Real-Time UWB-OFDM Radar-Based Navigation in Unknown Terrain

Kauffman, Kyle; Raquet, John; Morton, Yu; Garmatyuk, Dmitriy

doi:10.1109/taes.2013.6557998

Cited by 32 publications

(11 citation statements)

References 17 publications

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“…Owing to the large time bandwidth product, the constant envelope, and good Doppler tolerance, LFM waveforms are widely used in radar systems [17]. OFDM is a popular choice for a radar and communication signal because it offers advantages such as robustness against multipath fading and relatively simple synchronization [22,23]. Based on existing results [18], a random matrix is used to generate the initial…”

Section: Circulate Shifted Ofdm Chirp Waveformmentioning

confidence: 99%

Circulate shifted OFDM chirp waveform diversity design with digital beamforming for MIMO SAR

Liu

Zhang

Wang

2017

Sci. China Inf. Sci.

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Waveform diversity design has always been the key to multiple-input multiple-output (MIMO) synthetic aperture radar (SAR) systems, and it is known that synthetic integral side lobe ratio (SISLR) is a more optimal indicator than the integral side lobe ratio (ISLR) to evaluate the orthogonality between different MIMO SAR waveforms. This paper presents proof that it is difficult to obtain the SISLR of an existing waveform such that it is sufficiently low to achieve high SNR for SAR imaging. Thus, it is necessary to find a way to separate these MIMO SAR waveforms in other domains, for example, a spatial domain by digital beamforming (DBF). Learning from Krieger's idea of short-term shift-orthogonal waveforms and using joint time-frequency transforms (Gabor transform) to prove that for most existing SAR waveforms cyclic shift is a good operation with which to generate short-term shift-orthogonal waveforms. This paper presents the designs of four circulate shifted OFDM chirp waveforms, which have a much lower SISLR and retain all the advantages of the classical chirp waveform such as a large time-bandwidth product, constant amplitude, implementation simplicity, and good Doppler tolerance.

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Section: Circulate Shifted Ofdm Chirp Waveformmentioning

confidence: 99%

Circulate shifted OFDM chirp waveform diversity design with digital beamforming for MIMO SAR

Liu

Zhang

Wang

2017

Sci. China Inf. Sci.

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“…The concept of radar odometry (RO) for autonomous navigation has also been introduced in the literature recently. Kauffman et al [17] use UWB‐OFDM fused through the extended Kalman filter (EKF) to obtain an aircraft position. Approaches to RO proposed in Quist et al [18, 19] are tailored to fixed‐wing UAS.…”

Section: Introductionmentioning

confidence: 99%

A novel outlier removal method for two‐dimensional radarodometry

Scannapieco

2019

IET Radar, Sonar & Navigation

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Autonomous navigation of platforms in complex environments has a key role in many applications. However, the environmental conditions could negatively affect the performance of electro-optical sensors. Hence, the idea of using radar odometry has been recently developed. However, it suffers from the presence of outliers in the scene as its electro-optical counterparts. This work presents a method to classify radar echoes as inliers or outliers for two-dimensional radar odometry, based on their range rate and bearing angle. The range rate and bearing angle are in fact combined to give a classification value, different for each target. At each acquisition time, the median of all classification values is computed. Since classification values of stationary targets, i.e. the inliers, cluster around the median, while moving targets, i.e. the outliers, exhibit larger distance from the median, stationary targets and moving targets can be separated. This is also useful for Sense-and-Avoid purposes. The method has been tested in simulated scenario to show effectiveness in detecting outliers and in real case scenario to demonstrate significant improvement in reconstruction of trajectory of platform, keeping the final error around 10% of the travelled distance. Further improvement is envisaged by integrating the method in the target tracking strategy.

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“…A simulation for a navigation system in GNSS denied environments for UAVs based on ultra-wideband orthogonal frequency division multiplexed (UWB-OFDM) radar measurements is proposed by Kauffman in [ 17 ]. The tracking process is performed based on the Global Nearest Neighbor (GNN) tracker algorithms [ 18 ].…”

Section: Introductionmentioning

confidence: 99%

Radar and Visual Odometry Integrated System Aided Navigation for UAVS in GNSS Denied Environment

Mostafa

Zahran

Moussa

et al. 2018

Sensors

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Drones are becoming increasingly significant for vast applications, such as firefighting, and rescue. While flying in challenging environments, reliable Global Navigation Satellite System (GNSS) measurements cannot be guaranteed all the time, and the Inertial Navigation System (INS) navigation solution will deteriorate dramatically. Although different aiding sensors, such as cameras, are proposed to reduce the effect of these drift errors, the positioning accuracy by using these techniques is still affected by some challenges, such as the lack of the observed features, inconsistent matches, illumination, and environmental conditions. This paper presents an integrated navigation system for Unmanned Aerial Vehicles (UAVs) in GNSS denied environments based on a Radar Odometry (RO) and an enhanced Visual Odometry (VO) to handle such challenges since the radar is immune against these issues. The estimated forward velocities of a vehicle from both the RO and the enhanced VO are fused with the Inertial Measurement Unit (IMU), barometer, and magnetometer measurements via an Extended Kalman Filter (EKF) to enhance the navigation accuracy during GNSS signal outages. The RO and VO are integrated into one integrated system to help overcome their limitations, since the RO measurements are affected while flying over non-flat terrain. Therefore, the integration of the VO is important in such scenarios. The experimental results demonstrate the proposed system’s ability to significantly enhance the 3D positioning accuracy during the GNSS signal outage.

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Real-Time UWB-OFDM Radar-Based Navigation in Unknown Terrain

Cited by 32 publications

References 17 publications

Circulate shifted OFDM chirp waveform diversity design with digital beamforming for MIMO SAR

Circulate shifted OFDM chirp waveform diversity design with digital beamforming for MIMO SAR

A novel outlier removal method for two‐dimensional radarodometry

Radar and Visual Odometry Integrated System Aided Navigation for UAVS in GNSS Denied Environment

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