Sediment Transport Instrumentation Facility (STIF)- Engineering

Science Center Objects

The Sediment Transport Instrumentation Facility (STIF) primarily uses off-the-shelf instrumentation and sensors to collect observations.  STIF designs and implements novel configurations for logging of data from sensors, and for deployment of these instruments in a wide range of estuarine, coastal, and ocean environments.  STIF continually evaluates instrument and sensor performance.  Some examples of recent engineering efforts are listed below.

Divers prepare patterns of known targets for verification of sonar resolution.

Divers prepare patterns of known targets for verification of sonar resolution.

Instrument performance

We often use sonars to measure seafloor bedforms and how they change in response to storms.  In order to accurately quantify the size of bedforms, the response of the sonars must be understood.  We assessed the sonars we use by collecting data in a test tank using targets of known shapes and sizes (https://soundwaves.usgs.gov/2010/03/research2.html)

Data conversion, review, and release

Software to convert the raw data to a standardized form for release and evaluate data quality has been developed for each instrument deployed.  After review, all observations are released in the U.S. Geological Survey Oceanographic Time Series Measurement Database (Montgomery et al, 2016).  

Deployment systems

A variety of platforms have been developed and constructed for deployment of instruments near the sea floor.  Recent developments include a boundary layer profiler and a sled for bottom stress measurements.

Image of oceanographic equipment platform deployed off the coast of Martha's Vineyard

Steaming to the deployment site south of Martha's Vineyard, MA in 2011. The platform shown was specially adapted so the arm cycles up and down through the Benthic Boubdary Layer while deployed on the seafloor.  For more information see https://soundwaves.usgs.gov/2011/11/fieldwork2.html.

Benthic Boundary Layer Profiler

A profiling arm was added to a tripod to move sensors up and down through the benthic boundary layer.  This instrument system collected repeated optical and acoustic profiles in the 2 m above the seabed. A unique feature of this system is that the same sensors make the observations in the profile, eliminating uncertainty caused by calibration of multiple sensors.  A linux-based embedded system and software to control arm movement was developed and deployed (Sherwood, 2001, Sherwood et al, 2012).

 NIMBBLE sled

The New Instruments for Making Bottom Boundary Layer Evaluations (NIMBBLE) sleds were designed and built to measure bottom shear stress in 2014 for an experiment South of Martha’s Vineyard (https://soundwaves.usgs.gov/2014/10/fieldwork2.html).  These very low drag platforms support a pair of acoustic Doppler velocimeters (ADVs) that make rapid measurements of currents at two points that are about half a meter (a foot and a half) above the seafloor and separated horizontally by about a meter and a half (five feet).  These data are then used to compute turbulence and bottom stress. 

Photograph of Marinna Martini prepares to deploy a NIMBBLE from the R/V Connecticut south of Martha's Vineyard

Marinna Martini prepares to deploy a NIMBBLE from the R/V Connecticut south of Martha's Vineyard