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Eng ID Term Definition
2441
index mirror
The MIRROR attached to the INDEX ARM of a MARINE SEXTANT. Also called index glass.
2442
index of refraction
See REFRACTION: INDEX OF.
2443
index shade
On a SEXTANT, one of the pivoting colou­red glasses which can be swung before the INDEX MIRROR for reducing the glare of the SUN.
2444
Indian spring low water
An arbitrary TIDAL DATUM approximating the LEVEL of the mean of the LOWER LOW WATER at SPRING TIDES. It was first used in waters surrounding... more
An arbitrary TIDAL DATUM approximating the LEVEL of the mean of the LOWER LOW WATER at SPRING TIDES. It was first used in waters surrounding India. Also called Indian tide plane.
2445
Indian tide plane
See INDIAN SPRING LOW WATER.
2446
indicator
That part of electronic equipment in which the DATA obtained by the RECEIVER is presented for visual OBSERVATION. This is usually in the for... more
That part of electronic equipment in which the DATA obtained by the RECEIVER is presented for visual OBSERVATION. This is usually in the form of a SCOPE or DIAL.
2447
indirect levelling
See LEVELLING.
2448
indirect wave
See WAVE.
2449
induced magnetism
See MAGNETISM.
2450
inequality
A systematic departure from the mean value of a quantity. See ANNUAL INEQUALITY, DIURNAL INE­QUALITY, LUNAR INEQUALITY, PARALLAX INEQUALITY,... more
A systematic departure from the mean value of a quantity. See ANNUAL INEQUALITY, DIURNAL INE­QUALITY, LUNAR INEQUALITY, PARALLAX INEQUALITY, PHASE INEQUALITY.
2451
inertia: gyroscopic
See GYROSCOPIC INERTIA.
2452
inertial navigation
See NAVIGATION.
2453
inferior conjunction
See CONJUNCTION.
2454
inferior mirage
See MIRAGE.
2455
inferior planet (s)
See PLANET (S): INFERIOR.
2456
inferior transit
See MERIDIAN TRANSIT.
2457
infrared
(adj.). Having a FREQUENCY immediately beyond the red end of the visible SPECTRUM said of RAYS of longer WAVE LENGTH than visible light, but... more
(adj.). Having a FREQUENCY immediately beyond the red end of the visible SPECTRUM said of RAYS of longer WAVE LENGTH than visible light, but shorter than RADIO WAVES.
2458
infrasonic
(adj.). Having a FREQUENCY below the audible RANGE.
2459
ingoing stream
See FLOOD STREAM.
2460
initial great circle course
See COURSE: GREAT CIRCLE.