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Satellites – No Impact – Weather



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Satellites – No Impact – Weather


Remote satellite sensing fails—oil spill sensing failures prove dependence on weather conditions
Brown 8 (Carl, Merv Fingas, Mathias Fruhwirth, R. Lloyd Gamble, researchers, Environment Canada, 5/1, http://www.boemre.gov/tarprojects/161/161aq.pdf, accessed 7-3-11, CH)

There are several problems associated with a reliance on satellites for oil spill remote sensing. The first is the frequency with which overpasses occur (Clark, 1989). The second is the absolute reliance on clear skies to perform optical work. These two factors combined can give a very low probability of seeing a spill on a satellite image. This point is well illustrated in the case of the EXXON VALDEZ spill (Nocragcr and Goodman, 1991). Although vast amounts of ocean were covered by the oil spill for over a month, there was only one clear day that coincided with a satellite overpass, that on April 7, 1989. The third disadvantage of satellite remote sensing is the difficulty in developing algorithms to highlight the oil slicks and the long time required to do so. It took over two months in the case of the EXXON VALDEZ spill before the first group managed to "sec" the oil slick in the satellite imagery, although its location was unknown.
Satellite remote sensing can’t solve data collection—cloud coverage
Drescher 10 (Armin, researcher, Institute for Methods of Remote Sensing, 5/2, http://www.mssl.ucl.ac.uk/imaging/cloudmap/cloudmap/papers/DLR-IMF/essclom.pdf, accessed 7-3-11, CH)

Cloud monitoring from space is not only a routine task for every day's weather forecast, but also for climate analysis and modeling since clouds play a major role for the Earth's energy balance, as a result of their large area extent and their variability on all scales. Current climate models are severely limited by the poor knowledge of the feedback processes associated with changes of cloud amount and cloud properties (WCRP-Report 86, 1994). Even optically thin Cirrus layers must be considered, as was demonstrated first for the 1987 El Nino ocean warming (RAMANATHAN and COLLINS, 1991). It is important to estimate the impact of anthropogenic activities on cloudiness at all height levels, including contributions by air traffic, directly by the associated contrails and indirectly by the additional amount of water vapour injected into the upper troposphere. It is believed that rising temperatures will increase atmospheric humidity and global cloud amount. Cloud screening and tracking by geostationary satellites is presently the main information source for deriving 3D-cloud coverage and wind estimates on a global base. The horizontal and especially the vertical resolution of present space-borne imagers for meteorology is hardly sufficient for an accurate estimation of cloud cover due to the broken and scattered nature of most cloud fields (WIELICKI and PARKER, 1992) and it is insufficient to reveal the complex structural and statistical properties of cloud fields, that dominate their interaction with the radiation field (WISCOMBE et al., 1995). An accurate assignment of absolute height to cloud layers and their drift vectors is an important issue in all this cases. Presently height is derived only for optically thick clouds based on their infrared radiation temperatures, requiring simultaneous vertical sounding profiles of atmospheric temperature. The estimation of optically transparent clouds over land and coastal waters is completely based on models of spectral signatures and suffers from a lack of independent validation


Satellites—Impact Turn—Debris


Massive size of EOS means there’s a huge risk of space debris—ESA proves
De Selding 10 (Peter, Space Staff News Writer, Space.com, 7/26, http://www.space.com/8829-huge-satellite-poses-150-year-threat-space-debris.html, accessed 7-2-11, CH)

Space debris experts attending the 38th Congress of the Committee on Space Research (Cospar) here July 18-25 said an event last January brought home just how much of a threat to the low-Earth orbit environment Envisat will be. That was when the U.S. Space Surveillance Network warned ESA that a 3,306-pound (1,500-kg) upper stage from a Chinese rocket was bearing down on Envisat and that the "conjunction assessment" pointed to a likely impact. With Envisat still operational, ESA's European Space Operations Centre (ESOC) control facility in Darmstadt, Germany, fired Envisat's on-board thrusters to perform a collision avoidance maneuver. Heiner Klinkrad, head of ESA's space debris office at ESOC, said here July 21 that a post-event analysis showed that the Chinese stage probably would have collided with Envisat if the avoidance maneuver had not been done. Such maneuvers will not be possible once Envisat is retired. ESA officials, more accustomed to speaking of Chinese, Russian or American debris issues, are uncomfortable discussing the danger that Envisat represents, especially since the agency has showcased the satellite as a major success. Klinkrad is no exception. But he did say that if the collision with the spent Chinese upper stage had occurred, it likely would have polluted a highly used portion of low Earth orbit with 10 times as much junk as what was caused by the 2009 collision of an operational Iridium communications satellite with a retired Russian Cosmos spacecraft. That event occurred at about the same altitude where Envisat flies. Huge satellite debris risks Envisat's 17,636-pound (8,000-kg) mass alone would be enough to put it onto the top tier of space debris threats, even though there are nearly a dozen spent Russian rocket upper stages that weigh as much as or more than Envisat. But Envisat's configuration in orbit makes it a unique concern, even beyond its weight. The satellite's in-orbit size is 26 meters by 10 meters by five meters. Its suite of observing instruments uses a small farm of antennas that likely have become more fragile after a decade in orbit. That means that even a small piece of debris pieces too small to be cataloged by the Space Surveillance Network could cause what debris specialists refer to as a "fragmentation event" that would produce its own population of space garbage. An analysis of the space debris environment at Envisat's orbit suggests that there is a 15 percent to 30 percent chance of the satellite colliding with another piece of junk during the 150 years it remains in orbit. But that likelihood is based on the current population of space debris in low Earth orbit remaining constant during the period a scenario no one believes is remotely possible.


Satellites most prone to creating space debris
Williamson 9 (Ray, editor, Secure World Foundation, http://www.imagingnotes.com/go/article_free.php?mp_id=170, accessed 7-2-11, CH)

In the past, imaging satellite operators have generally not needed to worry much about the risk their satellites might face from collisions with other satellites or with orbital debris. More recently, however, they have begun to take notice of environmental conditions in Earth orbit. One immediate reason for increased interest in orbital safety is the February 10, 2009, collision of the Iridium-33 satellite with the defunct Russian Cosmos 2251 satellite. That collision created more than 800 pieces of debris 10 cm in length or above, in two clouds. Over time, these two clouds will slowly expand outward, threatening other working satellites that move in nearby orbits. Because the destroyed Iridium satellite flew in a near polar orbit, debris from this collision now poses an additional hazard to some remote sensing satellites. The Canadian RADARSATS 1 and 2 have been cited as threatened by this debris.(1) Other Earth observing satellites are likely to be affected in the future. Normal space operations unavoidably add debris to the space environment. In addition, fragmentations of spent rocket bodies in orbit and occasional explosions of old satellites add to the threat. Finally, anti-satellite tests by the Soviet Union and the United States in the 1970-80s and by China in January 2007 resulted in thousands of pieces of space debris. U.S. Air Force officials estimate that some 18,000 pieces of debris greater than 10 cm now circle Earth.





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