Statistical characteristics of bistatic sea surface scatter

1998 ◽  
Vol 103 (5) ◽  
pp. 3094-3094
Author(s):  
Peter D. Neumann ◽  
R. Lee Culver
Keyword(s):  
Sea Surface ◽  
Statistical Characteristics ◽  
Surface Scatter

The distribution of sun glints sizes on the sea surface

2011 ◽  
Vol 3 (2) ◽  
Author(s):  
Rauf Gardashov
Keyword(s):  
Experimental Study ◽  
Spatial Resolution ◽  
Total Curvature ◽  
Digital Camera ◽  
Fortran Program ◽  
Theoretical Distribution ◽  
Sea Surface ◽  
Statistical Characteristics ◽  
Statistical Distributions ◽  
Natural Experiments

AbstractThe problem is studied both theoretically and experimentally. Statistical distributions of the total curvature and the reciprocal to the total curvature at the specular points (SP) of a random Gaussian uniform sea surface are discussed. The theoretical distribution and its asymptotes are completely investigated. The validity of the theoretical distribution is verified by numerical simulations and natural experiments. In the experimental study of this distribution, Sun glint images taken with a high time and spatial resolution digital camera are used. Those images are developed by using a specially-designed Fortran program which calculates the statistical characteristics of the glints. The experimentally derived distribution of the glint areas is compared with the theoretical distribution. The main causes (origins) of small divergence between the theoretical and experimental results are discussed.

scholarly journals Detection of Multi-pixel Low Contrast Object on a Real Sea Surface

2021 ◽  
Author(s):  
Victor Golikov ◽  
Oleg Samovarov ◽  
Daria Chernomorets ◽  
Marco Rodriguez-Blanco
Keyword(s):  
Spectral Characteristics ◽  
False Alarm Probability ◽  
Sea Surface ◽  
Statistical Characteristics ◽  
Statistical Parameters ◽  
Low Contrast ◽  
Video Images ◽  
Floating Object ◽  
The Difference ◽  
Floating Objects

The video images captured at long range usually have low contrast floating objects of interest on a sea surface. A comparative experimental study of the statistical characteristics of reflections from floating objects and from the agitated sea surface showed the difference in the correlation and spectral characteristics of these reflections. The functioning of the recently proposed modified matched subspace detector (MMSD) is based on the separation of the observed data spectrum on two subspaces: relatively low and relatively high frequencies. In the literature the MMSD performance has been evaluated in generally and moreover using only a sea model (additive Gaussian background clutter). This paper extends the performance evaluating methodology for low contrast object detection and moreover using only the real sea dataset. This methodology assumes an object of low contrast if the mean and variance of the object and the surrounding background are the same. The paper assumes that the energy spectrum of the object and the sea are different. The paper investigates a scenario in which an artificially created model of a floating object with specified statistical parameters is placed on the surface of a real sea image. The paper compares the efficiency of the classical Matched Subspace Detector (MSD) and MMSD for detecting low-contrast objects on the sea surface. The article analyzes the dependence of the detection probability at a fixed false alarm probability on the difference between the statistical means and variances of a floating object and the surrounding sea.

scholarly journals Structure of the Field of the Colored Dissolved Organic Matter Concentration in the Kerch Strait

2021 ◽  
Vol 28 (5) ◽  
Author(s):  
P. D. Lomakin ◽  
A. I. Chepyzhenko ◽  
A.A. Chepyzhenko ◽  
◽  
◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Concentration Distribution ◽  
Vertical Structure ◽  
Concentration Field ◽  
Sea Surface ◽  
Statistical Characteristics ◽  
Colored Dissolved Organic Matter ◽  
Typical Structure ◽  
Kerch Strait

Purpose. Using the data obtained in the expeditions, 2001–2014, the authors intend to identify the typical features of vertical structure of the colored dissolved organic matter (fDOM) concentration field in the Kerch Strait, to type the fDOM(z) profiles, to zone the region under consideration according to a given set of the qualitative features, and also to determine the features of statistical characteristics of the fDOM concentration distribution on the sea surface layer for the water areas with a typical structure. Methods and Results. The typing was carried out by the method of visual expert assessment of the curves of vertical distribution of concentration of the considered value. It was based on analyzing the fDOM(z) profile shapes. To reveal the boundaries of the areas with typical stratification of the fDOM content field, the thermohaline field structure was analyzed. Three types of water vertical structure were identified; they differed in the fDOM(z) profile shape and in statistical indices of empirical distribution of this substance concentration on the sea surface. These are the Azov Sea and the Black Sea types peculiar to the Azov and Black seas waters not contaminated by dissolved organic matter, and the type, the structure of which identifies the waters containing the anthropogenic component in the concentration field of the analyzed value. The latter type is characterized by a special intrusive shape of the fDOM(z) profile. For each of the identified stratification types, the histograms of the fDOM concentration distribution on the sea surface were calculated. Conclusions. The fDOM(z) profiles were typed. The Kerch Strait water area was zoned in accordance with a given set of the preliminary revealed qualitative features. The boundaries of the areas with typical stratification and their displacements were determined. It is shown that each structure type has its own statistical distribution of concentration of the considered value on the sea surface

scholarly journals Effects of mixed scatter on SuperDARN convection maps

2008 ◽  
Vol 26 (6) ◽  
pp. 1517-1523 ◽  
Author(s):  
P. V. Ponomarenko ◽  
C. L. Waters ◽  
F. W. Menk
Keyword(s):  
Ionospheric Plasma ◽  
Doppler Frequency ◽  
Radar Data ◽  
Sea Surface ◽  
Plasma Drift ◽  
Fitting Algorithm ◽  
Sample Data ◽  
Convection Patterns ◽  
Surface Scatter ◽  
Electron Density Irregularities

Abstract. The SuperDARN radars map high-latitude ionospheric plasma drift velocities by measuring the Doppler frequency shift of HF signals scattered by decameter electron density irregularities. In many cases the ionospheric returns are contaminated by strong scatter from the ground or sea surface. In this paper we develop and test a two-component fitting algorithm to separate ionospheric and surface scatter components. Application of the technique to sample data reveals that mixed scatter may considerably distort ionospheric convection patterns derived from the radar data and can cause underestimation of the plasma drift velocity.

Statistical characteristics of bistatic surface scatter

1993 ◽  
Vol 93 (4) ◽  
pp. 2379-2379
Author(s):  
Peter D. Neumann ◽  
R. Lee Culver
Keyword(s):  
Statistical Characteristics ◽  
Surface Scatter
Sign in / Sign up

Export Citation Format

Share Document