Refractivity estimation from sea clutter: An invited review
نویسندگان
چکیده
[1] Non‐standard radio wave propagation in the atmosphere is caused by anomalous changes of the atmospheric refractivity index. In recent years, refractivity from clutter (RFC) has been an active field of research to complement traditional ways of measuring the refractivity profile in maritime environments which rely on direct sensing of the environmental parameters. Higher temporal and spatial resolution of the refractivity profile, together with a lower cost and convenience of operations have been the promising factors that brought RFC under consideration. Presented is an overview of the basic concepts, research and achievements in the field of RFC. Topics that require more attention in future studies also are discussed.
منابع مشابه
Effects of Sea Clutter on Atmospheric Refractivity Estimation
This paper addresses the effects of sea clutter on the clutter-based atmospheric refractivity estimation techniques. It provides a mean square error (MSE) metric for refractivity estimators based on the available clutter-to-noise (CNR) ratio, the type of the sea clutter statistics (Rayleigh, K-distributed and log-normal) and the parameters forming these probability density functions (pdf) such ...
متن کاملInversion for refractivity parameters from radar sea clutter
[1] This paper describes estimation of low-altitude atmospheric refractivity from radar sea clutter observations. The vertical structure of the refractive environment is modeled using five parameters, and the horizontal structure is modeled using six parameters. The refractivity model is implemented with and without an a priori constraint on the duct strength, as might be derived from soundings...
متن کاملRecursive Bayesian electromagnetic refractivity estimation from radar sea clutter
[1] Estimation of the rangeand height-dependent index of refraction over the sea surface facilitates prediction of ducted microwave propagation loss. In this paper, refractivity estimation from radar clutter returns is performed using a Markov state space model for microwave propagation. Specifically, the parabolic approximation for numerical solution of the wave equation is used to formulate t...
متن کاملRefractivity from Clutter by Variational Adjoint Approach
Inferring refractivity profiles from radar sea clutter is a complex nonlinear optimization problem. Previous works treat this problem as a model parameter estimation issue by using some idealized refractivity models, such as the Log linear evaporation duct model, bilinear model, and trilinear model, to describe the synoptic structure of the real atmospheric conditions. However, these idealized ...
متن کاملProbability distribution of low-altitude propagation loss from radar sea clutter data
[1] This paper describes the estimation of propagation loss and its statistical properties on the basis of observations of radar sea clutter data. This problem is solved by first finding an ensemble of relevant refractivity model parameters, and each refractivity model is weighted according to its data likelihood function. A parabolic equation propagation model is used both in mapping from envi...
متن کامل