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NASA | Robots on the Roof
Poziom:
Temat: Nauka i technologia
[ Holben ]: Hello, my name is Brent Holben. I'm the
project scientist for the AERONET project and I'd like to
welcome you all to Mount AERONET here on the top of building 33
where we provide calibration for all of our
instruments that are in the network.
AERONET is a relatively small program that
is designed to measure aerosol concentrations and
properties from a ground-based network
of sun photometers, these guys here, for
primarily for validation of satellite retrievals of aerosols.
We know the energy at the top of the atmosphere. We're measuring it at
the bottom of the atmosphere with these guys. We can actually point it
at the sun. It has a filter wheel here that, uh,
looks at nine spectral channels and we use
that difference between the top and the bottom of the atmosphere
to characterize the properties, as well as to measure
the concentration of those aerosols. Also, there
is a very large land surface community
that doesn't care anything about aerosols, but they want to see what's going on with the
vegetation and surface characteristics. So, they need to remove the
atmosphere. So, the data from
this basically provides that information to correct the
satellite imagery so you can get a better view of the surface
characterization. There's also the ocean community
which is interested in ocean color and the concentration of chlorophyll and
particulates in the water. And aerosols
contributed approximately 90% of the signals, so it's very important
to very accurately remove the aerosol signal
from that satellite ocean color
signal. All together, there are about 450
sites worldwide and they're very well distributed.
In all kinds of ecosystems and all kinds
of aerosol environments. And as satellites
come and go, this project is
simple enough and robust enough that it
keeps producing more and more information
at a higher and higher data rate, at a higher and higher
distribution. So, I suspect that
in the long term, we're going to grow to several thousand
instruments. And because it's a relatively
inexpensive program, I think that the future
bodes very well for providing more data
for not just NASA, but the entire globe.
