Four Dimensional System Engineering Demands on Radar Operating in a Coastal Sub-refractive Environment

Marshall, Robert; Haack, Tracy

doi:10.1109/radar.2007.374340

Cited by 8 publications

(4 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Sub‐refraction is the rarest of littoral non‐standard propagation events, but the ameliorating engineering costs can be prohibitively expensive. The Sensors Division at NSWCDD has been studying the impact of sub‐refraction on notional S‐, C‐, and X‐band radar designs using mesoscale NWP (Marshall and Haack 2007) in order to better understand these engineering demands.…”

Section: Sub‐refractionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling and Simulation of Notional Future Radar in Non‐Standard Propagation Environments Facilitated by Mesoscale Numerical Weather Prediction Modeling

Marshall

Thornton²,

LeFurjah

et al. 2008

Naval Engineers Journal

Self Cite

View full text Add to dashboard Cite

Normal near surface radio‐frequency (RF) propagation in the littorals across the land–sea boundary is rare due to the land–sea temperature difference, coastline shape, ground cover, urban density, coastal topography, and soil moisture content. The resulting frequent existence of coastal non‐standard vertical profiles of refractivity and the resulting RF propagation has a profound impact on the performance of Navy ship‐borne radars operating within 100 nm of the shore. In addition, these non‐standard RF propagation conditions are spatio‐temporally inhomogeneous. These spatial and time dependent propagation conditions and the resulting radar engineering implications cannot be revealed by a single vertical profile of refractivity taken near the ship borne radar. The results from single profile analysis techniques provide no spatiotemporal information and may lead to overly conservative radar design. Mesoscale numerical weather prediction (NWP) is a rapidly maturing technology with a strong operational Navy history that can provide a vertical profile of refractivity every 1 km in the battle space and every hour, up to 48 h, in the future. The Sensor Division at NSWCDD has applied mesoscale NWP for the last 2 years to better understand the performance of prototype radar in realistic four‐dimensional (4D) coastal environments. Modern RF parabolic equation models are designed to model specific radar designs and to employ 3D refractivity fields from mesoscale NWP models. This allows for a radar design to be tested in realistic littoral non‐standard atmospheres produced by stable internal boundary layers, sea breeze events, and the more rare sub‐refractive events. Mesoscale NWP is currently qualitative for this purpose, but a research and development program focused on sea testing of prototype radars is described with the purpose of developing a more quantitative mesoscale NWP technology to support radar acquisition, testing, and operations.

show abstract

Section: Sub‐refractionmentioning

confidence: 99%

“…This is due to modeled surface sub‐refraction as great as 0.280 m −1 or an effective earth radius of 0.560. A more detailed multi‐wavelength analysis indicates that sub‐refraction engineering costs increase with radar frequency (Marshall and Haack 2007).…”

Section: Sub‐refractionmentioning

confidence: 99%

Modeling and Simulation of Notional Future Radar in Non‐Standard Propagation Environments Facilitated by Mesoscale Numerical Weather Prediction Modeling

Marshall

Thornton²,

LeFurjah

et al. 2008

Naval Engineers Journal

Self Cite

View full text Add to dashboard Cite

show abstract

“…(2010) utilized S‐band radar data and showed finer vertical resolution improves performance predictions. Radar performances at S, C, and X‐bands were modeled and compared to COAMPS ® prediction by Marshall (Marshall & Haack, 2007). Burk et al.…”

Section: Introductionmentioning

confidence: 99%

“…LeFurjah et al (2010) utilized S-band radar data and showed finer vertical resolution improves performance predictions. Radar performances at S, C, and X-bands were modeled and compared to COAMPS ® prediction by Marshall (Marshall & Haack, 2007). Burk et al (2003) studied Kauai island wake dynamics on the evaporation duct parameters using radar clutter data and COAMPS ® mesoscale simulations.…”

mentioning

confidence: 99%

Evaluation of COAMPS Boundary Layer Refractivity Forecast Accuracy for 2–40 GHz Electromagnetic Wave Propagation

Yardim

Haack

2022

Radio Science

Self Cite

View full text Add to dashboard Cite

Variations in vertical temperature and humidity profiles result in the variations in lower atmospheric refractivity structures, which can create atmospheric ducts and trapping layers. In the marine atmospheric environment, ducts are common phenomena that cause the trapping of electromagnetic (EM) waves. The structure of the duct affects the propagation loss (PL) and alters the EM system performance. Thus, the ability to predict the effects of atmospheric refractivity on PL is essential in radio wave communication and radar system design and operations in the marine atmosphere.The refractive index n of the atmosphere is very close to that of vacuum. The parts-per-million deviation in n is called refractivity (Smith & Weintraub, 1953) 𝑁𝑁 = (𝑛𝑛 − 1) × 10 6(1)where T is the temperature in K, P, and e are the localized atmospheric and water vapor pressures in hPa. When radio waves propagate over long ranges, the Earth's curvature needs to be taken into consideration by modifying atmospheric refractivity aswhere a is the radius of the Earth and z is the height above the surface. Trapping layers occur when the vertical gradient of modified refractivity becomes negative (∂M/∂z < 0). Ducting conditions can be represented using the temporal, horizontal, and vertical variations of this modified refractivity M(t, r, z).Accuracy in the estimates of these M-profiles is crucial in radio wave propagation predictions. Several numerical weather prediction models have been developed that can be used to provide local refractivity profiles, such as

show abstract

On the knowledge of radar coverage at sea using real time refractivity from clutter

Douvenot

Fabbro

2010

IET Radar Sonar Navig.

View full text Add to dashboard Cite

Four Dimensional System Engineering Demands on Radar Operating in a Coastal Sub-refractive Environment

Cited by 8 publications

References 4 publications

Modeling and Simulation of Notional Future Radar in Non‐Standard Propagation Environments Facilitated by Mesoscale Numerical Weather Prediction Modeling

Modeling and Simulation of Notional Future Radar in Non‐Standard Propagation Environments Facilitated by Mesoscale Numerical Weather Prediction Modeling

Evaluation of COAMPS Boundary Layer Refractivity Forecast Accuracy for 2–40 GHz Electromagnetic Wave Propagation

On the knowledge of radar coverage at sea using real time refractivity from clutter

Contact Info

Product

Resources

About