Lidar description of the evaporative duct in ocean environments

Willitsford, Adam; Philbrick, C. Russell

doi:10.1117/12.620948

Cited by 16 publications

(11 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Refractivity estimation techniques aim to predict the vertical refractivity gradient which is essential to model the wave propagation at the lower atmosphere. There are various methods for predicting the refractivity of the lower atmosphere: the direct measurement techniques such as microwave refractometers and radiosonde balloons [5], LIDAR (Light Detection and Ranging) techniques [6], in situ bulk measurements and meteorological methods [7], GPS (Global Positioning System) measurements [8], and refractivity from clutter techniques [9], [10]. In this study, we utilize the refractivity measurement results presented in [11], which is based on the atmospheric measurements in Istanbul, Turkey, and [12] on the microwave refractometer measurements with a helicopter in Wallops Island, VA. We determine the parameters regarding to characterize the surface ducts as suggested in [11] and [12].…”

Section: Related Workmentioning

confidence: 99%

Channel Model for the Surface Ducts: Large-Scale Path-Loss, Delay Spread, and AOA

Dinc

Akan

2015

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

Atmospheric ducts, which are caused by the rapid decrease in the refractive index of the lower atmosphere, can trap the propagating signals. The trapping effects of the atmospheric ducts can be utilized as a communication medium for beyondline-of-sight (b-LoS) links. Although the wave propagation and the refractivity estimation techniques for the atmospheric ducts are well studied, there is no work that provides a channel model for the atmospheric ducts. Therefore, we develop a large-scale path-loss model for the surface ducts based on the parabolic equation (PE) methods for the first time in the literature. In addition, we develop a ray-optics (RO) method to analyze the delay spread and angle-ofarrival (AOA) of the ducting channel with the surface ducts. Using the developed RO method, we derive an analytical expression for the effective trapping beamwidth of the transmitter to predict the ranges of the beamwidth that can be trapped by the surface ducts according to the refractivity and the channel parameters.

show abstract

Section: Related Workmentioning

confidence: 99%

Channel Model for the Surface Ducts: Large-Scale Path-Loss, Delay Spread, and AOA

Dinc

Akan

2015

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

show abstract

“…Various traditional methods have been used to determine the atmospheric refractivity profile; these approaches include "bulk" models with in situ measurements as input, microwave refractometers [7], LIDAR techniques [8], and many numerical weather prediction models [9]. In recent years, a technique referred to as refractivity from clutter (RFC) has been widely used in retrieving the refractivity profile in maritime environments [10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Evaporation Duct Retrieval Using Changes in Radar Sea Clutter Power Versus Receiving Height

Zhang¹,

Wu²,

Zhang³

et al. 2012

PIER

View full text Add to dashboard Cite

Abstract-A method for retrieving evaporation duct height (EDH) is introduced in this paper. The proposed technique employs the changes in radar sea clutter power observed at different heights as input information. It identifies the EDH associated with the modeled clutter change pattern that best matches measured change patterns. The performance of the method is evaluated in terms of RMS errors in retrieving actual EDHs that range from 0 to 40 m. The comparison of the proposed method with the conventional clutter pattern matching method shows that the former more effectively retrieves actual EDHs.

show abstract

“…Conventionally atmospheric refractivity is measured using radiosondes and rocketsondes, microwave refractometers, and predicted by meteorological models such as the Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPS) [ Rowland and Babin , 1987; Thews , 1990; Hodur , 1996]. There also are other techniques that can predict refractivity using lidar [ Willitsford and Philbrick , 2005] and GPS [ Lowry et al , 2002] measurements. However, the radar itself can also be used to estimate the refractivity.…”

Section: Introductionmentioning

confidence: 99%

Sensitivity analysis and performance estimation of refractivity from clutter techniques

2009

View full text Add to dashboard Cite

[1] Refractivity from clutter (RFC) refers to techniques that estimate the atmospheric refractivity profile from radar clutter returns. A RFC algorithm works by finding the environment whose simulated clutter pattern matches the radar measured one. This paper introduces a procedure to compute RFC estimator performance. It addresses the major factors such as the radar parameters, the sea surface characteristics, and the environment (region, time of the day, season) that affect the estimator performance and formalizes an error metric combining all of these. This is important for applications such as calculating the optimal radar parameters, selecting the best RFC inversion algorithm under a set of conditions, and creating a regional performance map of a RFC system. The performance metric is used to compute the RFC performance of a non-Bayesian evaporation duct estimator. A Bayesian estimator that incorporates meteorological statistics in the inversion is introduced and compared to the non-Bayesian estimator. The performance metric is used to determine the optimal radar parameters of the evaporation duct estimator for six scenarios. An evaporation duct inversion performance map for a S band radar is created for the larger Mediterranean/Arabian Sea region.

show abstract

Lidar description of the evaporative duct in ocean environments

Cited by 16 publications

References 0 publications

Channel Model for the Surface Ducts: Large-Scale Path-Loss, Delay Spread, and AOA

Channel Model for the Surface Ducts: Large-Scale Path-Loss, Delay Spread, and AOA

Evaporation Duct Retrieval Using Changes in Radar Sea Clutter Power Versus Receiving Height

Sensitivity analysis and performance estimation of refractivity from clutter techniques

Contact Info

Product

Resources

About