The Kelvin Wake Infrared Radiance Model – Implementation into the Sea Surface Infrared Radiance Simulator

PDF

Authors
  1. Issa, V.
  2. Daya, Z.A.
Corporate Authors
Defence Research and Development Canada, Valcartier Research Centre, Quebec QC (CAN);Defence Research and Development Canada, Atlantic Research Centre, Halifax NS (CAN)
Abstract
The well known ‘V’ shaped ship Kelvin wake consists of a pattern of sea surface waves with predictable elevation and orientation. In the middle wave infrared, the surface waves are simultaneously emitters and reflectors. The radiance pattern from the Kelvin wake can be exploited for strategic surveillance, smart tracking algorithms and for naval platform vulnerability assessment. We have modeled the middle wave infrared radiance of the Kelvin wake of a ship approximated by a point source of pressure on the surface of infinitely deep water. The elevation field of the Kelvin wake is normalized against measurements from a ship trial. This elevation input is then meshed into facets whose orientation are calculated numerically with a central finite difference scheme. Thereafter we have used the Sea Surface Radiance Simulator, a in-house Matlab code, to calculate the middle wave infrared radiance emitted and reflected by each facet toward an observer. The calculation takes into account the source-receiver geometry, the environmental radiometric sources, and the effects of propagation through the atmosphere. Since there are on the order of a million surface facets, we have clustered facets with the same slopes and relative receiver position. This clustering accelerates significantly the numerical calculation. We find that the mid wave infrared radiance of the Kelvin wake and its contrast with the sea surface background is highly dependent on the receiver position which determine

Il y a un résumé en français ici.

Keywords
DRDC Scientific Report;sea surface reflectivity;sea surface emissivity;sea surface roughness;infrared sea radiance;sky radiance;trailing wake;Kelvin wake;turbulent wake
Report Number
DRDC-RDDC-2018-R246 — Scientific Report
Date of publication
01 Feb 2019
Number of Pages
21
DSTKIM No
CA049110
CANDIS No
809729
Format(s):
Electronic Document(PDF)

Permanent link

Document 1 of 1

Date modified: