# Questions tagged [radar]

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

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1answer
540 views

### FMCW Radar - Range-Doppler Plot

The FMCW radar with the following parameters was implemented: ...
1answer
22 views

### Cut-off frequency for Low-pass filters in Arctangent Demodulation

According to literature, the arctan-demodulation method commonly used in Radio-frequency radar systems is the one shown below: Is there a rule of thumb regarding the cut-off frequency of these Low-...
2answers
182 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: ...
1answer
158 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 ...
0answers
51 views

### Create a Range Doppler Map using “Arbitrary” phase coded Waveforms

This is my first questions I am asking to this community! I want to understand how to create a Range-Doppler Map (RDM) for a phase/frequency coded radar return using an arbitrary waveform generator (...
1answer
81 views

### Aliasing in Doppler Radar

my book about RADAR says that: If a Continuous wave radar sends a sine wave at frequency $f_T$ to a moving object (at speed V), a frequency $f_R$ is received. Their difference is called Doppler ...
1answer
78 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 ...
3answers
57 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 ...
0answers
63 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 ...
1answer
255 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 ...
1answer
98 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 ...
3answers
101 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 ...
1answer
86 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 ?
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 ...
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?
2answers
4k 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 ...
1answer
57 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 ...
1answer
104 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, ...
1answer
89 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/...
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://...
4answers
5k views

### Pulse Compression(Chirp) SNR Gain

I've created both single tone signal and a LFM chirp signal with same pulse duration and cross correlated both of them with their own(matched filter). Peak points of both results were same as expected ...
1answer
38 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 ...
1answer
718 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 ...
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 ...
1answer
53 views

1answer
74 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)...
1answer
110 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 ...
2answers
108 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 ...
1answer
53 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 ...
0answers
38 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. ...
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 ...
0answers
35 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 ...
1answer
122 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&...
0answers
75 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 ...
1answer
75 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 ...
0answers
49 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 ...
1answer
119 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 ...
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}...