Lucilla Alfonsi and Giorgiana De Franceschi, INGV, Rome, ITALY

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Upper Atmosphere Monitoring for Polar Year
2007-2008 (UAMPY)
Lucilla Alfonsi and Giorgiana De Franceschi,
INGV, Rome, ITALY Pierre Cilliers , Hermanus
Magnetic Observatory, Hermanus, SOUTH AFRICA
Massimo Materassi and Paolo Spalla, ISC-CNR,
Florence, ITALY Cathryn Mitchell, University of
Bath, UK Susan Skone, University of Calgary,
CANADA Andrzej Wernik, Polish Academy of
Sciences Warsaw, POLAND
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UAMPY - Aims

• The overall aim is to create new international
  cooperation in ionospheric research.
• We aim to develop polar upper-atmosphere
  observation networks for
• mapping ionospheric features continuously from
  mid through to polar latitudes
• making conjugate studies of magnetospheric-ionosph
  eric coupling processes
• relating the large-scale to the small-scale
  features, in particular the auroral and polar
  ionospheric irregularities causing scintillation
• Potential exists for many new studies with both
  scientific and practical investigations.

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UAMPY - equipment
GPS scintillation receivers in the Arctic at
Svalbard, at the mainland EISCAT sites and in
Canada. New receivers to be deployed in the
Antarctic at Mario Zucchelli Station (7469'S,
16412'E) DomeC (7506'S, 12324'E) SANAE
(7140'S, 251'W) and Digisondes at ISSA and/or
SANAE. Explore the possibility of running GPS
scintillation receivers on BAS ships.
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UAMPY software Multi-Instrument Data Analysis
System (MIDAS)

• MIDAS
• Algorithms for extracting electron density from
  linear TEC-related data
• MIDAS to become a fully non-linear inversion
  incorporating oblique data e.g., such as from
  SuperDarn
• Future - develop new techniques to assimilate
  images into physical models to investigate
  underlying physics

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Relating large-scale events to small-scale
events
Polar-cap patches moving over Svalbard and
Scandinavia edges are associated with
small-scale irregularities in the electron
density
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Polar-cap convection

• Mapped vertical TEC suggests convection of
  electron density from the American sector to
  Europe
• Data coverage not yet sufficient to produce full
  3D images right over the polar cap

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Polar-cap convection

• Overpasses of the low-Earth-polar-orbit CHAMP
  satellite can help with data coverage each hour
• In 2006 the USA and Taiwan will launch six LEO
  satellites (COSMIC), all with GPS receivers on
  board. This will increase the data coverage and
  enable polar-cap imaging in time for IPY

• Evidence of polar-cap patches on 30 October 2003
  from the GPS receiver on-board CHAMP

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Applications of the research

• The ionosphere causes two problems for GPS
  navigation
• Group delay to the signal propagation time that
  is proportional to the total electron content.
  This can change the apparent position by tens of
  metres.
• Scintillations of the signal are related to
  small-scale irregularities in electron density.
  These can cause temporary loss of the signals.

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GPS signal at ground fades as it passes through
aurora
Coloured map (top) shows All-Sky Camera 557 nm
intensity. The velocity of the auroral structure
causing the signal fading is projected with the
yellow line. An increase in local intensity of
the aurora occurs simultaneously with a deep
fading of the GPS signal (bottom).
thanks to K. Kauristie, Finnish Meteorological
Institute
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Applications of the research
These effects are not an issue for most GPS
users but they are important for safety-critical
applications. A clear example of a GPS signal
broken up in an auroral arc has already been
identified from the EISCAT GPS receiver. Relating
the physics to the impacts on systems is
important, especially in new technologies like
GPS and the new European Galileo.
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UAMPY Plans

• Bath are developing their imaging software to
  extend coverage over the poles using other data
  sources in the imaging
• INGV Rome and Hermanus plan to deploy GPS and
  scintillation receivers in Antarctica in 2006
• Workshop proposed for early 2006 at Hermanus in
  South Africa
• All are developing web-sites for increasing the
  public understanding of science activities

• Many thanks to Paul Spencer for graphics and Andy
  Smith (University of Bath) for auroral images.