of holes punched in successive columns of a card, the row of the card indicat­ing the digit.
4137
pycnocline
A vertical positive density GRADIENT in some LAYER of a body of water, which is appreciably greater than GRADIENTS above and below it.
4138
Q-factor
The pressure coefficient of the un­protected THERMOMETER expressed in °C.
4139
QTG station
A RADIO STATION which is prepared to provide QTG service, that is to say, to transmit upon request from a ship, a radiosignal, the BEARING o... more
A RADIO STATION which is prepared to provide QTG service, that is to say, to transmit upon request from a ship, a radiosignal, the BEARING of which can be taken by that ship.
4140
quadrant
A double-reflect­ing instrument for measuring angles. It is similar to a SEXTANT, but has an arc of 90°. Also a surveying or astronomical in... more
A double-reflect­ing instrument for measuring angles. It is similar to a SEXTANT, but has an arc of 90°. Also a surveying or astronomical instrument compo­sed of a graduated arc about 90° in length, equipped with a sighting device.