There are nine
science requirements for ICESat-2 when the mission was stood up
initially, and all of those were mostly for cryosphere science.
One of those capabilities was that the green wavelength
of ICESat-2’s laser altimeter does penetrate water.
And no one really thought from 300 miles in space that it would provide
a real value added to nearshore and coastal bathymetry, as an example.
One of those products or efforts, I should say,
is to develop a global bathymetry product.
And so that was ATL24.
So what this product does is it takes the,
geolocated point cloud data, which is ATL03,
and does a unique way of signal finding and then classifying that signal
these photons, detected photons, as either sea surface
or seafloor.
And we do this globally in areas that we know
ICESat-2 has a has a high probability of collecting bathymetric data.
A lot of
my work involves mapping of nearshore areas and particular
mapping of bathymetry, which means water depths, and nearshore areas.
And unfortunately, in areas all over the world,
we have a global nearshore data void, which basically means
we have these big gaps in coverage of water depths near the near the shoreline.
And so fortunately,
ICESat-2 has proven remarkable at measuring this nearshore bathymetry.
In my work, geospatial data products often include
bathymetric digital elevation models or DEMs.
So these are models of seafloor elevation.
And so although ICESat-2 wasn’t designed initially for a bathymetric
measurement--it was primarily designed for measuring ice sheets, glaciers and sea
ice--it really has proven to be great at measurement of nearshore bathymetry
and these other, nearshore, you know, seafloor data products.
So a lot of users of ICESat-2 bathymetry are hydrographic surveying offices.
And so these are offices which are charged with surveying
bathymetry and basically collecting data that goes on to nautical charts.
And these nautical charts are what keep mariners safe at sea when they’re
when they’re navigating at sea.
And so
some of the ways that hydrographic survey offices can use ATL24,
for example, if you’re getting ready to send small boats into an area
to do surveying in a place where you just don’t have great existing data.
This can potentially be dangerous, particularly if you’re working in areas
where there might be submerged hazards, rocks, for example.
I really think it’s important to, to know that ATL24 is right now
a product that gives you sea surface and seafloor elevations
at the native resolution of 70 centimeters in the along track direction,
but the way that we’re going to eventually offer it to the community through SlideRule
makes it so that you can customize your bathymetry product.
So SlideRule is a what I call a web-based data service.
At the core of SlideRule, the idea that we have
is that it is the idea that it would be more efficient and better
for NASA, better for the science communities, if we distribute
level-three and level-four science data products as a service
instead of a statically pre-generated archival data set.
And so scientists then don’t have to work with the hundreds
of terabytes of photon cloud data.
They can work with hundreds of gigabytes
or gigabytes of the specific ice sheet elevation
data that that they want for their investigation.
And so that's where SlideRule comes in, where we instead
of distributing pre-generated static files,
we are distributing in a sense the algorithms.
So they can ask hard questions about a lot of data over a lot of time,
using algorithms that had a lot of time invested
in them, sophisticated algorithms and tuning it for their application.
I think ICESat-2 with the expected lifetime of being another
maybe ten years based on the level of consumables on board.
It's it's poised to just be a component of the Earth-observing system
as a whole for a while, and can be a validation capability
in and of itself to other or new missions that are launched.