RSM Tool: Integrated CHIRP Sub-Bottom Profiler and Dual Frequency Sidescan Sonar Fact Sheet

<div>Understanding sediment dynamics in aquatic systems is a critical component of the USACE’s mission. For example, the volume of sand in a nearshore profile has significant impact on shoreline stability, and the type of sediment characterizing the seafloor influences not only the type and distribution of benthic habitats but also influences sediment transport. Traditional sediment characterization techniques, such as estimates of sediment volume derived from repeated bathymetric mapping or characterization of aquatic habitats by sidescan sonar alone, neglect the subsurface geology and thus provide an incomplete picture of a region. To address this gap, the Coastal and Hydraulics Laboratory’s Coastal Observation and Analysis Branch (under the Coastal Field Data Collection Program) has acquired an Edgetech 2000-CSS: a Compressed High Intensity Radar Pulse (CHIRP) sub-bottom profiler integrated with a dual simultaneous frequency CHIRP sidescan sonar. Sidescan sonar generates spatial maps of surficial sediment type (e.g., rock, sand, mud) via variations in the reflection of high-frequency acoustic pulses off of the seafloor. The Edgetech 2000- CSS has a dual-frequency side-scan sonar (300 kHz/600 kHz), allowing simultaneous characterization of surficial bottom type. </div>