Questions tagged [radar]
Anything related to RADAR (RAdio Detection And Ranging) systems and radar signal processing.
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39 views
Probabilistic Data Association - Particle Filter
I have to implement a Probabilistic Data Association (PDA) Filter based on a Particle Filter (SIR). I have already implemented a Probabilistic Data Association Filter based on a Kalman Filter but I ...
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1answer
42 views
Confusion about frequency illustration of FMCW in matlab [closed]
I am currently working through the FMCW radar example in the Matlab Docs and have a question concerning the following plot
Why is the frequency of the signal apparently decreasing if I have a linear ...
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1answer
36 views
Doppler Shift of Phase Coded Pulse Compression Waveform
Suppose I want to transmit the signal:
$$ x(t) = g\Big(\frac{t-t_{0}}{T}\Big) \cdot \cos(2 \pi f_{0} t + \theta_{0}) + g\Big(\frac{t-t_{1}}{T}\Big) \cdot \cos(2 \pi f_{1}t + \theta_{1}) $$
Where $g(...
2
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1answer
156 views
How to Calculate the Ambiguity Function
(Maybe this should be on Stackoverflow instead ...)
What is the best way to calculate the ambiguity function? There are different implementations out there for Python (like PyTFTB or from ...
2
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1answer
32 views
motion compensation for range migration algorithm
Is there a simple to follow explanation of how to do second order motion compensation for range migration algorithm?
The one described in Carrara et al is for the ideal case. For the Extended Omega K ...
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1answer
38 views
2D CFAR detectors
Constant False Alarm Rate is an adaptive detector used to distinguish between true and false detections. There are many types of CFAR and the number of these detectors reaches 25 like (CA-CFAR, OS-...
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0answers
64 views
Is there a situation when maximizing SNR doesn't also maximize probability of detection?
The problem I'm working on is signal detection of a radar signal, but I suspect this problem shows up in many different branches of signal processing.
Background:
From [1], the factor $I_f$, by ...
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1answer
132 views
FMCW Radar Signal Processing Flowchart / Ambiguity Function
I Read many papers on signal processing for pulsed and FMCW radars, taking the FMCW type, the signal processing start after mixing the received and transmitted signal, the result of this operation is ...
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0answers
77 views
Converting IQ value to distance in FMCW radar
I'm working with a FMCW radar to measure the distance. I'm receiving IQ as the output. I wonder, how to translate this data to millimeter?I have s parameters (<...
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1answer
101 views
Radar video signal and matched filtering
In order to make my question more clear and give more details
I'm trying to understand the processing signal procedure in radars,i understood till this moment that a transmitter generates a signal ...
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2answers
220 views
Deriving the resolution equation of an FMCW radar
I am interested in the equation that depicts the resolution of an FMCW radar. I write the same below.
$\Delta d = \frac{c}{2b}$
First I would like to have an intuitive explanation to the above ...
2
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2answers
67 views
Compressive sensing and sparsity
We apply compressive sensing to reconstruct a signal if it is sparse in the original domain or has a sparse represetation in some basis.
How we may know a if a signal is sparse or has a sparse ...
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2answers
115 views
DOA - 1D Music Algorithm
I am currently working on a MUSIC algorithm for DOA of RF emitters in 3D.
At the first stage, interested to apply the 1D MUSIC using a linear array of 4 antennas, and estimate only the azimuth of the ...
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0answers
59 views
Spectrum of received signal from radar fm-cw
I obtained actual data from a researcher, consisting of a matrix composed of several received signals from an up-ramp fm-cw radar.
Wouldn't be reasonable to plot the spectrogram of a ramp up and ...
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1answer
32 views
azimuth extent for range migration algorithm
Is it true that in the Range Migration Algorithm for synthetic aperture radar, the azimuth extent can be said to span the length of the flight path?
This makes sense but also does not make sense. ...
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0answers
74 views
How to remove echo/reflected-sound caused by stationary objects when building a ultrasound based radar
I am emitting ultrasound with a speaker and am trying to track moving objects with a microphone array by detecting doppler shifts. I have succeeded to detect movement. However, to detect the direction ...
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1answer
83 views
Derivation of range migration algorithm
Problem:
In Walter G.Carrara's book on synthetic aperture radar, the equation is presented:
$\Phi(K_X, K_R) = -K_XX_t - R_B\sqrt(K_R^2 - K_X^2) +K_RR_S $ (10.30)
And this is said to come from ...
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0answers
171 views
Getting the velocity in Radar FMCW
I have managed to get the frequency (the beat) frequency from an FMCW. Here is a screen shot of a wall that's detected by the Radar. I performed an FFT of complex I,Q data.
My questions are 1. How ...
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1answer
90 views
Radar Tracking Algorithms
I would like to know the algorithms to get the angle, range, distance.. so I'm planning to do antenna tracking. What should I do in basic steps to track objects using that module ?
what algorithms ...
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1answer
61 views
Scan shallow water
I need to scan a shower tray with & without the water running to assess the puddling at the drain, then export a point cloud or surface. Sonar & Laser dont seem to be able to deliver, can ...
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0answers
20 views
Is it possible to find a signal that reduce the PSLR without expanding 3dB main lobe for autocorrelation?
Considering a signal $s(t) = rect(t/T_p)exp(j\theta(t))$, the autocorrelation is $ACF=IFFT(s^2(f))$. It's possible to construct the $\theta(t)$ to get a signal which has the same 3dB main lobe as the ...
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1answer
73 views
Designing an efficient curve-matching algorithm
I'm currently designing a curve-matching algorithm and as I already explored many ideas I'm requesting your help. So, if you got some advices about how to handle this problem, feel free to answer!
...
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1answer
59 views
Increase Radar Detection range using Modulation
I have been reading about pulse compression which helps with the range resolution.
In my application I do not need to measure the range of the object however I am more interested in boosting the SNR ...
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0answers
661 views
Convert RGB image to meaningful data
I am trying to extract data from images and convert them to meaningful data. The images are mostly obtained from weather radar and have been transformed into some opaque numbers. I am trying to use ...
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1answer
90 views
Phase of FMCW linear chirp
I'm doing a project involving FMCW linear chirp signals.
Given the phase
$\phi = 2\pi\frac{k}{2}t^{2} + 2\pi f_{c} t + \theta$
where $k$ is the frequency increase rate.
When transmitting ...
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1answer
302 views
Probability of False Alarm versus SNR
I'm currently testing the performance of an energy detector using two tests. One test involves finding the optimal threshold to achieve a probability of detection(Pd) of 0.9 and a probability of false ...
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1answer
1k views
Simulation of FMCW radar in frequency domain
I would like to simulate a FMCW radar in the frequency domain. I used the code (Matlab) I attached below. Specially I am interested in the phase spectrum of the beat signal. In a further research I ...
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0answers
114 views
AOA for planar array
I have tried applying MUSIC and CAPON AOA algorithms for an N*N planar phased array and plotted the pseudo spectrum. Since the source is a point source and the array is a square, should the peaks at ...
1
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1answer
258 views
Radar Pulse Compression Gain (PCR)
Assume a monostatic radar is transmitting a pulsed waveform. The pulse has been modulated by a Barker code with$\ N$ chips or bits. The waveform chip rate is $\tau_c $, the radar receiver's detection ...
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0answers
606 views
Correct Radar Range Equation for SNR at Detection
Assuming you'd like to estimate the probability of detection of a target for a monostatic radar.
For estimating detection SNR of a monostatic radar for given target rcs signature, do you use the ...
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2answers
824 views
Is it possible to make 3D point cloud with RADAR?
Is it possible to make 3D point cloud with RADAR? Both LIDAR and RADAR are EM waves, but with different wavelength. So, if it is technically possible to make point clouds with LIDAR, why is it not ...
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1answer
61 views
Is it possible to get the velocity vector for tangential movement using radar?
When an object appears towards the radar sensor or goes away from the radar sensor, there is a change in the phase shift of the frequency and from that, the velocity can be inferred.
So, I have two ...
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1answer
356 views
How is angle of arrival estimated?
I have simulated a phased array antenna. I have also simulated a point source. I don't get how to calculate pseudo spectrum vector without using the position of the source. Algorithms such as Capon ...
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1answer
875 views
Time-Bandwidth Product
The following text is cited from a textbook, "Spotlight Mode Synthetic Aperture Radar: A Signal Processing Approach", I would like to ask if anyone knows the proof to the following statements, as the ...
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0answers
80 views
Finding the parameters and endpoints of a sinusoid
Suppose I have some signal
$$
s(t) = n(t) + \left\{\begin{aligned}
&0 &&: t < t_0\\
&A e^{i (2 \pi f t + \theta_0)} &&: t_0 \le t \le t_1\\
&0 &&: t > t_1
\...
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0answers
38 views
How to find the second maximum (Peak sidelobe Level) from the list of cell data and next convert to double data in the matlab?
I have matlab code like in the below,, I want to find the second maximum (Peak Sidelobe Level) from the list of cell data type ( PSL_LFM_Real_max{kk,:} ) and the next must convert to the type of ...
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0answers
184 views
Pauli decomposition of polarimetric SAR data
I am working these days with Pol SAR and I have read up on the Pauli decomposition and how it can help to detect the signal power which has been acquired over a single or odd number of bounces, two or ...
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1answer
189 views
Radar Imaging Method
I've been working with an FMCW Fast Chirp radar transceiver. Mainly, I've been looking at the Doppler range map but really it is not suitable as there is only one point per range/ speed and I want to ...
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2answers
146 views
Should the transmitted signal be continuous in FMCW?
I am a novice in this field and working on respiration detection through near ultra-sound between $18 \textrm{kHz}$ and $20 \textrm{kHz}$.
In the referece article and other radar use articles, the ...
3
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1answer
342 views
Array Signal Processing: What are snapshots in Direction of Arrival estimation?
I do have an overview of basic radar signal processing chain [Data cube, 3 stages of FFT, Range, Range-Doppler map, coherent/non-coherent integration, coarse DoA etc.].
I am now trying to understand ...
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1answer
597 views
FMCW Radar: Need for Second stage FFT for velocity determination?
I have understood that for the purpose of Range determination, the samples of the beat frequency are first assembled per chirp. The beat frequency is directly proportional to the range of the ...
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0answers
1k views
FMCW radar FFT processing
I'm working on the processing of raw FMCW radar data.
In my case the radar works in the [6.014-7.76] GHz band (I have 187 frequency points starting from 6.014 GHz and ended with 7.76GHz) and the data ...
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1answer
558 views
How to reduce spectral leakage?
We are looking at FMCW radar ADC signals and converting from the time domain to the frequency domain in order build a range doppler map but want to have the best signal to noise ratio possible.
In ...
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2answers
1k views
How to interpret an Ambiguity function
I need to evaluate several different waveforms regarding their doppler tolerance, for use in a radar application. So I came across something called the Ambiguity function.
The following picture shows ...
2
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1answer
162 views
High performance DSP processor with better on-chip memory
I am currently using a combination of 4 ADSP 21469 because of the complexity and huge chunk of code that I currently have. BOOT and application will execute from external Flash memory. The code for ...
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92 views
What is the unit of radar cross-ambiguity function for signals with given power?
I am trying to write my own radar simulator in MATLAB. In contrast to other simulators I found (Levanon etc.), my goal is to provide exact results with respect to signal power, antenna gains, path ...
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0answers
130 views
Help detecting target in pulsed radar signal
This signal is from the Pasternack $2.4\textrm{ GHz}$ development kit. The saved signal appears to be the pulsed waveform. It is sampled at $20\textrm{ kHz}$ for $4130$ points. I recorded a ...
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161 views
How to detect shape of an object with electromagnetic wave?
I am not sure whether this is the right place to ask. If not please let me know the correct one.
I want to create an imaging radar as simple as possible for now.
I know a bit about the ...
3
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1answer
898 views
Radar SNR for a LFM Waveform
How do you estimate the detection SNR for a radar transmitting an LFM (chirp) waveform? I'm looking for an SNR equation that is a function of chirp bandwidth and compressed (or uncompressed) ...
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2answers
952 views
Radar terminology - Specific meaning of “video signal”
In the radar literature, particularly in older references, the term "video signal", "downrange video", or just "video" is used to describe the radar signal at a certain point in the processing chain. ...
