Questions tagged [radar]

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

47 questions with no upvoted or accepted answers
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4
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97 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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156 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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0answers
58 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 ...
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2answers
189 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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222 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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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
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 ...
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1answer
620 views

FMCW Radar - Range-Doppler Plot

The FMCW radar with the following parameters was implemented: ...
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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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90 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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75 views

Precision accuracy radar

in radar systems how does one measure the precision and accuracy on a radar? I'm confused with differen definitions in the references: Richards define (Principles of Modern Radar: Basic Principles - ...
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93 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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2k 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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49 views

How does the error in azimuth angle vary as one moves away from the boresight direction of a radar

My question is basically same as the title. I am trying to find a mathematical model which provides the error, $d\theta$, in azimuth angle($\theta$) as one moves away from the boresight direction of ...
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27 views

mmWave Radars and 2-D point cloud from its IF complex signal

Given we have the IF complex signals from Rx channels, how can we construct point cloud from that? I have 128 chirps in each frame and total of 8 frames with 4 Rx channels and 3 Tx. It is AWR1443 ...
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1answer
30 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-...
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63 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 (...
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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 ...
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3answers
60 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 ...
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53 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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24 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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66 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
40 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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38 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, ...
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1answer
53 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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33 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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41 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 ...
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41 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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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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1answer
124 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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0answers
86 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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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 ...
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87 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
97 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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305 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
46 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
169 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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32 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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0answers
66 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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31 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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49 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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0answers
208 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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187 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
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 ...
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0answers
3k 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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386 views

Monostatic range-doppler algorithm

I was told that this question is too broad. Maybe I don't understand what this forum is about. My question is basically the same. I am looking for references to range Doppler algorithms so I can learn ...
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1answer
73 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) = |\...