State and Limits of Prediction Methods of Radar Wave Propagation Conditions Over Sea

Jeske, H.

doi:10.1007/978-94-010-2681-9_13

Cited by 33 publications

(31 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The resulting vertical profiles of temperature and humidity change the profile of the index of refraction n and the derivative quantities of radio refractivity N and modified refractivity M so as to form a duct that affects electromagnetic (EM) propagation at frequencies of 1 GHz and above. Evaporation duct refractivity profiles are most often calculated using Monin-Obukhov similarity-theory-based models of Jeske [1971Jeske [ , 1973 or Liu et al [1979] (known as LKB). The inputs to those models are time-averaged mea-ranges.…”

Section: Introductionmentioning

confidence: 99%

Estimating evaporation duct heights from radar sea echo

Rogers¹,

Hattan²,

Stapleton³

2000

Radio Science

103

116

View full text Add to dashboard Cite

Abstract. The evaporation duct is a downward refracting layer that results from the rapid decrease in humidity with respect to altitude occurring in the atmospheric surface layer above bodies of water. The evaporation duct affects radar detection ranges at frequencies of approximately 1 GHz and above. Models based on Monin-Obukhov similarity theory are usually used to calculate evaporation duct refractivity profiles from bulk measurements of air temperature, humidity, wind speed, and the sea surface temperature. Modeling results by Pappert et al. [1992] indicated that the falloff of radar sea echo as a function of range was an increasing function of the evaporation duct height. On the basis of those results, the authors proposed inferring the evaporation duct height by a slope fit to modeled clutter power, a nonlinear least squares inversion procedure. Data for testing the inversion procedure were obtained using the S band Space Range Radar at Wallops Island, Virginia. Evaporation duct heights were inferred from the radar data on the basis of the assumption of a range-independent evaporation duct height and sea clutter radar cross section (o-ø). Validation data consist of buoy and boat in situ bulk measurements. The result of comparing the radar-inferred evaporation duct heights and those calculated from bulk measurements indicates that the radar-inferred duct heights are strongly correlated with those from the in situ measurements, but there is some uncertainty as to whether they are biased or unbiased. That uncertainty arises from the assumed dependence of o -ø on the grazing angle ½. That ½ dependence is currently a matter of debate in the open literature, with the lower and upper ends of modeling results being o.O • ½0 and o -ø • ½4, respectively. We show results for both dependencies and note that the o -ø • ½0 provides the best agreement with our measurements. It should be noted that inferring the evaporation duct height from radar sea echo is a problem that stresses the modeling of low-grazing-angle backscatter. IntroductionEvaporation ducts result from the rapid change in humidity and temperature that occurs within the surface layer of the atmosphere over bodies of water. The resulting vertical profiles of temperature and humidity change the profile of the index of refraction n and the derivative quantities of radio refractivity N and modified refractivity M so as to form a duct that affects electromagnetic (EM) propagation at frequencies of 1 GHz and above. Evaporation duct refractivity profiles are most often calculated using Monin-Obukhov similarity-theory-based models of Jeske [1971, 1973] surements of the sea surface temperature Ts, air temperature Ta, relative humidity RH, and wind speed U at a reference height above the sea surface. These are commonly referred to as "bulk measurements." The Jeske profile under neutral conditions (T a = Ts) is uniquely defined by the evaporation duct height 3, which is the height at which the refractivity profile changes from downward to upward refracting. The J...

show abstract

Section: Introductionmentioning

confidence: 99%

Estimating evaporation duct heights from radar sea echo

Rogers¹,

Hattan²,

Stapleton³

2000

Radio Science

103

116

View full text Add to dashboard Cite

show abstract

“…The Paulus-Jeske (PJ) evaporation duct model is commonly used to define the M-profile given specific atmospheric conditions [30]. Assuming neutral conditions, when the airsea temperature difference (ASTD) is zero, a simple oneparameter, log-linear formula as a function of height above the sea surface (z) is given by Rogers [8] to define the Mprofile with the presence of an evaporation duct:…”

Section: Basic Definitionsmentioning

confidence: 99%

<inline-formula> <tex-math notation="LaTeX">$X$ </tex-math> </inline-formula>-Band Beacon-Receiver Array Evaporation Duct Height Estimation

Pozderac

Johnson

Yardim

et al. 2018

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

Abstract-Two recent experimental campaigns have provided the opportunity to measure radiowave propagation and atmospheric conditions with the X-Band Beacon-Receiver (XBBR) array system. The XBBR consists of vertical arrays of transmitters and receivers for measuring X-band radio frequency propagation. When used to measure propagation near the sea surface, the resulting data can be used to obtain information on the evaporation duct height (EDH) and the refractivity profile of the lower atmosphere. Since ducted propagation acts as a leaky waveguide, the vertical array elements in various transmit and receive height combinations effectively observe differing combinations of the modal components propagating in the duct. The use of all transmitter/receiver combinations therefore improves estimation of duct properties.The first campaign deployed the XBBR off the coast of San Diego, CA during the SoCal 2013 experiment. The second campaign took place in La Jolla, CA at the Scripps Institution of Oceanography Pier for long-term measurement of propagation in the marine atmospheric boundary layer. The propagation loss between transmitters at multiple heights and receivers at multiple heights was measured, and the received power recorded at each of the receivers from each of the transmitters, standardized by the total received power, was compared to Variable Terrain Radio Parabolic Equation (VTRPE) [1] model predictions in order to estimate the EDH. Point meteorological data was also recorded and used with the Navy Atmospheric Vertical Surface Layer Model (NAVSLaM) [2] to obtain in-situ measurements of the EDH. Comparisons show a high degree of correlation between EDH values inferred from XBBR and from meteorological information.

show abstract

“…Electromagnetic wave propagation modeling and atmospheric refractivity environment estimation necessitate a parametric refractivity profile model [23]. The modified refractivity profile for an evaporation duct is usually simulated using the log-linear Paulus-Jeske model [2,6] as follows:…”

Section: Radio Refractivity Environment Modelmentioning

confidence: 99%

“…The modified refractivity profile of an evaporation duct is classically modeled using the log-linear Paulus-Jeske model [2,6], in which evaporation duct height (EDH) is the only parameter that determines duct strength. 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].…”

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

State and Limits of Prediction Methods of Radar Wave Propagation Conditions Over Sea

Cited by 33 publications

References 3 publications

Estimating evaporation duct heights from radar sea echo

Estimating evaporation duct heights from radar sea echo

<inline-formula> <tex-math notation="LaTeX">$X$ </tex-math> </inline-formula>-Band Beacon-Receiver Array Evaporation Duct Height Estimation

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

Contact Info

Product

Resources

About