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Eng ID Term Definition
2341
hydrographic chart
See CHART: NAUTICAL.
2342
hydrographic circle
See CIRCLE.
2343
hydrographic data acquisition
All on-site measure­ments to collect hydrographic data.
2344
hydrographic data processing system
A system for verification, selection, and calculation of hydrogra­phic survey data.
2345
hydrographic datum
See DATUM: CHART.
2346
hydrographic sextant
See SEXTANT: SOUNDING.
2347
hydrographic signal
See SIGNAL.
2348
hydrographic survey
See SURVEY.
2349
hydrographic survey examination
Review of a hydrogra­phic survey that is directed toward evaluating compliance with, and the adequacy of, standards, rather than a careful e... more
Review of a hydrogra­phic survey that is directed toward evaluating compliance with, and the adequacy of, standards, rather than a careful examination of the data and their quality. The survey is carefully examined for adequacy with respect to data acquisition and confor­mance with applicable standards and project in­structions. In addition, the overall condition of the records and the Descriptive Report are examined. The digital data representing the survey is plotted and subjected to a cursory examination (spot check) to ensure that digi­tal data standards are being adhered to. The examina­ti­on of the survey data is limited only to that necessa­ry to evaluate the acquisition and processing procedu­res.
2350
hydrographic survey sheet
An inclusive term used to designate both BOAT SHEETS and SMOOTH SHEETS. Also called survey sheet.
2351
hydrography
Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of oceans, seas, coa... more
Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of oceans, seas, coastal areas, lakes and rivers, as well as with the prediction of their change over time, for the primary purpose of safety of navigation and in support of all other marine activities, including economic development, security and defence, scientific research, and environmental protection.
2352
hydrologic front
A relatively narrow transition zone separating two water masses in the ocean.
2353
hydrologic series
Simultaneous observations carried out to obtain oceanographic data at specified levels.
2354
hydrology
The scientific study of the waters of the EARTH, especially with relation to the effects of PRECIPITATION and evaporation upon the occur­ren... more
The scientific study of the waters of the EARTH, especially with relation to the effects of PRECIPITATION and evaporation upon the occur­rence and character of water in STREAMS, LAKES, and on or below the land surfaces.
2355
hydrometeor
METEOR consisting of an ensemble of liquid or solid water particles falling through or suspended in the ATMOSPHERE, blown by the WIND from t... more
METEOR consisting of an ensemble of liquid or solid water particles falling through or suspended in the ATMOSPHERE, blown by the WIND from the EARTH'S surface or de­po­sited on objects on the ground or in the free air.
2356
hydrometer
An instrument for determining the SPECIFIC GRAVITY of liquids.
2357
hydrophone
An electroacous­tic TRANSDUCER that re­sponds to water-borne SOUND WAVES and delivers essenti­ally equivalent electric WAVES. See also PRESS... more
An electroacous­tic TRANSDUCER that re­sponds to water-borne SOUND WAVES and delivers essenti­ally equivalent electric WAVES. See also PRESSURE HYDROPHONE.
2358
hydrophone streamer
A chain of separate receivers for seismic sound sources towed by a ship. The streamer contains many individual hydrophone elements and is di... more
A chain of separate receivers for seismic sound sources towed by a ship. The streamer contains many individual hydrophone elements and is divided electronically into a number of discrete sections or channels.
2359
hydrophotometer
An instru­ment used to measure the EXTINCTION COEFFICIENT of transmission of light in water. It consists of a constant light source placed a... more
An instru­ment used to measure the EXTINCTION COEFFICIENT of transmission of light in water. It consists of a constant light source placed at a specific distance from a photocell. When placed in water, the electrical OUTPUT of the photocell is proportional to the amount of light striking the cell which, in turn, depends upon the transparency of the water. The instrument is calibrated to read 100 per­cent light transmission in air.
2360
hydroplastic corer
See CORER.