Channel Master CM-6001 Specifikace stáhnout pdf (Strana 133)

Channel Master Operation Manual

P/N 95B-6001-00 (January 2005) page 127

common for bottom tracking measurements to lock onto a sediment layer

that is still moving, resulting in a bias to the bottom tracking velocity. This

is especially important for river discharge measurements, where the vessel’s

navigation must be substituted for the bottom track velocity to obtain accu-

rate results.

------ N ------

Navigator: Model name for the RDI Doppler Velocity Log.

Narrowband ADCP: An ADCP that uses narrowband processing.

Narrowband Processing: Uses a single pulse per ping to measure velocity.

The lack of coding in the pulse makes a narrowband measurement much

less precise, but it allows profiling over a longer range. Narrowband proc-

essing generally requires much larger ensembles to get a precise measure-

ment.

------ O ------

Ocean Observer: Low frequency Phased Array ADCP for cabled deploy-

ment, usually from an oilrig.

Ocean Surveyor: Low frequency Phased Array ADCP for vessel-mounted

operations.

------ P ------

Percent Good: A key quality control parameter, percent good indicates

what fraction of the pings passed the various error thresholds. Each depth

cell reports four values for percent good, and the meaning depends on the

coordinate frame. If data is collected in beam coordinates, then the

four percent good values represent the percentage of the pings collected by

each beam for that depth cell whose correlation exceeded a low correla-

tion threshold. In the other coordinate frames (ADCP, Ship and Earth

Coordinates), the four Percent Good values represent (in order): 1) The per-

centage of good three beam solutions (one beam rejected); 2) The percent-

age of good transformations (error velocity threshold not exceeded); 3) The

percentage of measurements where more than one beam was bad; and 4)

The percentage of measurements with four beam solutions.

Phase: An engineering measure of the propagation delay caused by radial

motion between scatterer and source. Phase is ambiguous in that it is cycli-

cal (e.g. 10 º is the same phase as 370 º).

Phased Array Transducer: A single, flat, multi-element transducer that

uses an RDI proprietary technique to simultaneously form all four beams.

Available phased array transducers are generally low frequency (38 kHz, 75

kHz and 150 kHz) long range devices.

1 2 ... 128 129 130 131 132 133 134 135 136 137 138

Žádné komentáře

Channel Master CM-6001 Specifikace Strana 133