Questions tagged [radar]
Anything related to RADAR (RAdio Detection And Ranging) systems and radar signal processing.
227
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Understanding Implementation of ULA Array Response and Beamforming Techniques in MATLAB [closed]
I am currently working on a MATLAB project where I aim to replicate the functionality of certain Phased Array System Toolbox functions (phased.ULA() and ...
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What does really Time Chirp contribute to Range and Doppler estimation in FMCW radar signal?
As I started researching FMCW radar signals, I discovered a popular reference code for FMCW simulation in Github. One of the most important things that I still don't understand is the parameters ...
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Image generation from Radar (IMAGEVK-74) I/Q signals
I have a millimeter wave radar (IMAGEVK-74). I am new to signal processing and I need to generate images from the radar data.
The specifications of the radar are- it has a 20 transmitter 20 receivers ...
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Calculating k-space coverage from antenna positions
I work with radar and I want to understand which spatial frequencies I can measure, i.e. the k-space coverage, given a set of coordinates of transmitter-receiver combinations. The ideal coverage for a ...
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Why does applying Fourier Transform on point Spread Function yield h(t) which is complex-valued
I wanted to understand why this text talks about applying the Fourier transform on H(f) to obtain h(t). I view Fourier transform as moving from the time or spatial domain to the frequency / spatial ...
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Cannot understand a simple example in Phased Array System Toolbox (MATLAB), regarding FREE SPACE
I am learning about radar and signal processing. I try to run a simple code snippet provided on Mathwork's official website
It is just about FREE SPACE, which I think you know very well, but I am new ...
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SAR Doppler centroid estimation
I read book Comming Wong Digital Processing of Synthetic apperture, where they describe in detail various metods for estimation doppler centroid. Fractional part and resolve ambiguous.
But in tne ...
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Cfar Algorithm Implementation
I am trying to implementation Cfar algorithm to our radar signal processing algorithm. I obtained some output but I want to be sure that is right. Cfar algorithm's output below like, I'm interpreting ...
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How can I apply a phase shift to an LFM pulse?
I am modelling radar scenarios in python and am trying to make a model which retains phase information. To do so, I'm envisioning something which works like this:
Generate samples of an LFM waveform ...
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How to plot a sawtooth chirp waveform using an array of frequency and time for an FMCW radar?
Before switching to use sawtooth I was using sine wave but in sine wave high frequency content was not clearly visible, But I don't have any experience with using sawtooth waveforms. I am going to ...
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FMCW Radar - What's wrong with the transmitted signal model?
I am new to FMCW radar and trying to plot the transmit signal over time.
As you know, the transmitted signal is modelled as:
$$s(t) = cos(2\pi f_c t + \pi S^2),$$
where $S = BW/T_{chirp}$ is the slope,...
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Can you please help me in generating a chirp signal in GNU radio by creating a module of your own?
I am currently working on a FMCW radar using a SDR I have done the simulations in python and am moving towards simulations on GNU radio. In python it was easy to generate a chirp, just use the scipy....
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How to control the Cross-range of a scene for a fixed resolution in SAR image processing?
In order to image a scene with a certain resolution I would have to fly a certain distance. The longer the flight, the better the azimuth resolution. This is determined by the following formula
$$\...
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Why does my range shift after applying Stolt interpolation?
I am working with an FMCW Radar Simulation, where I have generated 3 targets with slant ranges: 156m,137m 118m
The distances can be computed based on the formula,
Distance = (Bin_idx/Nrg * Fs) * (c / ...
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Which probability density functions to use in a likelihood ratio test for the radar detection problem?
I am trying to understand the radar detection problem in the form of the generalized likelihood ratio test and am having a little trouble with understanding the noise distributions. Perhaps this will ...
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Observing Artefacts along azimuth direction after applying RMA to FMCW radar data
I have simulated 3 scatterers for FMCW radar signal processing using Range Migration Algorithm.
Background:
The Range Migration algorithm steps are as follows:
Applying Azimuth FFT on the raw data
...
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Synthetic Aperture Radar model: Ground reflected energy
My question is related to a theoretical part of the book: Digital Processing of Synthetic Aperture Radar Data, Algorithms and Implementation by I.G. Cumming et al. [Chapter 4. Equation 4.25 (for those ...
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About generating MIMO FMCW IF Signal and angle detection
I want to detect some targets where their range, velocity and angle information can be given before creating the radar cube. Then using IF signal for MIMO FMCW radar I want to construct the radar cube....
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Trimming of Azimuth Frequency Extent After Stolt Interpolation
The space-variant impulse response can be circumvented by collecting SAR data over a larger angular aperture than is strictly needed to achieve the desired azimuth resolution. From Carrara's text, it ...
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Maximum Range of FMCW Radar
I am performing some simulations for FMCW radar for target detection. I am working with a dechirp on receive system. Therefore, the target distance can be determined from the Intermediate Frequency or ...
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FMCW Radar timing of transmission and reception
I have a question regarding the implementation of FMCW radars that seems rather basic to me, but for some reason I am a bit unclear about this.
So I understand that in FMCW radar, transmitter and ...
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Range Gating for FMCW Radars
I have a question regarding on how to select a particular range of interest for the dechirp-on-receive FMCW radar for application within Synthetic Aperture Radar signal processing. If RX01 is the ...
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How can I plot the power spectra of a ST (Stratosphere Troposphere) Radar in MATLAB to estimate the doppler shift
Respected all,
I am trying to plot the power spectra of a ST (Stratosphere Troposphere) Radar to estimate the doppler shift. I am able to obtain a 3D plot between range, FFT point and Power density ...
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What is the pdf of the received signal in MIMO radar for CRLB?
I studied a conference paper, High Resolution Capabilities of MIMO Radar and confused about its formula (3).
As mentioned in paper that the noise $n_{k,l}(t)$ in the received signal $r_{k,l}(t)$ ($r_{...
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Ambiguity function volume
I find myself confused how two properties of the ambiguity function relate to one another.
The properties in question are (presented here from wikipedia, but similar formulas can be found in books by ...
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MIMO Radar - Using statistical properties of the Fourier transform phase for detection
I currently researching the phase (between real and imaginary part) of the fourier transformation. It seems that one can use it for detection.
For the signal processing I use two fft transforms. One ...
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How to calculate the range bin size in FMCW radar?
In FMCW, we have range resolution calculated as delta_d = c/(2B), and dmax = fs * c/(2*S) where S is the slope.
my understanding is numRangeBins = dmax / delta_d. However, in the post (range-doppler ...
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unambiguous velocity $V_\max$ in radar doppler processing
In literature, $V_\max = \lambda\cdot \operatorname{PRF} / 2$; should it be $V_\max = \lambda \cdot \operatorname{PRF} / 4$, which would be consistent with FMCW $V_\max = \lambda / (4 \cdot T_c)$?
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Ambiguity function information
For a course that i'm taking im asked a question about the ambiguity function of a FMCW radar. However i have not found a good source for reading about this so don't quite understand it.
I get given ...
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Conditions for FMCW signal reconstruction using Hilbert Transform
I have an In-phase signal collected by an FMCW radar. I am trying to reconstruct the analytical signal by applying the Hilbert Transform to the In-phase signal.
Are there certain conditions that need ...
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Is it possible to generate SAR like pictures with a non moving MIMO radar and static scene?
Recently I study radar alot and was wondering if there is a possibility to generate SAR like pictures with MIMO radar.
Under the condition that the MIMO radar is not moving and the scene does not ...
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445
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Using radar IQ data to detect motion
I have a 24GHz motion detector (SMR-333 website, sparse datasheet) that gives I and Q, without signal processing. How can I use these values to detect motion? I only need to detect if a person moves ...
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871
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Time shifting a signal in python
I am currently modeling FMCW (linear FM) and SFCW (stepped FM) chirps in python. For my project, I need to simulate those signals as a transmit chirp and a received one, scattered from point targets ...
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Deconvolution of a ground-penetrating radar signal for further convolution with a desired source signal
I am following the instructions of this paper (https://www.earthdoc.org/content/journals/10.3997/1873-0604.2003015) to process a ground-penetrating radar (GPR) signal (a discrete signal sampled at a ...
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Stepped Frequency Modulated Waveform Continuity issues [duplicate]
I want to generate a stepped frequency modulated waveform (SFMW), similar to a linear frequency modulated chirp.
While approaching this, I wanted to consider the issue that there should be some ...
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Use FFT to compute only part of frequency response
I am working on a project in which I need to calculate the range of a target using an FMCW radar. Dependent on the target's range, I expect various beat frequencies to occur in the data from my ADC. I ...
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Minimal SNR to distinguish LFM target from noise at range doppler output
I am working on a radar signal processing project using MATLAB. I am required to simulate range doppler maps for Linear Frequency-Modulation (LFM) targets (non-fluctuating) in noise at various SNRs (...
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Distance and Velocity estimation from FMCW radar Transceiver (KLD-7 by RFbeam)
Module that I am using is KLD-7 radar Transceiver from RFbeam
I am new to FMCW radar systems and I recently started working on distance and velocity calculations from such a system. Although the ...
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Is the maximum possible bandwidth of a radar system dependent (or related) to its center frequency?
One of the core parameters of any radar system is its center frequency. Another core parameter is its bandwidth, which is the reciprocal of its ranging resolution. I am wondering: Is there some sort ...
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Cramer-Rao Bound for Time Delay given a Chirp Waveform with AWGN
In multiple sources (e.g. Richards, Mark A. "Fundamentals of Radar Signal Processing, Second Edition"), I come across the following expression for the CRLB for the time-delay parameter, ...
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Azimuth image extent in frequency domain SAR algorithms (RDA, omega-k)
When looking at the practical implementation of frequency domain SAR imaging algorithms like the range Doppler algorithm (RDA) and the omega-k algorithm (also called range migration algorithm, RMA) as ...
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How to calculate SNR with White gaussian noise
Im working on a Pulsed Doppler Radar
What is the way to calculate the SNR (with WGN)? What will be the lowest SNR for detectability?
Im using matched-filter(xcorr) to process the signal+noise.
My ...
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Doppler Map for a beginner pulsed radar
I have been assigned to simulate a Pulsed radar with Chirps hitting a moving target and then analyzing the data to create a Doppler-Range map.
Im having trouble completing some of the "algorithm'...
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Range-Time Radar Data Processing
I am learning to how it is working this data processing. But I am little bit a confused. There are different ways to obtain this range-time table.
As you can see the picture, obtaining the range-fft ...
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Doppler radar: phase shift sign convention
In my reading about Doppler radar principles, both of the sources I've been using have made a peculiar choice of sign convention: the phase shift of the received pulse relative to the transmitted ...
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Estimating the Most Likely Harmonic Signal in a Spectrogram
Experimental data description: below image is from spectrogram of doppler radar return as I walk toward sensor. Bright sinusoid shape modulated with frequency F is from motion of small retroreflector ...
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FMCW radar IQ data constellation
I am trying to replicate the basic method of vital signal detection based on FMCW radars I found in classical literature on the subject. The issue I am facing at the moment is that of IQ data DC ...
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Deriving the IF phase equation of FMCW
My understanding of the FMCW was limited to one chirp and was mostly focused on frequency analysis. (Mostly built upon this answer)
I wanted to expand my understanding to multiple chirps and was ...
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Phase Unwrapping [duplicate]
I'm also quite new to world of radar signal processing. I don't understand why we have to make phase unwrapping process. Could you light in me about it? It would be nice conversation speak about it.
I ...
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