A Low-cost Vehicle Detection and Classification System based on Unmodulated Continuous-wave Radar

2007 ◽  
Author(s):  
Jianxin Fang ◽  
Huadong Meng ◽  
Hao Zhang ◽  
Xiqin Wang
Keyword(s):  
Classification System ◽  
Continuous Wave ◽  
Low Cost ◽  
Vehicle Detection ◽  
Wave Radar

scholarly journals A Local Oscillator Phase Compensation Technique for Ultra-Wideband Stepped-Frequency Continuous Wave Radar Based on a Low-Cost Software-Defined Radio

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 780
Author(s):  
Kazunori Takahashi ◽  
Takashi Miwa
Keyword(s):  
Software Defined Radio ◽  
Initial Phase ◽  
Continuous Wave ◽  
Low Cost ◽  
Local Oscillator ◽  
The Other ◽  
Ultra Wideband ◽  
Single Frequency ◽  
Wave Radar ◽  
Stepped Frequency

The paper discusses a way to configure a stepped-frequency continuous wave (SFCW) radar using a low-cost software-defined radio (SDR). The most of high-end SDRs offer multiple transmitter (TX) and receiver (RX) channels, one of which can be used as the reference channel for compensating the initial phases of TX and RX local oscillator (LO) signals. It is same as how commercial vector network analyzers (VNAs) compensate for the LO initial phase. These SDRs can thus acquire phase-coherent in-phase and quadrature (I/Q) data without additional components and an SFCW radar can be easily configured. On the other hand, low-cost SDRs typically have only one transmitter and receiver. Therefore, the LO initial phase has to be compensated and the phases of the received I/Q signals have to be retrieved, preferably without employing an additional receiver and components to retain the system low-cost and simple. The present paper illustrates that the difference between the phases of TX and RX LO signals varies when the LO frequency is changed because of the timing of the commencement of the mixing. The paper then proposes a technique to compensate for the LO initial phases using the internal RF loopback of the transceiver chip and to reconstruct a pulse, which requires two streaming: one for the device under test (DUT) channel and the other for the internal RF loopback channel. The effect of the LO initial phase and the proposed method for the compensation are demonstrated by experiments at a single frequency and sweeping frequency, respectively. The results show that the proposed method can compensate for the LO initial phases and ultra-wideband (UWB) pulses can be reconstructed correctly from the data sampled by a low-cost SDR.

A 34 to 36 GHz Vector Modulator for Reflected Power Canceller Techniques in LFMCW Radar

2010 ◽  
Vol 40-41 ◽  
pp. 283-286
Author(s):  
Min Zhang ◽  
Jun Xu ◽  
Xin Kai Cheng
Keyword(s):  
Theoretical Model ◽  
Theoretical Analysis ◽  
Millimeter Wave ◽  
High Performance ◽  
Continuous Wave ◽  
Low Cost ◽  
Wave Radar ◽  
Vital Component ◽  
Vector Modulator ◽  
Reflected Power

In this paper, a 34 to 36 GHz vector modulator for using in low cost and high performance RPC (Reflected Power Canceller) is presented. The key circuit consists of two push-pull (bi-phase) attenuators arranged in phase quadrature and a 3dB quadrature coupler (branch line couplers but not Lange couplers which is different from traditional circuits in Ka band) and a Wilkinson combiner, and then transition from micro-strip to waveguide using antipodal finline. To fully exploit this circuit’s capacity to generate accurate constellations at millimeter-wave frequencies, a generalized theoretical analysis of the (push-pull) vector modulator is presented. Based on the theoretical model and the measured results, the I-Q (push-pull) vector modulator promises to be a vital component for the realization of reflected power canceller in LFMCW (Linear Frequency Modulated Continuous Wave) radar.

scholarly journals Accuracy Bounds and Measurements of a Contactless Permittivity Sensor for Gases Using Synchronized Low-Cost mm-Wave Frequency Modulated Continuous Wave Radar Transceivers

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3351 ◽  
Author(s):  
Andreas Och ◽  
Jochen O. Schrattenecker ◽  
Stefan Schuster ◽  
Patrick A. Hölzl ◽  
Philipp F. Freidl ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Low Cost ◽  
Time Of Flight ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Primary Concern ◽  
Fmcw Radar ◽  
Wave Radar ◽  
Concentration Measurements ◽  
Permittivity Measurements

A primary concern in a multitude of industrial processes is the precise monitoring of gaseous substances to ensure proper operating conditions. However, many traditional technologies are not suitable for operation under harsh environmental conditions. Radar-based time-of-flight permittivity measurements have been proposed as alternative but suffer from high cost and limited accuracy in highly cluttered industrial plants. This paper examines the performance limits of low-cost frequency-modulated continuous-wave (FMCW) radar sensors for permittivity measurements. First, the accuracy limits are investigated theoretically and the Cramér-Rao lower bounds for time-of-flight based permittivity and concentration measurements are derived. In addition, Monte-Carlo simulations are carried out to validate the analytical solutions. The capabilities of the measurement concept are then demonstrated with different binary gas mixtures of Helium and Carbon Dioxide in air. A low-cost time-of-flight sensor based on two synchronized fully-integrated millimeter-wave (MMW) radar transceivers is developed and evaluated. A method to compensate systematic deviations caused by the measurement setup is proposed and implemented. The theoretical discussion underlines the necessity of exploiting the information contained in the signal phase to achieve the desired accuracy. Results of various permittivity and gas concentration measurements are in good accordance to reference sensors and measurements with a commercial vector network analyzer (VNA). In conclusion, the proposed radar-based low-cost sensor solution shows promising performance for the intended use in demanding industrial applications.

scholarly journals Review article: Performance assessment of electromagnetic wave-based field sensors for SWE monitoring   

2021 ◽  
Author(s):  
Alain Royer ◽  
Alexandre Roy ◽  
Sylvain Jutras ◽  
Alexandre Langlois
Keyword(s):  
Electromagnetic Waves ◽  
Gamma Ray ◽  
Continuous Wave ◽  
Snow Water Equivalent ◽  
Low Cost ◽  
Cosmic Ray ◽  
Satellite System ◽  
Fmcw Radar ◽  
Wave Radar ◽  
Global Navigation Satellite

Abstract. Continuous and spatially distributed data of snow mass (snow water equivalent, SWE) from automatic ground-based measurements are increasingly required for climate change studies and for hydrological applications (snow hydrological model improvement and data assimilation). We present and compare four new-generation non-invasive sensors that are based on electromagnetic waves for direct measurements of SWE: Cosmic Ray Neutron Probe (CNRP); Gamma Ray Monitoring (GMON) scintillator; frequency-modulated continuous-wave radar (FMCW-Radar) at 24 GHz; and Global Navigation Satellite System (GNSS) receivers for SWE retrieval. All four techniques are relatively low cost, have low power requirements, provide continuous and autonomous measurements, and can be installed in remote areas. Their operating principles are briefly summarized before examples of comparative measurements are provided. A performance review comparing their advantages, drawbacks and accuracies is discussed. Overall instrument accuracy is estimated to range between 9 and 15 %.

Concept and realization of a low-cost multi-target simulator for CW and FMCW radar system calibration and testing

2018 ◽  
Vol 10 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Werner Scheiblhofer ◽  
Reinhard Feger ◽  
Andreas Haderer ◽  
Andreas Stelzer
Keyword(s):  
Continuous Wave ◽  
Doppler Radar ◽  
Dynamic Range ◽  
Low Cost ◽  
Intermediate Frequency ◽  
Radar System ◽  
Fmcw Radar ◽  
Radar Systems ◽  
Single Target ◽  
Wave Radar

AbstractWe present the realization of an frequency-modulated continuous-wave radar target simulator, based on a modulated-reflector radar system. The simulator, designed for the 24 GHz frequency band, uses low-cost modulated-reflector nodes and is capable to simultaneously generate multiple targets in a real-time environment. The realization is based on a modular approach and thus provides a high scalability of the whole system. It is demonstrated that the concept is able to simulate multiple artificial targets, located at user-selectable ranges and even velocities, utilized within a completely static setup. The characterization of the developed hardware shows that the proposed concept allows to dynamically and precisely adjust the radar cross-section of each single target within a dynamic range of 50 dB. Additionally, the provided range-proportional target frequency bandwidth makes the system perfectly suitable for fast and reliable intermediate frequency-chain calibration of multi-channel radar systems. Within this paper we demonstrate the application of the concept for a linear sweeped frequency-modulated continuous-wave radar. The presented approach is applicable to any microwave-based measurement system using frequency differences between transmit- and receive signals for range- and velocity evaluation, such as (non-)linear sweeped as well as pure Doppler radar systems.

scholarly journals Analysis of the Snow Water Equivalent at the AEMet-Formigal Field Laboratory (Spanish Pyrenees) During the 2019/2020 Winter Season Using a Stepped-Frequency Continuous Wave Radar (SFCW)

2021 ◽  
Vol 13 (4) ◽  
pp. 616
Author(s):  
Rafael Alonso ◽  
José María García del Pozo ◽  
Samuel T. Buisán ◽  
José Adolfo Álvarez
Keyword(s):  
Software Defined Radio ◽  
Continuous Wave ◽  
Snow Water Equivalent ◽  
Cosmic Ray ◽  
Relative Dielectric Permittivity ◽  
Near Surface ◽  
Wave Radar ◽  
Spanish Pyrenees ◽  
Snow Water ◽  
Stepped Frequency

Snow makes a great contribution to the hydrological cycle in cold regions. The parameter to characterize available the water from the snow cover is the well-known snow water equivalent (SWE). This paper presents a near-surface-based radar for determining the SWE from the measured complex spectral reflectance of the snowpack. The method is based in a stepped-frequency continuous wave radar (SFCW), implemented in a coherent software defined radio (SDR), in the range from 150 MHz to 6 GHz. An electromagnetic model to solve the electromagnetic reflectance of a snowpack, including the frequency and wetness dependence of the complex relative dielectric permittivity of snow layers, is shown. Using the previous model, an approximated method to calculate the SWE is proposed. The results are presented and compared with those provided by a cosmic-ray neutron SWE gauge over the 2019–2020 winter in the experimental AEMet Formigal-Sarrios test site. This experimental field is located in the Spanish Pyrenees at an elevation of 1800 m a.s.l. The results suggest the viability of the approximate method. Finally, the feasibility of an auxiliary snow height measurement sensor based on a 120 GHz frequency modulated continuous wave (FMCW) radar sensor, is shown.

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