Phase-Coded FMCW for Automotive Radars

Autonomous driving is a new emerging technology that will enhance traffic safety. Automotive radars are essential to attaining autonomous driving since they can function in adverse weather conditions and are used for detection, tracking, and classification in traffic settings. However, the dramatic growth in the number of radar sensors used for...

Radio Receiver with Internal Compression of Input Signals Using a Dispersive Delay Line with Bandpass Filters

This article proposes a receiving device in which arbitrary input signals are subject to pre-detector processing for the subsequent implementation of the idea of compressing broadband modulated pulses with a matched filter to increase the signal-to-noise ratio and improve resolution. For this purpose, a model of a dispersive delay line is...

Phase-Coded FMCW for Coherent MIMO Radar

The phase-coded linear-frequency-modulated continuous-wave (PC-FMCW) waveform with a low sampling processing strategy is studied for coherent multiple-input multiple-output (MIMO) radar. The PC-FMCW MIMO structure, which jointly uses both fast-time and slow-time coding, is proposed to reduce sidelobe levels while preserving high range resolution...

Receiver Structures for Phase Modulated FMCW Radars

Two receiver structures of phase modulated FMCW signals with low ADC sampling requirement are investigated, namely the matched filter of the dechirped signal and the group delay filter approach. The sensing performance of the investigated receiver strategies are analyzed in application to BPSK modulated chirp. Numerical simulations demonstrate...

Sensing Performance of Different Codes for Phase-Coded FMCW Radars

The sensing properties of the binary phase codes are investigated with their application to phase-coded (linearly) frequency modulated continuous waveform (PC-FMCW). It is shown that the ambiguity function of FMCW signal modulated with a binary phase code corresponds to sheared ambiguity function of the code itself. The range profiles of PC...

Matrix-Pencil Approach-Based Interference Mitigation for FMCW Radar Systems

A novel matrix-pencil (MP)-based interference mitigation approach for frequency-modulated continuous-wave (FMCW) radars is proposed in this article. The interference-contaminated segment of the beat signal is first cut out, and then, the signal samples in the cutout region are reconstructed by modeling the beat signal as a sum of complex...

Modeling the unstable DelftaCopter vertical take-off and landing tailsitter unmanned air vehicle in hover and forward flight from flight test data

The DelftaCopter is a tilt-body tailsitter unmanned air vehicle which combines a large swashplate controlled helicopter rotor with a biplane delta-wing. Previous research has shown that the large moment of inertia of the wing and fuselage significantly interacts with the dynamics of the rotor. While this rigid rotor cylinder dynamics model...

Analysis of FBG reflection spectra under anti-symmetrical strain distributions using the approximated transfer matrix model

In this paper, we used the efficient formulation of the approximated transfer matrix model (ATMM) for the analysis of fibre Bragg grating (FBG) sensors' response under anti-symmetrical strain fields. Exploiting the flexible representation of the transfer matrices in this new model, we will analytically prove that any sort of anti-symmetrical...

A seismic vibrator driven by linear synchronous motors: Developing a prototype vibrator, investigating the vibrator-ground contact and exploring robust signal design

The seismic method is an important indirect method to investigate the subsurface of the earth. By analyzing how the earth affects the propagation of mechanical waves, the structure of the earth and its seismic properties can be inferred. The seismic vibrator is the most commonly used land source in active-source exploration and monitoring to...

Establishing a sea bottom model by applying a multi-sensor acoustic remote sensing approach

Detailed information about the oceanic environment is essential for many applications in the field of marine geology, marine biology, coastal engineering, and marine operations. Especially, knowledge of the properties of the sediment body is often required. Acoustic remote sensing techniques have become highly attractive for classifying the sea...

Intravascular ultrasound chirp imaging

We demonstrate the feasibility of intravascular ultrasound (IVUS) chirp imaging as well as chirp reversal ultrasound contrast imaging at intravascular ultrasound frequency. Chirp excitations were emitted with a 34?MHz single crystal intravascular transducer and compared to conventional Gaussian-shaped pulses of equal acoustic pressure. The...

Time-frequency distribution of interferograms from a frequency comb in dispersive media

We investigate general properties of the interferograms from a frequency comb laser in a non-linear dispersive medium. The focus is on interferograms at large delay distances and in particular on their broadening, the fringe formation and shape. It is observed that at large delay distances the interferograms spread linearly and that its shape is...

High-accuracy long-distance measurements in air with a frequency comb laser

We experimentally demonstrate that a femtosecond frequency comb laser can be applied as a tool for longdistance measurement in air. Our method is based on the measurement of cross correlation between individual pulses in a Michelson interferometer. From the position of the correlation functions, distances of up to 50 m have been measured. We...