Optimal spatial filtering and transfer function for SAR ocean wave spectraThe impulse response of the SAR system is not a delta function and the spectra represent the product of the underlying image spectrum with the transform of the impulse response which must be removed. A digitally computed spectrum of SEASAT imagery of the Atlantic Ocean east of Cape Hatteras was smoothed with a 5 x 5 convolution filter and the trend was sampled in a direction normal to the predominant wave direction. This yielded a transform of a noise-like process. The smoothed value of this trend is the transform of the impulse response. This trend is fit with either a second- or fourth-order polynomial which is then used to correct the entire spectrum. A 16 x 16 smoothing of the spectrum shows the presence of two distinct swells. Correction of the effects of speckle is effected by the subtraction of a bias from the spectrum.
Document ID
19820013596
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Beal, R. C. (Johns Hopkins Univ. Silver Spring, MD, United States)
Tilley, D. G. (Johns Hopkins Univ. Silver Spring, MD, United States)