Questions tagged [radar]
Anything related to RADAR (RAdio Detection And Ranging) systems, their operations and circuits. RADAR systems are used to detect and locate a target by sweeping a beam of microwaves across a region of space and detecting echo signals reflected by the target.
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HB100 range extension with dish antenna
I have interfaced an HB100 sensor with an ATMega microcontroller. It easily detects my hand movement upto 5-6" away only.
I want to extend the range of the sensor so that it detects movement upto ...
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Skills to build an airborne radar [closed]
I am currently working on a project to develop an airborne ground penetrating radar - a payload to be put on a drone - we are aiming to develop a synthetic aperture ground penetrating radar of this ...
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Keysight vs Tektronix: AWG+RT SigAn or VSG+RT Oscilloscope?
I'm evaluating some new RF hardware for one of my university's research labs, for antenna testing. We are between a Keysight vector signal generator and a real-time oscope versus a Tektronix AWG and a ...
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Radar received RF signal phase-shifted by 90 to obtain I/Q signals
I am trying to get idea how marine radar works before start any repairing process. And this part confused me, most articles that i saw explain that in mixing stage we obtain I/Q signals using LO ...
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Advice on measuring relative speed and position of an active transmitting and reveiving object
Using multiple transmitter/receiver stations on ground and the doppler shift to measure relative velocity and position of an airborne active receiver/transmitter in low altitude (0-2 km).
I want to ...
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Uniform Linear Array (ULA) beamwidth and angular resolution using FFT
I have a four element uniform linear array receiver and I want to know what will be the angular resolution if I perform perform Fast Fourier Transform (FFT) over antenna elements. As I think that it ...
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How is Doppler beam sharpening and synthetic aperture forming the same thing?
There's a quote here from Carl Wiley, the inventor of synthetic aperture radar:
"I had the luck to conceive of the basic idea, which I called Doppler Beam Sharpening (DBS), rather than Synthetic ...
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Chirp pulse compression as described in Stimson's book
I reference the below diagram, from Stimson's Airborne Radar, 2nd Ed. In the text he discusses how the frequency increases linearly throughout the duration of tau. The sketch of the frequency x time ...
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LED limit to short pulse and high power
I’m studying the viability of a small footprint distance detector that relies on a LED, a photodetector and some lenses. It’s meant for a distance above 150m, where the light beam travel time is ...
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SAR: Why can images have complex pixels?
I come from an astronomical long-baseline interferometry background, where images are synthesized from sampled complex visibilities (Fourier components). LBI and polarization can be combined when ...
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FMCW or FSK radar signal processing using an Arduino Nano
I have been trying to build a car detection system with range measurement using an Arduino Nano, an AgilSense AP88 (this provides I/Q output, butI am using only the I output,) and an MPU4725 DAC (...
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Why are sound waves the best choice for many location detectors?
I'm currently working on my high school final project, which is basically a radar.
I'm using the SRF05 detector to detect objects that are near the surface of the device. My current assignment is to ...
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Recommendation for 5 V, >2.5 A supply brick with 2.1 mm barrel jack (center positive) power supply
I purchased an AWR1843BOOST automotive radar sensor evaluation module. The power supply must be purchased separately.
The specifications say I need a 5 V, >2.5 A supply brick with a 2.1 mm barrel ...
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Why use convolution for pulse compression in radar instead of correlation?
I have not understood the way to process pulse compression in radar signal processing. I think it's correct to use correlation for pulse compression, but I saw many materials about pulse compression. ...
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Why doesn't CDM324 (CW doppler radar) work as an FMCW radar when a fluctuating voltage is applied
Yes, I know CDM324 is a doppler radar module, however, Signal Path posted a nice video taking a deep dive into this module and observed that when the VCC applied is varied between 4 and 5 volts there ...
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Frequency response of antennas
Electromagnetics and antennas are not my main area of expertise. However, I have a specific question about antennas that I want to get right in order to make sure my signal processing is right.
What ...
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Is it possible to couple Tx signal to RTL-SDR Rx signal for a FMCW radar?
Above one can see a typical (AFE) diagram for a FMCW. Other block diagrams I found include the processing blocks and and so on as well, but my question rests on the following: can I mix the TX and RX ...
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STM32 DMA for IQ modulation
I’m trying to develop an application where I use an STM32F405RGT6 microcontroller IC to drive a radar that operates in multiple ISM bands (433.92 MHz, 915 MHz, 2.4 GHz, and 5.8 GHz).
The overall idea ...
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Applying FFT on I/Q signal to get range and velocity
I managed to get correct I/Q signal from an FMCW radar.
From my last questions I understand that I have to do FFT on the root of I^2+Q^2
so I will have an array of I^2+Q^2 then do FFT on it.
My ...
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What is the bandwidth of a radar operating at 5 GHz?
This is the question I have been working on recently. I am trying to figure out how the time-bandwidth product is calculated.
If anyone can send me any useful links that I can learn from I'd be very ...
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What methods can be used for sampling an analog signal using a microcontroller?
I'm in the early stages of design a project I'm working on for fun - a radar speed detector using a simple Doppler radar module and an Arduino (or possibly another similar microcontroller).
I've ...
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Basic question about radar
I am learning about automotive radars and have a very basic question about them.
If two or more cars on a road have the same radar, using the same radar tech (e.g. CWFM radar) how will one car's radar ...
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What does "desying" mean in polarimetric radar studies?
Do you see these two papers? paper1and paper2
It seems that desying has a special professional meaning in polarimetric radar studies.
I'm reading this paper and ...
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What kind of low-cost equipment do I need to learn and experiment with RADAR at home?
I am interested in RADARs. However, I don't have enough time to go to school for studying RADARs. Therefore, I am thinking about self-study.
What kind of low-cost equipment do I need to learn and ...
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A question on radar cross section of rain by using radar reflectivity factor
The question is one of the past exam papers of the RADAR 1 course given in TUDelft, unfortunately, solutions are not provided to the past paper yet.
The question:
What will be the radar cross-section ...
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How could you determine the point in time a Radar antenna is directly facing a stationary RF receiver station?
I am currently doing experiments involving Software Defined Radio and Radar systems. Since I am new in this field and currently try to refresh my physics/math skills, I encountered some problems along ...
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Is it possible to build radar system for drones detection at home? [closed]
Can I build DIY radar system using ESP32 or Raspberry Pi modules + a bit of soldering that will be able to detect drones in a radius 1-2km? Is it possible? What do I need for this and how much will it ...
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Range Profile in Radar System
I am slightly confused on the range profile I am obtaining from my SCFW radar dataset. I am understanding of how fftshift works in shifting positive and negative frequency components to be centered ...
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Active Radar Homing with single antenna
From what I remember there are a few A2A and S2A missiles which have their own onboard radar system but I don't think they have multiple radar antennas for phased Array use.
I'm curious how radar ...
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Why are many radar antenna arrays not rectangular but rather octagonal÷icosagonal?
I've seen that, despite some phased array antennas are rectangular, many of them are not. They are octagonal, decagonal and even more.
Why are they built in this way?
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Using LIDAR in a 360-degree configuration
(I do not know an appropriate place for this on Stack Exchange. There does not appear to be any groups dedicated to LIDAR or ranging, so this will do for now. Please let me know if there is a better ...
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Creating a Range Profile
I am relatively new to the radar/signal processing community. However, my team has been struggling in developing a range profile in our programming. Here are the details for a NI LabVIEW forum I ...
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Why does an isotropic antenna becomes anisotropic inside a phased array (mutual coupling neglected)?
in this paper the following statement is written:
An area A is allotted to each element in the infinite array. This is
the maximum area available to each element, and is usually greater
than the ...
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Radial velocity of two moving targets [closed]
The radial velocity is the velocity which is in the direction of the connecting line.
I would like to find the Doppler frequency of two moving targets, but as you know, this frequency only shows me ...
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Problem in the book "Radio Antennas and Propagation"
I came across a problem in an electronics textbook by William Gosling, Radio Antennas and Propagation.
I am an undergraduate and I sent this to my lecturer to help solve but unfortunately, her answer ...
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How did old WW2-era radars accurately measure time delay and integrate this into an oscilloscope?
The speed of light is about 300,000 km per second. An error of just 1 ms would result in being off by about 300 km, which is far too much error for a radar. I would guess it needs accuracy on the ...
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Sampling Frequency of a pulsed radar signal
I'm new to radar. please excuse my question if it doesn't make sense to you.
In a pulsed radar signal, why is the required sampling frequency "2 times the inverse of pulse width" instead of "2 times ...
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How does the author get to his equation for the ellipse and the antenna's beam?
I am trying to understand how the author of this textbook (Basic Radar Analysis by Mervin C. Budge) realizes the equation for the ellipse shown in the image attached labeled Figure 2.3 (found in ...
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Confusion on what the RF input to a PLL does
I am designing an FMCW radar, for which I need to generate an RF signal ramped in frequency. To accomplish this, I want to use a direct digital synthesizer (DDS) to generate the ramp at baseband then ...
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FMCW radar FFT(Fast Fourier Transform)
I am trying to design a simple FMCW radar for the ideal case. Below are steps I planned.
Transmit signal, Tx = cos(T)
receive signal, Rx = cos(R)
Mix transmitted signal and received signal, Sx1 = cos(...
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Meaning of 'Scatterer' and 'point scatterer' as opposed to just using the word 'target'?
https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/ers/instruments/sar/applications/radar-courses/content-3/-/asset_publisher/mQ9R7ZVkKg5P/content/radar-course-3-the-radar-equation
"...
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Need help with the choice of a motion sensor for use in arctic temperatures
We are a group of students, who are currently investigating how to build a robot that is meant to work at arctic temperatures (peaks at roughly -30 degrees Celsius). We would like to equip our robot ...
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Can traffic counting be done with just doppler radar?
I'm planning on using radar to count car traffic on a slow speed road. What I'm wondering is if I should expect doppler radar to be good enough to get an accurate count? Alternatively I could also use ...
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Why do the Duga-1 dipoles look like an array of birdcages?
Looking for sources for the question What Soviet signals attempted to scramble communication and sabotage Apollo missions? I ran across the Wikipedia article for Duga Radar. Below are cropped and ...
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Why is my clipping circuit involving 1N5819 Schottky diodes in my radar receiver not working?
I have built the circuit shown below and been testing it on a breadboard.
Everything works except the positive half clipping circuitry.
I need it to clip after 3.3V. It currently just clips below 0V, ...
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Low Voltage Oscillation in OpAmp Circuit
I have a small signal from a radar sensor (in the range of 300 µV) which I want to amplify to something I can reliably measure. Fortunately the application notes of the sensor provide a recommended ...
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Uniform circular array (UCA) beamforming using FFT
As far as I know, conventional beamforming using FFT can return a range-angle map. However, this only works with a uniform linear array (ULA).
I'm wondering if the same approach works for UCA. I guess ...
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How do I compute the angular resolution of a radar system?
I hope this is the right place to ask a radar related question, otherwise I would be grateful for a pointer to the correct forum.
I want to compute the angular resolution of a radar system but so far ...
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Which is the cause of "scan losses" in a linear phased antenna array?
in a linear phased array it is possible to move the peak angle ("beam steering") by applying proper phase shift between the excitation currents:
The second picture represents the array ...
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What is the difference (and the link) between the RADAR cross section (RCS) and the equivalent area of the target?
Here it is written that:
The radar cross section (RCS) σ of a target is the equivalent area seen
by a radar. It is the fictitious area intercepting that amount of
power which, when scattered equally ...
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