Marine Mammal Census Using Space Satellite Imagery

A new era of commercial high-resolution imagery from space began late in 1999 resulting in resolution that is now sufficient to resolve marine mammals. This encouraged investigating the use of satellite imagery for marine-mammal population census and related studies. The question was raised: Can marine mammals be reliably detected above sensor noise and ocean clutter? To answer this question, a signal model was developed and simulated 14-meter targets were injected into IKONOS satellite imagery. A variation of a well-known, two-color method was used to subtract the ocean clutter. After clutter mitigation, it was possible to detect the simulated animals to depths of approximately 20 meters depending on the animal’s size, spectral reflectivity, and the optical properties of the ocean. The first images of marine mammals from space are presented. These examples, however, were targets of opportunity without ground truth. The preliminary assessment on the detectability of marine mammals rests largely on models and simulations.