[meteorite-list] Impact Crater Discovery Project (Proba)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Mar 28 01:12:21 2005
Message-ID: <200503280611.j2S6Bu122629_at_zagami.jpl.nasa.gov>

http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=1501&mode=thread&order=0&thold=0

Impact Crater Discovery Project
Astrobiology Magazine
March 27, 2005

Summary (Mar 27, 2005): In orbit for three and a half years now, ESA's smallest
Earth Observation satellite is making a big contribution to science, a
workshop heard this week. Proba applications range from studying land
vegetation to water quality monitoring, assessing productivity of
Italian vineyards, even helping hunt for meteorite impact craters.

  
Impact Crater Discovery Project
based on ESA report

In orbit for three and a half years now, ESA's smallest Earth
Observation satellite is making a big contribution to science, a
workshop heard this week. Proba applications range from studying land
vegetation to water quality monitoring, assessing productivity of
Italian vineyards, even helping hunt for meteorite impact craters.

ESA's Proba microsatellite is about the same size and shape as a washing
machine. It was launched on 22 October 2001 as a one-year technology
demonstrator, but continuing high in-orbit performance has led to it
being adopted as an Earth Observation Third Party Mission.

Proba's largest instrument is the Compact High Resolution Imaging
Spectrometer (CHRIS), a hyperspectral imager that can view the Earth's
surface to a spatial resolution of 18 meters in a combination of up to
19 out of 62 programmable spectral bands to return highly detailed
environmental information.

Some 56 scientific teams worldwide are either currently using or
planning to use CHRIS data. This week saw the Third Proba/CHRIS Workshop
take place at ESRIN in Frascati, ESA's establishment in Italy. Starting
on 21 March, the three-day event was an opportunity for researchers to
share current results and future plans, and have an input into future
CHRIS acquisition planning.

"What this workshop makes clear is that CHRIS/Proba is no longer a
technology demonstrator but has become a real tool for actual research
and applications," stated Professor Jose Moreno of the University of
Valencia.

CHRIS images are planned to be used as part of the Impact Crater
Discovery Project, a collaboration between ESA, the University of Vienna
and Logica CMG to utilise data mining techniques to automatically sift
through the terabytes of Earth Observation data acquired each year to
detect possible meteorite impact craters.

Only about 160 impact craters have been found on the Earth, a small
number compared to the Moon and neighbouring planets. They are
comparatively difficult to find on Earth because of its active geology
and climate - old craters can end up eroded away, buried under sand or
sediment or flooded.

However they are valuable subject for study, particularly because of
their proposed role in the mass extinctions that punctuate the fossil
record. All impact craters share a circular shape and shocked and
fractured rock morphology, features that can potentially be used to
differentiate them from similar features such as volcanic craters or
circular lakes.

The plan is to acquire CHRIS images of the BP impact crater in Libya,
which has already been studied extensively from the ground. With a
diameter of up to 2.8 kilometers the crater is large enough to fit
within a single CHRIS, and will be used to assess ways of increasing the
accuracy of the automatic sorting process.

One leading application for CHRIS - both by itself or in combination
with other satellite sensors - is the study of land vegetation and
forests. The imager's combination of high resolution and wide spectral
range means that a large amount of important biophysical and biochemical
properties can be gathered, including chlorophyll and water content,
leaf area index and overall biomass and health.

CHRIS has another advantage in this area, as Moreno explained: "The
really unique capability of the instrument is being able to provide
multi-angular views of the same site".

CHRIS can acquire up to five images of a desired target at a time.
Meanwhile the entire satellite is able to perform a continuous roll, so
that the target is acquired at different angles, especially useful when
trying to assess vegetation or woodland canopy structure and density and
differentiate individual plant or tree species.

Heike Bach of the German company VISTA GmbH explained how CHRIS images
of agricultural crops were being used to estimate crop type and state.
Meanwhile Anne Bourguignon of the French geosciences organisation BRGM
is utilising CHRIS to study water run-off and soil erosion from crops at
sites in Toulouse and Strasbourg.

The workshop also heard how CHRIS images are being used to help study
the state of woodland in the Rhineland Palatine in Germany and measure
the carbon flux of Harwood Forest in Northumbria in the UK, to study the
role of woodland as both sinks and sources of carbon dioxide, the single
most important greenhouse gas.

A German team from the Universities of Kaiserslautern and W?rzburg plans
to use CHRIS imagery to study an often-overlooked zone of life in South
African and Namibian deserts. They are interested in studying changes in
soil reflectance caused by Biological Soil Crusts (BSCs), communities of
organisms and their by-products found at the surface of desert soils not
occupied by vegetation.

CHRIS is also playing a part within ESA's TIGER Initiative, intended to
apply Earth Observation to the integrated management of developing
nation water resources, with a particular focus on Africa.

The University of the Western Cape in South Africa wants to use CHRIS
imagery to differentiate stressed and non-stressed tree stands in the
vicinity of Johannesburg gold mines, to evaluate the possibility of
planting trees to absorb water polluted by heavy metal waste from the
mine, in order to avoid the further spread of contamination.

CHRIS imagery of the Frascati vineyards surrounding ESRIN is also being
applied to an ambitious European Commission project called Bacchus. It
aims to apply Earth Observation to inventory vineyards and optimise the
management of wine production.

Envisat radar imagery and very-high resolution QuickBird images are
already being used to survey the 8000-hectare Frascati 'Denominazione
d'Origine Controllata' (DOC), the subject of a pilot study. Fabio Del
Frate of Tor Vergata University stated that the hyperspectral view
provided by CHRIS has the potential to yield extra information on
vineyard 'phenology' - the link from grape health and ripening to local
climate.

A team from Cranfield University's Space Research center plan to use
CHRIS data in combination with other space-based instruments to identify
and classify solid waste landfill sites, in order to track changes over
time and detect illegal landfill sites.

The workshop heard that use of CHRIS imagery is extending beyond the
land to the water. Its spectral measurements of water color can be used
to derive its precise contents, such as chlorophyll and by extension
phytoplankton concentrations as well as suspended matter.

Work is currently going on based on images of Lake Constance in Central
Europe, inland water in Belgium and water reservoirs in Spain along with
the sea off Plymouth. With atmospheric correction a major part of data
retrieval over water, one workshop recommendation was that a means be
set up to share tools and algorithms developed by users.

CHRIS images - along with those from the High Resolution Camera (HRC),
Proba's other remote sensing instrument - have also proved useful within
the context of the International Charter on Space and Major Disasters,
an international agreement for the rapid provision of Earth Observation
data to civil protection agencies responding to disaster situations. The
Charter has been activated more than 70 times since 2000.

Proba images have been provided on a best-effort basis by ESA, with a
standardised CHRIS product for Charter use having been defined in Spring
2004.

So far Proba images have been supplied in response to forest fires in
the Var region of France in September 2003, the Arles River flood in
southern France in December that year, the December 2004 tsunami
disaster in South-East Asia and two separate earthquakes in Iran
occurring in December 2003 and February 2005.
------------------------------------------------------------------------
Proba is a microsatellite developed by ESA's General Support Technology
Programme (GSTP) Special Projects Office, based in ESTEC in the
Netherlands. It was built by an industrial consortium led by the Belgian
company Verhaert, launched from India on 22 October 2001 and operated
from ESA's Redu Ground Station in Belgium. Its CHRIS instrument, funded
by the British National Space center (BNSC), has been built by the UK
company SIRA Space. A follow-on technology demonstrator called Proba-2
is due to be deployed by ESA during 2007. As with its predecessor the
new mission will prove new technologies and new products in orbit. The
system built around these developments is intended to support a Sun
observation and plasma measurement mission. A new type of solar
spectrometer combined with high spacecraft performance will provide for
the first time, high-data rate imaging of the Sun.
Received on Mon 28 Mar 2005 01:11:56 AM PST