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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1answer
27 views

Signal processing in FMCW and SFCW

With regard to signal processing, how is frequency modulated continuous wave (FMCW) radar similar/different from stepped frequency continuous wave (SFCW) radar? Do we actually modulate the RF carrier ...
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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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CST simulation results about monostatic RCS calculations

I'm trying to understand how CST Microwave Studio works when one asks him to calculate the mono static RCS of an object. In particular, what does the results 'theta phase' and 'phi phase' means in a ...
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2answers
446 views

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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Pulsed Power Charging Resistor and Choke

I am currently attempting to build a pulsed power supply that requires an 8 H inductor to produce 50 kV 17 A square pulses with widths of 100 uS. Please see the attached schematic for more details (...
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2answers
89 views

radar attenuation calculations

I would like to ask a few questions that are probably not difficult for engineers to figure out. Personally, I am not an engineer but want to learn about radars. I am having trouble understanding the ...
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1answer
31 views

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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58 views

What is meant by “doppler extent”?

A google search of "doppler extent", Where I found the term: Extracting Target Features from Angle-Angle and Range-Doppler Images 1993 - ‎Cited by 5 - ‎Related articles Doppler extents (as for ...
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1answer
64 views

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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Measured doppler shift error biggest on direct flight on target

Following scenario: There is a radar on a plane which emits a CW Signal and outputs the measured doppler shifts from the reflection of a static target. I can see from the data, that the error of the ...
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RCWL-0516 Microwave Radar Sensor

I have recently been interacting with these cheap radar modules from China and works fine specifically the RCWL-0516 Microwave Radar Sensor. Now I wanted to integrate the entire circuit into a custom ...
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3answers
200 views

Is it common practice to connect power supply to a DB9?

I got a project where many sensors which uses CAN were connected to a DB9. And sensor power (24V and GND) too. I want to connect the DB9 terminal to power however how can I do it in a safe way? If I ...
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2answers
435 views

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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1answer
49 views

Intuition behind ambiguity of direction using linear array

I have recently started studying array signal processing. I am struggling to understand the intuition behind ambiguity of direction using a single linear array and how it is solved using two parallel ...
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54 views

Cycle time / transmission cycle in short range automotive radar

I am somewhat newbie in the radar field. I am reading SRR20X-datasheet from Continental. I have two question. What are definitions of Cycle time/transmission cycle (second page)? And in the document,...
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1answer
92 views

How close to P1dB can I go?

I'm trying to decide on a safe input power to a power amplifier. The amplifier in question is SE5004L. The datasheet specifies that the amplifier output 1-dB compression point has a minimum value of ...
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1answer
103 views

Doppler frequency formula (for HB100)

I have a question about the formula provided on the application notes of the HB100 sensor. It is: $$f_d = 2v \frac{f_t}c\cos(\vartheta)$$ where \$f_d\$ is the doppler frequency, \$v\$ the velocity of ...
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1answer
86 views

How to convert raw radar sensor data into custom compressed data format for efficiently storing and archiving on file system

The binary raw data from the SAR sensor is processed in fpga and outputted as hex. Now, this data we currently store as ASCII in .txt files. However, it takes lots of space in storing. Is there an ...
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1answer
71 views

How the azimuth of the time base is synchronized with the azimuth of the rotating antenna?

How the early radars could know the angle of a basic radar rotating antenna? How the direction of the time base on radar screen is synchronized with the direction of the radar rotating antenna?
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1answer
118 views

Horn antenna for radar sensor

I have InnoSenT SMR-314 and SMR-334 radar sensors that have quite wide horizontal radiation pattern of over 100 degrees (see datasheet on page 3). I would like to make the sensors far more directional ...
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1answer
131 views

UHF transmitter Range for 50 W

Very curious to know the range of 50 W transmitter of UHF range in nautical miles? The antenna used is 1/4 wave antenna of Jaybeam company. Can someone tell the exact formulation to find out the ...
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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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102 views

Radar system for micro meter accuracy

I need a radar system to sense a movable object within [0..150 meter] range. The desired accuracy is around 100 micron. However, at far distance 1 mm could be fine. As far as I read, 3D Lidar systems ...
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4answers
371 views

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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7answers
10k views

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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1answer
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Dramatic improvement in radar energy use? [closed]

I was reading over a history of RAF Saxa Vord - everyone needs a hobby. This station started in the 1950s with an S-band Type 80 which had either 1 or 2 MW focussed into a 0.3 degree beam. That was ...
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2answers
60 views

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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471 views

Interpretation of FFT FMCW Doppler radar results

After a lot of research and help from the users here, I managed to do some FFT and signal processing in my first time in my life :) I have got the following figure, which shows one peak frequency, ...
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129 views

Getting the velocity in Radar FMCW

I have managed to get the frequency (the beat) frequency from an FMCW. Here is a screen shot of a wall that's detected by the Radar. I performed an FFT of complex I,Q data. My questions are 1. How ...
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2answers
116 views

Waveform from an FMCW Radar

I have the following waveform from a Radar thats IVQ-3005 https://www.innosent.de/fileadmin/media/dokumente/datasheets/180222_Datenblatt_IVQ-3005.pdf That Radar is using the PLL ADF4158 http://www....
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1answer
674 views

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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1answer
127 views

Signal processing of an IVQ-3005 Radar Module

I'm going to use that module for detecting range, velocity and angle, for that radar. https://www.innosent.de/fileadmin/media/dokumente/datasheets/180222_Datenblatt_IVQ-3005.pdf So I have read a lot ...
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64 views

How to find stepped frequency continuous wave gpr range?

As far as I know, the range of a sfcw (stepped frequency continuous wave) GPR is affected by bandwidth and number of frequency steps. However, when playing with Matlab's Radar Waveform Analyzer, I ...
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5answers
316 views

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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1answer
73 views

In heterodyn receiver circuits, why is the LO not chosen to match the target frequency?

I'm trying to design a device that detects motion using sonar. I'm basing it on a common superheterodyne receiver like this: Now from what I've read, in radio audio receivers the local oscillator is ...
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3answers
124 views

Radar Receiver How to detect 1 nsec pulse

I need to design a very short range pulsed radar for classroom/lab use. For this purpose the pulse width needs to be very short 1-5 ns to avoid the radar blind range. My preference is to digitize the ...
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1answer
110 views

Purpose of L2,L3 & C6 in the following CW transmitter circuit

I have been trying really hard to understand the purpose of L2, L3 and C6 in this CW transmitter, especially L3 and C6. I have received many conflicting answers such as that L3 is acting as a ...
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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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1answer
332 views

Analog Signal HC SR04 [closed]

I am very interested in this project: Sonar HC-SR04 analog output. Multipoint Sonar Radar I have not much experience in electronics and don't know where I have to connect my wire on the Ultrasonic ...
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6answers
5k views

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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1answer
78 views

Vehicle tracking and direction processing

Im trying to find a good way for tracking vehicles. Its like counting all the vehicles (cars, motor cycle or any vehicles)through a point on the road. Also it needs to count like how many in total and ...
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1answer
128 views

Automotive Pulse Doppler Maximum unambiguous range?

I am trying to calculate the maximum unambiguous range for FMCW automotive radar. In automotive, the pulse repetition rate (Tp) is typically 50 - 60ms. My equation is as follows: where c is the ...
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3answers
294 views

What is the shortest range radar system?

I've been reading up a bunch on radar and most applications exploit the long range capabilities (rightfully so), but I'm wondering what is the smallest range a radar system can operate at? I'm ...
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1answer
161 views

What are the practical differences between pulse and stepped frequency radars?

Books on the subject of ground penetrating radars provide definitions of pulse and stepped frequency radars, mentioning the structure of their signal and other technical details. However, I was not ...
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2answers
114 views

How is phase recovered from wireless signals?

I've wondered for a long time how phase information is captured for wireless signals. It's used in applications like QAM for decoding symbols and radar beam forming to to locate targets, but I've ...
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106 views

Microwave Waveguide Power Ratio

Had a waveguide system set up similar to picture, to compare measured to calculated power ratio or path loss (differences between positions). With an SWR meter the following was recorded at various ...
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2answers
159 views

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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3answers
2k views

Average power dissipation in radar

Hello there here i want to calculate average power dissipation of radar My question is here i tried to solve it this way Average power = peak power*Duty cycle here transmitted power is 300kW and ...
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2answers
6k views

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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2answers
326 views

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 ...