Mapping water depths in clear water from space
Stumpf RP, et al. (2003). "Mapping water depths in clear water from space." Proceedings of the 13th Biennial Coastal Zone Conference
Knowledge of water depth in clear water in shallow habitats, such as coral reef environments, is required at scales from the global to the local. Extracting depths from data from a variety of satellite sensors allows the possibility of examining and mapping shallow water at all these scales. A new algorithm to simplify depth determination may be applied to sensors such as SeaWiFS, Landsat, and IKONOS, and digital photography from the International Space Station (ISS). The method can provide detail on structure independent of bottom albedo, allowing new information to be obtained from each platform. SeaWiFS provides a capability for global mapping with 1-km pixels, which is comparable to the accuracy of a number of the maps on which the current global coral reef map is based (Spalding et al., 2001). Landsat, with 30-m pixels, can provide regional data which can help find banks and characterize massive atolls. IKONOS, with 4-m pixels, provides the detail necessary to map morphology and features relevant to coral habitat mapping. Space Station photography offers pixels of 6-10 m, and additionally could provide repetitive imagery for cloud removal and change analysis. These data sets are being developed and will be incorporated into a common database for improved understanding of coral habitats.