scholarly journals Ocean Wave Measurement Using Short-Range K-Band Narrow Beam Continuous Wave Radar

2018 ◽  
Vol 10 (8) ◽  
pp. 1242 ◽  
Author(s):  
Jian Cui ◽  
Ralf Bachmayer ◽  
Brad deYoung ◽  
Weimin Huang
Keyword(s):  
Short Range ◽  
Continuous Wave ◽  
Ocean Waves ◽  
Sea Surface ◽  
Ocean Wave ◽  
Narrow Beam ◽  
Wave Measurement ◽  
Wave Radar ◽  
Wave Orbital Velocity ◽  
K Band

We describe a technique to measure ocean wave period, height and direction. The technique is based on the characteristics of transmission and backscattering of short-range K-band narrow beam continuous wave radar at the sea surface. The short-range K-band radar transmits and receives continuous signals close to the sea surface at a low-grazing angle. By sensing the motions of a dominant facet at the sea surface that strongly scatters signals back and is located directly in front of the radar, the wave orbital velocity can be measured from the Doppler shift of the received radar signal. The period, height and direction of ocean wave are determined from the relationships among wave orbital velocity, ocean wave characteristics and the Doppler shift. Numerical simulations were performed to validate that the dominant facet exists and ocean waves are measured by sensing its motion. Validation experiments were conducted in a wave tank to verify the feasibility of the proposed ocean wave measurement method. The results of simulations and experiments demonstrate the effectiveness of the short-range K-band narrow beam continuous wave radar for the measurement of ocean waves.

Experimental Investigation of Ocean Wave Measurement Using Short-Range K-Band Radar: Dock-Based and Boat-Based Wind Wave Measurements

2019 ◽  
Vol 11 (13) ◽  
pp. 1607
Author(s):  
Jian Cui ◽  
Ralf Bachmayer ◽  
Brad de Young ◽  
Weimin Huang
Keyword(s):  
Experimental Investigation ◽  
Doppler Shift ◽  
Short Range ◽  
Ocean Waves ◽  
Ocean Wave ◽  
Stokes Drift ◽  
Bragg Scattering ◽  
Wave Measurement ◽  
Shift Frequency ◽  
K Band

In this paper, an ocean wave measurement technique and a newly developed short-range K-band radar are tested. In previous work, the technique and its feasibility were studied based on numerical simulations and wave tank experiments, while its performance at sea was still unknown. Surface current, Stokes drift, and wave breaking can greatly complicate interpreting radar backscatters. The feasibility of the technique needed to be further investigated with sea experiments. Experiments were carried out at a stationary site and from a moving platform. The short-range K-band radar transmitted continuous wave and received backscatters at low-grazing angles. The Bragg-scattering from the radar’s effective footprint dominated the backscatters. The Doppler shift frequency of the Bragg-scattering was attributed to the phase velocity of Bragg waves and modulated by the surface motions induced by current, Stokes drift, platform, and gravity waves. These sources of the Doppler shift frequency were analyzed, and the components induced by wind waves were successfully retrieved and converted into wave spectra that were consistent with the measurements of wave rider buoy. The experimental investigation further validated the feasibility of using short-range K-band radar to measure ocean waves.

scholarly journals A Doppler Range Compensation for Step-Frequency Continuous-Wave Radar for Detecting Small UAV

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1331
Author(s):  
Massimiliano Pieraccini ◽  
Lapo Miccinesi ◽  
Neda Rojhani
Keyword(s):  
Short Range ◽  
Continuous Wave ◽  
Range Shift ◽  
Specific Method ◽  
Step Frequency ◽  
Wave Radar ◽  
Small Uav ◽  
The Doppler Effect ◽  
Set Up ◽  
Free Falling

Step-frequency continuous-wave (SFCW) modulation can have a role in the detection of small unmanned aerial vehicles (UAV) at short range (less than 1–2 km). In this paper, the theory of SFCW range detection is reviewed, and a specific method for correcting the possible range shift due to the Doppler effect is devised. The proposed method was tested in a controlled experimental set-up, where a free-falling target (i.e., a corner reflector) was correctly detected by an SFCW radar. This method was finally applied in field for short-range detection of a small UAV.

Wave Heights in a 4D Ocean Wave Field

2008 ◽  
Author(s):  
Paul C. Liu ◽  
David J. Schwab ◽  
Chin H. Wu ◽  
Keith R. MacHutchon
Keyword(s):  
Ocean Waves ◽  
Ocean Wave ◽  
Past Century ◽  
The Past ◽  
Preliminary Examination ◽  
Wave Measurement ◽  
New States ◽  
Wave Heights ◽  
D Wave ◽  
Made In

This paper presents a preliminary examination and analysis of a small suite of 4-D wave data to explore what new insight or inference we can garner — particularly toward the realm where conventional approaches have not been traversed. While we caught a few glimpses that might indicate a need for new conceptualizations, it by no means to negates the vast positive contributions the conventional approaches have been made in the past century. We feel it is timely to encourage further 4-D ocean wave measurement and thereby facilitate fresh new states of study and understanding of ocean waves.

Short range continuous wave radar for target detection in various mediums

2014 ◽  
Vol 56 (11) ◽  
pp. 2484-2489
Author(s):  
Tauseef Tauqeer ◽  
Maira Islam ◽  
A. K. Aziz
Keyword(s):  
Target Detection ◽  
Short Range ◽  
Continuous Wave ◽  
Wave Radar

scholarly journals Experimental Proof of the Characteristics of Short-Range FM Radar Converted Signal Spectrum for a Smooth Surface

2016 ◽  
Vol 3 (1) ◽  
pp. 52-61 ◽  
Author(s):  
Deniss Brodņevs ◽  
Igors Smirnovs
Keyword(s):  
Experimental Data ◽  
Short Range ◽  
Smooth Surface ◽  
Natural Experiment ◽  
Continuous Wave ◽  
Signal Spectrum ◽  
Spectral Processing ◽  
Experimental Proof ◽  
Wave Radar ◽  
Converted Signal

Abstract This paper presents a natural experiment of the spectral processing of 4.3 GHz Frequency Modulated Continuous Wave Radar (FMCWR) converted signal. The FMCWR antennas are fixed above a smooth reflective surface. The converted signal spectrum is theoretically calculated and compared with the experimental data.

scholarly journals Extended Kalman Doppler tracking and model determination for multi-sensor short-range radar

2016 ◽  
Vol 14 ◽  
pp. 39-46 ◽  
Author(s):  
Thomas J. Mittermaier ◽  
Uwe Siart ◽  
Thomas F. Eibert ◽  
Stefan Bonerz
Keyword(s):  
Doppler Shift ◽  
Short Range ◽  
Continuous Wave ◽  
Three Dimensional ◽  
Likelihood Estimation ◽  
Wave Radar ◽  
Dynamic Estimation ◽  
Doppler Tracking ◽  
Linearization Errors ◽  
Stochastic Properties

Abstract. A tracking solution for collision avoidance in industrial machine tools based on short-range millimeter-wave radar Doppler observations is presented. At the core of the tracking algorithm there is an Extended Kalman Filter (EKF) that provides dynamic estimation and localization in real-time. The underlying sensor platform consists of several homodyne continuous wave (CW) radar modules. Based on In-phase-Quadrature (IQ) processing and down-conversion, they provide only Doppler shift information about the observed target. Localization with Doppler shift estimates is a nonlinear problem that needs to be linearized before the linear KF can be applied. The accuracy of state estimation depends highly on the introduced linearization errors, the initialization and the models that represent the true physics as well as the stochastic properties. The important issue of filter consistency is addressed and an initialization procedure based on data fitting and maximum likelihood estimation is suggested. Models for both, measurement and process noise are developed. Tracking results from typical three-dimensional courses of movement at short distances in front of a multi-sensor radar platform are presented.

Short-range multi-mode continuous-wave radar for vital sign measurement and imaging

2018 ◽  
Author(s):  
Avik Santra ◽  
Raghavendran Vagarappan Ulaganathan ◽  
Thomas Finke ◽  
Ashutosh Baheti ◽  
Dennis Noppeney ◽  
...  
Keyword(s):  
Vital Sign ◽  
Short Range ◽  
Continuous Wave ◽  
Wave Radar ◽  
Vital Sign Measurement ◽  
Multi Mode
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