Using panchromatic imagery in place of multispectral imagery forkelp detection in water

摘要

Multispectral imagery (MSI) taken with high-spatial resolution systems provides a powerful tool for mapping kelp in water. MSI are not always available, however, and there are systems which provide only panchromatic imagery which would be useful to exploit for the purpose of mapping kelp. Kelp mapping with MSI is generally done by use of the standard Normalized Difference Vegetation Index (NDVI). In broadband panchromatic imagery, the kelp appears brighter than the water because of the strong response of vegetation in the NIR, and can be reliably detected by means of a simple threshold; overall brightness is generally proportional to the NDVI. Confusion is caused by other bright pixels in the image, including sun glint. This research seeks to find ways of mitigating the number of false alarms using spatial image processing techniques. Methods developed in this research can be applied to other water target detection tasks.