Increasing the accuracy of melt estimation using microwave instruments by focusing on sub-day time scales is addressed. Three Special Sensor Microwave Imager (SSM/I) instruments operating simultaneously over the summer of 2002 are combined to estimate brightness temperature (Tb) over daily cycles. Normalized radar cross-section (σ) measurements from SeaWinds on QuikSCAT are employed to provide ...

Following up on the successful NSCAT mission, the QuikScat/Seawinds scatterometer (Qscat) provides normalized radar cross section ( o) measurements of the Earth's surface at unprecedented coverage and resolution. While originally designed for wind observation, scatterometers have proven useful in a variety of land and ice studies. To further improve the utility of the data, resolution enhanceme...

An approximate method to compute rough estimates of the broadside radar return from axially symmetric ionized gas columns is presented and applied to an illustrative example The method uses a continuum approach and takes into account the electron-neuti al collision frequency and both axial and radial variation of electron density The local reflectivity is determined as a function of axial posit...

Simultaneous microwave and video measurements of shallow water breaking waves are presented. A comparison of the data from the two sensors shows that short-duration spikes in the measured X-band radar cross section are highly correlated with the presence of breaking waves in the video imagery. In addition, the radar backscatter from shallow water breaking events is responsible for 40% to 50% of...

We present an algorithm that is able to smooth out the speckle from many SAR images and which does not suuer from the drawbacks of multilooking. The algorithm is able to preserve the detail and resolution of the original image while producing a smooth, real-valued output. In many cases the quality of the smoothed image is suuciently high that it may be used with standard optical post-processing...

abstract according to the adventages of passive radars they have been reconsidered recently due to development of signal processing technology. in the field of sea targets detection using passive radar few research have been reported. this paper presents a new method to detect sea targets using adaptive filter weights variation model and using the fact that the radar cross section of sea target...

Modern spaceborne radar scatterometers such as the NASA Scatterometer (NSCAT) and SeaWinds radar instruments require precise determination of the normalized backscattered radar cross section within a few tenth of a decibel in order to achieve the desired wind velocity and direction measurement accuracy of 2 m/s and 20 degrees respectively. This high level of precision requires a priori prelaunc...

he high resolution and large coverage of satellite synthetic aperture radar (SAR) offer a unique opportunity to derive mesoscale wind fields over the ocean surface and to investigate their spatial variation. For this purpose, different algorithms were developed and tested using SAR images from two European Remote Sensing satellites. In this article, the methods for deriving wind fields from SAR...

this paper points out the frequency dependence on the polarimetric radar scattering behavior of the ocean surface in the frequency range 1-18 GHz (Lto Ku-band). We treat this problem with a unifying scattering model named Small Slope Approximation (SSA) to evaluate the Normalized Radar Cross Section (NRCS). The calculations were made by assuming the surface-height spectrum of Elfouhaily et al f...

[1] The anomaly of radar sea spikes, defined here as the non-Bragg scattering events with backscattering cross-section of horizontal polarization exceeding that of the vertical polarization, has been associated with steep wave features possibly going through wavebreaking process, with or without whitecap manifestation. This property is exploited for using a dual polarized radar as a remote sens...