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Eng ID Term Definition
3661
overfalls
Short, breaking WAVES occurring when a strong CURRENT passes over a SHOAL or other submarine OBSTRUC­TION or meets a contrary CURRENT or WIN... more
Short, breaking WAVES occurring when a strong CURRENT passes over a SHOAL or other submarine OBSTRUC­TION or meets a contrary CURRENT or WIND. See RIPS.
3662
overlap
In CARTOGRAPHY and SURVEYING, the amount by which one CHART or SURVEY SHEET extends also over an adjoining CHART or sheet. The amount by whi... more
In CARTOGRAPHY and SURVEYING, the amount by which one CHART or SURVEY SHEET extends also over an adjoining CHART or sheet. The amount by which different sets of survey data, obtained with the same system, cover the same area; customarily expressed as a percentage.
3663
overlapping pair
In PHOTOGRAMMETRY, two PHOTO­GRAPHS taken at different exposure stations in such a manner that a portion of one PHOTOGRAPH shows the same te... more
In PHOTOGRAMMETRY, two PHOTO­GRAPHS taken at different exposure stations in such a manner that a portion of one PHOTOGRAPH shows the same ter­rain as shown on a portion of the other PHOTOGRAPH. This term covers the general case and does not imply that the PHOTOGRAPHS were taken for stereoscopic exami­nation. See also STEREOSCOPIC PAIR.
3664
overlay
In mapping, a record on a transparent medium to be superimposed on another record.
3665
overlay tracing
A plotting on TRACING CLOTH at the SCALE of the smooth sheet used in conjunction with the smooth sheet. See FAIR CHART.
3666
overprint
In CARTOGRAPHY, an additional PLATE, gene­ral­ly in a distinctive colour, printed down on a MAP or CHART which is already complete in itself... more
In CARTOGRAPHY, an additional PLATE, gene­ral­ly in a distinctive colour, printed down on a MAP or CHART which is already complete in itself. Over­prints may be used to reproduce specialized informati­on (e.g., to add aeronautical information to a TOPO­GRAPHIC MAP) or to incorporate revision data without the amendment of existing PLATES.
3667
overtide
A shallow water harmonic tide constituent with a SPEED that is a multiple of the SPEED of one of the basic constituents of the TIDE-PRODUCIN... more
A shallow water harmonic tide constituent with a SPEED that is a multiple of the SPEED of one of the basic constituents of the TIDE-PRODUCING FORCE. See HARMONIC CONSTITUENT, and SHALLOW WATER CONSTITU­ENT.
3668
ozalid print
See PRINT: OZALID.
3669
pack ice
Term used in a wide sense to include any area of SEA ICE, other than FAST ICE, no matter what form it takes or how it is disposed. Pack ice ... more
Term used in a wide sense to include any area of SEA ICE, other than FAST ICE, no matter what form it takes or how it is disposed. Pack ice may be des­cribed as VERY OPEN PACK ICE (1/10ths-3/10ths), OPEN PACK ICE (4/10ths-6/10ths), CLOSE PACK ICE (7/10­ths-9/10ths), VERY CLOSE PACK ICE (almost 10/10th with little if any water visible).
3670
pair of compasses
See COMPASS.
3671
paleomagnetism
Remanent MAGNETISM produced by the EARTH's field when a material was initially formed.
3672
Pan American Institute of Geography and History (PAIGH)
Develops, coordinates, and disseminates geographical, cartographic, historical, geophysical and related scientific studies.
3673
pancake ice
Pieces of NEW ICE, usually approximately circular, about 30 cm to 3 m across, and with raised rims, due to the pieces striking against each ... more
Pieces of NEW ICE, usually approximately circular, about 30 cm to 3 m across, and with raised rims, due to the pieces striking against each other as the result of WIND and SWELL.
3674
panchromatic
(adj.). Sensitive to light of all colours, as a film or plate emulsion.
3675
panel
In cartography, the completed assembly of pieces of film positives onto a grid or projection which is used as a base for compilation. In pho... more
In cartography, the completed assembly of pieces of film positives onto a grid or projection which is used as a base for compilation. In photogrammetry, an element of a target used for control station identification on aerial photography.
3676
pantograph
An instrument for copying a CHART, dra­wing, etc., to any desired SCALE within the limits of the instrument.
3677
paper
For printing hydrographic charts, heavyweight, single layer paper is used. Such paper is generally made wholly or partly from rags and simul... more
For printing hydrographic charts, heavyweight, single layer paper is used. Such paper is generally made wholly or partly from rags and simulates hand-made paper. It is stron­g, moisture resistant and manufactured to withstand surface erasu­re.
3678
parabola
An open curve all points of which are equidi­stant from a fixed point, called the focus, and a straight line.
3679
parachute drogue
See DROGUE.
3680
parallactic angle
That angle of the ASTRONOMICAL TRIANGLE at the CELESTIAL BODY; the angle between a body's HOUR CIRCLE and its VERTICAL CIRCLE. Also called p... more
That angle of the ASTRONOMICAL TRIANGLE at the CELESTIAL BODY; the angle between a body's HOUR CIRCLE and its VERTICAL CIRCLE. Also called position angle. In PHOTOGRAMMETRY, the angle subtended by the eye of the observer at the object viewed. Also called angle of convergence or angular parallax.