Questions tagged [radar]

Anything related to RADAR (RAdio Detection And Ranging) systems and radar signal processing.

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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 ...
BobbyChun's user avatar
2 votes
2 answers
147 views

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 ...
user70096's user avatar
1 vote
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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 ...
DominikR's user avatar
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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 ...
Hari's user avatar
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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 ...
pej's user avatar
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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 ...
J Jack's user avatar
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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 ...
Paroz's user avatar
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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 ...
Jim's user avatar
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110 views

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 ...
Raj Patil's user avatar
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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,...
pej's user avatar
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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....
Raj Patil's user avatar
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21 views

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 $$\...
Hari's user avatar
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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 / ...
Hari's user avatar
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1 answer
80 views

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 ...
Jim's user avatar
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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 ...
Hari's user avatar
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2 answers
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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 ...
Lucas's user avatar
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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....
esi's user avatar
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41 views

Beam Center Range for FMCW radar

I am provided with the following information: ...
Hari's user avatar
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1 answer
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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 ...
Hari's user avatar
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2 votes
2 answers
357 views

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 ...
Hari's user avatar
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3 votes
2 answers
141 views

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 ...
Lucas's user avatar
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1 answer
50 views

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 ...
Hari's user avatar
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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 ...
Shashank's user avatar
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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_{...
Loco Citato's user avatar
2 votes
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205 views

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 ...
Narrava's user avatar
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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 ...
magi's user avatar
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1 answer
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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 ...
Linda's user avatar
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1 answer
494 views

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 $V_\max = \lambda / (4 \cdot T_c)$? ...
Linda's user avatar
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3 votes
1 answer
135 views

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 ...
cooldanietje's user avatar
1 vote
0 answers
76 views

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 ...
Hari's user avatar
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2 votes
1 answer
56 views

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 ...
jang's user avatar
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1 answer
445 views

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 ...
NateS's user avatar
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2 votes
1 answer
871 views

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 ...
Lucas's user avatar
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1 vote
0 answers
78 views

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 ...
Luis Fraga's user avatar
1 vote
0 answers
19 views

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 ...
Lucas's user avatar
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0 votes
1 answer
101 views

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 ...
CMH12's user avatar
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1 vote
3 answers
226 views

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 (...
spacey's user avatar
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1 vote
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176 views

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 ...
Haris Khan's user avatar
1 vote
1 answer
218 views

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 ...
Michael's user avatar
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2 votes
0 answers
58 views

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, ...
StackMonkey's user avatar
1 vote
0 answers
75 views

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 ...
contiguousCentipede18's user avatar
0 votes
2 answers
853 views

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 ...
Processor48's user avatar
1 vote
1 answer
246 views

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'...
Processor48's user avatar
0 votes
0 answers
195 views

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 ...
Paroz's user avatar
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0 votes
0 answers
72 views

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 ...
the_Demongod's user avatar
3 votes
1 answer
158 views

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 ...
John Beale's user avatar
1 vote
0 answers
179 views

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 ...
obatala100's user avatar
1 vote
0 answers
102 views

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 ...
Moses Kim's user avatar
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0 answers
38 views

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 ...
Paroz's user avatar
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