Multispectral Applications

Abstract

Multispectral satellite sensors have been used widely for coral reef applications. There is a long history of multispectral image acquisition, second to photography, with data available at global coverage for relatively low cost. This chapter summarizes the history, observation targets, and image processing meth-ods of multispectral remote sensing of coral reefs. A variety of applications are presented in a progression from image classification and mapping to monitoring and modeling. Insight into the future directions of multispectral coral reef imaging is then provided, with a focus on higher spatial resolution, higher spectral reso-lution, greater data acquisition capacity, and integration with other data sources. 3.1 Introduction Large-scale, synoptic mapping and monitoring are a basic requirement for the management and conservation of coral reefs (Green et al. 2000; Newman et al. 2006). One of the most practical solutions for meeting this need is multispectral remote sensing. Multispectral sensors are typically broadband, with three or four 60–100 nm wide wavebands in the visible to near infrared regions of the elec-tromagnetic spectrum. Although the broadband limits detailed discrimination of specific benthic features (e.g., coral, seagrass and macroalgae) that have similar reflectance characteristics (Hochberg et al. 2003), multispectral sensors have been used widely for mapping, monitoring and management of coral reefs, mostly