Cruise inventory

RRS Discovery D46_leg1

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD46_leg1
Cruise period1972-04-27 — 1972-04-29
Port of departureBarry, United Kingdom
Port of returnBarry, United Kingdom
ObjectivesLeg 1 of 3 of D46

1) An assesment of the telesounder. This is a side-scan sonar with many loads produced by an interferometer arrangement, and is intended as a tool to allow the bathymetric survey of a swathe of sea bed 400 to 500m wide in shallow water. The device used on this cruise was an experimental 'lash-up' to allow an investigation of the potentialities and problems.
2) Observations were made with a 36 kHz Side-scan sonar on the sea bed.
3) Set up of the new software system for the shipbourne computer
Chief scientistM J Tucker (National Institute of Oceanography)
Cruise reportRRS Discovery D46_leg1 cruise report d46.pdf — access key 'C' (0.99 MB) 
Ocean/sea areas 
GeneralBristol Channel
SpecificHorshoe Rocks
Track chartsRRS Discovery D46_leg1 cruise track — d46track.pdf (0.01 MB)  RRS Discovery D46_leg1 cruise track — d46track_leg1.pdf (0.02 MB) 
Occasional standard measurements
Geology and geophysics 
Multi-beam echosoundingQuantity: 250
Description: Echos were obtained out to almost 250m
Long/short range side scan sonarQuantity: number of hauls = 50
Description: Records were obtained in depths down to about 50m. The signal from the telesounder was fed into the Side-scan sonar receiver, which included TGV circuits and whose bandwidth was temporarily modified to handle the shorter ().4mS) telesounder pulses. An external wide-band marking amplifier was then used to display signals on the 11" Mufax recorder and which triggered a pulse in the normal way.