Long-Term Data Archiving
Earth observation activities from meteorology and geology to gas concentrations, vegetation and forest fires, have considerably increased in the past decade. These activities provide scientists and engineers with a great deal of insight and information. However, this increase in data gathering is resulting in an information overload; there is a lot of data to understand and no universal way to understand and preserve it.
The study involved analyzing the current data-archiving technology available. GMV looked at various archiving-system designs and worked with Long Term Data Preservation (LTDP), a leading, worldwide data archiving firm, to create a systematic evaluation system. Using the classification system, GMV developed methodology and assessment models to evaluate the existing technologies objectively and thoroughly.
The study resulted in improved assessment of current systems, allowing manufacturers to better understand these systems and make more informed decisions when comparing future systems.
The assessment models developed through the study can be shared publicly, openly debated, and tweaked over time to change and improve with technology. In addition, the models can be used by different benchmark archiving firms developing their own conclusions on the technologies being used. Lastly, new metrics have been put forward for tracking a system’s technological progress in comparison with others on the market.
“Preservation of all compiled data is crucial to be able to analyze the cause-effect relationships, evolving developments and more happening through earth observation activities,” said Jorge Potti, general manager of GMV Aerospace. “The analysis of this data will give much more information that will be useful in terms of forecasting future situations and recognizing patterns.”
For further information, please access the GMV Company website.
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South Africa’s Satellites Focus
South Africa is planning to build its third satellite, to form part of a new African satellite constellation, as part of a government drive to grow the country’s share of the global market for small- to medium-sized space systems.
The country’s second satellite, the two-year-old SumbandilaSat, has been out of commission since a blast of solar radiation damaged its on-board computer in July.
Sandile Malinga, chief executive of the SA National Space Agency (Sansa), announced in September that South Africa hoped to start building a new, fully operational satellite — not just a prototype or “pathfinder” satellite such as SumbandilaSat — as early as 2012, for possible launch by 2014/15.
The new satellite would cost in the region of R400-million — compared to the R26-million spent on SumbandilaSat — and would also be used for Earth observation, in line with the country’s space strategy, which seeks to apply satellite data to help to improve livelihoods, reduce poverty and manage natural disasters in the country and the region.
“The basic idea behind the ARM concept is that a number of African countries each contribute one satellite to the constellation, but can access data from all the other satellites as well,” Pandor said in Cape Town this week, adding that ARM was “open to other interested African countries to join on the basis of their needs and capabilities.”
Nigeria and Algeria each have two satellites already operating, Business Day noted, as does Egypt, while Angola has one, leaving South Africa somewhat lagging behind in Africa’s “space race”.
“But unlike the others, we build our own satellites,” Business Day quoted Malinga as saying.
SumbandilaSat was built by Stellenbosch-based company Sun Space and Information Systems (SunSpace). Its predecessor, Sunsat, launched in 1999, was designed and built by Stellenbosch University staff and postgraduate students, leading to the formation of SunSpace, in which the state is seeking to acquire a majority shareholding.
“SunSpace has secured orders from international clients for satellites and subsystems, and has also demonstrated that it can train engineers in other emerging space nations,” Pandor told delegates at the IAF’s congress. “In the field of satellite development, South Africa possesses some space facilities that are unique in Africa. These include a satellite assembly, test and integration facility, situated not far from here in Grabouw, and a launch facility situated at Arniston [also in the Western Cape].”
Further development in this field, Pandor said, would be accompanied by the development of applications for the provision of geospatial, telecommunications, timing and positioning products and services in the country.
“Here we are working to develop our capabilities in Earth observation, communication and position, timing, and navigation,” which would play a big role in understanding the causes and effects and climate change, among other applications. “We are particularly interested in South Africa in tele-medicine and tele-education, and we have only just begun to tap the possibilities,” Pandor said.
While SumbandilaSat is now out of action, it had succeeded as a satellite technology demonstrator program, Malinga said. The satellite was designed and built from scratch in one year, at low cost, by South African engineers, who also developed a world-class mission control system for the program.
SumbandilaSat delivered more than 1,000 usable, cloud-free images before being damaged by solar radiation, and became well-known by the worldwide amateur radio satellite society for the excellent results from its amateur radio payload.
Malinga said that Sansa was also exploring whether or not South Africa should try to establish its own satellite launch capability.
At least one South African company has an interest in this. Marcom Aeronautics & Space recently announced that it was developing a rocket engine as part of its development of a two-stage, liquid-fueled launch vehicle capable of delivering a 1,000kg payload into low-Earth orbit.
The South African Sunday Times reported last year that the government was considering reopening apartheid-era space rocket launch sites in order to fast-track the country’s national space program.
Last month, defenceWeb reported that South Africa “has existing infrastructure that could be utilised for local satellite launches, notably facilities at Air Force Base Overberg.”
Marcom head Mark Comninos told defenceWeb that, although Overberg’s launch pad was destroyed as part of South Africa’s nuclear stand-down and the payload processing facility was mothballed, the site had retained almost all of its space launch capability, including mission control centre, radar and telemetry tracking facilities and range safety systems.
“According to the U.K. Space Strategy, the overall world market for the space industry is likely to grow from £160-billion in 2008, to at least £400-billion by 2030, with a yearly growth rate of 5 percent,” defenceWeb wrote.
“In September 2010, Space News reported that the global satellite market stands at between 20 and 30 satellite launches a year.
“An estimated 20 new satellites with coverage on Africa will be launched in the next five years to address the current capacity shortage on the continent.”
(Source: SAinfo reporter)
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Kelp Captures By Satellite
Marine scientists have a new view of the giant kelp in the Pacific Ocean — through a scuba mask and a satellite’s “eye.”
In a melding of data from the beneath the waves and from the skies above, researchers have developed a method for studying how environmental factors affect the kelp forests.
The results have allowed scientists to look at changes in giant kelp across hundreds of square miles in California’s Santa Barbara Channel over 25 years, from 1984 through 2009. The findings are published in the journal Marine Ecology Progress Series.
Obtaining a quarter-century of imagery from the same satellite, in this case the Landsat 5 Thematic Mapper, is unprecedented, said David Siegel of the University of California at Santa Barbara (UCSB), one of the paper’s co-authors.
“A satellite mission that goes on for more than 10 years is rare,” says Siegel. “One that continues for more than 25 years is a miracle.”
Until recently, the high cost of Landsat images limited their use in research. Then, in 2009, the Landsat image library was made available at no charge.
“In the past, it wasn’t feasible to develop long time series using Landsat images,” said Kyle Cavanaugh of UCSB, the paper’s lead author. “Once these data were released free of charge, however, we could access hundreds of pictures that show an area over time.”
“Giant kelp forms a dense floating canopy at the sea surface that’s distinctive when viewed from above,” write the scientists in their paper. “Water absorbs almost all incoming near-infrared energy, so the kelp canopy is easily differentiated using its near-infrared reflectance signal.”
In southern California, giant kelp is found primarily on shallow rocky reefs distributed in patches. The plants’ numerous fronds extend upward in oceans and bays, forming a canopy at the surface. The plants grow to lengths of more than 100 feet, at a rate of up to 18 inches per day.
“Giant kelp provides food and habitat for many ecologically and economically important near-shore fish and other species,” said David Garrison, program director in the National Science Foundation’s (NSF) Division of Ocean Sciences, which funded the research along with NSF’s Division of Environmental Biology.
The kelp is also an important source of food for many deep-sea species. Giant kelp that’s uprooted from the seafloor is transported offshore into deeper waters, where it sinks and fuels deep-sea ecosystems with “phytodetritus.”
Through the recent research, scientists found that giant kelp growth in exposed areas of the Santa Barbara Channel is mostly controlled by large waves. The kelp’s growth in more protected areas, however, is limited by low nutrient levels.
During winter months, storms in the north Pacific Ocean create large swells that enter the Santa Barbara Channel. Waves breaking during and after these storms are a major source of giant kelp death in this region. Giant kelp is particularly sensitive to changes in climate that alter wave and nutrient conditions.
Short lifespans of both fronds and entire plants — four to six months for fronds, and two to three years for plants — produce a kelp forest that renews itself six to seven times each year.
“We know from scuba observations that individual kelp plants are fast-growing and short-lived,” says Cavanaugh. “The new data show the patterns of variability that are also present within and among years at much larger spatial scales. Entire kelp forests can be wiped out in days, then recover in a matter of months.”
Information collected by scientists at the Santa Barbara Coastal Long-Term Ecological Research (LTER) site, one of NSF’s 26 such LTER sites around the world, was added to the satellite data.
“The kelp occurs in discrete patches,” he says, “but the patches are connected genetically and ecologically. Species that live in them can move from one patch to another. “Having the satellite capability allows us to look at how the different patches are growing, and to get a better sense of how they’re connected,” said Reed. “We can’t get that information through diver plots alone.”
Continued large-scale and long-term observations are needed, he says, to understand how ecosystems — including giant kelp forests — might behave in a future climate.
The fourth co-author of the paper was Philip Dennison of the University of Utah. The research was also funded by NASA.
— Story by Cheryl Dybas, NSF
cdybas@nsf.gov
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Three Decades Of Climate Data
On August 16, 1981, the Meteosat-2 geostationary weather satellite began operationally to supply data relevant for climate monitoring. The imager on Meteosat-2 and subsequent satellites in the series has now provided 30 years of data.
The data collected by the first generation Meteosat Visible and Infrared Imager’s (MVIRI’s) three channels — visible, infrared and water vapour — are also provided by Meteosat Second Generation (MSG), whose 12-channel Spinning Enhanced Visible and Infrared Imager (SEVERI) includes similar channels to those used by MVIRI, providing continuity in climate data over three decades. The Flexible Combined Imager (FCI) on Meteosat Third Generation (MTG) will also include similar channels, meaning that all three generations will have provided over 60 years of climate data.
The long series of Meteosat observations has already provided benefits to users, helping protect lives and property around the world. The observations were successfully used for the monitoring and analysis of precipitation and vegetation changes during the severe drought in the Sahel area of Africa in the 1980s. MSG satellite observations just became available when Europe suffered one of the worst heat waves ever in 2003. The data were used to estimate surface temperatures and also to monitor the occurrence of fires.
“Three decades is just enough to start looking at decadal variations,” Schulz explained, adding, however, that “there is no guarantee of detecting climate trends.” EUMETSAT carefully analyses, reprocesses and validates the satellite data, which are then used by National Meteorological Services, the European Centre for Medium-Range Weather Forecasts (ECMWF), and research institutions for several climate applications. The longer Meteosat is in orbit, the better their analysis of the climate system will be.
U.S. Geostationary Operational Environmental Satellite (GOES) and polar-orbiting satellites with the Advanced Very High Resolution Radiometer (AVHRR), (Advanced) TIROS Operational Vertical Sounder ((A)TOVS) and the Solar Backscatter UltraViolet (SBUV) instruments have also provided climate data since the late 1970s. The analysis of these long series of satellite data is a challenge for all satellite operators because of instrument changes and failures, as well as changing calibration algorithms and sampling strategies, and the data are not, per se, consistent over the three decades. However, the gain in scientific understanding of the Earth’s climate system is worth the investment into a reanalysis of the satellite data, according to Schulz.
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Getting The Picture
As cinema owners worldwide begin to embrace new digital technologies via satellite, audiences are being given more ways to enjoy an evening at the movies.
Thanks to ISIDE, cinema operators can now browse a catalog of hundreds of movies, order online from the comfort of their office, and their selections will be downloaded via satellite.
Satellite capacity is a costly resource. In order to make distribution via satellite cost effective, the same content has to reach a sufficient number of cinemas. ISIDE brings the convenience of satellite technology within reach. When multiple locations in the network download a film, the costs of satellite capacity are shared among them.
Top quality digital standards must be maintained, which involves the transmission of high volumes of data. A single movie can exceed 200 gigabytes – the contents of four blue ray discs. High transmission rates of up to 100 megabits per second must also be achieved.
The system is being put to use by Italian companies Microcinema and OpenSky. Today, Microcinema, with more than 200 cinemas connected in a network over satellite, has become a leader in Italy for providing film, audovisual content, live opera from Italian and European theatres and supporting cultural events. Microcinema distributes two or three live events per month, plus one or two flims per week.
OpenSky mainly delivers movies from major Hollywood studios and distributes live events to more than 500 cinemas spread throughout Italy, France and Germany. Most of the cinemas are equipped with the state-of-the-art receivers and projectors.
“The successful pilot phase of the system, developed and tuned in 2010 during the ISIDE project, proved to be fundamental for cinemas owners’ persuasion.”
According to Walter Munarini from OpenSky; “The ISIDE project was fundamental to Opensky to implement the first European network of digital cinema capable of receiving satellite services like the live events and movies via satellite, as well as its evolution to live 3D events.”
ISIDE was developed through ESA’s ARTES applications program. The companies involved in the consortium included Microcinema, OpenSky, Skylogic and Digital Pictures, with the support of the Business Incubator Centre BIC Lazio in Rome.