Questions tagged [radar]
Anything related to RADAR (RAdio Detection And Ranging) systems and radar signal processing.
134
questions
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57 views
Requirement on sampling rate for Doppler shift estimation
What is the requirement of sampling rate on channel impulse response (CIR) for Doppler shift estimation? Suppose that there is a bi-static radar system with perfect synchronization, the receiver ...
0
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3answers
87 views
Is there processing gain for FMCW using heterodyne-style receiver as opposed to matched filter?
Beat signal of a single target will be a sinusoid in the idealized world, so theoretically the signal processing gain of an FMCW pulse correlated with Tx waveform in this way should be analogous to ...
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0answers
10 views
How does one go about choosing a Radar Cross Section for a human when modelling a Pulse micro-Doppler microwave radar?
So as part of a personal project I'm in the process of simulating and making a fall detector using a 2.7GHz microwave sensor with a range of 8m. I've been using MATLAB's example code to simulate each ...
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1answer
38 views
Friendly target identification in radar
How do radar systems identify friendly targets to avoid AA locks during combat scenarios?
Do friendly planes broadcast a known signal or is something else going on?
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3answers
51 views
Beginner Educational Resources
New member here. Recently got hired into a mid level EE position. Have a BSEE but performed more radar performance analysis at a higher system level previously. In my new group we're doing a lot of ...
2
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1answer
74 views
What is the advantage of using a Stepped Frequency waveform over FMCW?
What is the advantage of using a Stepped Frequency Waveform instead of a traditional linear FMCW ?
1
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1answer
56 views
Can velocity be calculated in first stage FFT?
I understand that, For an FMCW radar, the velocity of a target is proportional to the phase changes at same time instants across the chirps.
I have a MxN data cube with N chirps(columns) & M ...
2
votes
1answer
36 views
Relation between Gaussian derivatives and Gausian-windowed Cosine function
I am doing some research on UWB radars which transmit a pulse given by:
$$
g(t) = p(t) cos(2\pi f_{c}t) = A e^{(-\frac{t^{2}}{2\tau ^{2}})} cos(2\pi f_{c}t)
$$
In some other papers, the transmitted ...
0
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1answer
48 views
Expression for Frequency-shifted Gaussian pulse
I am doing some research on UWB radars which transmit frequency-shifted Gaussian pulses. These pulses are given by:
$$
g(t) = p(t)cos(2\pi f_{c}t) = V_{TX}exp(-\frac{t^{2}}{2\tau^2})cos(2\pi f_{c}t)
$...
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0answers
42 views
FMCW range doppler response problem
I'm trying to learn radar simulation using Matlab. I used this example in Matlab
https://www.mathworks.com/help/driving/ug/radar-signal-simulation-and-processing-for-automated-driving.html
But when I ...
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0answers
21 views
Beamforming and AoA with a small number of elements
So I have an antennae array with only three elements. I want to know what kind of beamforming and AoA estimation I can do with such a small number of elements.
I understand that there are lots of ...
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54 views
How does the Hilbert Transform extract the in-phase and quadrature phase components of a real passband signal?
I am taking an intro to radar signal processing course and we are discussing the Hilbert Transform and how it take a real input and its output is analytically complex. I'm trying ) how a radar ...
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1answer
32 views
SAR spotlight raw signal database
For practicing spotlight processing, i am looking for I/Q baseband signal from a SAR airborne or spaceborne system. In my research I have only found processed image from :
eoweb geoportal https://...
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0answers
36 views
Advice on generating stable FMCW waveform
I am trying to derive parameters for a triangular FMCW waveform such that the phase of the signal has consistency from one period to the next. Perhaps this is arbitrary and feel free to tell me so, ...
0
votes
1answer
49 views
How is a Particle Filter used to Estimate Parameters of a State Transition Function?
In the tutorials on particle filters that I have seen, it seems that the state transition function is already known. This example from Matlab, for example, states the the Plant or State Transition ...
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32 views
Transceiver for TDoA measurements
Could someone advise me on some module for making the TDoA position system for my research work? I need to have measurements with an accuracy of a few meters. It equals a bandwidth of about 20 MHz. I ...
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0answers
54 views
Compressed Sensing in DOA processing
I'm trying to apply the compressed sensing theory (CoSaMP algorithm) to the DOA estimation in FMCW ULA (made of 48 elements). In the dechirped signals processing I use a first FFT to solve the range ...
1
vote
1answer
44 views
What is the importance of signal bandwidth in radar systems for velocity and localization estimation
So I know about the basics of doppler shift which relates the velocity of a moving object with the frequency carrier shift seen at the reciever.
But, I don't understand the importance of the ...
1
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1answer
73 views
DOA for bistatic radar
Consider a circular antenna array (UCA) with $N$ antenna elements as part of the CW bistatic radar system.
For each element we receive a signal of length $L$: $x_n[k]$, $k=1...L$, $n = 1...N$.
Оne of ...
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0answers
32 views
Pulse Width and Duty cycle in Gaussian pulses
I have a pulse-based radar which transmits frequency-shifted Gaussian pulses. The Gaussian pulse ($p(t)$) is given by:
$$
p(t) = V_\text{TX} e^{\frac{-t^2}{2 \tau ^2}}.
$$
The frequency shifted ...
0
votes
1answer
64 views
Distortion in phase difference measurement using FFT
I am doing distance measurements by transmitting a 100 kHz tone and receiving it and measuring the phase difference.The distance is simulated by a delay simulator which is very precise (around 10 psec)...
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1answer
436 views
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2answers
170 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:
...
3
votes
1answer
102 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 ...
0
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2answers
90 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 ...
1
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1answer
49 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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37 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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0answers
30 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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0answers
33 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 ...
0
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1answer
111 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&...
0
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1answer
109 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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vote
1answer
614 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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64 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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0answers
14 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 ...
0
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1answer
64 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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0answers
48 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 ...
0
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1answer
113 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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vote
4answers
54 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}...
0
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1answer
98 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, ...
2
votes
1answer
407 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 ...
0
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2answers
87 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 ...
0
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1answer
22 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
46 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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0answers
85 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 ...
0
votes
1answer
86 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/...
0
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1answer
58 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
259 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
40 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. ...
0
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1answer
95 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
99 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 ...
