LIDAR is being used to observe lots of different ocean animals from the air.
Lidar (also called LIDAR, LiDAR, and LADAR) is a surveying method that
measures distance to a target by illuminating the target with pulsed
laser light and measuring the reflected pulses with a sensor.
Differences in laser return times and wavelengths can then be used to
make digital 3-D representations of the target.
This group is looking at commercially important fish and plankton schools.
Because of the limited penetration depth, LIDAR is most effective when
surveying fish that live near the surface. Those that have been
successfully surveyed include menhaden , sardines , mackerel, salmon ,
mullet , capelin , anchovies , herring , squid, and jellyfish. The
agreement between lidar results and more traditional echosounder
results is good if both instruments cover the same area at the same
time, and gets progressively worse is several days elapse. To get this
agreement, the lidar data must be thresholded in some fashion to
remove the return from background scattering levels.
For survey purposes, we would like to convert the lidar signal into a
depth profile of the biomass density for each species. This means that
we need to know the reflectivity of each target species and we need to
be able to identify the species responsible for our signals. At this
time, laser reflectivity measurements have been made on three species
of live fish: sardines mackerel and menhaden
Image scale is established via an independently powered LIDAR/GPS
data-logging system recording altitude and GPS location at 1 Hz.
Photogrammetric calibration of the camera and lens allowed distortion
parameters to be rigorously accounted for during image analysis, via a
custom-programmed Graphical User Interface (GUI) running in MATLAB.
The datalogger, camera calibration methods and measurement software
are adaptable to a wide range of UAV platforms. Mean LIDAR accuracy,
measured from 10 bridges 9–39 m above water, was 99.9%. We conducted
136 flights in New Zealand's subantarctic Auckland Islands to measure
southern right whales. Mean lengths of 10 individual whales, each
photographed between 7 and 15 times, had CVs (SD/mean) ranging from
0.5 to 1.8% (mean = 1.2%). Repeated measurements of a floating reference target showed a mean error of c.1%. Our system is relatively
inexpensive, easily put together, produces accurate, repeatable
measurements from single vertical images, and hence is applicable to a
wide range of ecological questions in marine and terrestrial habitats.
The LIDAR of an image will not look like a whale to a person. You have to know how the whale (or squid, or plankton school, or fish) looks with LIDAR and so you need to establish an image base, which is what the first group is doing with fish.
LIDAR can be used at night or from an altitude high enough that sentient animals are not aware of you.
In the linked articles there is mention of infrared images but I was not clear if they are using infrared LIDAR or if this is an adjunct imaging modality.