An HRPT (High Resolution Picture Transmission) station for the reception of SeaWiFS (Sea-viewing Wide Field-of-view Sensor) ocean color data was installed at the Hong Kong University of Science & Technology (HKUST) in 1994. Since then, we have been receiving transmissions from NOAA (National Oceanic and Atmospheric Administration)-12, -14 satellites and the SeaStar satellite which contains the SeaWiFS instrument. |
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All NOAA and SeaStar satellites operate in near-polar sun-synchronous orbits at heights of about 850 km and 750 km respectively, and provide global coverage twice a day. The sensors on the satellites scan the earth continuously and broadcast data at the same time.AVHRR (Advanced Very High Resolution Radiometer) is available on all NOAA platforms. It has a 1.1 km field of view at nadir and is a five-channel device transmitting in the visible, near-infrared and infrared wavelengths. |
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Data Processing
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Applications Indonesian Fire Tropical Cyclone Red Tide Observation Air Pollution in Hong Kong |
Indonesian Fire
AVHRR data were used to track and analyze the 1997 Indonesian fires and the dispersion of smoke. Although Indonesia is at the southern extremity of our reception area, high quality pictures though with partialview were received.
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Tropical Cyclone
Tropical cyclones with maximal sustained winds of greater than 118 km per hour (33 m/s or 64 knots) are called typhoons. Using visible and infrared images from AVHRR, cloud patterns and overall structures can help us determine the location and intensity of tropical cyclones and typhoons. |
Red Tide
Observation
China has been experiencing increasing red tides off the Chinese coast since the 1990s due to increasing pollution caused by industrial waste water. During the past decade, a total of 200 red tides have been registered and over the past three years there have been 45 major red tides, causing 240 million U.S. dollars in direct economic losses. With the help of remote sensing technology, we can monitor red tides based on the satellite images of chlorophyll concentrations and sea surface temperatures in water. |
Air Pollution in
Hong Kong
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