The first Taiwan's scientific experimental satellite, "ROCSAT- 1," will be launched by February 1999 to a 600 km circular orbit with a 35° inclination. It will carry an ocean color instrument named "Ocean Color Imager (OCI)" on board to monitor ocean color. The OCI has a 700 km swath within SOO-m square footprint on the ground. It will perform imaging any time between 9:00 to 15:00 local time. Data from the OCI instrument will be processed and then distributed by the OCI Science Data Distribution Center. The data will be free to the scientific communities.
The color of ocean is not blue only. It may be green, yellow, or even red. Generally, ocean color is affected by the concentrations of phytoplankton, suspended matters and gelbstoffe (yellow substance). The change of ocean color means the change of concentrations of such materials near the sea surface and it may also relate to marine productivity and pollution. In coastal waters, for instance, abundant marine organism, suspended matters and dissolved organic substances absorb light caused the water color changes from the bluish region typical of clear ocean water to longer wavelengths. It is an accepted tool now by using imaging spectrometers in the visible region to investigate ocean colors. From remote sensing point of view, we mean that ocean color is the relative amounts of water-leaving radiance in the various portions of the visible spectrum. Measuring water-leaving radiance can derive concentrations of pigment or chlorophyll a. Therefore, ocean color maps are typically presented in a "false color" format that highlights this information. Because of the role of phytoplankton in the global carbon cycle, to understand its distribution and variability can help us to assess the role of ocean in the global change.
