The number of cycles per second between the limits of a frequency band.

Same as marine rainbow.

A radar which is used to obtain the azimuth elevation, and slant range of an airborne target.

Same as contact anemometer.

In general, any self-recording instrument carried aloft by any means to obtain meteorological data.

The time required for an instrument to register a designated percentage (frequently 90%) of a step change in the variable being measured.

A sunshine recorder of the type in which the time scale is supplied by a chronograph. It consists of two bulbs, one of which is blackened, which communicate through a glass tube of small diameter. The tube is partially filled with mercury and contains two ...

A graphical aid used in the reduction of data from a winds aloft observation.

Precipitation of white, opaque, spherical or conical ice particles that are crisp and easily crushed and that have diameters of 2 to 5 mm.

Precipitation of very small, white opaque particles of ice, fairly flat or elongated, with diameters less than 1 mm. The solid equivalent of drizzle.

A device which automatically records the water equivalent of snow on a given surface as a function of time. A small sample of a radioactive salt is placed in the ground in a shielded collimator which directs a beam of radioactive particles upwards. A Geig ...

A flower-like diagram indicating the relative frequencies of different wind directions for a given station and period of time.

A forecast of the expected stage or discharge at a specified time, or of the total volume of flow within a specified Interval of time, at one or more points along a stream.

A thermometer. the sensitive element of which consists of two metal strips which have different coefficients of expansion and are brazed together. The distortions of the system in response to temperature variations are used as a measure of temperature. It ...

The element directly responsive to the value of the measured variable.

An instrument for measuring the relative speed of a fluid. It consists of a concentric pipe arrangement in which the inner pipe is open at one end and the outer pipe is perforated and closed at both ends. Each pipe is connected to a manometer. The unit is ...

A numbering system using a base number of 16 and including the ten decimal digits (0 to 9) along with six alpha digits (A to F). Thus. a digit is available to represent each of the possible values of a 4-bit binary digit.

A weakly colored lunar halo identical in form and optical origin to the solar parhelion.

The total infrared radiation emitted from the earth's surface. To be carefully distinguished from atmospheric radiation, effective terrestrial radiation, and insolation.

The volume of water required to cover one acre to a depth of one foot: 43,560 cubic feet.