AUV sensor integration and science |
Quantitative low-light imaging module for MBARI's AUV
Project Manager/Lead Scientist: Kim Reisenbichler
Lead Engineer: Ed Mellinger
One of the great successes of MBARI’s midwater research program has been
the creation of a time-series database from quantitative video transects of the
mesopelagic environment. This is the first data set of its kind anywhere, and it
has been acquired by using the unique resources that MBARI has at its disposal, readily available ships and
remotely operated vehicles (ROVs) ported close to deep water.
However, there are some limitations to conducting midwater transects with ROVs
that can be overcome by adapting autonomous underwater vehicle (AUV) technology for this task. The advantages of
using an AUV in this role include: extending transect lengths; increasing
functional transect depths; increasing the resolution of the transect depth
profile and allowing for more extensive day/night comparisons. In addition,
these advantages can be achieved at a lower platform cost in comparison with
equivalent ROV operations. Imaging surveys are an ideal example
of how AUV technology can have a significant impact on meso- and bathypelagic
research at a relatively low development cost.
The goal of this two-year project will be to develop an AUV payload that is
capable of imaging a known volume of water, with 1) sufficient sensitivity to
detect stimulated bioluminescence, and 2) sufficient resolution to allow visual
identification of animals, comparable to what we can currently achieve with
MBARI ROVs. Due to differences in size and available power specifications of
MBARI’s ROVs and AUVs, this is not a simple issue of re-packaging an existing
ROV video system to fit on an AUV.
The first year of this project will
be used to determine what combination of illumination sources, imaging system,
data storage and vehicle configuration(s) will work best to achieve our goals.
Because lights demand the most power in the existing video system, we intend to
use a more sensitive camera that can operate with dimmer light sources. This has
the additional advantage of making the system adaptable to bioluminescence
transecting. The primary resources required during the first year will be
engineering and science time to help make these assessments. In addition, we
plan to test likely systems, as available, on the ROV Ventana during midwater
ecology transecting operations. No major equipment purchases are planned for the
first year.
Based upon the results of our first year’s efforts, the second
year will be devoted to detailed design, manufacture, integration and testing of
the module on an AUV and validation of this system in comparison to ROV-based
transecting. Although the main emphasis of this project is to develop a system
for midwater imaging, we believe that the results of the first year’s research
will also be useful for developing a benthic AUV imaging system, as well.
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