Bathymetry Retrieval from Hyperspectral Imagery in the Very Shallow Water Limit: A Case Study from the 2007 Virginia Coast Reserve (VCR'07) Multi-Sensor Campaign

Abstract

We focus on the validation of a simplified approach to bathymetry retrieval from hyperspectral imagery (HSI) in the very shallow water limit (less than 1–2 m), where many existing bathymetric LIDAR sensors perform poorly. In this depth regime, near infra-red (NIR) reflectance depends primarily on water depth (water absorption) and bottom type, with suspended constituents playing a secondary role. Our processing framework exploits two optimal regions where a simple model depending on bottom type and water depth can be applied in the very shallow limit. These two optimal spectral regions are at a local maximum in the near infra-red reflectance near 810 nm, corresponding to a local minimum in absorption, and a maximum in the first derivative of the reflectance near 720 nm. These two regions correspond to peaks in spectral correlation with bathymetry at these depths.

Keywords:

• Hyperspectral
• shallow-water bathymetry
• bottom type
• IOP
• Hydrolight
• Virginia Coast Reserve

Acknowledgement

The NRL authors gratefully acknowledge platform support from the Office of Naval Research. This article was also funded by the National Geospatial-Intelligence Agency (NGA). The opinions, views, and conclusions found within the article do not necessarily reflect those of the U.S. Department of Defense or the NGA.