In recent years, non-contact radar detection technology has been able to achieve long-term and long-range for the breathing heartbeat signals. Compared with contact-based methods, it brings a more comfortable faster experience human body, gradually received attention in field of sensing. Therefore, this paper extends application millimeter-wave health care. The first transmits frequency-modulated continuous wave (FMCW) collects echo signals body. Then, phase information intermediate...

With the broad deployment of Wi-Fi networks, Received Signal Strength (RSS) based indoor localization has attained much interest both academia and industry. At present, most currently available techniques focus on increasing accuracy. However, few them take into account diversity signal distributions measurement error associated with RSS values owing to complicated environment, which consequently results in low robustness systems. Thus, motivation tackle this gripping problem, we design a...

The Internet of Things (IoT) has gradually changed the way people's lives due to its ability connecting everything together, and meanwhile accurate location sensing plays a crucial role in achieving this goal. Up now, as one most representative outdoor localization systems, global positioning system been widely used, but performance may be dramatically declined indoor environment serious multipath effect signal attenuation caused by complicated structure. At same time, fingerprint-based...

In this letter, a simultaneous measurement system of temperature and relative humidity is proposed, which consists fiber Bragg grating (FBG) Fabry-Perot (FP) interferometer. The FP interferometer was fabricated by splicing the hollow capillary with single-mode end filled layer polyimide, achieving sensitivity 22.07 pm/%RH in range 20-90 %RH. FBG insensitive to humidity, can be used measure eliminate obstruction on probe formula conversion. 9.98 pm/°C. Due low cost good stability, has broad...

Channel state information (CSI) can provide phase and amplitude of multichannel subcarrier to better describe signal propagation characteristics. Therefore, CSI has become one the most commonly used features in indoor Wi-Fi localization. In addition, compared geometric localization method, fingerprint method advantages easy implementation high accuracy. However, as scale database increases, training cost processing complexity fingerprints will also greatly increase. Based on this, this...

Aiming at the problems of noise impact on parametric image hand gestures, difficulty gesture feature extraction, and inefficient utilization continuous time sequential information, we propose a inflated 3 dimensions (TS-I3D) convolutional neural network approach for recognition based frequency modulated wave (FMCW) radar sensor. Specifically, FMCW is used to acquire data, range speed in each frame signal are calculated by 2 fast Fourier transform. Then, range-Doppler map (RDM) generated...

In this article, a novel method for continuous hand gesture detection and recognition is proposed based on frequency modulated wave (FMCW) radar. Firstly, we adopt the 2-Dimensional Fast Fourier Transform (2D-FFT) to estimate range Doppler parameters of raw data, construct range-time map (RTM) Doppler-time (DTM). Meanwhile, apply Multiple Signal Classification (MUSIC) algorithm calculate angle angle-time (ATM). Secondly, segment gestures using decision threshold. Thirdly, central...

Since respiration and heartbeat are important vital signs of humans, it is meaningful to measure them throughout the day with comfortable experience. This paper proposes use frequency-modulated continuous wave (FMCW) radar for non-contact non-invasive measurement. Specifically, fast Fourier transform applied intermediate frequency signal obtain human chest position, phase information on measured position collected. Then, extracted processed by extended differential cross-multiply algorithm....

The expansion of tunnel scale has led to a massive demand for inspections. Light Detection And Ranging (LiDAR) been widely applied in structure inspections due its fast data acquisition speed and strong environmental adaptability. However, raw point-cloud contain noise point clouds, such as non-structural facilities, which affect the detection lining structures. Methods filtering machine learning have denoising, but these methods usually require lot manual preprocessing. In order directly...

With the development of radar sensing technology, hand gesture and recognition has attracted much attention. This letter adopts a frequency-modulated continuous wave (FMCW) to achieve short-range recognition. Specifically, range, Doppler, angle parameters gestures are measured by fast Fourier transformation (FFT) multiple signal classification (MUSIC) algorithm, respectively. The mixup (MP) algorithm combined with augmentation (AU) using weight factor is applied expand data. Then,...

Change detection based on synthetic aperture radar (SAR) images is an important application in the remote-sensing technology field. However, lack of labeled data has been a difficult problem SAR image detection, especially for pixel-level change detection. In this letter, we propose novel unsupervised algorithm, which improves accuracy by exploring features from both spatial and frequency domains images. particular, first clustering used as preclassification to obtain pseudo-labels then...

Simulation tests were accomplished in this paper to evaluate the performance of gravity matching aided navigation (GMAN). Four essential factors focused study quantitatively performance: database (DB) resolution, fitting degree measurements, number samples matching, and changes area. Marine anomaly DB derived from satellite altimetry was employed. Actual dynamic gravimetry accuracy operating conditions referenced design simulation parameters. The results verified that improvement accuracy,...

Abstract Respiration and heartbeats rates are important physiological assessment indicators that provide valid prior-knowledge for the diagnosis of numerous diseases. However, most current research focuses on vital signs measurement single target, multi-target detection has not received much attention. In this paper, we use frequency-modulated continuous wave (FMCW) radar to measure signals multi-target. First, apply three-dimensional fast Fourier transform (3D-FFT) method separate multiple...

Numerous methods have been proposed to address the issue of insufficient data for human activity recognition based on millimeter wave (mmWave) radar. However, few these studied augmentation mmWave radar point cloud while taking into account characteristics signals. In this letter, a method is proposed. The includes three operations: distance translation, degree rotation, and velocity simulation, which generate samples with varying distances, angles, motion velocities. experimental results...

With the development of human–computer interaction(s) (HCI), hand gestures are playing increasingly important roles in our daily lives. gesture recognition (HGR), users can play virtual games together, control smart equipment, etc. As a result, this paper presents multi-hand system using automotive frequency modulated continuous wave (FMCW) radar. Specifically, we first constructed range-Doppler map (RDM) and range-angle (RAM), then suppressed spectral leakage, dynamic static interferences....

Theoretical analyses of stimulated Raman scattering (SRS) in high-power ytterbium-doped double-clad fiber lasers and power amplifiers with bidirectional end pump distributed are comprehensively presented. The effects quantitatively compared these schemes different lengths, core diameters, signal wavelengths, absorption, facet reflections, etc., the related restrictions also illustrated. Fiber amplifiers, characteristically low have advantage significantly higher SRS thresholds than laser...

Abstract With the development of radar technology, automotive millimeter wave is widely applied in fields including internet vehicles, Artificial Intelligence (AI)-based autonomous driving, health monitoring, etc. Eye blink, as one most common human activities, can effectively reflect person’s consciousness and fatigue. The contacted eye blink detection often leads to uncomfortable experience camera-based has privacy issues. As an alternative, non-contacted based on resolves aforementioned...

The heat dissipation and output power characteristics of kilowatt ytterbium-doped double-clad (YDDC) fiber amplifiers are investigated through numerical modeling. Solutions to facilitate reduce operating temperature in YDDC fibers under bi-directional end pump distributed presented compared. It is shown that the issue can be effectively solved by optimizing arrangement powers, absorption coefficients, lengths.