Radar Definition and 151 Threads

Hi, I was reading the Bondi k-calculus as introduced in R. d'Inverno book and Bondi k-calculus. As far as I understand, in the context of SR, the radar time coordinate from an inertial observer/clock is basically the same as the coordinate time ##t## assigned to any event from an inertial frame...

My research is on radar images and the images are collected in several conical surfaces. These conical surfaces have the same origin, the same maximum length (max flare or max range), but different elevations angles. The images are collected on the surface of the cones only. I want to determine...

Why can't satellites be equipped with radar systems so that they can detect (and then avoid) impending collisions?

This question comes from my experience in radar signal processing. As I am going more deep into the theory of sampling, statistical signal processing and estimation theory in general, I have a very silly but important mathematical question that I want to ask here. For example, we are estimating...

Greetings, Please imagine a huge pile of rubble, meters deep. Somewhere inside, there's a device emitting a certain signal. This signal can be picked up by a radar-like device which locates the origin of that signal, with the least interference from the pile of rubble, concrete blocks, metals...

Hello : As the news coming from Syria and Turkey about earthquake devastation, is it possible to use ground penetrative radar or sound identification and wave frequency spectrum analysis to locate survivours ? The human sound are in the range of 20 kHz shouldnt we be able to use microphones...

With this current war I'm thinking more about military electronics. I noticed that a lot of drones are used lately in various military exercises/conflicts as well as missiles. Most missiles except those that are "dumb" use some sort of radio communication. So there is the use of jammers or...

I was wondering if radar is safe, can it detect near objects (lets say 50 feet away) and does it accurately see 3D shapes? I am looking for a technology that could maybe supplement augmented reality in the sense that VR objects can be given GPS locations, but don't know if there is something in...

Please Notice That the Toroid Coil is Outside the Discharge Tube and yet able to influence electrons moving inside the Tube.

I want to simulate the time domain data for a rotating radar. I assume that the space around the radar is filled up with a very big extended object and it moves with a constant speed in one direction. Picture attached.I don't take range information here. I am only concerned about the velocity as...

I am interested in the physics of ground penetrating radar. 1) Does anyone know where I can find a derivation of the formula in the attached jpg for the energy reflected? K=the dialectic constant. 2) An intuitive explanation of why the dialectic constant is important in determining the energy...

Hello everyone! This is from The Fundamentals of Astrodynamics Chapter 2 Questions. I'm doing this as a self-study (and never took Linear Algebra) so my "technique" might be a little sloppy 😖😖 Finding specific angular momentum Finding the orbital parameter Finding Eccentricity Vector...

The polarization referes to the direction of the electric field of a light wave which is to be one direction. The unpolarized light interacts with a material in various ways such as reflection, scattering, refraction. and each of which can transform an unpolarized light into a vertically or...

A question I’ve been trying to figure out for the last 5 years with a friend of mine: Would the radar reflection from an object be different if the object is charged or not charged?

u is the aircraft speed. c is light speed f is the initial frequency λ is the initial wavelength λ' is the apparent wavelength λƒ = u +λ'ƒ λƒ = u + (c/ƒ')*ƒ c = u + (c/ƒ')*ƒ u = c(1-(ƒ/ƒ')) u = 1500m/s The answer is half of it, where is my error?

I've seen these devices on shores as well as on ships , like a horizontal tube rotating slowly around it;'s axis. Now from what I know it's a type of radar, and unlike phased array it rotates it's beam physically by means of using a motor to rotate the antenna itself , what I want to know is...

I was watching "Northwest Law" last night (a TV show that follows Fish & Game Rangers in the Northwest), and when I saw an officer checking the calibration of their radar gun before using it on an ATV trail, I was very confused by it. He held it so that the tuning fork vibrated orthogonally to...

https://www.popularmechanics.com/military/a28818232/quantum-radar/ https://www.asiatimes.com/2019/09/article/stealth-killer-quantum-radar-actually-works/?_=3274804 I don't know, whether the above sources are reliable, or not, that is why i ask. "Quantum radars involve pairing photon particles...

I tried to workout the problem but I find motion in different coordinates systems a bit weird at the moment, so only thing I could do is realize that the x component of ##\vec r(t)## is: $$vt +x_0$$ but for simplicity we will use the initial condition ##x_0=0## so that ##t_0## is the moment the...

I'm trying to understand how CST measures the RCS of an object. If not specified by me, it gives me (with a very brief simulation even for complex objects) graphs, both 3D and 2D, entitled 'Bistatic RCS'. With this wording I think that there is an antenna in a different direction than the one...

I was reading this, and got concerned: https://slate.com/technology/2019/05/spectrum-auction-bandwidth-weather-forecasting-fcc-noaa.html

Homework Statement [Answer is V = 25m/s, however, how do I get that answer? Thank you!] A police cruiser sets up a novel radar speed trap, consisting of two transmitting antennas at the edge of a main north-south road. One antenna is 2.0 m [W] of the other. The antennas, essentially point...

I have been reading up on clear-air pulsed radars and am wondering if it is possible to scale down a large radar system to one with reduced power and gain, but also greatly reduced range. Here are the specs for a large radar: Output power = 2.5 mega Watts Antenna gain = 47db. Range = 15km. If...

Hello All, The goal is to formulate a multiple hypothesis test for a radar tracking problem when false alarms are occurring and to apply a particle filter on this update step, however I first need to come to/understand the multiple hypothesis formulation in this problem. Say we are interested...

Previously I made this post, and soon after realized how woefully unprepared I am to approach such a topic. As stated in the post, I think my best use of time would be to gain background knowledge on the topic before attempting a project, but now I think I've found a better focus as to what...

I've done a good bit of online research and have concluded that both in the past and AFAIK currently there is a significant risk of cancer if I work for companies that make military or civilian radar systems. I'm looking at high powered systems for missle detection, defense radar of all types...

I am working on HFSS and designing Antennas for LOW RCS , in all previous works they calculate the S11 parameter for the unit cell then make an array form this unit cell and calculate the RCS , my question is what is the relation between S11 and RCS and why we calculate S11 for the unit...

Homework Statement I am asked to find the Max detection range of the following radar system: Transmitter Power, Pt = 10Kw RCS = 1 m sq. Frequency = 3Ghz Losses, Ls = 5dB radar dish radius, r = .5m Noise level, N = -140dbW SNR= 13 dB Homework Equations Radar Max range =...

So I printed this antenna with some conductive filament , however the microwaves seems to be going between the layers of the plastic. I surrounded it with Aluminum and still leaking, what can I do to fix it? Can conductive silver paint work?

I'm currently working on a novel RF and MW sensor and I wanted to know whether there is a paper that shows the current very best receiver sensitivity for a range of wavelengths in the RF-MW range in dBm preferably so I can directly compare to my device.

This is the AN/APG-81 AESA Radar antenna by Northrop Grumman currently found in the F-35 (photo from wikipedia article). It seems to have a very different structure than past AESA/PESA antennas. For example the APG-68 from the F-16 looks a lot like stacked, slotted wave guides to me. So...

The company Patriot One Technologies is marketing a system called PatScan using AI and microwave technology to detected concealed weapons (gun, knives, explosives) without imaging (Cognitive Microwave Radar). https://patriot1tech.com/solutions/how-it-works/ Apparently it detects reflected...

Hi all, Is there any way to impart a transformation upon a radio wave's reflection from an object, such that the reflected wave is different from the original signal in some way (frequency, phase, etc.)? Not sure what this would require (maybe a constant and active coordinated interference...

I am looking for what the high end radar receivers can achieve in terms of sensitivity? I have had trouble finding examples online, I have seen -100 to -103dBm as typical sensitivities, but I'm looking for the cutting edge stuff. I've also seen the GPS satellites also have a sensitivity of...

I am making a video game using Game Maker Studio 2.0 and am making a radar. To give you some background, one object is obj_Player, and the other is obj_Sub. The radar gives the sub's position and distance from the player (center of radar). The first part of my radar works perfect. I normalized...

Fair warning: I can handle basic physics stuff, but probably nothing post-collegiate. :) Specifically, I'm looking for a primer on phased array radar that will tell me two things: 1) what are the practical physical (antenna) requirements for running a PAR system in the 800MHz/5GHz bands, and 2)...

Ever since the first Pioneer spacecraft sent back closeup photos of Jupiter's Great Red Spot ("GRS") back in 1978(?), I noticed the GRS looks like a wave-cloud. There is a thick lip of wave-cloud on one side of the GRS, caused by air sweeping over an enormous volcano, it then bends around on...

Consider at stationnary radar at the origin ##z=0## and a target (speed ##v##) moving along the ##z## axis and away from the radar. The radar is sending plane waves (frequency ##f_i##) to the target and they come back to the radar (the radar is then both an emitter and a receiver). I am...

More specifically, does anybody know the sampling frequency of a mounted 360 degree cop radar? NOT a conical/directional hand-held radar gun.

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 phased array, L would be the maximum distance between antennas (correct me if I'm wrong :) ). But...

Homework Statement I have been working through “Basic Concepts in Relativity and Early Quantum Theory” by Resnick and Halliday. I've read about and done most of the problems about time-dilation, length-contraction, and Doppler effect. But then I got to problem 2-76, and I’ve been swirling in...

Homework Statement Radar (radio wave) is placed 35m above sea level. Calculate working range of radar. Homework Equations So I have found various different formulas for range but they all are very complicated with respect to my example. I only have 1 known variable - height. The Attempt at...

I have difficulty finding the mosquitoes in my room so my electric swapper can't hit them.. is there any device that can find their exact location maybe some kind of mini radar.. what sensitivity before such radar can locate mosquitoes? Mosquitoes disturb my sleep at night.

Normally when I cite something, it's to an article I consider credible, but this one is not: http://www.popularmechanics.com/military/research/a22996/china-quantum-stealth-radar/ The specific assertion in question is this paragraph: The article also asserts that Lockheed has patented this...

I think the relativity provides the Doppler shift (in a radar - double version) in a form: ##\frac{1-v}{1+v}## which is quite simple, as a square of a single Doppler: ##f' = f\sqrt{\frac{1-v}{1+v}}## But I never seen what is a classical version of this - what is a formula for a radar shift in...

I'm doing a high school paper on the effects of frequency alterations on a radar image. Can someone recommend a book which I can use?

Homework Statement A radar device detects a rocket approaching directly from east due west. At one instant, the rocket was observed 10 km away and making an angle of 30 degrees above the horizon. At another instant the rocket was observed at an angle of 150 degrees in the vertical east-west...

A police radar gun emits radio waves at 10.5 GHz, and measures the beats between this frequency and the returned waves to determine the speed of an object. It registers a tuning fork as "traveling" at 24.6 m/s. What is the frequency of the tuning fork. I can get the answer, but I don't...

Hello everyone. This is my first post.. I have been given the task of building some large RF reflectors that will reflect 35GHz RF energy. Can anyone give me an idea of what material / thickness of material I could use. For an example.. Would a pyramid made from wooden pallets covered in...

Why is the brightest part of the asteroid radar image below the upper edges? From, http://astronomynow.com/2015/08/03/peanut-shaped-near-earth-asteroid-1999jd6-imaged-by-radar/ Is it a software effect? I would naively think that the greatest radar intensity would be reflected from the parts...