English

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.