In this article, simulated GOES-I imagery has been presented for comparison with imagery from the current GOES-7. Those simulations show that GOES-I should represent a notable advance in geostationary satellite imaging capability and will provide another 5) powerful tool for analysis of the earth's atmosphere. Expected improvements and anticipated advances using each spectral band are summarized in the following.
1) At 0.52-0.72 µm (visible), major improvements are in 10-bit versus 6-bit imagery and increased sampling frequency. The increased sampling frequency should allow for better cloud-edge detection, while the 10-bit versus 6-bit improvement will provide 1024 versus 64 brightness levels. With proper image enhancement, those new capabilities should allow for (a) improved cloud-edge and cloud-top feature detection, which should lead to improvements in cloud-drift winds and severe storm identification; (b) extended use of visible imagery into low-light situations; (c) detection and potential assessment of pollution and haze; and (d) highly accurate cloud height measurements during daylight hours using both stereo and cloud shadow techniques.
2) At 3.7-4.03 µm (shortwave infrared window), major improvements in resolution (2 km x 4 km versus 4 km x 16 km) and sensitivity (0.15 K versus 0.25 K at 300 K) will greatly increase our ability to identify fog at night, locate water clouds over snow during the daytime, delineate between supercooled and ice cloud during daytime (with longwave IR), and detect hot areas such as fires and volcanoes. The improved resolution should also aid in hurricane eye location when the eye is covered with thin cirrus. At night, this band has the potential of improving sea surface temperature measurements due to decreased diffraction effects (versus longwave IR bands).
3) At 6.47-7.02 µm (water vapor band), there is a twofold improvement in spatial resolution and a factor of 3 improvement in signal to noise. Those improvements will be obvious in the routine loops of water vapor imagery used to estimate regions of midlevel moisture advection and drying. Additionally, GOES-I should yield better winds in cloud-free areas and improved identification of synoptic-scale features.
4) At 10.2-11.2 µm (longwave infrared window), a near fourfold improvement in spatial resolution should lead to improvements in cloud-edge and cloud-top feature detection. This should allow for improvements in cloud-drift winds, severe storm identification, and location of storms with heavy rainfall. In combination with the 11.5-12.5-µm band improvements, better low-level moisture identification should result. With the 11.5-12.5- and 3.7-4.03-µm bands, improvements in nighttime SST determination should be realizable.
5) At 11.5-12.5 µm (split window), there is an eightfold increase in resolution over what is available today. Furthermore, this band covers a larger spectral width than with GOES-VAS, and its resulting signal-to-noise improvement (equivalent to the 10.2-11.2-µm band) should lead to the development of much more accurate low-level moisture and improved sea surface temperature products. Improved low-level moisture products are valuable for all types of convective forecasting and in other situations where diabatic heating is important. In stable situations, this information has value for use in recognizing areas with a potential for radiation fog development.
The sounder is now an independent instrument on GOES-I and capable of supporting routine operations for the first time. It includes 18 infrared bands. An ozone band is added, more shortwave bands enhance low-level vertical resolution, an accurate split window provides atmosphere-corrected views of the earth surface, and three moisture-sensing bands improve the vertical resolution for moisture sounding. Simulations show that the improved signal to noise achieved by the earth-oriented sounder enables improved coverage of soundings in and around cloudy weather systems as well as improved delineation of vertical variations of atmospheric moisture. Improved soundings in severe storm and hurricane situations are expected to further understanding and improve forecasts of those weather phenomena.