The Watson Forward Looking Sonar (WFLS) System was developed to fulfill the market need to collect extremely high quality sonar imagery and precision depth data over the ice. An automated rotating platform tripod assembly with heading and tilt sensor mechanisms allow for the acquisition of high quality sonar imagery, as well as precise depth data using interferometric techniques. The WFLS sonar imagery and bathymetry data is acquired simultaneously .
The WFLS System
(Patent #5173882) was designed to collect data in harsh Arctic marine environments. This requirement led to the development of instrumentation that can withstand these conditions and can be operated in a straight forward manner by taking advantage of the sonars platform stability. The Watson Company Inc. technical approach required the design of a aluminum tripod structure as the main component of the system, so that the sonar array orientation and stability could be established.
For WFLS System orientation a precision heading sensor and an optical level is used for the exact orientation of the sonar transducers. To index the WFLS System to a given bearing, the visual level is sighted at a survey monument. A compass rose with 360 increments for individual degrees in a circle, is located on the tripod table. The compass rose can be manually adjusted, and is used to ground truth the output of the heading sensor.
For practical operation the range scale of the sonar is variable from 25 meters to 200 meters. The rotation rate is slowed for distant ranges, and sped up for close range data acquisition.
Data products generated from WFLS include electronic sonar mosaics shown to the left. Ice gouges are apparent in the mosaic shown to the left.