The current GOES filter-wheel sounders have provided quality broad-band hourly radiances and derived products over the continental U.S. (CONUS) and adjacent oceans for over 10 years. Current GOES Sounder operational products include: radiances, temperature and moisture profiles; Total Precipitable Water vapor (TPW); atmospheric stability indices, such as Lifted Index (LI); cloud-top properties and winds derived from the moisture-sensitive channels. The GOES-N sounder will continue this mission. The GOES-N/O/P instruments will be similar to the GOES-8/12 instruments, but will be on a different spacecraft bus. The new bus will allow improvements on both navigation and registration, as well as improved radiometrics.
Since the ABI acquisition process started earlier than HES and because of the complexity of the instrument suite, there is a possibility that the first satellite in the GOES-R series will fly without a HES. If, HES is delayed, then legacy products that are used by the NWS from the current GOES Sounder can be generated from ABI data. The needed ‘continuity' products (radiances, TPW, LI, skin temperature, clouds, and winds) from today's low-spectral resolution sounder can be compatibly provided by ABI. In general, the ABI has improved temporal and spatial attributes, while the GOES-N class sounder has improved accuracies on products. It is postulated that the ABI plus forecast information will be comparable to the GOES-N class sounder, yet the ABI plus forecast information will still be much worse than HES (with respect to information content). A HES-type capable sounder with faster scanning and high spectral resolution is needed for regional Numerical Weather Prediction (NWP), surface emissivity, better nowcasting products, moisture profiles, moisture flux, better cloud heights, and many additional environmental applications.