Session - Cross calibration of high energy particle measurements for heliospheric environment modelling
D. Heynderickx, P. Jiggens, J.V. Rodriguez
Measurements of SPE and GCR particle populations have been collected for many decades, both on ground, in the atmosphere and in
space, with a variety of instrument types (Geiger counters, cloud chambers, photographic emulsions, particle telescopes,
dome detectors, dosimeters, ...). Combining these different data collections into a homogeneous data resource is very
challenging. Even data collected by spacecraft with similar instruments are notoriously difficult to cross calibrate into a
common set of spectral energies and particle species. The need, both societal and scientific, to have accurate and consistent
space weather observations from multiple platforms continues to drive cross-calibration efforts. Several efforts have been
undertaken, or are ongoing, to re-process historical datasets in order to obtain absolute flux values from the various
instruments that have flown (or are still flying) on spacecraft. These efforts are often hampered by a lack of detailed
information on instrument characteristics and responses, and sometimes by the poor availability of the data itself.
There has been a renewed interest in calibration issues as evidenced by the organisation of a calibration mini-workshop at
this year's Space Weather Workshop in Boulder, Co, and the submission of an ISSI workshop proposal. ESWW11 provides an
excellent opportunity to continue and increase international collaboration on this crucial aspect of environment modelling.
We solicit contributions on recent calibration efforts and development of new methodologies. Contributions on standardisation
of calibration methods and on archiving and dissemination of calibrated datasets are also welcome, as are successful models
from the discipline of meteorological observations.
Talks
Tuesday November 18, 09:00-11:00, 12:00-13:00, auditorium Reine Elisabeth
Poster Viewing
Tuesday November 18, 11:00-12:00, area in front of auditorium Reine Elisabeth
Talks
| Oral - invited |
9:00 am |
Cross-Calibration Activities at
The Aerospace Corporation |
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Blake, B1; Claudepierre, S1; Fennell, J1; Guild, T1; Looper, M1; Mazur, J1; O'Brien, P1 |
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1The
Aerospace Corporation |
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Cross calibration of high energy
particle instruments has been an ongoing concern for the scientists in the
Aerospace Space Sciences Department literally for decades, since we have
fielded a large number of instruments of varying complexity and using a variety
of experimental techniques. This work has substantially increased recently
because of the development of the AE9 & AP9 radiation models and the NASA
Van Allen Probes mission. Each of the two spacecraft contains six energetic
particle instruments fielded by Aerospace. The Van Allen probes also carry
three other energetic particle instruments, and of course there are other
well-known and routinely used sources of space environmental data such as
GOES and POES to be used with the Van Allen Probes measurements. Aerospace
also has energetic particle instruments aboard several other missions that
are currently returning data and have been for many years, including the HEO
and TWINS missions. Other historical missions with extensive databases include
Polar and SAMPEX. A variety of tools are used to calibrate and
cross-calibrate energetic particle instrumentation including proton and heavy
ion accelerators such as the LBNL cyclotron, electron accelerators such as
the NASA Goddard Van de Graff and a beta spectrometer. Geant4 is extensively
and routinely used, including modeling hardware fielded by other
institutions. Specific examples of calibration studies and modeling will be
presented. |
| Oral |
9:30 am |
Capabilities of the Space
Instrument Pamela for Solar Research |
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Roberta Sparvoli, R1; Mergè, M2; Di Felice, V2; Martucci, Matteo3 |
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1Università
Tor Vergata e INFN; 2INFN Section of Rome Tor Vergata, Rome, Italy; 3INFN Laboratori
Nazionali di Frascati, Frascati Italy. |
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The Payload for Antimatter
Matter Exploration and Light-nuclei Astrophysics (PAMELA) is a space-based
cosmic-ray detector built by the Italian/Russian WiZard collaboration
launched into orbit aboard a Soyuz TM2 rocket on 15 June 2006. PAMELA is
attached to the upward looking mounting point on the Russian Resurs-DK1
Earth-observing satellite. The satellite is in a sun-synchronous, semi-polar
(70°) circular orbit at an altitude of 600 km. The objective of the PAMELA mission is to
measure cosmic antiparticles, electrons and light nuclei in the energy range
10^2-10^6 MeV. The core of the
instrument is a magnet spectrometer with a permanent Nd-Fe-B magnet and a
silicon tracking system. Together, these provide a measure of the incident
particle rigidity. A time-of-flight (ToF) system distinguishes upward from
downward moving particles. The imaging Si-W calorimeter provides information
on the particle interactions with matter and measures the energy of the
particle. Together, these detectors measure the light nuclei up to carbon and
the isotopes of hydrogen and helium, with energies above 80 MeV/nucleon (0.4
GV). The PAMELA instrument covers an
energy range that bridges two disparate groups of measurements, the
low-energy SEP observations of in-situ spacecraft and the highest energy
observations that of GLEs from ground-based instrumentation. This is the
first instrument of its kind to bridge this critical gap in solar energetic
particle energy while providing important composition measurements of the
highest energy GLE particles. PAMELA also measures the incident trajectory of
the detected particles employing a combination of trajectory reconstruction
and the silicon tracking system. The
unique observations from PAMELA provide an essential link between the highest
energy GLEs and the low-energy in-situ observations and are able to bridge a
critical gap in energy that makes it possible for the first time to constrain
the effects of transport over a broad range in energy. |
| Oral |
9:50 am |
Extended Measurement
Capabilities of the Electron Proton He- lium INstrument aboard SOHO - Energy
Spectra up to 1 GeV and Anisotropies during GLE 71 |
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Kühl, P1; Banjac, S1; Heber, B1; Labrenz, J1; Terasa, C1 |
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1University
of Kiel |
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The Electron Proton Helium
INstrument (EPHIN) on board the SOlar and Heliospheric Observatory (SOHO) has
performed measurements of the cosmic ray intensity at the Lagrangian point L1
since its launch in December 1995. The detector consists of a stack of six
solid-state detectors enclosed in a scinitilator as anti-coincidence. The
first two detectors are segmented in order to improve particle
identification. By design the instrument is capable of determining the energy
spectrum of hydrogen and helium up to energies of 53 MeV/n as well as
electrons up to 8.3 MeV using the dE/dx-E-method. Above these energies,
particles penetrate all detector elements and thus, a separation between
different particle species becomes more complicated. To overcome this restriction,
we developed new methods to 1) distinguish between different penetrating
particles, 2) to calculate the incidence energy of a particle based on the
energy deposit in the detector elements and 3) to derive the energy spectrum
for penetrating ions up to almost 1 GeV/n based on GEANT4 simulations and the
pulse high analyses data of the instrument. Furthermore, Monte-Carlo
simulations that exploit the segmentation of the first two detectors allow a
correction for different path length and the detection of anisotropies. As an
example we present the EPHIN Proton spectrum from 0.1 to 1 GeV and the
anisotropy variation for the Ground Level Enhancement observed on May 17,
2012 in comparison to published PAMELA results. |
| Oral |
10:10 am |
Cross-Calibration of SOHO/ERNE
Proton and Heavy ion Measurements with other Particle Instruments at L1 |
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Valtonen, E1; Paassilta, M1; Raukunen, O1; Vainio, R1 |
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1University
of Turku |
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In the SEPServer project1) a
comprehensive set of solar energetic particle (SEP) observations was
collected and made available through a single server. The observations
included measurements of eleven instruments on six missions from inner
heliosphere (HELIOS A and B) through ~1 AU-orbits (WIND, SOHO, ACE, STEREO A
and B) to beyond 1 AU and out of ecliptic (ULYSSES). Within the project, SEP
data quality assessments and comparisons of measurements of several
instruments were performed. For five events of various sizes covering the
years 1997 – 2007 the proton measurements of SOHO/ERNE, SOHO/EPHIN and
ACE/EPAM and the helium measurements of SOHO/ERNE, SOHO/EPHIN and ACE/SIS
were compared. In general, the spectral shapes measured by various
instruments agreed fairly well, but in some cases significant differences in
intensities were found at specific energies. The overall spectral shapes of
carbon and oxygen ions measured by SOHO/ERNE and ACE/SIS and ACE/CRIS also
agreed reasonably well, but relatively large deviations in intensities at
certain energies were also found. The goal of the present work is to explain
and try to minimize these differences.
1) http://www.sepserver.eu/sepserver/ |
| Oral |
10:30 am |
Intercalibration of the Solar
Proton Channels from the GOES 8-15 Energetic Particle Sensors |
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Rodriguez, J1; Krosschell, J2; Green, J3 |
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1University
of Colorado; 2University
of Wisconsin; 3Geosynergy, LLC |
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In this paper we report on a
relative intercalibration analysis of the solar proton channels from the GOES
Energetic Particle Sensors (EPS). This
analysis uses a technique that depends on features that arise during high
solar wind dynamic pressure. These channels are used by NOAA for alerts of
the radiation hazard posed to spacecraft and humans by solar energetic
particle events; therefore, it is important to know their relative responses.
Based on observations of solar energetic protons from polar-orbiting and
geostationary satellites, we conclude that solar proton fluxes are isotropic
at geostationary orbit during periods of high solar wind dynamic pressure
(Pdyn>5−10 nPa). The observed isotropy results from the solar proton
fluxes having rigidities (momenta per unit charge) greater than their
geomagnetic cutoffs over the complete energy and angular responses of the
satellite-borne detector. (The cutoff in a given direction is the rigidity
below which an interplanetary particle cannot reach that location.) From
observations under such conditions (1998–2013), we determine the relative
responses of the EPS flown on GOES 8 through 15. The results of this low-scatter intercalibration
analysis show that the relative responses agree to 20% or better (sometimes
better than 1%). The effect of such relative calibration differences on the
derived integral fluxes used by NOAA for its real-time solar radiation storm
alerts is small (<10%) due to partial cancellation of systematic errors. |
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10:50 am |
Poster Summaries |
| Oral |
12:00 pm |
Cross Calibration of NOAA
GOES/EPS Detectors using NASA IMP8/GME Corrected Proton Flux Measurements |
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Sandberg, I1; Jiggens, P2; Heynderickx, D3; Daglis, I4 |
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1National
and Kapodistrian University of Athens; 2European Research and Technology Centre; 3DH Consultancy; 4Department of Physics,
National and Kapodistrian University of Athens |
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Solar proton flux measurements
on-board Geostationary Operational Environmental Satellites (GOES) are of
great importance as they cover several solar cycles, increasingly
contributing to the development of long-term solar proton models and to
operational purposes such as now-casting and forecasting of space weather. A
novel approach for the cross-calibration of GOES solar proton detectors is
presented, using as reference the energetic solar proton flux measurements of
NASA IMP-8 Goddard Medium Energy Experiment (GME). In order to increase as
much as possible the quality of the cross-calibration results, we also have
developed and present a method to reduce the spurious behavior in part of the
IMP8/GME measurements, which is attributed to a failure of the Low Energy
Detector. The derived effective energy values of GOES detectors lead to a
significant reduction of the uncertainties in solar proton spectra and can be
used to refine existing scientific results, available models and data
products based on measurements over the past three decades. It is also shown,
that for some cases the measurements of GOES high-energy channel correspond
to energies much smaller than the nominal ones. The methods presented are
generic and may be used for calibration processes of other datasets as well.
The numerical calibration applied to the IMP8/GME Low Energy Detector enables
the determination of improved spectra for one of the most widely used
instruments for the evaluation of Solar Energetic Particle (SEP) events. The resulting datasets and processing
procedures will be integrated into the ESA SEPEM platform for SEP modeling,
where data are accessible to the community.
This work has been funded through ESA Contract No. 4000108377/13/NL/AK |
| Oral |
12:20 pm |
Construction of a Long Term
Interplanetary He Dataset in the Framework of the ESA ESHIEM Project |
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Heynderickx, D1; Varotsou, A2; Samaras, A2; Sandberg, I3; Truscott, P4; Lei, F5; Vainio, R6; Valtonen, E6; Jiggens, P7; Hilgers, A7 |
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1DH
Consultancy; 2TRAD;
3NKUA; 4Kallisto Consultancy; 5RadMod Research; 6Univ. Turku; 7ESA/ESTEC |
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During the ESA SEPEM project, a
long term (1973-2013) cross-calibrated interplanetary proton dataset was
constructed using data from the IMP8/GME instrument and the EPS instruments
on a series of GOES spacecraft. In the
new ESA ESHIEM project, a similar effort is ongoing to construct a long term
He dataset. IMP8/GME and GOES/EPS again were the original prime data sources.
However, it turned out that the sensitivity of the EPS instrument is not
sufficient to resolve medium size and small He events, especially at high
energies. In addition, the energy range of the GME instrument is limited to
80 MeV/nuc. We are therefore investigating the use of ACE/SIS and SOHO ERNE
He data to extend the energy range of the GME data and complement the EPS
data. At the same time, He/H abundance ratios will be produced over as a long
a time series as possible. |
| Oral |
12:40 pm |
Processing of the ACE/SIS Heavy
Ion Data in the Frame of the ESA ESHIEM Project |
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Varotsou, A1; Samaras, A1; Heynderickx , D2; Truscott, P3; Lei, F4; Jiggens, P5 |
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1TRAD;
2DH
Consultancy BVBA; 3Kallisto Consultancy; 4RadMod; 5ESA/ESTEC |
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One of the main goals of the ESA
ESHIEM project (Energetic Solar Heavy Ion Environment Models) is to update
the existing SEPEM database to include all relevant cleaned, processed solar
energetic ion data and develop new space environment models. Solar heavy ion data from the SIS
instrument onboard the ACE spacecraft have been chosen for the ion abundance
definition. The SIS spectrometer provides high resolution heavy ion data for
14 ions (He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, Ni) and 8 different
energies for each of these ions (He data start at 4 MeV/nuc and Ni data are
available up to 150 MeV/nuc). The instrument’s high sensitivity allows to
measure even smaller SEP (Solar Energetic Particle) events. However, during
big events and high rate periods SIS applies a priority system to the
collected particle counts resulting in important flux dropouts especially for
He and low energy CNO. In the frame of the ESHIEM project, ACE/SIS 256-sec
heavy ion data have been processed to produce a clean and continuous 1-hour
data base for SEP events from November 1997 to March 2013. Data processing
includes data drop-out correction and data gap filling. Saturation issues
have also been investigated as well as data spikes. Comparisons with the
1-hour Level 2 data available from the ACE science centre show that for the
big events processed fluxes can be of a factor of 2 to 3 higher. Comparisons
of the output flux profiles with available solar heavy ion data from the WIND
and SOHO spacecrafts show that there can be notable differences in the flux
levels defined by the three databases. Results will be presented and
conclusions will be discussed. |
Posters
| 1 |
Snow effect, long-term
heliospheric modulation, and 27-day CR variations for total NM intensity and
different multiplicities on Mt. Hermon during 1998 - 2013 |
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Dorman, L1; Applbaum, D S2; Ben Israel , I2; Dai , U2; Kazantcev, V2; Kozliner, L2; Pustil'nik, L2; Sternlieb, A2; Zukerman, I2 |
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1Israel
Cosmic Ray and Space Weather Centre of Tel Aviv University, Israel Space
Agency and Golan Research Institute; 2ICR and SWC, Tel Aviv University |
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For using CR data for space
weather forecasting, it is necessary to determine the snow effect for each
moment in time and correct observation data not only from barometric and
temperature effects (as usual), but also from the snow effect. According to
observations on Mt. Hermon, the snow effect in the NM total intensity and
different multiplicities is comparable with 11-year variation. The other
problem is, that with increasing of snow depth, the sensitivity of the CR
detector changed – it moved to higher energies. To determine the snow effect
in NM on Mt. Hermon, we made step by step the following investigations: 1) we
determined the connection of CR intensity observed on Mt. Hermon during
summer periods without snow with CR intensity on stations which are never
covered by snow; 2) by finding the regression coefficients we determine the
expected CR variations on Mt. Hermon in winter time on the basis of data of
stations which in winter time are not covered by snow; 3) the difference
between observed CR intensity and that calculated in point 2 will give the
snow effect. This method can be used for any CR station that is covered at
some periods by snow. By this method data of CR station can be corrected on
snow effect. As an example we determined the snow effect on Mt. Hermon for
total neutron intensity and different multiplicities for 1998 – 2013 (the
amplitude of this effect in some years reached a big values – more than
40%). After correction NM data on snow
effect we determined long-term CR variations according to NM Mt. Hermon in
total neutron intensity and different multiplicities. Obtained results for
total neutron intensity we compare with results on other CR stations in
dependence of altitude and cut-off rigidity. Results for different
multiplicities we use for estimation of long-term CR rigidity spectrum. We
estimate also the hysteresis effect and the effective size of the modulation
region and expected size of the Heliosphere. After correction NM data on snow
effect we determined also CR 27-day variations (caused by the rotation of the
Sun) according to NM Mt. Hermon in total neutron intensity and different
multiplicities. Obtained results for total neutron intensity we compare with
results on other CR stations in dependence of altitude and cut-off rigidity.
Results for different multiplicities we use for estimation rigidity spectrum
of the CR 27-day variations. We estimate also the long-term changes in CR
27-day variations and its connection with 27-day variations of solar
activity. |
| 2 |
Long-term and 27-day variations
of the phase and amplitude of the CR solar-daily anisotropy according to NM
Mt. Hermon: effects in total intensity and different multiplicities |
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Dorman, L1; Applbaum, D S2; Ben Israel, I2; Dai, U2; Kazanzev, V2; Kozliner, L2; Pustil'nik, L2; Sternlieb, A2; Zukerman, I2 |
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1Israel
Cosmic Ray and Space Weather Centre of Tel Aviv University, Israel Space
Agency and Golan Research Institute; 2ICR and SWC, Tel Aviv University |
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After correction NM data on snow
effect we determined long-term variations of the phase and amplitude of 1-st
and 2-nd harmonics CR solar-daily anisotropy according to NM Mt. Hermon in
total neutron intensity and different multiplicities. Obtained results for
total neutron intensity we compare with results on other CR stations in
dependence of altitude and cut-off rigidity. Results for different
multiplicities we use for estimation of long-term CR anisotropy
spectrum. After correction NM data on
snow effect we determined also 27-day variations in the phase and amplitude
of the 1-st and 2-nd harmonics of CR solar-daily anisotropy according to NM
Mt. Hermon in total neutron intensity and different multiplicities. Obtained
results for total neutron intensity we compare with results on other CR
stations in dependence of altitude and cut-off rigidity. Results for
different multiplicities we use for estimation rigidity spectrum of the CR
27-day variations in the 1-st and 2-nd harmonics of CR solar-daily
anisotropy. We estimate also the long-term changes in the 27-day variations
of CR anisotropy and its connection with 27-day variations of solar activity. |
| 3 |
The on-line each hour
automatically correction data of total NM intensity and different
multiplicities on snow effect |
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Dorman, L1; Applbaum, D S2; Ben Israel, I2; Dai, U2; Kazantsev, V2; Kozliner, L2; Pustil'nik, L2; Sternberg, A2; Zukerman, I2 |
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1Israel
Cosmic Ray and Space Wearther Center of Tel Aviv University, Israel Space
Agency and Golan Research Institute, Israel; IZMIRAN, Russia; 2ICR and SWC, Tel Aviv
University |
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In our report Dorman et al.
“Snow effect for total NM intensity and different multiplicities on Mt.
Hermon during 1998 – 2013”, we described the method to determine the snow
effect in the total NM intensity and different multiplicities. By using
regression coefficients obtained for the long period of observations,
obtained in this paper, we developed method of automatically correction
on-line each hour and each minute data of total NM intensity and different
multiplicities on snow effect. We show that expected average errors in this
method for one hour observation is about 0.2%, what is comparable with the
statistical error. We show also how to correct on-line automatically
one-minute data on snow effect. Corrected on-line one minute data can be now
used for the forecasting of great radiation hazards from solar flares and
estimation of expected total fluency and radiation hazards for satellites
electronics and astronauts health, as well as for people and electronics on
regular airlines at altitudes about 10 km. Corrected on-line one hour data
can be now used for the forecasting of great magnetic storms, dangerous for
satellites, technologies, and people health. |
| 5 |
Re-Calculating NOAA GOES
Integral Solar Proton Flux Products |
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Sandberg, I1; Rodriguez, Juan2; Onsager, Terry3; Jiggens, P4; Daglis, I5 |
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1National
and Kapodistrian University of Athens; 2National Geophysical Data Center, NOAA, Colorado; 3Space Weather Prediction
Center, NOAA, Colorado; 4European Research and Technology Centre; 5Department of Physics,
National and Kapodistrian University of Athens |
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Solar proton flux measurements
on-board Geostationary Operational Environmental Satellites (GOES) are of
great importance contributing to the development of long-term solar proton
models and to satellite operational needs. Recently, new approaches have been
proposed for the determination of the effective energies of the EPS
(Energetic Particle Sensor) units by developing either generic iterative
algorithms (Kress et al 2013) orexhaustive cross-calibration schemes
(Sandberg et al 2014). In this work we evaluate these approaches focusing on
proton integral flux calculations over different energies for a series of
solar proton events. Preliminary results - based on these approaches –
exhibit significant differences with respect to the values provided by the
Space Weather Prediction Center of NOAA. Lessons learned from these studies
may be used to further improve numerical algorithms applied for the
calibration of the solar proton detectors on board GOES-R and for the
calculation of past and present integral flux products that are widely used
by the space weather community. |
| 5 |
Comparative Data Quality
Assessment for ACE SIS, ACE EPAM, WIND 3DP, SOHO/ERNE, and SOHO EPHIN during
Selected Solar Energetic Particle Events |
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Heber, B1; Dresing, N1; Kuehl, P1; Goméz-Herrero, R2; Malandraki, O3; Papaioannou, A4; Marhavilas, P K4; Valtonen, E6; Raukunen, O6; Riihonen, V6; Heynderickx , D7 |
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1Christian-Albrechts-Universitaet
zu Kiel; 2Universidad
de Alcalá, Departamento de Física y Matemáticas; 3National Observatory of Athens; 4National & Kapodistrian University of Athens |
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Significant developments in our
understanding of energetic particles in the heliosphere are based on both
theoretical understanding and observational evidence especially due to
more-detailed near-Earth observations. Thus, in anticipation of this network of
spacecraft near Earth close to the Langragian point L1, it is a perfect time
to develop techniques and strategies for combining the different energetic
particle measurements. Different instrumentation measure the energy spectra
and pitch angle distribution of ions from a few tenth of keV/nucleon to
several hundred of MeV/nucleon as well as electrons in the range from below
20 keV to above 10 MeV. Among other SEPServer was an EU funded project that
provides data and a data comparison of ACE SIS, ACE EPAM, WIND 3DP,
SOHO/ERNE, SOHO EPHIN and partially STEREO SEPT. The Comparisons were
undertaken for selected sample of events. In some cases not only the
intensity time profiles but higher order data products such as energy spectra
or pitch angle distributions of different instruments were investigated. The
results for the November 1997, May 1999, November 2004, July, 2005, January
2007 and May 2007 events will be presented |
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