Questions tagged [radar]

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

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1answer
57 views

FMCW Radar - Range-Doppler Plot

The FMCW radar with the following parameters was implemented: ...
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2answers
66 views

Radar for Vital Signs – Matlab Simulation

Interested to design and simulate FMCW radar for Vital Signs sensing. The initial signal parameters are(1): When using the following Matlab code to generate the waveform: ...
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1answer
59 views

MTI RADAR, DSP algorithm question

Im new to RADAR signal processing. I using this doc for ref: https://www.mathworks.com/help/phased/examples/ground-clutter-mitigation-with-moving-target-indication-mti-radar.html I trying to rebuild ...
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2answers
51 views

What is the best to confirm that the output of a matched filter for a linear FM chirp is correct?

I have written a matched filter in matlab to compress a linear FM chirp signal and would like to confirm that the results of my range compression. My question is what is the best way to do this? I ...
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1answer
44 views

Radar type application for narrow band only?

Not sure if this is the proper forum to ask this question, but still I am trying my luck. I am looking for an application (in any area, medical, defence, or any other area) if exist, such that we want ...
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23 views

How do you perform range compression of SAR data on a 2D matrix?

I am building a Matlab program to process RADARSAT-1 data that came with this book. The book describes the steps to creating SAR image as follows I am currently implement the range compression step. ...
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25 views

How can i identify number of return of the ping in the sonar?

I am writing a fake function which is actually doing active pinging (basically SONAR). I am little confuse here about how to identify the number of sonar return i got ? Let's say i am continuously ...
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18 views

In FMCW RADAR, how to use signal difference to calculate the position of a new object entered a clutter

Radar setup: FMCW radar with 1 TX and 2 RX both have IQ channel. So a single (stationary) object's range and angle can be calculated. Problem: If two objects are at about same distance but different ...
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1answer
52 views

FMCW Radar using FSK Superimposed LFM ramp

While reading the datasheet of the ADF4159 I came upon a section describing how to create an FMCW ramp with FSK superimposed to "enable unambiguous (distance and velocity) multitarget detection&...
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1answer
66 views

Cant find Doppler shift with LFM signal

Im stuck on this one. I hope someone helps me! Problem: I need to find Dopler shift with array of reflected chirps. I have bursts of chirps which then i sampled, and calculated fft. Im suposed to ...
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1answer
152 views

Generating IF signal for FMCW radar

I am trying to generate a signal that represents mixer output of FMCW radar. I am using MATLAB and already tried out this tutorial. There, Phased Array System Toolbox is used to showcase how FMCW ...
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0answers
24 views

How to calculate FMCW Radar Chirp STFT?

I have received signal from FMCW Radar which is of the shape [128x64] = [Number of samples per chirp x Number of chirps per cycle] and i want to calculate the stft i am calculating it with stft ...
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12 views

Advantage of “multi-static” transceiver configuration

Assume I have a system with one mobile station and multiple Transceivers (similar as in a "multi-static" RADAR system), in this example 4 transceivers: The bit error rate from RTX $i$ to the mobile ...
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1answer
36 views

Why does my I/Q data from radar are not centered?

I am working on the IQ raw data from FMCW radar. I plot the I and Q data, they seem to be strongly shifted from the center. And the amplitude of I and Q also varies. I don't understand why it looks ...
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42 views

Does a time varying gain (AGC) mitigate clutter in radar signals?

Trying to implement an MTI filter for flatland clutter in a radar received pulses. However, after the matched filter output instead of implementing directly the MTI filter, I normalized with an ...
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1answer
86 views

DSP based FMCW radar

I have an SDR receiver I'm interested in making into a FMCW radar. The bandwidth is somewhat narrow as it only samples at 64 MSPS. There is a problem in that without a bunch of embedded programming ...
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4answers
38 views

Doppler frequency when down-converting a receiving signal

Suppose we have a monostatic radar system, with only one target crossing at a speed $v$ at the main lobe of the antenna. The Doppler frequency for this case will be given by $ f_d = \frac{2v}{\lambda}...
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1answer
43 views

FMCW radar: Linear phase change determination with sinusoidal decomposition

I am struggling to understand how linear phase shift can be determined with a transform whose main purpose is to determine frequencies rather than rate of change of a function. In FMCW radar, ...
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1answer
61 views

Is it fast time or slow time for the delay in the ambiguity function domain for radar signal?

I am confused about the delay concept in the ambiguity function. The FFT of slow time is the doppler frequency. However, people usually relate the range-doppler domain with the ambiguity function ...
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2answers
50 views

Coherent detection in radar and radio signals

Coherent demodulation\detection is usually done via matched filtering in RF signal processing. In radar signals, coherent integration can be done if the phases of the returns are known. In terms of ...
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1answer
20 views

Is it possible to detect or localize movement of objects using LPWA (or LPWAN) such as LoRa, DASH7, NB-FI?

Assume that there is a moving human in the room without any device (or receiver). Is it possible to detect or localize movement of objects using LPWA (or LPWAN) such as LoRa, DASH7, NB-FI by analyzing ...
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0answers
42 views

Sign of manifold vectors in monostatic phased-array radar

I am reading some notes where the impulse response of phased-array to is given by; $$ \beta S(\theta, \phi) \bar{S}^H(\theta, \phi) \cdot \delta(t-\tau) $$ where \begin{align} \bar{S}(\theta, \phi)...
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30 views

Block Processing to Plot Phase in Real Time

I am trying to modify an LTFAT demo script that records and plays back streaming audio simultaneously. The objective is to read in the block to a vector, and take the DFT of the block samples, and ...
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0answers
82 views

Identify an obstacle in front of the radar

I use the K-LC6 24 GHz microwave module in the linear frequency-modulated signal mode to determine the distance to moving objects. But if I put a barrier in front of this radar while it is moving, I ...
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1answer
59 views

Digital beamforming and phase shift stage insertion

I have read some literatures about the different topologies of beamforming and it came to my mind a question : where is applied the phase shift for each channel depending on the type of topology/...
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1answer
51 views

Is it possible to observe more area in azimuth than physically traveled in stripmap SAR?

I have been examining stripmap SAR algorithms, mainly Range Migration Algorithm. When I check the textbook examples so far I always saw the data trajectory is larger than scene that is observed. An ...
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0answers
17 views

Detect number of targets from the FMCW data matrix

Currently, I already have an FMCW data matrix which was acquired by the SISO radar. Based on this data matrix, I want to estimate number of targets in it. And then I can apply some blind source ...
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0answers
112 views

Stolt interpolation and ifft in range migration algorithm

I am using range migration algorithm for focusing stripmap synthetic aperture radar data. I have successfully tested my algorithm using the following steps after range compression (similar to this ...
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0answers
32 views

Motion compensation for stripmap SAR

I am trying to perform motion compensation for an airborne stripmap SAR data following the book Synthetic Aperture Radar Processing by Franceschetti and Lanari. The algorithm flowchart is on page 145. ...
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1answer
64 views

Range Compression

How exactly is the SAR image resolution increased by the linear frequency modulation of the transmitted signal and further by the compression of range and azimuth?
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3answers
96 views

3D model from high speed videos?

Is there a way to convert or somewhat replicate RADAR data from a set of given high speed videos taken from multiple angles. The problem is quite ill defined but the task I have in hand is to ...
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1answer
65 views

How to perform dechirping of SAR image in MATLAB?

I have the transmitted pulse and the raw SAR image before range compression (dechirping). I understand the pulse compression its a convolution along the columns but I am not able to make it work. I've ...
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1answer
108 views

Synthetic Aperture Radar (SAR). How to do Range Compression?

I am trying to perform range compression to a raw SAR image [fast times, sensor position], Dr in code. I have the transmitted signal (chirp), g in code, and literature says range compression is ...
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0answers
25 views

modelling radar system for image generation

I am trying to find or derive some model for radar using python and blender which should hopefully create a simulation of what a radar image of the blender environment would look like. I have been ...
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1answer
208 views

Radar signal processing flow chart

I'm new to Radar in general, and I'm studying RADAR using online resources. I came across the following slide which shows the process flow of the Radar signal processing. The thing I don't get in ...
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2answers
112 views

Pulse Doppler Radar: time delay in down conversion

My understanding of Pulse Doppler Radar is the system measures Time Of Flight for the pulse. My confusion is that during the down conversion process prior to ADC the lowpass filter causes some time ...
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1answer
53 views

Coherent Radar — How do we justify it?

How can we justify doing coherent radar when the phase of the return is unknown? For instance, after a reflection, assuming a stationary target, we should get something akin to: $$ x_{rx}(t) = |\...
2
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1answer
51 views

Minimizing Time Sidelobes with Pulse Compression

I am trying to compute a compression filter function to minimize the error from a a desired pulse compression result. The usual approach to doing this is to minimize the RMS error of the the ...
3
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1answer
140 views

FFT strong signal in middle frequency bin

I've developed a radar that I'm using to determine the distance to remote objects. It uses a custom PCB with an onboard FPGA that performs the DSP algorithms. The data from it is then plotted on a ...
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0answers
47 views

Range Migration Algorithm in FMCW MIMO radar

I’m using a FMCW MIMO radar [77-79 GHz] with a virtual linear array made of 48 channels. I’m wondering if the adaptation of the range migration algorithm (typically used in SAR processing) is ...
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0answers
36 views

MIMO FMCW radar - back-projection

any suggestion how to start implementing the back-projection algorithm in a FMCW MIMO radar? Currently I'm using 2D FFT to get radar image, I would try time-domain algorithms to improve the overall ...
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0answers
77 views

Root MUSIC and solution of conjugate palindromic polynomials

The root-MUSIC algorithm gives direction of arrival angles directly and avoids the computational overhead of computing the MUSIC estimator curve (see Direction of Arrival Estimation using a Root-MUSIC ...
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1answer
52 views

How is ESPRIT pronounced?

I'm implementing high resolution DOA algorithms including ESPRIT for radar systems. The word ESPRIT is obviously an acronym but, even so, how is it pronounced? Is the second i long like "ESPREEE" as ...
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0answers
70 views

Combining two images with different resolutions?

I am attempting to combine two radar images, each of which is a 3-dimensional cube with a range dimension, an azimuth angle dimension, and an elevation angle dimension. One image has high azimuth ...
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2answers
166 views

Doppler Shift and the Pulse Repetition Interval

Suppose that I have a signal $x(t)$ consisting of $N$ pulses at a given frequency $\omega_{c}$. I space them $T$ seconds apart, ie the Pulse Repetition Interval (PRI) for the waveform is $T$. Now ...
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1answer
251 views

Advantages and disadvantages in term of radar performance of LFM chirp

Which are the advantages and disadvantages of a LFM chirp regarding its radar performance?
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2answers
66 views

Matched Filters for attenuation detection?

I have been reading about matched filters and I'm interested in possible uses for them, I have seen they are used very often in radar, in such a way that you send out a signal, and then you read the ...
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30 views

Why the ideal ambiguity function (AF) for radar has the maximum in (0, 0) and zero otherwise?

I was wondering why is the ideal AF has zero value in all the function except in (0, 0).
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39 views

RRC filter or rectangular pulse shaping filter in LFM chirp signal

I am working with a LFM up chirp signal, and I wanted to embed some data on it using a BPSK constellation. My doubt was, ¿should I use a RRC filter, like in usual communications schemes, or should I ...
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1answer
167 views

Question about FMCW range-velocity plot

I am working on plotting range-velocity heatmap of the receiving FMCW signal. I actually have already plotted. However, I do not really understand the mapping relationship between Doppler FFT bin and ...