RADAR FOR BATHYMETRY

Water is good radar reflector. It reflects radar better than rock (Svitil 1997). Romeiser (2004) states that microwave (radar wavelength) has penetration in sea water only in the order of millimeter only. Hence, water doesn’t pretty much absorb radar energy. That is quite strange as we know that Infrared wavelength will almost 100% be absorbed by water. How much percentage water reflects radar wave is not clearly defined however.

Cambpell (1996) mentions that smooth ocean surface, which has smaller waves rather than radar wavelength, appears dark regions on the image. Radar energy is reflected away from the sensor. Lillesand & Kiefer (1994) also have the same finding that smooth water surface makes no reflectance returns to the sensor. However, coarse water surface may returns radar wave. Furthermore they mention if water surface is roughened by the wind, it will appear lighter tone on radar image. On the other hand, oil spill on the ocean’s surface have a dampening effect on water’s wave, thus appearing darker on radar image because calm water surface has a greater specular reflection than surrounding water.

Therefore, the response of the ocean to radar energy depends on its surface. Figure 1 above shows simplification of radar reflectance on seawater. Figure (1.a) will produce bright radar image because it gives some reflectance back to the sensor. Figure (1.b) will produce dark radar image because it reflects radar signal away from the sensor.

Fortunately – even we can’t use radar to penetrate sea water – there is correlation between radar image appearance and seafloor depth. Lillesand & Kiefe (1994) mention that by observing refraction of waves in shallow water, water depth can be predicted. Another study by Romeiser (2004) reveals an algorithm between radar (InSAR-derived) currents and known water depth from echosoundings. Resulted regression function is used to predict water depth from the currents at other points. Though, that regression should be considered only works locally.

In summary, most radar energy will be reflected by water. Ocean surface response to radar depends on its roughness. Calm seawater will reflect radar away from satellite and rough seawater will reflect some radar energy back to satellite (sensor). Since there is strong relationship between wave refraction and water depth, we can regress the seawater’s roughness (observed by radar) and reference points depth (which its depth is known by sounding). Finally, the observer can predict the depth of certain area, and therefore seafloor terrain using that regression.

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Indian rocket puts a record 10 satellites into orbit

by Anil Penna

BANGALORE, India (AFP) - An Indian rocket launched a record 10 satellites into orbit in a single mission Monday, underlining the nation's emergence as a major competitor in the multi-billion-dollar space market.
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The PSLV rocket ejected all the satellites within minutes of each other after liftoff at 9:20 a.m. (0350 GMT) in clear weather from the Sriharikota space station in southern India, the Indian Space Research Organisation said.

"The initial signals indicate normal health of the satellites," the Bangalore-based agency said in a statement posted on its website, www.isro.org.

The mission's success demonstrated India's ability to launch multiple payloads into precise orbit as it seeks to reap commercial benefits from its 45-year-old space programme.

It was the 13th flight of the Polar Satellite Launch Vehicle, which has "repeatedly proved itself as a reliable and versatile workhorse launch vehicle," said ISRO.

Soaring into clear skies and leaving behind a trail of orange and white smoke, the rocket first put into orbit the 690-kilogram (1,518-pound) remote-sensing Indian satellite, Cartosat-2A.

It also launched an 83-kilogram Indian mini-satellite and a cluster of eight so-called nano-satellites, each weighing between three kilograms and 16 kilograms, built by research institutions from Europe, Canada and Japan.

"The mission was perfect," said ISRO chairman G. Madhavan after the launch was telecast live by public broadcaster Doordarshan.

"It is a historic moment for us because it is the first time that we have launched 10 satellites in a single mission," he added.

The flight broke the previous record of eight satellites launched at one go by a Russian rocket, according to Indian news reports.

ISRO marketing arm Antrix Corporation charged a fee for the launch of the miniature foreign satellites. India has been offering its services at about 60 to 70 percent of the cost charged by other space agencies.

New Delhi wants to compete alongside the United States, Russia, China, the Ukraine and the European Space Agency in offering commercial satellite launch services.

"By launching so many satellites at one go, India has showcased the commercial applicability of its space programme," said Ajay Lele, a space expert at the Institute of Defence Studies and Analyses in New Delhi.

"It wants to market its launch systems and also its capability in earth imagery," Lele said. "The mission is very significant from a commercial point of view."

India first staked its case for a share of the commercial launch market by sending an Italian spacecraft into orbit in April last year. In January, it launched an Israeli spy satellite in the face of Iranian protests.

India carried out the first successful launch of a domestic satellite by a home-built rocket in 1980, when it was less preoccupied with reaping commercial benefits and more with harnessing space technology to boost deficient communications and broadcasting facilities.

Cartosat-2A, the main satellite launched Monday to an altitude of 630 kilometres (391 miles) above earth, also has a domestic economic dimension and can be used for intelligence gathering as well, officials say.

More advanced than a predecessor launched in January 2007, it will boost India's efforts to reinforce urban and rural infrastructure to keep pace with economic growth that averaged nearly nine percent in the past four years.

The all-weather satellite, whose camera will beam "very clear and detailed images of even miniscule objects" on earth, will aid economic planners in land and water resources management, said space expert Lele.

Monday's mission precedes the planned launch this year of a lunar mission, which will see India join Asian nations Japan and China in moon exploration.

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Polar Satellite Launc Vehicle (PSLV)

The second operational launch of India's Polar Satellite Launc Vehicle (PSLV) will place three satellites - Indian Remote Sensing Satellite (IRS-P4) as the main payload and Korean KITSAT-3 and German DLR-TUBSAT as auxilary payloads - into a 727 km polar sunsynchronous orbit. It is for the first time that ISRO is launching three satellites in a single vehicle. While IRS-P4(OCEANSAT) Weight 1050 kg, KITSAT-3 and DLR-TUBSAT weight 107 kg and 45 kg respectively. The two auxilary payloads are mounted on PSLV equipment bay diametrically opposite to each other. The main payload, IRS-P4,is mounted on top of the equipment bay as in earlier flights of PSLV. In the flight sequence, IRS-P4 is injected first, followed by KITSAT-3 and DLR-TUBSAT in that order.

With a lift of weight of 294 tone, the 44.4m tall PSLV is a four stage vehicle employing solid propellant stages in the first and third stages and liquid propellant stages in the second and fourth stages. It also employs six solid propellant strap-on motors for the first stage. PSLV is launched from ISRO's Satish Dhawan Space Centre, SHAR, Sriharikota, about 100 km north of Chennai.

The first operational flight of PSLV took place on September 29,1997 which has put IRS-1D into polar sunsynchronous orbit. Antrix Corporation, the commercial front of the Department of Space, markets PSLV launch services on behalf of ISRO.

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Spitzer Sees Shining Stellar Sphere

For Release: April 10, 2008

Millions of clustered stars glisten like an iridescent opal in a new image from NASA's Spitzer Space Telescope.

Called Omega Centauri, this sparkling orb of stars is like a miniature galaxy. It is the biggest and brightest of the more than 150 similar objects, called globular clusters, that orbit around the outside of our Milky Way galaxy. Stargazers at southern latitudes can spot the stellar gem with the naked eye in the constellation Centaurus.

While the visible-light observations highlight the cluster's millions of jam-packed stars, Spitzer's infrared eyes reveal the dustier, more evolved stars tossed throughout the region.

"Now we can see which stars form dust and can begin to understand how the dust forms and where it goes once it is expelled from a star," said Martha Boyer of the University of Minnesota, Twin Cities. Boyer is lead author of a paper about Omega Centauri appearing in the April issue of the Astronomical Journal. "Surprisingly, Spitzer revealed fewer of these dusty stars than expected."

Globular clusters are some of the oldest objects in our universe. Their stars are more than 12 billion years old, and, in most cases, formed all at once when the universe was just a toddler. Omega Centauri is unusual in that its stars are of different ages and possess varying levels of metals, or elements heavier than boron. Astronomers say this points to a different origin for Omega Centauri than other globular clusters: they think it might be the core of a dwarf galaxy that was ripped apart and absorbed by our Milky Way long ago.

In the new picture of Omega Centauri, the red- and yellow-colored dots represent the stars revealed by Spitzer. These are the more evolved, larger, dustier stars, called red giants. The stars colored blue are less evolved, like our own sun, and were captured by both Spitzer's infrared eyes and in visible light by the National Science Foundation's Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile. Some of the red spots in the picture are distant galaxies beyond our own.

"As stars age and mature into red giants, they form dust grains, which play a vital role in the evolution of the universe and the formation of rocky planets," said Jacco van Loon, the study's principal investigator at Keele University in England. "Spitzer can see this dust, and it was able to resolve individual red giants even in the densest central parts of the cluster."

NASA's Hubble Space Telescope and Gemini Observatory on Cerro Pachon in Chile recently found evidence that Omega Centauri is home to a medium-sized black hole (http://hubblesite.org/newscenter/archive/releases/2008/14/).

Other authors of the paper include Iain McDonald and Nye Evans of Keele University; Robert Gehrz and Charles Woodward of the University of Minnesota; and Andrea Dupree of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA. Spitzer's infrared array camera, which took the Omega Centauri picture, was built by NASA's Goddard Space Flight Center, Greenbelt, Md. The instrument's principal investigator is Giovanni Fazio of the Harvard-Smithsonian Center for Astrophysics.

Cerro Tololo Inter-American Observatory is part of the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy under contract with the National Science Foundation.

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.

jpl2008-057
ssc2008-07

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DNA Tests Confirm the Deaths of the Last Missing Romanovs

By THE ASSOCIATED PRESS


MOSCOW (AP) — For nine decades after Bolshevik executioners shot Czar Nicholas II and his family, there were no traces of the remains of Crown Prince Aleksei, the hemophiliac heir to Russia’s throne.
Some said the prince, a delicate 13-year-old, had somehow survived and escaped; others believed he was buried in secret as the country lurched into civil war.

Now an official says DNA tests have solved the mystery by identifying bone shards found in a forest as those of Aleksei and his sister Grand Duchess Maria.

The remains of their parents, Nicholas II and Empress Alexandra, and three siblings, including the czar’s youngest daughter, Anastasia, were unearthed in 1991 and reburied in the imperial resting place in St. Petersburg. The Russian Orthodox Church made all seven of them saints in 2000.

Researchers unearthed the bone shards last summer in a forest near Yekaterinburg, where the royal family was killed, and enlisted laboratories in Russia and the United States to conduct DNA tests.

Eduard Rossel, governor of the region 900 miles east of Moscow, said Wednesday that tests done by an American laboratory had identified the shards as those of Aleksei and Maria.

“This has confirmed that indeed it is the children,” he said. “We have now found the entire family.”

Mr. Rossel did not specify the laboratory, but a genetic research team working at the University of Massachusetts Medical School has been involved in the process. Evgeny Rogaev, who headed the team that tested the remains in Moscow and at the medical school in Worcester, Mass., was called into the case by the Russian Federation Prosecutor’s Office.

He said Wednesday that he had delivered the results to the Russian authorities, but that it was up to the prosecutor’s office to disclose the findings.

“The most difficult work is done, and we have delivered to them our expert analysis, but we are still working,” he said. “Scientifically, we want to make the most complete investigation possible.” Despite the earlier discoveries and ceremonies, the absence of Aleksei’s and Maria’s remains gnawed at descendants of the Romanovs, history buffs and royalists. Even if the announcement is confirmed and widely accepted, many descendants of the royal family are unlikely to be fully assuaged; they seek formal rehabilitation by the government.

“The tragedy of the czar’s family will only end when the family is declared victims of political repression,” said German Lukyanov, a lawyer for royal descendants.

Nicholas abdicated in 1917 as revolutionary fervor swept Russia, and he and his family were detained. They were shot by a firing squad on July 17, 1918, in the basement of a house in Yekaterinburg.

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What Happened to Pluto?

from : www.mos.org/visitor_info/museum_news/press_releases&d=2640

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Museum's new Planetarium show brings clarity to one of the most controversial science debates of recent years

Poor Pluto. For almost 80 years it was in the big time, the ninth planet in the solar system. But in August 2006, the International Astronomical Union (IAU) demoted the icy orb to a "dwarf" planet, igniting an uproar among scientists and amateur star gazers alike. Controversy flourished when the IAU defined a planet as a sphere orbiting the Sun that has cleared its "neighborhood" of debris. Although Pluto is relatively round and orbits the Sun, it's also part of the Kuiper Belt — a band of frigid, rocky chunks and a known source of comets. Experts believe that Pluto shares many features with comets, suggesting that if Pluto were placed near the sun it would develop a firey tail.

To help bring clarity to this debate, What Happened to Pluto?, a new show created by Museum of Science staff for the Charles Hayden Planetarium, explores one of the most talked about scientific issues of recent years. In this 45-minute presentation, audiences will get a sense of what it's like to become an astronomer searching for undiscovered space objects. Audiences will also explore why Pluto was reclassified and how classification techniques help scientists identify subjects in their fields of study. Viewers will have a front row seat on NASA's New Horizons spacecraft as it travels through our solar system to study Pluto's composition, topography, atmosphere, and light variations more closely than ever before.

By outlining the characteristics that identify a planet, the IAU changed a fundamental part of science education. Robin Symonds, manager of the Museum's Charles Hayden Planetarium, sees the bright side of Pluto's new identity. "This is what science is all about," she says. "We have to go where the evidence points. We constantly have to revise what we know and keep an open mind."

What Happened to Pluto? makes its debut on Saturday, April 19. Admission to the Charles Hayden Planetarium is $9 for adults, $8 for seniors (60+), and $7 for children (3 - 11). For information and for show schedules, visit mos.org. The Charles Hayden Planetarium at Museum of Science is wheel chair accessible.

About the Museum of Science:

One of the world's largest science centers, the Museum of Science takes a hands-on approach to science and technology, attracting approximately 1.6 million visitors annually with its vibrant programs and over 700 interactive exhibits. Highlights include the Thomson Theater of Electricity, home of the world's largest air-insulated Van de Graaff generator; the Charles Hayden Planetarium; the Mugar Omni Theater, New England's only 180-degree IMAX® domed screen theater; and The Gordon Current Science & Technology Center (GCS&T), which offers breaking news stories to the public with interpretation by Museum staff. In 2004, the Museum launched the National Center for Technological Literacy® (NCTL®) — helping facilitate a nationwide expansion of technology literacy by working with regional schools, offering educational products and programs for pre-K-12 students and teachers, creating curricula, and supporting an online resource center. For more information, visit mos.org.

Press Contacts:

Mike Morrison: 617-589-0250 or mmorrison@mos.org, Sofiya Cabalquinto: 617-589-0251 or scabalquinto@mos.org

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