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Passive surveillance systems are working on Passive coherent locator principle and are new perspective of air-surveillance. This paper is following basic PCL principles and proposes the key points for successful interference of PCL signal processing to disrupt right work. Paper briefly describes geometry of the PCL and processing cycle of generic system. There is described every single part of processing...
N-FUELS (FUll Educational Library of Signals for Navigation) is a software-based generator of Global Navigation Satellite System (GNSS) signals [1]. One of the most relevant aspects of N-FUELS can be individuated in its versatility, being a collection of MATLAB® modules. This paper introduces a new module of N-FUELS suitable to simulate realistic GNSS signals from multiple satellites, with plausible...
Doppler effect manifests in the form of changing instantaneous frequency (IF) of the received signal of a moving acoustic source. Several parameters characterizing a moving source are inherently embedded in the received IF. Thus, a careful analysis of the IF is required to obtain the source motion parameters. In this paper, we show how the IF captures the source information, such as speed, closest...
This contribution reports the results of a large broad band measurement campaign on the frequency response of radio channels at 5.8 GHz band. Up to five scenarios, in both line of sight and obstructed line of sight, configure the testbed of this work. After gathering data along linear paths, Doppler Effect principles allow the estimation of the angle of arrival of any multipath contribution. The analysis...
The main focus of this work is on analysis of the Differential Doppler method having a designed algorithm for computing and 2-D visualization of the iso doppler curves for three-positional and two-positional moving stations with a stationary target. This work also describes the effect of the target position and velocity vectors of the moving stations on the shape of the iso doppler curves. Using the...
Most pollination of commercial blueberries is carried out by honeybees from hundreds of hives. An activity sensor for monitoring the health and productivity of beehives is presented. Honeybees flying near the entrance of a beehive were observed with a low-powered 5.8 GHz Doppler radar. Spectral moments, entropy, diversity, and root-mean-square (rms) power were evaluated to identify foraging bees and...
In the context of global navigation satellite systems, this paper addresses the problem of refining the Doppler frequency estimation provided in the acquisition stage for highorder binary offset carrier (BOC) signals in post-correlation. The refinement of Doppler frequency must be done because the estimation obtained from the acquisition stage is not usually accurate enough to track the signal in...
We discuss the advantages of using a vector delay/frequency-locked loop (VDFLL) architecture for GNSS receivers operating in scenarios disturbed by radio-frequency interference. Narrowband (sinusoidal) and wideband (chirp) interference signals are considered in the analysis. The VDFLL is constituted by a bank of code and frequency discriminators feeding a central extended Kalman filter that estimates...
GNSS signals are vulnerable to various types of interference including jamming and spoofing attacks. Spoofing signals are designed to deceive target GNSS receivers without being detected by conventional receiver quality monitoring metrics. This paper focuses on detecting an overlapped spoofing attack where the correlation peaks of the authentic and spoofing signals interact during the attack. Several...
L1-L2C is the first dual-frequency pair of civilian GPS signals, expected to become available over the full constellation by 2019. Pre-operational CNAV broadcast is made available to support development of L2C signal processing capability in modernized GPS receivers. The transmission of synchronized L1 C/A and L2C codes by Block IIR-M and follow-on generations of GPS satellites allows GPS receiver...
The recovery of polarization and direction of arrivals (DOAs) of multiple targets locating at the same range but different angles in the forward-looking direction is of great trouble for conventional active radar. Based on compressive sensing (CS) framework, a joint polarization-DOA estimation strategy for single-input-multiple-output (SIMO) radar is proposed, which can reconstruct the sparse target...
In this paper performance of a symbol-based WCP-OFDM radar estimation algorithm is studied. Particularly, benefits of using orthogonal time-frequency localized pulses rather than biorthogonal rectangular pulses (traditionally used in CP-OFDM receiver) is investigated in presence of white Gaussian noise. Numerical examples show that the former provide better dynamic range and tolerance to Doppler for...
This paper presents a WiFi-based device-free crowd counting and occupancy estimation system that can be used in rooms/environments different from the ones in which the training process has been performed. Therefore, crowd counting is achieved without requiring another training phase in each new environment. The proposed approach analyzes the shape of the Doppler spectrum of the received signal which...
Mobile Communication systems are affected apparently by the Doppler Frequency and Doppler Rate. In multicarrier systems, because of sensitiveness to frequency offset, estimation and compensation are of great importance, which determine system performance directly. In this paper, we consider this problem in FBMC-OQAM system, and based on the property of it, a proper structure of preamble sequence,...
Collective Detection (CD) is an interesting technique for acquiring highly attenuated satellites signals in harsh environment. The idea of this approach is to process all signals in view collectively to take advantage of the spatial correlation between GNSS signals as vector acquisition. In this way, the acquisition of weak signals will be facilitated by the presence of stronger ones. Increasing the...
This paper proposes a Doppler resilient modulation approach that can be used in acoustic local positioning systems with Binary Phase-Shift Keying (BPSK) modulated signals for Time-of-Flight (ToF) estimation. The proposed approach is implemented in the receiver and can be performed in parallel with other classic techniques to improve the position estimation process. The technique is based on Differential...
The mathematical description of the method of changes the wavelength of the laser radiation 670 nm and 850 nm is formed. Mathematical calculations prove the new method of laser stimulation of biologically active points of a living organism. Effect on biological point happens from is moving the laser source by the variable speed. The study allows to calculate the dependence of the wavelength on the...
At the end of 2012, the ITU issued Resolution 612, which allotted designated secondary radio spectral slots to coastal oceanographic radars (3 – 50 MHz). Part of the condition for authorized use of these bands is the requirement that each radar transmit a Morse-coded call sign issued by its national authority. The unique call sign identifies the transmitter. The worldwide process of implementing this...
In order to attain high data rate in underwater acoustic communication the use of a high carrier frequency is inevitable due to the limited ratio between the bandwidth and the center frequency. Recently studies on communication systems using carrier frequencies of a few hundred kHz have been done for this purpose. Currently Korea Research Institute of Ships and Ocean Engineering (KIRSO) is also developing...
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