DGPS Antenna & Receiver
This device functions as a positioning and heading sensors. As a positioning device, it can obtain frequency differential positioning system or ultra-high differential positioning system capable of maintaining a minimum of +/-1.0 meter accuracy. With the use of Satellite constellations set at desired height, the device is built to give an update rate for the differential signal not to exceed 12 seconds during the survey operation.
The TSS SG Brown Gyro Compass unit utilizes a DTG gyro element which provides exceptional performance with accuracy unmatched by even the latest fibre optic designs. Unlike conventional spinning mass gyrocompasses, the TSS digital marine gyrocompass Meridian Surveyor uses a dry tuned element (DTG) that removes the need for routine maintenance. The remarkably stable heading can be maintained for turn rates in excess of 200º per second.
The Odom MKIII Echotrac sounder is a dual frequency system, with over-the side mounted transducers operating at 33 kHz and 210kH. Digital technology is employed so that the equipment comprises one unit incorporating an analogue/ digital recorder, transceiver electronics and digitizer, together with a hull mounted transducer assembly and cabling.
A monitoring sensor to record the pitch, roll and heave of the survey vessel. A lever arm can be entered into the software to take into account the movement at a remote monitoring point. The TSS DMS-25 Motion Sensor is a microprocessor-based system for independent measurement of the Vertical motion and real time correction of echo sounder data. Vertical motion of the survey vessel is determined and compensated for by applying an inertial method. An accelerometer, with its axis vertically stabilized by a horizontal gyro compass, measures the vertical acceleration resulting from heave.
Side Scan Sonar System
This sensor uses acoustic pulses it emits to create the model of the seabed in two-dimensions (2-D) per time while acquiring data. The processed data can however be enhanced to acquire 3-D attribute information.
This is a digital device which is unaffected by vessel noise and offer high resolutions. Caesium vapour is used in a magnetic resonance system. This system operates as the frequency controller of an oscillator. The oscillator frequency varies directly with the external magnetic field at the sensor location. The frequency can then be measured with great accuracy, giving precise measurements of the magnetic field.
Sub bottom Profiler
This is used to detect the buried pipes and cable, including fibers of any kind. DST Parametric Sub bottom profiler or EdgeTech 216S is used for the seabed profiling. The system consists of Seaking sensor head which is designed as a side mounted transducer and Seanet control and display software. The DST Parametric SBP head is essentially a 200 kHz echo sounder which uses a complex transmit pulse pattern to generate a low frequency secondary, which is normally around 20 KHz while essentially retaining the 4-degree beam pattern of the high frequency signal.
Gravity Corer is a simple and reliable instrument for collecting sediment cores from coastal and deepwater sites for sample analysis. The corer uses the pull of gravity to penetrate the seabed with it’s carbon steel core barrel, which can collect samples of up to six metres in length.
During seabed profiling, a side-scanning sonar is mounted to a vessel, scanning a fan-shaped swath either side of the vessel. A downward-looking acoustic altimeter acts as a nadir gap filler and is integrated within the overall acquisition system. The acoustic transducers, pitch/roll sensor, GPS and True Heading reference mounted onto a single rigid instrument frame which is itself is mounted to the hull of the vessel in such a way that it can safely be stowed for transit shall be deployed into a vertical position for data acquisition. Soundings would be georeferenced to known horizontal and vertical datum using RTK-corrected dual-GPS which also provided a True heading reference. Errors in soundings due to vessel roll and pitch shall be mitigated using a specialized motion reference unit (MRU).
To obtain a pertinent geotechnical data for drilling location, a Jack up rig would be placed with conductor supported platform to be located at the coordinates to be given.
Cone Penetrometer Test
Pie zone Cone Penetrometer Test during Geotechnical Survey