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Remote sensing

Advance in orbit

New generation of satellites promise to drive research and keep watch over the Amazon Region

INPEThe Inpe Testing and Integration Laboratory: development of two new satellites.INPE

Within the next three years, Brazil plans to launch two satellites that will allow full coverage of the Earth in less than five days, with medium resolution images. Today, the coverage provided by Cbers-2B (which stands for Chinese-Brazilian Earth Resources Satellite) is 26 days.Cbers-3, to be launched in mid-2011, will replace Cbers-2B, launched in 2007, and will continue to supply the images used by researchers, government agencies and several segments of society. Cbers-3 is being tested in China, Brazil’s partner in the development of this class of satellites since 1988. It will carry a new generation of cameras meant to provide more accurate image quality. One of these is AWFI/Cbers-3, which will cover the Amazon Region every five days, but with a resolution of some 70 meters, rather than the 260 meters of Cbers-2B’s WFI camera. The second satellite, with its launch scheduled for 2012, is the Amazonia-1, which should improve the precision of the Amazon Region’s monitoring and upgrade the work of Deter, the Real Time Deforesting Detection System of Inpe (the National Institute of Space Research). The AWFI/Amazonia-1 camera will operate in both the visible and infrared light bands and will have a 40-meter resolution, which is more detailed than what the AWFI in Cbers-3 will provide. An agreement currently being discussed with the United Kingdom may incorporate the English camera Ralcam-3, that has  resolution of some 10 meters, into the satellite. Developed by Inpe, the Amazonia-1 will be the first satellite built on the PMM Multi-mission Platform, a generic base that can carry a  payload of up to 280 kilograms and that will be used for other projects as well, thereby reducing its cost.

The new satellite generation’s prospects, though promising over the next decade, may stumble on short-term barriers. The Cbers-3 schedule has already been postponed twice. Originally meant to be launched in 2009, it had to be delayed as a result of US government restrictions on the sale to Brazil of components for making equipment and sensors. This was caused, among other issues, by the fact that the partner in this undertaking is China, a country subject to certain US embargoes in the area of space. Because of these restrictions, it will be impossible to launch the Amazonia-1, which uses several American components, from a Chinese rocket, which is how the Cbers are launched. If further delays occur, there will be an increasing risk of an interruption in the supply of images, as the Cbers-2B has been in orbit for almost two years and its useful life is estimated at less than four years. Its predecessor, Cbers-2, launched in 2003, stopped working recently, on January 15, after running for almost five years. If a gap in the supply of images were to occur, Brazil would have to depend solely on the US remote sensing satellite Landsat-5, whose pictures are currently used to complement the Cbers images.

Though this is a hypothetical risk, it looks more serious when one considers the importance of Cbers images for Brazil. As from 2004, the country started supplying Cbers pictures to any interested party, free of charge. As a result, the images’ uses increased tenfold. The service has more than 20 thousand users frorm some 3,500 institutions. On average, 750 downloads occur daily, according to the Cbers catalog. Over the last five years, more than 400 thousand images were supplied and used to assess environmental degradation, deforestation, agricultural areas and increased urban density, among other applications. A substantial portion of the images’ use is academic. All government universities and a wide range of research institutes resort to these pictures via the web. However, the users also comprise technical schools, which use the material for teaching purposes, farming co-ops, which assess cultivation areas via their images, environmental public prosecutors, who obtain evidence of environmental crimes by means of historical series of pictures, and firms, which develop products based on Cbers data.

INPEImages taken by the Cbers satellites: available on the web at no charge multiplies their useINPE

Researchers and institutions from other countries, especially from Africa and South America, have also become clients of the catalog. “Government bodies and academic milieus used to have little access to satellite data, as it was hard to acquire. The outcome is that there was little appropriation by society of the space program’s results”, says José Carlos Neves Epiphanio, an Inpe researcher and coordinator of the Cbers applications program. “Our strategy of making images available free of charge is influencing other countries. Even the Americans have decided to make Landsat images freely available”, he states.

One piece of information that reflects the importance of the Cbers family of satellites for Brazilian research involves the scientific work presented at the 14th Brazilian Symposium of Remote Sensing, taking place in the city of Natal, state of Rio Grande do Norte, from the 25th to the 30th of this month. No less than 162 articles of the 1,014 articles in the event are connected to research based on data produced by these satellites. There are some works of scientific interest, such as an analysis of the images’ potential for the extraction of relief and drainage lines, the assessment of image merging techniques, or the development of algorithms that help to interpret information. Most of the studies, however, are connected to practical applications, such as using the images to quantify the expansion of sugarcane plantations in Brazil, in order to draw up strategies for the production of food and ethanol, or to assess the influence of rainfall and  the type of vegetation on the incidence of the Aedes aegypti mosquito in the municipality of Rio de Janeiro, one of the cities hardest hit by dengue fever.

Forest fires
One of these studies highlights the images’ usefulness in the public policy field. Signed by experts from the Federal Police in Curitiba and Foz do Iguaçu, the article shows three situations in which the satellite pictures were decisive. In one, these pictures revealed that deforestation in the west of Paraná state, identified through inspections in 2008, had actually occurred four years earlier, as evidenced by a historical series of images of the area. In another, they helped pinpoint where the vast forest fires of the National Park of Ilha Grande, in Paraná State, had started, providing some guidance for the field work of the experts assessing the problem. In the third case, it enabled experts to track at a distance compliance with a legal ruling to replant a deforested area in the west of the state. “This technology is highly useful for planning field work ahead of time, rendering its objective feasible and its execution efficient”, concludes the study, led by forestry engineer and expert Aiga Jucy Fuchshuber da Silva Caldas.

INPEImage taken by the Cbers satellitesINPE

The advance of scientific work based on these images results from the progress of research linked to the satellites’ development and applications. An algorithm to transform the satellites’ data was created in the 1980’s by Yosio Shimabukuro, an Inpe researcher. A more recent example involves the advent of Spring, a free software program that comprises image processing functions, spatial analysis and database consultations. It has been fundamental for handling and using satellite images. Recently, Opto Eletronica, a Brazilian firm, was asked to develop a multi-spectrum camera, named MUX, to be installed in Cbers-3 (see Pesquisa FAPESP issue 148). As we are reminded by Petrônio Noronha de Souza, head of the Testing and Integration Laboratory of Inpe, the Cbers satellites resulted from an effort that goes back to the 1970’s, that aimed at making the so-called Mecb (the Complete Brazilian Space Mission) feasible. This led to the launch, in the early 1990’s, of two Inpe data gathering satellites that continue running to this day: SCD-1 and 2. The second part of this mission, to build a Brazilian launching rocket, is yet to come true. “Despite their different technology, the SCD satellites created a Brazilian competency that was important for Cbers”, he states. Weighing 115 kilograms, the two satellites had a high percentage of domestic components: 73% of the SCD-1 equipment and 85% of the SCD-2 equipment was made in Brazil. The Mecb program foresaw the launch of the data gathering satellites and of two more for remote sensing. “It was at this point that difficulties arose, leading Inpe to pursue a partnership with China, whose technological level, at the time, was similar to Brazil’s; however, its industrial platform and human resources complemented our requirements”, recalls Petronio.

The partnership with China will continue. Besides Cbers-3, Cbers-4 is to be launched in 2014, to ensure an ongoing supply of images. The cooperation agreement for the launch of the earlier satellites established that 70% of the program’s cost would be born by China and 30% by Brazil. This meant a Brazilian investment of US$118 million in Cbers-1 and 2, plus another US$15 million in Cbers-2B (the cost was lower because equipment and parts left over from Cbers-2 were used). The two countries’ investment amounted to US$350 million. In 2002, when the agreement to continue the program by building Cbers-3 and 4 was signed, a fifty/fifty division of technical and financial responsibilities for Brazil and China was established. Brazil is investing about US$150 million in these satellites. The two partners are already discussing the possibility of extending the program further and the  technology to be used for Cbers-5 and 6. One possibility is to install a radar system that would allow the assessment of deforestation regardless of clouds. On another front, the launch of other satellites, built on a multi-mission platform, is also forecast. According to the Inpe schedule, a scientific satellite designed for physics and astrophysics research, the Lattes-1, should be launched in 2013. In 2014, it will be the turn of the Mapsar Earth observation radar. The platform will also be used by a meteorological satellite that will measure rainfall, the GPM-Br, whose launch date is yet to be determined.