TITLE:
A Preliminary Assessment of Hyperspectral Remote Sensing Technology for Mapping Submerged Aquatic Vegetation in the Upper Delaware River National Parks (USA)
AUTHORS:
Slonecker Terrence, Kalaly Siddiq, Young John, Furedi Mary Ann, Maloney Kelley, Hamilton Don, Evans Richard, Zinecker Elizabeth
KEYWORDS:
Lotic systems, Submerged Aquatic Vegetation, Didymo germinata, Hyperspectral Remote Sensing, Hyperspectral processing methods
JOURNAL NAME:
Advances in Remote Sensing,
Vol.7 No.4,
December
14,
2018
ABSTRACT: Hyperspectral remote sensing of submerged aquatic vegetation
is a complex and difficult process that is affected by unique constraints on
the energy flow profile near and below the water surface. In addition, shallow,
winding, lotic systems, such as the Upper Delaware River, present additional
remote sensing problems in the form of specular reflectance, variable depth and
constituents in the water column and sometimes extremely weak signal strength
due to absorption and scattering in the water column that can be statistically
overwhelmed by the reflectance from upland vegetation in any individual image
scene. Here we test hyperspectral imagery from the Civil Air Patrol’s (CAP),
Airborne Real-time Cueing Hyperspectral Enhanced Recon (ARCHER) system in the
scenic waters of two National Parks on the Upper Delaware River. A number of
unique image processing problems were encountered, including specular
reflectance from winding lotic systems, variable depth and flow dynamics of the
riverine environment, and disproportionate signal strength from surface
reflectance in this riverine environment. These problems were solved by
applying a specular reflectance removal algorithm, applying field data
collections to classification results and masking upland vegetation so as to
not statistically overwhelm the weak reflectance signal from surface and
near-surface water. Much was learned about conducting imaging spectroscopy in
such difficult conditions. Important results include successful mapping of
Submerged Aquatic Vegetation (SAV) presence/absence, advantages of upland masking
of the reflectance signal, and a number of processing approaches that are
unique to this environment. In this paper we summarize our results and identify
unique issues that must be addressed in this environment.