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Multi beam pre-dredge monitoring survey for the Nigerian Content Development, Management Board/ Dar Construction in Brass Estuary, Nigeria..

The job involved the establishment of a primary tide reference port using a Valeport Automatic Tide Gauge system and a manual calibrated tide staff for data comparison. The project was a further investigation into the previous acquisition, putting into consideration this time FIG/IHO basic requirements as the minimum benchmark of our precision. The following equipment were deployed for the project:
*MB1 MultiBeam Echo Sounder
*TSS Motion Sensor
*Hemisphere DGPS
*CNAV DGPS
*Odom Digibar Pro S SVP
*Hypack Hysweep 
*Naviedit/Navimodel
*ArcGIS 
To achieve a quality data we did the following:
1. Proper fabrication was done and MB1 MBEs was properly installed
2. Motion sensor was symmetrically aligned to the boat azimuth to reduce Pitch/Row
3. Hemisphere heading was checked alongside boat heading
4. The CNAV antenna was logged on a known point for a few hours and the values tallied. Instrument line of sight check was done to eliminate multipath. PPS was used to eliminate latency errors.
5. Offsets were done properly to reduce human errors. MRU was used as our center of reference.
6. Patch test was done every morning before commencement of the survey as the equipment was dismounted after work each day.
It was an adventurous sojourn with multiple challenges that were mitigated.