Abstract
Abstract. The first geostationary Earth observation satellite of Korea – the Communication, Ocean, and Meteorological Satellite (COMS) – was successfully launched on 27 June 2010. After arrival at its operational orbit, the satellite underwent an in-orbit test (IOT) that lasted for about 8 months. During the IOT period, the main payload for the weather application, the meteorological imager, went through successful tests for demonstrating its function and performance, and the test results are introduced here. The radiometric performance of the meteorological imager (MI) is tested by means of signal-to-noise ratio (SNR) for the visible channel, noise-equivalent differential temperature (NEdT) for the infrared channels, and pixel-to-pixel nonuniformity for both the visible and infrared channels. In the case of the visible channel, the SNR of all eight detectors is obtained using the ground-measured parameters with the background signals obtained in orbit. The overall performance shows a value larger than 26 at 5% albedo, exceeding the user requirement of 10 by a significant margin. Also, the relative variability of detector responsivity among the eight visible channels meets the user requirement, showing values within 10% of the user requirement. For the infrared channels, the NEdT of each detector is well within the user requirement and is comparable with or better than the legacy instruments, except for the water vapor channel, which is slightly noisier than the legacy instruments. The variability of detector responsivity of infrared channels is also below the user requirement, within 40% of the requirement, except for the shortwave infrared channel. The improved performance result is partly due to the stable and low detector temperature obtained due to spacecraft design, i.e., by installing a single solar panel on the opposite side of the MI.
Highlights
Geostationary meteorological satellites have played important roles as storm trackers, a global source of important geophysical information such as sea surface temperature, and providers of long-term records for climatic applications (Purdom and Menzel, 1996; Schmetz et al, 2002)
The noise performance is presented as the signal-to-noise ratio (SNR) for the visible channel and noise-equivalent differential temperature (NEdT) for the infrared channels
A new coating material for the scan mirror was applied for COMS/meteorological imager (MI), and the performance is evaluated using the space look count (Astrium EADS, 2011a), which is obtained by scanning the full width of the E–W direction for the area well above the Earth disk edge
Summary
Geostationary meteorological satellites have played important roles as storm trackers, a global source of important geophysical information such as sea surface temperature, and providers of long-term records for climatic applications (Purdom and Menzel, 1996; Schmetz et al, 2002). While a detailed description for the IOT is provided in Appendix A2, several interesting activities such as the acquisition of the first image, a successful outgassing operation, and the beginning of the full test are introduced here. From the two window channels (Fig. 3c and b), several prominent cloud patterns associated with important weather processes such as tropical convective activities (center of image), weakened Asian monsoon (upper part of the image), and well-developed polar cyclones in the Southern Hemisphere are clearly captured. The most important tasks with full operation are the fine tuning of the imagenavigation-and-registration (INR) algorithms and extensive verification of performances at system level, i.e., INR validation, band-to-band registration, and navigation performance During this period, the simulated algorithm parameters for the INR processes are fine-tuned with the actual observation data and all of the algorithm parameters are finalized. The original plan for the length of the IOT was about 6 months; it took about 8 months, which is still considered quite successful compared to other similar programs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
