Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: NASA Embraces Space Day '98
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Renee N. Juhans
Headquarters, Washington, DC May 19, 1998
(Phone: 202/358-1712)
NOTE TO EDITORS: N98-34
NASA EMBRACES SPACE DAY '98
NASA Administrator Daniel S. Goldin will "chat" with students
around the world on May 21 between 10 a.m. and 10:30 a.m. EDT via
the Internet, as part of this year's Space Day celebration.
Cyber Space Day, an interactive webcast devoted to space,
will broadcast from the Mall in Washington, DC, from 10 a.m. to 6
p.m. EDT. The webcast will allow students to conduct live
interviews with prominent figures from the public and private
sectors who have made significant contributions to space
exploration. Other "chat" participants include: Senator John
Glenn; Barbara Morgan, astronaut candidate/education mission
specialist; David Levy, amateur astronomer, author and comet
discoverer; and Dr. Mae Jemison, former astronaut and college
professor.
"I am pleased to see Space Day focus on education and embrace
children as well as their parents and teachers," said
Administrator Goldin. "NASA appreciates the role Space Day plays
in helping to communicate the importance of science, mathematics
and technology education. These efforts help lay the foundation
for inspiring the children of the world to reach for the stars."
Space Day is sponsored by the National Advisory Board co-
chaired by Sen. Glenn and Norman Augustine, Chairman of the Board
of Lockheed Martin, to stimulate interest in science, math and
technology education through the excitement of space exploration.
NASA along with more than 34 partner organizations in the
educational, scientific, public and private sectors have joined to
celebrate this national event.
The global celebration of Space Day '98 will kick off at 9
a.m. EDT. In recognition of Space Day, NASA Centers around the
country will host the following events:
NASA Headquarters, Washington, DC - May 21st -- Senator John
Glenn, Payload Specialist, STS-95, will serve as featured speaker
at the NASA Research and Human Health Symposium at George
Washington University in the Dorothy Betts Marvin Theatre from 2
p.m. - 5 p.m. For more information please visit:
http://www.gwu.edu/~spi
Ames Research Center, Moffet Field, CA - May 21st -- 1,250
elementary school students and their teachers will participate in
over twenty-five activities about the Moon and space exploration.
Students will build a Lunar Prospector model, participate in a
mission simulation, make their own craters, construct a lunar
habitat, and meet astronauts. Additional information on this
event can be found at:
http://lunar.arc.nasa.gov
Jet Propulsion Laboratory, Pasadena, CA - May 20-21st -- "A
Day on Europa" will take place on May 20-21, since daylight on
Europa lasts about two Earth days. Scheduled activities in numerous American
cities will be transformed into global village events via the Internet.
Highlights will include new imagery of Europa taken by the Galileo
spacecraft and a free panel discussion entitled "Europa - Another
Water World?" For more information go to:
http://www.caltech.edu/~tickets/to.htm
For other A Day on Europa events and activities go to:
http://www.jpl.nasa.gov
Kennedy Space Center, Cocoa Beach, FL - May 22-25 -- From May
22-25, the Visitor Complex will host Discover Magazine, Star Trek,
Fox 35 Kids and Cool 105.9 Day. These events will feature
exhibits and appearances by former astronauts including Capt. Alan
Bean, Dr. Ed Gibson, Col. Mike Mullane, Col. Buzz Aldrin, Capt.
Gene Cernan, Cdr. Scott Carpenter, Capt. Wally Schirra, and Dr.
Story Musgrave; as well as special character appearances; a
scavenger hunt; and promotional giveaways. For more information
please call 407/494-4254.
Goddard Space Flight Center, Greenbelt, MD - May 21 -- More
than 100 fourth grade students will participate in variety of
activities which include: Space Bingo; Send Your Name to Mars;
Planet Garden; How to Calculate Your Age and Weight on Another
Planet; Exploring Earth From Space; Cyber Space Day; 101 Reasons
to Explore Space; and tours. For more details call 301/286-7031.
Johnson Space Center, Houston, TX - May 20 -- In anticipation
of Space Day, the Challenger Center for Space Science Education
will take fourth through eighth grade students on a special
electronic field trip (EFT) that celebrates the human spirit of
exploration. The event, will be broadcast via satellite, brings
youngsters behind the scenes to witness first-hand how robotic,
human and ground-based missions are used to unveil the mysteries
of our universe.
More information on Space Day '98 activities can be found at the
following URL:
www.spaceday.com
-end-
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: Scientists Report TRMM Data Exceeding Expectations
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David E. Steitz
Headquarters, Washington, DC May 19, 1998
(Phone: 202/358-1730)
Lynn Chandler
Goddard Space Flight Center, Greenbelt, MD
(Phone: 301/286-9016)
RELEASE: 98-83
SCIENTISTS REPORT TRMM DATA EXCEEDING EXPECTATIONS
The world's first spaceborne rain radar -- aboard the
Tropical Rainfall Measuring Mission (TRMM), a joint U.S.-Japanese
mission -- is exceeding expectations for accuracy and resolution,
and the spacecraft is providing unprecedented insights into
rainfall producing cloud systems over tropical land masses and
oceans.
"We're extremely excited about these new images and the
quality and quantity of the data we're receiving. In several
instances, the data resolution is much better than we had
anticipated," said Dr. Christian Kummerow, TRMM Project Scientist,
at NASA's Goddard Space Flight Center, Greenbelt, MD.
"Previously, it was not possible to gather radar precipitation
data over the oceans and TRMM has changed all that."
TRMM is NASA's first mission dedicated to observing and
understanding tropical rainfall, which comprises more than two-
thirds of all rainfall, and how it affects the global climate.
Global rainfall is the primary distributor of heat through
atmospheric circulation. The recent El Nino serves as a perfect
example of the atmospheric circulation changes that can result
from a displacement of the normal precipitation patterns in the
central Pacific. More precise information about this rainfall and
its variability is crucial to understanding and predicting global
climate and climate change.
The Precipitation Radar aboard TRMM is the first rain radar
ever launched into space. It measures precipitation distribution
over both land and sea areas. Some of the most dramatic
Precipitation Radar data was received on March 9 over Melbourne,
FL, during the passage of a line of very severe thunderstorms. In
comparing the TRMM radar data of the storm with that taken by
ground-based radars, the three dimensional TRMM radar showed
better vertical resolution of the storm structure. The vertical
structure is critical for determining a storm's overall intensity
as well as determining the height at which the heat release
associated with precipitation is occurring.
Another image released today shows TRMM's radar-derived view
of a severe thunderstorm over Houston, TX. The TRMM radar
demonstrated significantly better capability to define
ambiguities, or occasional "false readings," associated with
ground-based radars.
The TRMM spacecraft fills an enormous void in the ability to
calculate world-wide precipitation because so little of the planet
is covered by ground-based radars. Presently, only two percent of
the area covered by TRMM is covered by ground-based radars.
"Since rainfall represents energy conversion, hurricane
researchers are eager to use the rainfall data as input to
hurricane forecast models," notes Jerry Jarrell, director,
National Hurricane Center.
Also aboard TRMM is the Microwave Imager, providing
exceptional resolution of storm systems. TRMM's Microwave Imager
has better spatial resolution and a new lower frequency channel
than previous instruments, according to Kummerow.
An interesting preliminary finding from the Lightning Imaging
Sensor (LIS), another instrument on the TRMM satellite, is that
its data indicate little lightning over the oceans and 90 percent
of lightning occurring over land. Researchers believe that the
greater lightning activity over land is primarily due to a larger
convection -- or heat -- effect associated with land. This
results in greater ice production and, consequently, more
lightning. "The beauty of TRMM is that with the Precipitation
Radar and the microwave imager, we can test this hypothesis time
and again," said LIS Principal Investigator Hugh Christian, at the
Global Hydrology and Climate Center at the Marshall Space Flight
Center, Huntsville, AL. "TRMM will enable us to gain fundamental
insights into the properties of these convective storms and thus
better estimate the effects on global weather patterns."
The Clouds and the Earth's Radiant Energy System (CERES)
instrument aboard the spacecraft measures how much sunlight the
planet's atmosphere, surface and clouds reflect and how much
energy it radiates to space from its store of heat energy. "CERES
achieved new levels of calibration that we've never reached before
in looking at the Earth," said Dr. Bruce Barkstrom, a scientist at
NASA Langley Research Center, Hampton, VA, which manages CERES.
"Those new levels will help us reduce the uncertainty of how the
Earth uses the energy from the Sun to drive the climate system."
By studying rainfall regionally and globally, and the
difference in ocean and land-based storms, TRMM is providing
scientists the most detailed information to date on the processes
of these powerful storms, leading to new insights on how they
affect global climate patterns. TRMM's complement of state-of-the-
art instruments will provide extremely accurate measurements of
the distribution and variability of tropical rain and lightning,
and the balance of solar radiation absorbed and reflected by
Earth's atmosphere.
-end-
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: Hughes To Send HGS-1 Satellite On 2nd Lunar Flyby
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HUGHES GLOBAL SERVICES, INC.
Communications and Customer Relations
P.O. Box 92919 (S10/S323)
Los Angeles, CA 90009
Media Relations (310) 364-6363
Investor Relations (310) 662-9688
www.hughesglobal.com
HUGHES TO SEND HGS-1 SATELLITE ON 2ND LUNAR FLYBY
LOS ANGELES, May 18, 1998 -- Hughes Global Services, Inc., (HGS), which
successfully sent a stranded communications satellite around the moon last
week in an unprecedented salvage mission, is mounting a second lunar flyby
to further improve the orbit.
The satellite, known as HGS-1, passed behind the moon at noon PDT May 13 and
returned to Earth, making its closest approach about 8 p.m. PDT Saturday.
Instead of doing the planned retro burn at that time, Hughes' mission
controllers fired the satellite's motor for a shorter period of time,
allowing the satellite to glide into a looping 15-day orbit. An additional
small burn on June 1 will send the satellite toward its second lunar
encounter.
"While the first pass by the moon was completely successful and accomplished
all of our objectives, we always said we were going for the best obtainable
orbit," said HGS President Ronald V. Swanson. "A second lunar flyby will
make the orbit even better and will increase the satellite's attractiveness
to potential customers. We do not plan any additional lunar maneuvers since
additional passes will result in diminishing improvements."
When the satellite was sent into space last Christmas, the launch vehicle
malfunctioned and left the spacecraft in an unusable, highly elliptical
orbit. Most communications satellites operate from a circular orbit around
the equator.
By sending the satellite around the moon, Hughes used lunar gravity to
improve the resulting orbit once the satellite returned to Earth.
When HGS obtained title to the satellite last month, it agreed to try to
find revenue-producing uses for the satellite and to share profits with the
insurers. A consortium of 27 insurers had owned the satellite after the
original mission was declared a total loss. HGS' primary business is
packaging satellite communications services for governmental entities,
although it is actively seeking commercial interest in the entire satellite
as well.
"Our orbital analysts have done a fantastic job of planning this mission and
predicting the satellite's trajectory thus far," Swanson said. "So we
challenged them to evaluate whether we could improve the orbit further.
"They said one more loop around the moon would improve the orbit, with
little impact on the satellite's operational life -- so we're going for it,"
Swanson said.
The new mission plan involves the same number of post-lunar motor firings,
four. Only the times and durations have changed. The first burn successfully
occurred Saturday night, as scheduled. That burn reduced the satellite's
speed by roughly one-half of what was originally planned. Saturday night's
burn placed HGS-1 into a 15-day orbit with an apogee -- the farthest
distance from the Earth -- of about 293,000 miles (488,000 km).
A second, smaller burn, scheduled for June 1, will nudge the satellite into
position for its second lunar encounter on June 6. The spacecraft will pass
the moon's surface from a distance of 27,000 miles (43,000 km), which is
about seven times farther than the initial lunar encounter on May 13. An
additional motor firing is planned for June 12, to further position the
satellite for its final orbit. The final burn, currently scheduled for June
13, will place the HGS-1 spacecraft into geosynchronous orbit.
Hughes Global Services is a subsidiary of Hughes Space and Communications
Company (HSC), the world's leading manufacturer of geostationary commercial
communications satellites. Scientists and engineers from both HGS and HSC
are taking part in the mission. Both companies are units of Hughes
Electronics Corporation. PanAmSat Corporation, of which Hughes Electronics
is the majority owner, has been providing critical command and tracking
support for the mission through its ground station in Fillmore, Calif.
The earnings of Hughes Electronics are used to calculate the earnings per
share attributable to GMH (NYSE symbol) common stock.
###
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: New Mars Global Surveyor Image Available
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NEW MARS GLOBAL SURVEYOR IMAGE
A new image taken by the Mars Global Surveyor spacecraft is now available
on the MGS home page:
http://mars.jpl.nasa.gov/mgs/msss/camera/images/5_15_98_ascraeus_release/index
.html
The image caption is appended below.
Ron Baalke
Mars Global Surveyor
Mars Orbiter Camera
Mars Orbiter Camera (MOC) High Resolution Images:
Lava Flows On Ascraeus Mons Volcano
Mars Global Surveyor Mars Orbiter Camera Release: MOC2-47a, -47b
Mars Global Surveyor Mars Orbiter Camera Image ID: 578204600.26705
P267-05
(A) [Image]
(A) Portion of U.S. Geological Survey Mars Digital Mosaic. Volcano is about
400 km (250 miles) across at its center. Sun illumination over most of
mosaic is from upper right. Arrow points to location of MOC image shown in
(B).
(B) [Image]
(B) MOC image 26705 (subframe) reproduced at full resolution, about 4.1
meters/pixel (13.4 feet/pixel). Picture shows an area approximately 3.3 x
3.3 km (2.1 x 2.1 miles) in size. Sun illumination is from the lower right.
CAPTION
Ascraeus Mons Volcano:
Like Earth, Mars has many volcanoes and volcanic features. This
high-resolution view shows some of the lava flows near the summit of
Ascraeus Mons, one of the three giant shield volcanoes known as the "Tharsis
Montes". Volcanoes form when magma (molten rock) erupts out onto the surface
of a planet. Based on Viking-era observations, Ascraeus Mons is considered
to be one of the tallest volcanoes on Mars... its summit is more than 11 km
(6.8 miles) above the surrounding plain. The summit is more than 23 km (14
miles) higher in elevation than the place where Mars Pathfinder landed in
July 1997.
Description of MOC Image:
This picture shows an area that is about 20 km (12 miles) higher in
elevation than the Mars Pathfinder landing site. The picture shows three
main features: (1) a crater at the center-right, (2) a sinuous,
discontinuous channel across the upper half, and (3) a rough and pitted,
elevated surface across the lower half of the image.
(1) Crater at center right. Distinguishing meteor craters from volcanic
craters can sometimes be a challenge on Mars. This particular crater was
most likely formed by meteor impact because it has a raised rim and a faint
radial ejecta pattern around the outside of it. This crater is 600 m (2000
feet) across, about 3/4 the size of the famous "Meteor Crater" near Winslow,
Arizona.
(2) Sinuous channel. The type of discontinuous channel running across the
upper half of the image is sometimes refered to as a "sinuous rille". These
are common on the volcanic plains of the Moon and among volcanoes and
volcanic plains on Earth. Such a channel was once a lava tube. It is running
down the middle of an old lava flow. The "tube" looks like a "channel"
because its roof has collapsed. The discontinuous nature of this channel is
the result of the collapse, or "cave-in" of what was once the roof of the
lava tube. It is common for certain types of relatively fluid lavas to form
lava tubes. As it is being emplaced, the outer margins of the lava flow cool
and harden, but the interior remains hot and and continues to flow down-
hill. Eventually, the eruption stops and the lava inside the tube cools,
contracts, and hardens, leaving behind a tube (basically, a long narrow
cave).
(3) Rough elevated surface. The rough, pitted, and elevated surface across
the bottom half of the image is a lava flow. The margins of this feature are
somewhat lobate in form, and the entire feature is elevated above its
surroundings, indicating that it was the last lava flow to pour through this
region.
Putting it All Together: Aa and Pahoehoe Lava Flows:
Shield volcanoes such as Ascraeus Mons form from relatively fluid lavas.
Shield volcanoes on Earth include the well-known Islands of Hawai'i. The
kind of lava that is fluid enough to make shield volcanoes is called basalt.
This is an iron- and magnesium- rich silicate lava that, when cooled, is
usually black or very dark brown.
Basalt lava flows come in two main varieties: Aa and Pahoehoe. These are
Hawai'ian names. "Aa" (pronounced "ah-ah") lava flows have very rough,
jumbly surfaces, and they usually lack lava tubes. "Aa" lava flow surfaces
are very rough to walk on-- thus the term "aa" probably refers to the sound
a person might make when walking on a cooled/solidified aa flow in bare
feet!
"Pahoehoe" (pronounced "pa-hoy-hoy") is a term that means "ropey". The
surfaces of pahoehoe lava flows are generally very smooth and billowy.
Sometimes they have a ropy texture like melted taffy or caramel. Pahoehoe
flows very commonly contain lava tubes.
The rough-surfaced flow across the lower half of the MOC image is
interpreted to be an "aa" lava flow, and the smoother surface with a sinuous
channel running down its center is interpreted to be a "pahoehoe" lava flow.
Both would indicate that the lavas on Ascraeus Mons, at least at this
location, are probably composed of basalt.
More Picture Information:
The MOC picture (B) is a subframe of image #26705, centered approximately at
11.5°N latitude, 103.5°W longitude. It was taken on April 28, 1998, at 4:23
AM Universal Time, on Mars Global Surveyor's 267th orbit around Mars. Orbit
267 was the second-to-last orbit on which observations were obtained before
Mars and the spacecraft passed behind the Sun for several weeks known as
"Solar Conjunction".
The context frame (A) is from a U.S. Geological Survey photomosaic of Viking
Orbiter images obtained in the late 1970s. The bright, wispy feature on the
west (left) side of the volcano is a plume of dust being lofted by wind.
This plume casts a shadow that can be seen below it.
Malin Space Science Systems and the California Institute of Technology built
the MOC using spare hardware from the Mars Observer mission. MSSS operates
the camera from its facilities in San Diego, CA. The Jet Propulsion
Laboratory's Mars Surveyor Operations Project operates the Mars Global
Surveyor spacecraft with its industrial partner, Lockheed Martin
Astronautics, from facilities in Pasadena, CA and Denver, CO.
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: STARDUST Update - May 15, 1998
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STARDUST Status Report
May 15, 1998
Ken Atkins
STARDUST Project Manager
Assembly, Test, and Launch Operations (ATLO) activities: ATLO
this past week involved harness modifications to achieve a
compatible timing interface and grounding for the Navigation Camera
scan-mirror motor, Inertial Measurement Unit (IMU #2) installation,
Attitude Control System interface testing and spacecraft functional
testing.
The formal ATLO Pre-Environmental Test Review was conducted. The Board
concluded that STARDUST is ready to proceed to its environmental test.
Aerogel: The ATLO Test Unit (ATU) aerogel trays were installed in the
Sample Return Capsule (SRC). The installation procedure was practiced
in the SRC Structural/Thermal Model. JPL aerogel team members
participated in the aerogel collector inspection and installation.
Outreach: After the film "Deep Impact" opening and the announcement of
the new round of name collections, the STARDUST home page jumped to a
peak of 64,239 hits on May 11, and has been averaging 51,600 hits
per day for the week. About 86,000 names have already been
collected. There is a link to the Stardust name collection form
from the Deep Impact homepage at:
http://www.deepimpactmovie.com
STARDUST was also the highlighted feature on the
Space Day home page at:
http://www.spaceday.com/thisweek/index.htm
For more information on the STARDUST mission - the first ever comet sample
return mission, please visit the STARDUST home page:
http://stardust.jpl.nasa.gov
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: NASA Selects Initial Members Of New Virtual Astrobiology Institute
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Douglas Isbell/Don Savage
Headquarters, Washington, DC May 19, 1998
(Phone: 202/358-1547)
RELEASE: 98-84
NASA SELECTS INITIAL MEMBERS OF NEW VIRTUAL ASTROBIOLOGY INSTITUTE
NASA has selected 11 academic and research institutions as
the initial members of the agency's new Astrobiology Institute,
thus launching a major component of NASA's Origins Program.
The selected institutions represent the best of 53 uniformly
first-class proposals submitted, according to NASA officials.
Given that the institute members will remain at their home
organizations, the partnership among the members and NASA will be
carried out primarily via the Internet. This electronic 'virtual'
Institute will bring together astrophysicists, biologists,
chemists, physicists, planetologists and geologists to conduct
interdisciplinary research on the multifaceted issue of life in
the Universe and its cosmic implications. It will also help to
train young scientists in this emerging field.
"These initial members of NASA's Astrobiology Institute will
be at the forefront of the increasingly important link between
astronomy and biology, which has been a fundamental interest of
mine for the past several years," said NASA Administrator
Daniel S. Goldin. "The 'office hallways' of this virtual
institute will be the fiber optic cables of the Next Generation
Internet, and the groundbreaking research that this group
generates will help guide our space exploration priorities well
into the 21st century."
The selected initial members of the Institute are:
*Universities
Harvard University, Cambridge, MA
University of California, Los Angeles
University of Colorado, Boulder
Arizona State University, Tempe
Pennsylvania State University, University Park
*Research Institutions
Carnegie Institution, Washington, DC
The Scripps Research Institute, La Jolla, CA
Woods Hole Marine Biological Laboratory, Woods Hole, MA
*NASA Centers
Ames Research Center, Moffett Field, CA
Johnson Space Center, Houston, TX
Jet Propulsion Laboratory, Pasadena, CA
NASA has developed the Origins Program with its Office of
Space Science to search for signs of life in the Universe, both in
our Solar System and beyond. The Astrobiology Institute will
foster the interdisciplinary research and training necessary for
future exploration of this theme. Funding for the Institute will
begin with $9 million in 1999 and $20 million in 2000. This total
is expected to grow as research directions are developed and the
capabilities of the Next Generation Internet are expanded and
fully utilized.
The Astrobiology Institute members will conduct a broad range
of interdisciplinary and synergistic research on topics including:
the formation of organic compounds important to the origins of
life, such as from meteorites; the formation and characteristics
of habitable planets; the emergence of self-replicating systems
and possible pre-biotic worlds; how the Earth and life have
influenced each other over time, including the evolution of
ancient metabolism and the interplay of evolved oxygen; the
evolution of multicellular organisms and the evolution of complex
systems in simple animals; organisms in extreme environments such
as hydrothermal vents; and the identification and development of
biomarkers to determine terrestrial and extraterrestrial
biosignatures.
The selection of the members, encompassing academic
institutions and government labs, was based on a competitive
evaluation process that began with the release of a Cooperative
Agreement Announcement in October 1997. The next solicitation
opportunity for new members will take place in about a year.
For further information on the Institute and the field of
astrobiology, see the following Internet site:
http://astrobiology.arc.nasa.gov/
The Institute's director and staff will reside at NASA's Ames
Research Center, Moffett Field, CA. NASA Ames will manage the
Institute's operations for NASA's offices of Space Science, Earth
Science, and Human Exploration and Development of Space at NASA
Headquarters in Washington, DC.
- end -
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: YOUR TICKET TO SPACE (sm) webchat discusses space tourism
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FOR IMMEDIATE RELEASE
May 19, 1998
Contacts:
Karen Rugg, National Space Society, 202-543-1900
Jennifer Hwang, Yahoo!, 408-731-336
Steven A. Werner, X PRIZE Foundation, 314-533-2002
"YOUR TICKET TO SPACE" WEBCHAT DISCUSSES FUTURE OF SPACE TOURISM
National Space Society hosts Yahoo! Chat with X PRIZE Foundation chairman,
X PRIZE competitor and NASA Associate Administrator
(Washington, DC) -- May 19 -- This Wednesday, May 20, the National Space
Society will host a Yahoo! Chat with X PRIZE Foundation chairman, Peter
Diamandis, X PRIZE competitor, Michael Kelly, and NASA Associate
Administrator, Alan Ladwig, following an announcement made earlier that day
by the Foundation regarding a space-related sweepstakes. Webchat guests
will discuss the announcement, the X PRIZE competition, and the future of
space tourism. The webchat will take place on Wednesday from 9:00 - 10:00
pm ET (6:00 - 7:00 pm PT) at <http://chat.yahoo.com>.
"This webchat will give the public almost immediate access to several
people who will be among the day's newsmakers," said Robert Pearlman, NSS
Online Programs Director. "The Society, which represents 23,000 space
enthusiasts, is proud to present this webchat as a service to our members
and the general public. The chat will help answer their questions and raise
excitement about the morning's announcement."
More information about the chat, including biographies and photographs of
the guests, is available at the National Space Society's website at
<http://www.nss.org/xprize>. The site will also include a transcript of
the May 20 chat within 48 hours following the event.
The X PRIZE Foundation will award a $10 Million prize to the first pioneer
who privately finances and builds a spaceship that can carry three adults
on a 62-mile sub-orbital space flight. Patterned after the Orteig
International Prize, which was won 70 years ago by Charles Lindbergh in his
solo flight from New York to Paris, the X PRIZE is to challenge the best
engineers and innovators to build a spacecraft that eventually could be
used to develop a commercial space transportation and tourism industry.
The National Space Society, founded in 1974, is an independent, nonprofit
space advocacy organization headquartered in Washington, DC. Its 23,000
members and 90 chapters around the world actively promote a spacefaring
civilization. Information on NSS and space exploration is available at
<http://www.nss.org/>.
###
NOTE: The next issue of NSS's magazine, Ad Astra, will be a special report
on space tourism, including an update on the X PRIZE competition. Reporters
interested in receiving a copy should contact Karen Rugg at 202-543-1900 or
<krugg@nss.org>.
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: Discovery Launch To Mir On Mission STS-91 Set For June 2
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Jennifer McCarter May 20, 1998
Headquarters, Washington, DC
(Phone: 202/358-1638)
Joel Wells
Kennedy Space Center, FL
(Phone: 407/867-2468)
Ed Campion
Johnson Space Center, Houston, TX
(Phone: 281/483-5111)
RELEASE: 98-85
DISCOVERY LAUNCH TO MIR ON MISSION STS-91 SET FOR JUNE 2
Space Shuttle managers selected June 2 as the official
date for the launch of Shuttle Discovery on the ninth planned
docking mission with the Russian Space Station Mir.
The flight, designated STS-91, will deliver logistics
and supplies to Mir and bring home NASA Astronaut Andrew
Thomas, the seventh and final NASA astronaut to serve as a
Mir crew member. Thomas has been on the orbiting station
since late January.
Discovery will launch from Kennedy Space Center Launch
Complex 39A. The current launch time of 6:10 p.m. EDT may
vary slightly because of calculations of Mir's precise
location in space at the time of lift-off due to Shuttle
rendezvous phasing requirements. The STS-91 mission is
scheduled to last 9 days, 19 hours, 53 minutes. An on-time
launch and nominal mission duration would have Discovery
landing back at Kennedy on June 12 at 2:03 p.m. EDT
"The nine joint Shuttle-Mir docking missions and the
seven astronauts who served as station crew members have
provided us with a wealth of insight and experience to be
used as we begin construction of the International Space
Station later this year," said George Abbey, Director of the
Johnson Space Center, who chaired the review.
The launch team is evaluating a minor overboard water
leak from the fuel cell No. 3 relief valve to determine its
acceptability for flight. The leak was first seen during
Monday's super lightweight tank test when the fuel cell was
brought on line to support tanking test operations.
The launch date decision follows completion of the
Flight Readiness Review at Kennedy by Shuttle managers from
NASA and prime contractor United Space Alliance. STS-91 will
be Discovery's 24th mission into space and the 91st Space
Shuttle flight in the program's history.
-end-
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: NASA Selects Teams For Research Agreements - A "Weather Channel" In Ev
Subject: NASA Selects Teams For Research Agreements - A "Weather Channel" In Ev
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Dwayne Brown
Headquarters, Washington, DC May 20, 1998
(Phone: 202/358-1726)
Kathy Barnstorff
Langley Research Center, Hampton, VA
(Phone: 757/864-9886)
RELEASE 98-86
NASA SELECTS TEAMS FOR RESEARCH AGREEMENTS --
A "WEATHER CHANNEL" IN EVERY COCKPIT?
Airlines and smaller airplanes are one step closer to having
up-to-the-minute, graphical weather displays in their cockpits,
thanks in part to a new NASA aviation safety initiative.
NASA has selected research proposals from eight industry
teams to develop Aviation Weather Information (AWIN) systems for
commercial airliners and general aviation aircraft.
"Pilots tell us their number one priority is graphical
weather information. We want to make it as easy to get a weather
channel in the cockpit as it is in your living room. Technologies
already exist that could help make that happen," said Michael
Lewis, Director, NASA Aviation Safety Program (AvSP), based at the
Langley Research Center in Hampton, VA.
AvSP is a partnership with the Federal Aviation
Administration (FAA), the aviation industry (manufacturers and
operators) and the Department of Defense (DOD). This partnership
supports the national goal announced by President Clinton last
year to reduce the fatal aircraft accident rate by 80 percent in
10 years and by 90 percent over two decades.
The weather information selections are one of NASA's new
investments in that ambitious challenge. NASA asked U.S.
companies to submit proposals for research, development,
prototyping and implementation of AWIN systems and components.
Industry teams submitted more than 40 proposals in three weather
information categories: a national and worldwide system, a general
aviation system and topical areas or specific components. NASA,
FAA and DOD researchers evaluated the proposals based on technical
merit, cost and feasibility.
NASA has set aside more than $8 million that will be matched
by industry to fund AWIN projects over the next eighteen months.
More money is expected to be designated later to accelerate
commercialization and make some systems available within five years.
For the first phase of the program, teams led by Honeywell
and Boeing/McDonnell Douglas Corp. will receive up to $2.4 million
apiece to develop a national and worldwide AWIN solution. Over
the same 18-month period, the NavRadio group will be awarded up to
$1.2 million and the ARNAV team, up to $400,000, for a general
aviation weather information system. Other teams led by Rockwell
International, Honeywell and NavRadio will split $1.6 million to
develop specific components for AWIN.
NASA envisions a futuristic system that would allow aircraft
to be both a source and user of weather information. Airborne
sensors would provide data for weather systems on board the plane,
on the ground and in other aircraft. In the cockpit would be
easy-to-read, real-time displays that can show weather across the
country, not just a limited number of miles ahead. That way
pilots could more easily monitor possible trouble spots and make
better, more cost-efficient routing decisions.
That weather information would get to and from aircraft by
satellite and ground transceivers using broadcast datalink and two
way communications systems. Many industry teams also propose to
incorporate decision aids into their AWIN designs. Those could
include, among other tools, alarm systems or displays of suggested
routes to help pilots better avoid potentially hazardous weather
situations.
The aviation safety initiative was created in the summer of
1997 by NASA Administrator Daniel S. Goldin in response to a
report from the White House Commission on Aviation Safety and
Security, chaired by Vice President Al Gore. NASA has designated
about $500 million over five years for aviation safety, with more
funding expected to follow.
Researchers at four NASA field installations are working with
the FAA and industry to develop affordable, implementable
technologies to make flying safer: Langley; Ames Research Center
in Moffett Field, CA; Dryden Flight Research Center in Edwards,
CA; and Lewis Research Center in Cleveland, OH.
Because of advances in the last 40 years commercial airliners
are already the safest of all major modes of transportation. But
with an accident rate that has remained relatively constant in the
last decade and air traffic expected to triple over the next 20
years, the U.S. government wants to prevent a projected rise in
the number of aircraft accidents.
For more information on the NASA Aviation Safety Program
please check the Internet at:
www.hq.nasa.gov/office/aero/oastthp/programs/avsaf/avsafpro.htm
For a list of AWIN industry teams, please see:
http://oea.larc.nasa.gov/news_rels/1998/May98/98_23.html
- end -
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: Strongest Stellar Magnetic Field Yet Observed Confirms Existence of Ma
Subject: Strongest Stellar Magnetic Field Yet Observed Confirms Existence of Ma
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Douglas Isbell
Headquarters, Washington, DC May 20, 1998
(Phone: 202/358-1753)
Tim Tyson
Marshall Space Flight Center, Huntsville, AL
(Phone: 256/544-0034)
RELEASE: 98-87
STRONGEST STELLAR MAGNETIC FIELD YET OBSERVED CONFIRMS EXISTENCE OF MAGNETARS
A neutron star, located 40,000 light years from Earth, is
generating the most intense magnetic field yet observed in the
Universe, according to an international team of astronomers led by
scientists at NASA's Marshall Space Flight Center in Huntsville, AL.
The discovery confirms the existence of a special class of
neutron stars dubbed "magnetars." Magnetars have a magnetic field
estimated to be one thousand trillion times the strength of
Earth's magnetic field. A neutron star is a burned-out star
roughly equal in mass to the Sun that has collapsed through
gravitational forces to be only about 10 miles across. Magnetars
have a magnetic field that is about 100 times stronger than the
typical neutron star.
The discovery, to be published in the May 21 issue of the
journal Nature, was made by a team of astronomers at the Marshall
Space Flight Center led by Dr. Chryssa Kouveliotou of the
Universities Space Research Association, working with Dr. Stefan
Dieters of the University of Alabama in Huntsville (UAH),
Professor Jan van Paradijs of UAH and the University of Amsterdam,
and Dr. Tod Strohmayer of NASA's Goddard Space Flight Center in
Greenbelt, MD.
"This finding should help us better calculate the rate at
which stars die and create the heavier elements that later become
planets and other stars," Kouveliotou said.
Kouveliotou and her team determined the strength of the
magnetic field by combining data gathered by NASA's Rossi X-Ray
Timing Explorer satellite with data from the Advanced Satellite
for Cosmology and Astrophysics, a collaborative mission between
Japan and the United States.
"The magnetic field generated by this star is truly
incredible," Kouveliotou said. "It is so intense that it heats
the surface to 18 million degrees Fahrenheit. Periodically, the
field drifts through the crust of the neutron star, exerting such
colossal forces that it causes a 'starquake.' The 'starquake'
energy is then released as an intense burst of low-energy gamma
rays."
Since these bursts happen quite often and the bulk of their
energy is in low-energy (soft) gamma rays, the objects associated
with them had been named Soft Gamma Repeaters. When bursting, Soft
Gamma Repeaters are among the brightest objects in the sky, giving
off as much energy in a single second as the Sun does in an entire
year. The magnetar in question, called SGR 1806-20 by
astronomers, was first discovered when it emitted soft gamma ray
bursts.
Astronomers have debated the origin of Soft Gamma Repeaters
since they were first observed in 1979. With this discovery,
however, researchers believe the origin of Soft Gamma Repeaters
lies in the 'starquake' phenomena of magnetars. The magnetar
theory was first proposed in 1992 by astrophysicists Dr. Robert
Duncan of the University of Texas at Austin and Dr. Christopher
Thompson of the University of North Carolina at Chapel Hill.
Astronomers believe that at least 10 percent of neutron stars
are born with magnetic fields that are strong enough to be
considered magnetars. Neutron stars are created in supernovae
explosions and they spin rapidly, at rates up to hundreds of
revolutions per second.
The magnetar SGR 1806-20 is observed to be spinning once
every 7.5 seconds and is slowing down roughly three milliseconds
per year. Superstrong magnetic fields cause a neutron star to
'brake' and 'cool down,' making it practically impossible to
observe them in radio waves or X-rays. This means there could be
thousands or even millions of these dark relics scattered
throughout our Milky Way galaxy. This could account for the large
number of observed supernovae remnants without detectable neutron
stars at their centers.
For more information on magnetars and this discovery, visit
NASA Marshall's Space Sciences Laboratory website at:
http://science.msfc.nasa.gov
-end-
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: Latest Computers Will Boost Asteroid Tracking Efforts
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MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Diane Ainsworth
FOR IMMEDIATE RELEASE May 20, 1998
LATEST COMPUTERS WILL BOOST ASTEROID TRACKING EFFORTS
NASA astronomers conducting a monthly sweep of the night sky
to identify previously unknown asteroids and comets will be able
to double their coverage and the number of discoveries they make,
thanks to new, state-of-the-art computer and data analysis
hardware.
The new equipment was purchased with funds from NASA, which
recently doubled its resources for near-Earth object research.
The new real-time analysis system, which serves a fully
automated charged-couple device (CCD) camera and telescope atop
Mt. Haleakala, Maui, HI, is part of the Near-Earth Asteroid
Tracking (NEAT) project, based at NASA's Jet Propulsion
Laboratory, Pasadena, CA. The new system features four 300-
megahertz processors that will be devoted solely to the enormous
amount of data coming back from the NEAT telescope on a nightly
basis.
"This new system will speed up the processing of data and
allow us to analyze up to 40 gigabytes of data each night, or the
equivalent of nearly 70 CD-ROMs," said Dr. Steven Pravdo, NEAT
project manager at JPL. "We will be able to double the amount of
sky we search each night, which is currently 500 square degrees,
as well as the number of new asteroids and comets we find during
each monthly observation cycle."
Installed in 1995, the NEAT camera uses a very large, very
sensitive 4,096- by 4,096-pixel CCD chip. The camera is located
on a 1-meter-diameter (39-inch) telescope operated by the U.S.
Air Force and located at an elevation of 3,000 meters (nearly 2
miles) above the Pacific Ocean. With stable climate, clear, dry
air and little light pollution, the NEAT tracking system has been
highly successful and continues to operate six days out of each
month. With additional support, the project hopes to increase
this six-day observational run to 18 nights of observations each
month.
Asteroids are considered relics of the formation of the
early solar system. Most of them are rocky materials, with some
composed of nickel and iron. Most range in size from boulders up
to the largest main belt asteroid, Ceres, which is approximately
965 kilometers (600 miles) in diameter. Comets, on the other
hand, are bodies of ice with embedded rock and organic materials
which heat up and become active, spewing gases and dust as they
approach the Sun.
The NEAT telescope detects these small bodies by observing
the same part of the sky three times during an interval of about
one hour and comparing the three images to determine the location
of objects moving across the sky. Since its inception, this
fully automated system has detected more than 25,000 objects,
including 30 near-Earth asteroids, two long-period comets and the
unique 1996 PW, which has the most eccentric orbit of all objects
discovered to date. More information about NEAT discoveries,
along with black-and-white images of the objects, is available at
http://huey.jpl.nasa.gov/~spravdo/neat.html .
Most recently, the NEAT team has discovered two new Earth-
crossing asteroids. One, designated 1998 HT31, is a relatively
small Apollo-type asteroid 270 meters (800 feet) in diameter; the
other, 1998HD14, is the 30th Aten to be discovered since JPL
astronomer Eleanor Helin first identified this class of asteroid
22 years ago, and the fifth discovered with the NEAT tracking
system. Both are classified as potentially hazardous asteroids
because their orbits come within 5 million kilometers (3 million
miles) of Earth, or about 20 times the distance of the Moon.
However, neither currently poses a threat to Earth.
"Atens are a rare class of asteroid because of their small
orbits, which are smaller than that of Earth's, and which never
allow them to wander far from our planet," said Helin, who is the
principal investigator of the NEAT program. "1998 HD14 passed
within 5 million kilometers (3 million miles of Earth) just a
week after we discovered it on April 29. This is relatively
close but poses no threat in the foreseeable future. Atens are
of particular interest to us because they stay so close to
Earth's orbit."
Along with near-Earth asteroids, astronomers are also
interested in tracking long-period comets, which travel vast
distances from the Oort Cloud, a region far beyond Pluto's orbit,
which is believed to house trillions of incipient comets. These
objects travel in very long paths through the solar system, and
can appear unannounced, with no calling cards.
"We are particularly interested in these comets because they
give us little time before appearing in Earth's vicinity," Helin
said.
Astronomers dedicated to discovering and tracking near-Earth
objects are eager to find all of the potentially dangerous
asteroids and comets long before they are likely to approach
Earth. For instance, the NEAT team at JPL is developing two new
CCD cameras and hopes to install them at Mt. Haleakala or other
facilities.
"With additional telescopes, longer observational runs and
our new operating system, we will be able to detect 90 percent of
the Earth-crossing asteroids that are larger than 1 kilometer
(6/10ths of a mile) in diameter in the next 10 years," Pravdo
said. "As our knowledge about these objects grows, we will be
able to provide better information which can be used in studies
of ways to divert Earth-crossers on threatening orbits toward
Earth."
NEAT was built and is being managed by the Jet Propulsion
Laboratory for NASA's Office of Space Science, Washington, DC.
JPL is a division of the California Institute of Technology in
Pasadena, CA.
#####
Hа сегодня все, пока!
=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: New Galileo Images Of Europa
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NEW GALILEO IMAGES OF EUROPA
May 21, 1998
The following images of Europa taken by the Galileo spacecraft are now
available on the Galileo home page: http://www.jpl.nasa.gov/galileo
o Europa's Scrambled Ice
o Inside Europa's Mannann'an Crater
o A Closer Look At Chaos On Europa
o Small Craters on Europa
o A Dark Spot on Europa
o Topography Within Europa's Mannann'an Crater
o Europa Imaging Highlights During GEM
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ Pasadena, CA | The truth always turns out
/___| | | | ___/ | |/__ /| | to be simpler than you
|_____|/ |_|/ |_____|/ | thought. Richard Feynman
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=SANA=
Дата: 22 мая 1998 (1998-05-22)
От: Alexander Bondugin
Тема: Neural nets in space research
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Session: Space Applications
Session chair: Clark Lindsey
16.00-17.30
Keynote Talk:
Sven Grahn (Swedish Space Corporation) "Spacecraft design in the modern world"
Spaceflight does no longer push technology, but is rather pulled by other, more
financially stronger industries such as the
telecom business. This, and other trends set the stage for spacecraft design in
the modern world: The demise of
MIL-STD EEE parts, the appearance of production batches of satellites similar
to those of airplanes, modern methods
of software engineering. Basic technologies such as solar cells and electrical
storage batteries are also pulled by
non-space industry. So, one may say that space technology has left the
experimental age and finally, staggeringly,
entered the industrial age, primarily driven by commercial pressures.
Talks:
U. Brandstrom (IRF, Kiruna), "ALIS, a multi station imaging facility in
Northern Sweden"
Urban Brandstrom, Swedish Institute of Space Physics (IRF),
Peter Rydesater, Mitthogskolan, Institutionen for IT,
Ake Steen, IRF,
Bjorn Gustavsson, IRF,
ALIS (Auroral Large Imaging System) is an imaging facility in Northern Sweden.
The system consist of six
unmanned, fully remote controlled stations. Each station has a high
performance CCD imager, and some stations
also have other scientific instrumentation (e.g pulsation magnetometers).
ALIS is capable of producing large amounts
of data in a short time. For that reason, novel (AI) techniques for data
analysis, are of high priority in order to be able to
handle the large data sets.
In this paper we will try to address the questions of how to interface such
(AI) applications to an existing multi station
research facility, in terms of real-time experiment control, selective imaging
(SIT), real-time data analysis, etc. We will
also discuss the scientific objectives for ALIS, the current implementation,
plans for the future, and present an overview
of recent results.
P. Rydesater(Ostersund), "Classifying Auroras using Artificial Neural
Networks"
Peter Rydesater, Mitthogskolan, Institutionen for informationsteknologi,
Urban Brandstrom, Swedish Institute of Space Physics (IRF),
Ake Steen, IRF,
Bjorn Gustavsson, IRF,
In ALIS (Auroral Large Imaging System) there is need of stable methods for
analysis and classification of auroral
images and images with for example mother of pearl clouds. This part of ALIS
is called SIT (Selective Imaging
Techniques) and is intended to sort out images of scientific interest. It's
also used to find out what and where in the
images there is for example different auroral phenomena .
This work is concentrated on how to find auroral arcs and how they are placed
in images. Special care have been taken
to make the algorithm robust since it's going to be implemented in a SIT unit
which will work automatic and
unsupervised and some extends control the data taking of ALIS. The method for
finding auroral arcs is based on a
pattern matching
algorithm as preprocessing which then is feed to a Neural network classifier.
We will discuss the results and the possibilities to use this algorithm in the
selective image system, and possible further
improvements to do even better results.
B. Denby, (France) "Measuring Raindrops with a Neural Network"
B. Denby1,2,*, P. Gole1, J. Tarniewicz2
1Centre d¦Etudes des Environnements Terrestre et Planetaires, 10-12 avenue de
l¦Europe, 78140 Velizy, France
2Universite de Versailles St. Quentin-en-Yvelines, 45 avenue des Etats Unis,
78035 Versailles Cedex, France
*corresponding author: tel. +33 1.39.25.48.59; fax. +33 1 39.25.47.78; email:
denby@cetp.ipsl.fr
We describe a structured neural network solution to a signal processing problem
in the meteorological and
telecommunications domains. Optical disdrometers measure raindrop sizes and
velocites by registering changes in
photodiode current as the droplets pass through a collimated light beam. In an
improved dual-beam device being built
at CETP, feature extraction MLP¦s applied to 20-sample windows of photodiode
current provide input to a
higher-level network which reconstructs droplet velocities and diameters in
real time. In tests on simulated data,
measurement precision is quite good for droplets as small as
05 mm radius. The algorithm can be executed either directly on the acquisition
PC, or on a neural net coprocessor,
such as the Univ. of Trento TOTEM, for additional speedup.
Olle Norberg (IRF, Kiruna) "The Munin nanosatellite and future
applications for AI in
microspacecraft"
Olle Norberg and Rickard Lundin
Swedish Institute of Space Physics, Box 812, SE-981 28 Kiruna, Sweden
The Munin satellite is a new type of monitoring spacecraft which can
cost-effectively provide global monitoring of the
space environment. Usingmodern technology, this very small satellite (<6 kg)
has all the necessary
functions needed to support its specific mission: monitoring of the auroral
activity on both the northern and southern
hemispheres. This paper will present the Munin satellite and instrument
miniaturization effort, which
can provide a precursor for future missions with several very small, dedicated
and intelligent spacecraft. Future
enhancements to the "intelligent nanosatellite" concept will include AI
applications such as 3-axis stabilization and
attitude determination using neural networks, on-board data classification and
categorization, and autonomous
operation.
The Munin satellite has a 1.7 kg payload consisting of three scientific
instruments:
- A combined electron and ion spectrometer with simultaneous coverage of all
pitch angles, covering the energy range
10 eV -- 18 keV
- Two detectors for high-energy ions and neutral particles with pitch angles 0
degrees and 90 degrees, covering the
energy range 30 -- 1200 keV
- A CCD camera for imaging of the Aurora Borealis at visible and infrared
wavelengths. The camera has a field-of-view
of 50 degrees, and a resolution of 340 x 240 pixels
L. Andersson (IRF, Kiruna) "Prediction of Spacecraft Anomalies Using Local
Environmental Data"
Andersson, L., O. Norberg, L. Eliasson, Swedish Institute of Space Physics,
Kiruna
J. Waldemark, Royal Institute of Technology, Dept. of Physics
L. Liszka Swedish Institute of Space Physics, Umea
Spacecraft are affected by the space environment. One can consider this
environment as "space weather" just as on the
Earth with quiet times, storm times, and different environmental regions. A
spacecraft will experience
changes of the weather and move in the environment regions with time scales
from a few seconds to the length of the
solar cycle. Due to space weather, spacecraft can experience anomalies, ranging
from a bit flip to a total
loss of the spacecraft. The anomalies depend on the spacecraft design and the
severity of the conditions the spacecraft
is exposed too. A loss of a commercial satellite is very costly and therefore
space weather prediction has become more
and more of interest to satellite owners. In order to be able to predict the
space weather for geostationary (GEO)
satellites an investigation of a GEO satellite and the onboard electron monitor
instrument has been made. The natural variance of the electrons are larger than
the difference between times with
anomaly and no anomaly. The largest variance of the electron fluxes is due to
the spacecraft motion in the
orbit (24 hour period). A principal component analysis (PCA) of the electron
fluxes was first made. The PCA resulted
in a possibility to easily separate the anomalies into two groups. One category
predicts with 70%
certainty that an "anomaly will occur", further improvement seems to be
impossible probably due to that the direct cause
is not monitored. The second category can easily be predicted, i.e. wether or
not an anomaly will
occur or will not occur within 24 hours. The result from an ordinary back
propagation net is that the "no anomaly will
occur" is predicted with more than 90% certainty, and the "anomaly will occur"
is also predicted with over 90%
certainty. A description of the method and the data set will be presented in
this paper.
Michail Pudovkin (St. Petersburg) "Auroral Form Recognition"
Michail Pudovkin Institute of Physics, University of St. Petersburg,
Ake Steen, Urban Brndstrm, Bjrn Gustavsson Swedish Institute of Space Physics
Peter Rydester Mid Sweden University, Ostersund, Sweden
A method of recognition of the geometrical shape of auroras is proposed. The
method is based on the analysis of the
characteristics of isolines of the auroral luminosity (isophotes) which
represent outlines of the object and reflects all the
peculiarities of its shape. The basic variable in this analysis is the angle,
F(S/L), between the tangent of the contour
and the X-axis of an arbitrary coordinate system given as a function of the
distance, S, along the contour normalised
to the entire length, L, of that contour. The differential, dF(S/L), is a
function periodic in the length, L, and is invariant to
any linear transformation such as e.g. shift, rotation, and change of scale.
The procedure allows for the representation of
any flat 2D image as a set of one-dimensional periodic functions, which greatly
simplifies the recognition problem.
The further analysis includes Fourier transformation of experimental functions,
dF(S/L), and comparison of
corresponding spectra with those obtained for a series of model contours, such
as ellipse, spiral, folds and others. The
method is applied to some experimental auroral data from the ALIS multi-station
imaging experiment.
Thomas Lindblad phone (office) +468 16 11 09
Dept. Physics - Frescati phone (secr) +468 16 10 01
Royal Institute of Technology fax (office) +468 15 86 74
24, Frescativagen fax (home) +468 792 1543
S-104 05 STOCKHOLM Sweden cellular phone: +46707677493
email: lindblad@particle.kth.se
http://msia02.msi.se/~lindblad/lindblad.html
My office phone has a voice mail service, just let it ring until you reach it.
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