Remote sensing of the coastal zone: An overview and priorities for future research

Environmental and Sensor Limitations in Optical Remote Sensing of Coral Reefs: Implications for Monitoring and Sensor Design

“…However, these studies have focused on variation in benthic type in situ spectral reflectance and sensor noise as the primary sources of noise in the system. In reality, within the spatial scale of a single remotely-sensed image, coral reef waters can exhibit a wide range of water clarity from Case 1 oceanic-like fore-reef sites through shallow lagoonal sites subject to wind and tidal driven re-suspension of sediments, to complex sediment and CDOM-loaded terrestrial inputs [11,12]. Around spur and groove zones and on patch reefs depth can also vary with vertical scales almost equal to the total height of the water column.…”

On the Benefits of Using Both Dual Frequency Side Scan Sonar and Optical Signatures for the Discrimination of Coral Reef Benthic Communities

“…Knowledge of the upper and lower limits of habitats is important for management purposes (Malthus & Mumby, 2003), and the synergistic use of optical and acoustic data can be useful for such studies since optical systems perform best in shallow waters while sonar systems, are limited to depths generally over 2 m but can be used to depths of hundreds of metres, depending on the system employed. Similar conclusions were reached by Riegl and Purkis (2005) when investigating the synergy of IKONOS and single-beam sonar data.…”

“…The side scan sonar survey had a number of limitations which may have contributed to the misclassifications of some of the classes. Positional and locational errors are in general greater for acoustic data compared with satellite data (Malthus & Mumby, 2003). Positional errors may have been introduced from a variety of sources including inadequate positioning of the towfish in relation to the survey boat, and the approximate nature of the manual georectification of the sonograms.…”

“…This additional information may improve the discrimination of spectrally similar but structurally different bottom types. Despite the increasing evidence of the benefits to be gained there is presently a lack of studies on the synergistic use of alternative remote sensing approaches for mapping shallow www.intechopen.com water marine near shore habitats (Malthus & Mumby, 2003). The most obvious advantage of using acoustic and optical methods in combination is the different depth ranges that each of the systems operate; optical systems perform best in shallow waters (generally up to a maximum of 25 m in the clearest waters), while the deployment of sonar systems (single and multibeam) can be used to depths of hundreds of metres, but it is very much limited in shallow waters.…”

Guest Editorial: Coastal Aquatic Remote Sensing Applications for Environmental Monitoring and Management

“…Very few papers, with the exception of large scale physical-biological oceanographic applications, published in scientific journals show a global uptake of the science and techniques of aquatic remote sensing into environmentally relevant monitoring and management applications. The majority of past reviews of remote sensing for coastal applications have focused on two areas: (1) improvements to technology, techniques and applications, with limited assessment of accuracy and true costs [1,3,[5][6][7][8][9][10][11] and (2) understanding light interactions in shallow water environments [6,12]. Both of these activities were essential to underpin the use of remote sensing for monitoring and managing coastal resources.…”