River deltas and wetlands play a pivotal role in protecting
coastlines from storm surge and rising seas.
But as sea level continues to rise instead of an inputs are
reduced, these vast areas of land are drowning. NASA's
Delta-X mission set out to determine which parts of land
will survive and continue to grow, which parts will be lost
and why.
Specifically, the mission is looking to answer the question
what are the hydrological and ecological processes responsible
for both the resilience and vulnerability of river deltas to
relative sea level rise or RSLR?
To do this, field teams deploy by land and boat to measure the
flow of water and the sediment transport across the region.
An airborne campaign also sets out to take large scale
measurements to estimate water and sediment flow as well as
vegetation production.
Planes outfitted with three different instruments will
collect this important data via remote sensing. One of the
instruments is NASA's airborne visible infrared imaging
spectrometer, or AVIRIS-NG. It's flying on a King Air B200
aircraft.
I helped build the instrument and it's an Imaging Spectrometer
as we fly along, we've imaged a swath and every pixel of the
swath, we collect the full reflectance spectrum. And with
our instrument we can see into the water, we can get the
chemical composition of the vegetation and get a whole lot
of very important environmental factors. With each image, we
rent airplanes with a hole in the floor. That's the whole big
deal about this type of a survey aircraft, the goes into end
where the light goes into that's reflected off of the surfaces on
the bottom of the plane. And there's a little narrow glass
window where we look out of with the instrument when we see like
a slit projected on the ground so that as the plane goes along,
that slit builds up a map or an image of what's going on. We're
looking at the instrument Imaging Spectrometer vacuum
vessel optics, CRO coolers, we will have an operator up in this
seat, and we will be looking at the screen and we have another
scene over here for a person that's working the navigation
system that helps us get to show the pilots where we want to be
flying over the on the ground. And they have a screen that goes
up on the windshield that they can look at to see where our
target is relative to the plane so they can steer the plane
cleanly and accurately over the for the target site.
The UAVSAR instrument or the uninhabited Aerial Vehicle
synthetic aperture radar will measure how land features have
changed over time.
The AirSWOT instrument focuses on the natural properties of our
surfaces, gathering data for things like water elevation
mapping, and surface characterization.
Together these measurements make up models that scientists can
then use to understand and forecast land gain or loss in
deltas.