..., forward scat- tering, back scattering and irradiance are measured The system is unique in using a green HeNe laser (543 5 nm) for this application and in prowding an airborne instrument for measunng optical water quality data zn sztu This development had two main objects (1) to map variations in optical...

... in a sea bed frame, on a mooring and on a ship-are presented Only by deploying the instruments and by comparing their results with other observations will faults in the instrumentation become apparent and the necessary confidence in the technique be gained. ACOUSTIC DOPPLER CURRENT PROFILERS Good...

..., the jaw buckets possessing a leading edge that is vertical as the instrument descends Figure l(b) shows the bite profiles of these samplers produced under test tank conditions using a hard-packed fine- sand substratum (Riddle, 1984) These profiles were Smith-Mclntyre 7 0 Kg van Veen grab proflle 1 2 0 Kg...

.... Such instruments are generally used for the measurement of suspended load and are known as transmissometers. McCave (1979) describes the principles and the theore- tical basis for these techniques. In general, a light beam is directed between a source and a detector and is arranged so that sedime-nt-laden water...

...RALPHNET: An Underwater Local Area Network Dave Heffir, Geological Survey of Canada INTRODUCTION Many instruments that operate m the marine environment use microcomputers for control and data-logging. RALPH, designed to study seabed s e h e n t transport processes, is such an instrument. Although...

...PUPPZ - A tkee-fall Seabed Piezometer for Geotechnical Studies S. D. McPhazl and P J Schulthezss, Institute of Oceanographc Sciences, Wormley, near Godalrning, Surrey GU8 5UB, UK A free-fall plezometer (Pop Up Pore Pressure Instrument, PUPPI) has been developed to measure excess pore pressures m...