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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Will radar/lidar still work when every car is equipped with them?
Self driving cars rely on cameras, radar, and lidar to recognize the environment around them. Cameras of course don't interfere with each other, since they are passive sensors. Since a signal ...
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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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How does LIDAR avoid getting confused in an environment being scanned by hundreds of other LIDAR?
(Meta: I do not know an appropriate place for this on Stack Exchange. There does not appear to be any groups related to autonomous driving technology and computer 3D vision / perception systems.)
For ...
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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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What power limitations was chirped radar designed to overcome?
Chirped Pulse Amplification (CPA) is an optics technique, winner of the 2018 Nobel Prize in physics, which is used for producing short laser pulses at intensities which are high enough that the gain ...
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Can I improve the directivity of an X-band radar module with integrated plane-patch antenna?
Lots of detail provided in case it's needed.
I'm continuing to tinker with remote proximity sensors driven by an Arduino (and eventually just an ATMEGA* chip and its safety buddies) and have a pretty ...
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How does / can this radar wave detector circuit work?
I have difficulties to understand how the below circuit can detect radar waves by only using C1 and the lengths of its wires to ...
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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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Help reverse engineering RCWL-0516 microwave proximity detector module
I got a cheap RCWL-0516 microwave doppler radar proximity sensor module to evaluate. The RF part of this has surprisingly few components (what looks like a MMBR941M NPN and a hand full of passives)... ...
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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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Does this VCO produce a sine wave or square wave
I'm looking at the datasheet for the analog devices hmc431lp4 voltage controlled oscillator, and I can't tell if its output waveform is a sine wave or square wave. The datasheet doesn't label the ...
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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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How does one measure the Fourier components of a signal?
I attended a lecture on ground penetrating radar (GPR). I am used to reflection seismic where the incoming pressure amplitude is measured as a function of time.
In GPR, instead the Fourier components ...
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Why does medical ultrasound use pulses instead of chirps?
My background is in radar where it's quite common to use chirped excitation signals (i.e. pulse compression).
I have noticed that this method seems to not be used in medical ultrasound. Why not?
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IC / logo identification: 5.8 GHz radar MMIC marked "5810"
Can anyone identify the pictured IC or the manufacturer logo on it? It's a 5.8 GHz radar MMIC with 1 Tx, 1 Rx, PLL, power amplifier, mixer, and low noise amplifier, presumably from an Asian ...
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24GHz Radar : IF amplification and strange mixer output
I am currently working on a project where I have to study a microwave Doppler Radar.
Here are some details so that you can better understand it : a local oscillator (LO) at 24GHz is linked to an ...
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Short-range radar and LIDAR, how do they work?
I was wondering how does short-range radar and LIDAR work? Considering the speed of light, the receiver sampling rate would need to be extraordinarily high to detect short-range distances(sub 1-2 feet)...
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Radar antenna for distance measurement
I am working on a project where we have decided to use radar to measure the distance of an object from the device.
I have been using Infineon's BGT24MTR11 (24GHz) evaluation board, (Sense2go), which ...
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How to model Phase noise?
I want to model phase noise. Code below shows how I am adding phase noise in the signal. However, i am not getting correct output. That means, the signal sprectrum shoud be spreading in the frequency ...
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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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Can radar/lidar sensors for self-driving cars be designed to ignore deliberate interference?
A previous question asked about how to avoid interference between sensors on different self driving cars. The answer was that systems could be designed to avoid interference, with correct signal ...
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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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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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ADC and DSP Requirements for FMCW Radar
I am building an FMCW radar that has a bandwidth of 1 GHz. The IF frequency is up to 1 MHz. Would the ADC requirements simply be that it has to b 2 times the IF frequency of 1 MHz? If that's the case ...
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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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Finding a material transparent to 26GHz radio waves for radome protecting a radar rangefinder probe
I want to use a 26GHz radar probe to measure water levels for some outdoors applications. These are pretty common devices, one manufacturer among many others is for example:
https://en.supmea.com/...
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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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Radar and Standing Waves
I have a doubt about the working principle of a simple Radar.
Consider a stationary object, which does not move with respect to our transmitter. We send an electromagnetic wave to it, and it will ...
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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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Radar maths I and Q components
I have just started work with radars. I read that incoming signal in case of Doppler radar is frequency shifted. On adding it to original signal we get Doppler shift. But we don't do it directly. ...
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Feasibility of rat-race as RF mixer without active devices
My understanding is that RF mixers generally use some sort of active device (sometimes diodes) to produce output rich in harmonics, and rat-race couplers can be used to get the sum or difference ...
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What detection method does phased array radar use?
I have been learning about radar technologies for a while, with the intent of building one for fun. When looking at Phased Array radars, there is plenty of information on the beamforming math and cool ...
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Radar Snr improvement
I have a simple radar module (k-band) that is capable of fm modulation and it provides both I and Q as baseband outputs. I like to extend the measurement range of this module by just signal processing ...
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Why CW radar I-Q signals do not contain Doppler frequency component?
I have a question about I/Q signals in Doppler radar, but I couldn't find a solution for this.
As far as I understand, the received signal at receiver side will be down-converted by mixing it with ...
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Radars and high frequency relation
Whenever I seach for radar implementations, independently of application (weather, military, autonomous vehicles, speed limiters, etc) it always comes in many flavours: huge antennas, small antennas, ...
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Radar - How to keep IF constant?
A basic block diagram for FMCW radar I will be using, modified MIT radar project:
MIT block diagram
I
My transmit frequency is 2200-2600 MHz, my receive frequency is ~2200-2600.
I want my IF ...
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How are radar returns sorted in range space in Synthetic Aperture Radar?
I'm trying to understand how a SAR system is able to place returns it receives in range space.
Consider the scenario when an airplane is passing over terrain and is imaging it using SAR, as shown in ...
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What do you mean by cross range dimension of a radar's resolution cell?
I'm reading a book on radars and found this term. Any help is appreciated.
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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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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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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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Phased array radar basics
So, I already understand that the maximum resolution of a radar system is λ R / L, where lambda is the wavelength, R is the range to the target, and L is the diameter of the antenna, and that for a ...
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What's the difference between a monostatic and a colocated radar?
I have heard the two terms thrown around in a somewhat interchangeable manner it seems. Are there any major differences? I haven't gathered that they have a different meaning, but I don't understand ...
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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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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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Pulse Doppler radar system simulation using MATLAB
How to code this project in MATLAB
I'd tried coding this project (prob. 3-2, third paragraph) in MATLAB through this tutorial :
https://www.mathworks.com/help/phased/ug/doppler-shift-and-pulse-doppler-...
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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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Radar correlators and matched filters
I'm trying to understand the real-world construction of 1950's radar correlators. The articles on the topic I have seen so far are jargon-filled explanations with no real-world examples. Does anyone ...
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Comparison between FMCW radar modulation techniques
In designing a Frequency modulated continuous wave (FMCW) radar system for target detection, there is a possibility of choosing the modulation technique amongst triangle or saw-tooth modulation. What ...
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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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