In recent months, NOAA has taken a more detailed look and has done technical studies related to future satellite need for coastal observations. This is in response to serving users better and to aid in future designs of instruments for geosynchronous and polar satellites.

In earlier work, NOAA's Coastal Services Center in Charleston, S.C. had listed, with vivid examples, 25 possible needs for improved coastal measurements. These included: coastal development, habitat, water quality, living resources, and waterways. This community does not want to underutilize the technology of remote sensing when it is most effective.

The effectiveness was qualitative earlier, and showed that over one-half of the 25 coastal uses were strong satellite contenders and this included new technology like hyper-spectral sensors.

In this newer investigation, we have applied select quantitative plateau levels of remote sensing to the applications above. For example we have specified spatial resolution from geo-satellites at 250 meters, 100 meters and 25 meters. We have specified spectral resolution width at 10-nm (nanno-meters) bands, 1-nm, and finer than 1-nm bands across a wide range of possible channels from 400 to 2500-nm. And finally, with temporal resolution we explored daily, 3 hours, and hourly measurement frequency.

This more quantitative approach shows that some coastal targets or uses are easlier to do (and more efficient) from space. Floodplains and oceanfront setbacks are easier to measure than in-water targets like oil spills and marsh grasses. The most difficult to measure from space are submerged targets like oyster beds or coral reefs. Our study gives decision makers more clarity and helps to scale the trade space designs of sensors.

Finally, as a validation check, we continue analysis of remote sensing needs for the most difficult use which is the health and mapping of coral reefs. We study other technologies including: high-definition acoustic imaging, multispectral fluorescence line scanning, airborne LIDAR, and multibeam sonar. For some coral applications, in-situ and airborne imaging excell over space measurements, but the extent of coverage and temporal resampling must be considered.

The integration of user needs, measurement attributes, system design levels, utility definition and cost need to be done carefully for future coastal remote sensing programs. We hope our studies point the way for better decisions and strong progress in future satellite systems.