Regardless, "it is sensible to extend the scope of the mapping exercise to include those habitats which most strongly resemble the habitat of interest…By incorporating those habitats which are most likely to create misclassifications and errors in the habitat maps, the accuracy of the mapping objective can be determined" (Mumby 2009). Comparing the images of known habitat areas, to see if the images are distinct, lends greater credence to the portrait generated of the area as a whole. Sensors can be used to map both geomorphological zones and more broadly-defined ecological habitats. Properly executed, with the use of 'control' groupings and 'ground-truthing,' the technology can be highly effective. "The number of ground-truthing sites required per habitat is difficult to quantify and depends on the size of the area and distribution (i.e. complexity) of habitats: smaller study areas and areas of relatively uniform habitat (e.g. sand banks) require less ground-truthing. For example, 10 sites per habitat may be acceptable for a single bay whereas 30 may be required to map an entire coastline. However, whereas ground-truthing requirements may vary, it is imperative that an adequate number of sites are visited for accuracy assessment -- ideally at least 50 independent sites per habitat" (Mumby, Green, Edwards & Clark 2009). Adequate ground-truthing can increase accuracy as high as 75%-100%.

The future opportunities of remote sensing in coastal environments

Because of its cost-effective nature, in contrast to land-based sensing, remote is likely to become more popular in the future. Granted, habitat-mapping can be an expensive undertaking. However, after the initial set-up costs, "using remote sensing to augment field survey is the most cost-effective means of achieving outputs for scientific and management purposes. Four types of cost are encountered when undertaking remote sensing: (1) set-up costs, (2) field survey costs, (3) image acquisition costs, and (4) the time spent on analysis of field data and processing imagery. The largest of these are set-up costs, such as the acquisition of hardware and software, which may comprise 40 -- 72% of the total cost of the project depending...

The major cost is the GPS (global positioning software) needed for the system. However, once the technology becomes ubiquitous, costs will likely decrease, in contrast to the continued maintenance costs of previous ground and sea-based operations.
Works Cited

Edwards, A. "Part 1: Remote Sensing for Coastal Managers An Introduction."

From Remote Sensing Handbook for Tropical Coastal Management. Edited by Edmund P. Green, Peter J. Mumby, Alasdair J. Edwards, & Christopher D. Clark

January 9, 2010. http://www.unesco.org/csi/pub/source/rs.htm

Mumby, P., E. Green, A. Edwards, & C. Clark. "Cost-effectiveness of Remote Sensing for Coastal Management." From Remote Sensing Handbook for Tropical Coastal

Management. Edited by Edmund P. Green, Peter J. Mumby, Alasdair J. Edwards, & Christopher D. Clark. January 9, 2010.

http://www.unesco.org/csi/pub/source/rs14.htm

Mumby, P. & E. Green. "Field Survey: Building the Link between Image and Reality." From

From Remote Sensing Handbook for Tropical Coastal Management. Edited by Edmund P. Green, Peter J. Mumby, Alasdair J. Edwards, & Christopher D. Clark

January 9, 2010.http://www.unesco.org/csi/pub/source/rs9.htm

Mumby, P. "Methodologies for Defining Habitats." From Remote Sensing Handbook for Tropical Coastal Management. Edited by Edmund P. Green, Peter J. Mumby, Alasdair J.

Edwards, & Christopher D. Clark. January 9, 2010.

http://www.unesco.org/csi/pub/source/rs11.htm

Polidori, Laurent. "Remote sensing and costal ecosystem monitoring in French Guiana: Research and achievements over a decade." The International Archives of the Photogrammetry,

Remote Sensing and Spatial Information Sciences. 37. B8. (2008): 627-632.

January 9, 2010.

http://www.isprs.org/congresses/beijing2008/proceedings/8_pdf/4_WG-VIII-4/01.pdf

Sudarshana, R. "Remote Sensing." Indian Institute of Remote Sensing. January 9, 2010.

http://www.unesco.org/csi/act/other/projec14.htm