1 July 1991 Infrared clutter measurements of marine backgrounds
Author Affiliations +
Observations in the infrared wavelength band between 8 and 12 micrometers of sea backgrounds have been recorded with a CCIR compatible imager for a large number of sea states (0 - 6). Recordings took place in coastal areas as well as on open seas. The behavior of clutter in the infrared data was analyzed in space and in time. Clutter values are analyzed to give estimates for the physical appearance of the sea, such as wave structure. Elevation profiles are evaluated for sea state characteristics and show that the variation of the RMS with elevation (- dRMS/d(epsilon) ) decreases with increasing sea state number. Infrared sequences are used to derive periods in the RMS clutter values and to derive time constants of about 1 second for the images in the sequence to become uncorrelated. A constant azimuthal wave velocity is found from the radiance images. Sunglint images were recorded with FEL-TNO's Multi Path Transmissometer Radiometer (MPTR) simultaneously in six wavelength bands at 0.6, 0.8, 1.3, 2.1, 4.0, and 10.0 micrometers in coastal areas. The presented images are very similar in all six bands with a pattern width of 8.8 degree(s). The elevation averaged profiles are well fitted by a Gaussian pattern. Characteristic hotspot duration times were estimated to be 0.15 to 0.20 seconds. The spectral correlation is investigated and found to be present only on a global scale.
© (1991) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Piet B. W. Schwering, Piet B. W. Schwering, } "Infrared clutter measurements of marine backgrounds", Proc. SPIE 1486, Characterization, Propagation, and Simulation of Sources and Backgrounds, (1 July 1991); doi: 10.1117/12.45749; https://doi.org/10.1117/12.45749

Back to Top