The Maximum Peak Height (MPH) algorithm exploits bottom-of-Rayleigh reflectance peaks in the red and near-infrared bands above a baseline, which is drawn between the bands at 664nm, and 885nm (Matthews et al., 2012). This baseline technique is basically the same used in the Fluorescence Line Height (FLH) and Maximum Chlorophyll Index (MCI) algorithms (Gower et al., 1999).

Different reflectance peak positions occur mostly as a consequence of pigment concentration levels, and these peaks' heights depend on specific optical drivers (Figure 1).

For the most common water types, MPH selects a suitable baseline using a sequence of predefined conditions and thresholds (Figure 2).

References

Gower, J.F.R., R. Doerffer, and G.A. Borstad: Interpretation of the 685 nm peak in water-leaving radiance spectra in terms of fluorescence, absorption and scattering, and its observation by MERIS, Int. J. Remote Sensing, 9, 1771-1786, 1999.

Matthews, M. W., S. Bernard and L. Robertson: An Algorithm for Detecting Trophic Status (chlorophyll-A), Cyanobacterial-Dominance, Surface Scums and Floating Vegetation in Inland and Coastal Waters, Remote Sensing of Environment 124 (0): 637?52, 2012.

Matthews, M. W. and D. Odermatt: Improved maximum peak height algorithm for the BEAM toolbox, Remote Sensing Letters: In preparation.