Sidescan sonar and towed camera: A combined system of low-cost mapping for shallow water

The combination of two devices of cost effective, sidescan sonar and towed camera was used for mapping of benthic habitat. The application of this system in shallow water allowed the recognition of habitat more detailed and validated the acoustic images through the videos, establishing a ground truth. Two towed wings were constructed from recycled materials and hosted a digital camera and two sources of lasers points. Thereby, this system was enabled to mapping of some areas in the Marine State Park of Laje de Santos from June to October 2014. The blind flights of the wing and the sidescan were conducted synchronized and, therefore, the altitude of the wing was adjusted to local depth through of track sonar, moments before. Thus, was calculated the layback from sonar GPS receiver and confirmed the positions of the detected structures in both devices during images processing. The sand and hardbottom habitats, benthic fauna and school of fish based on datasets collected through of the combined devices were coincident in its entirety and show great potential to mapping shallow water at low-cost.