What is Detection: Definition and 338 Discussions

In general, detection is the action of accessing information without specific cooperation from with the sender.
In the history of radio communications, the term "detector" was first used for a device that detected the simple presence or absence of a radio signal, since all communications were in Morse code. The term is still in use today to describe a component that extracts a particular signal from all of the electromagnetic waves present. Detection is usually based on the frequency of the carrier signal, as in the familiar frequencies of radio broadcasting, but it may also involve filtering a faint signal from noise, as in radio astronomy, or reconstructing a hidden signal, as in steganography.
In optoelectronics, "detection" means converting a received optical input to an electrical output. For example, the light signal received through an optical fiber is converted to an electrical signal in a detector such as a photodiode.
In steganography, attempts to detect hidden signals in suspected carrier material is referred to as steganalysis. Steganalysis has an interesting difference from most other types of detection, in that it can often only determine the probability that a hidden message exists; this is in contrast to the detection of signals which are simply encrypted, as the ciphertext can often be identified with certainty, even if it cannot be decoded.
In the military, detection refers to the special discipline of reconnaissance with the aim to recognize the presence of an object in a location or ambiance.
Finally, the art of detection, also known as following clues, is the work of a detective in attempting to reconstruct a sequence of events by identifying the relevant information in a situation.

View More On Wikipedia.org
  1. JasonGodbout

    I Detecting Gravitational Waves & Alcubierre Drive

    I saw a conference from a Ligo physicist she said they are detecting gravitation wave of collapsing star. I also read the Doppler effect is working on gravity due to limited speed (c). I want to know if it is possible to detect a big mass traveling close to the speed of light in ours frame of...
  2. M

    Calculate the Max Detection Radar Range

    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 =...
  3. nmsurobert

    I Detecting Protostars: Light Processing Explained

    How are protostars detected? I doubt that someone is just looking at a poster of a nebula looking for stars. I'm guessing the image is ran through some kind of light processing program that looks for... something? Thanks!
  4. C

    Photon Detection: Learn About Interaction, Detection & Angles

    Hello, I have always been curious about physics and decided to try this forum. However I am a bit concerned due to my lack of knowledge on the subject, so I’m hoping my questions won’t be unacceptable for the forum. I have always wondered about photons and how they interact with the world. If I...
  5. J

    B Direct detection of Planck mass WIMPs?

    Are the current dark matter detection experiments sensitive to Planck mass WIMPs? I've just looked at the Wikipedia WIMP article. It shows the excluded parameter space for the CDMS experiment with WIMP-nucleon cross section vs WIMP mass curves but they only go up to a WIMP mass of 1000 GeV.
  6. K

    B Photon detection in the EPR experiment

    In the photon version of the EPR experiment, how is the final polarization state of the photon detected? I have read a number of high level descriptions of the EPR experiment, but I am having trouble with understanding the detection part. Here is my understanding, please correct me where I am...
  7. Telemachus

    Photodiode for light detection

    Hi. I am willing to make an experiment with light. The idea is to have a light source (specifically a led light) and a photodiode to detect the light and make some spectroscopy. The photodiode has to detect the light in the same frequency that is emitted by the led. I'm not an expert in...
  8. K

    I Detecting Gravitons: Challenging the Foundations of General Relativity

    If we were to able to detect gravitons then is it not that the basic assumption over which the general theory of relativity is flawed ?
  9. ORF

    Gamma detection -- Cherenkov radiation in gamma-scintillator interaction

    Hello During a simulation of light in gamma-scintillator interaction, it seems that there are a lot of Cerenkov photons. I don't know their contribution to the final intensity (it will need a long time to compute it). The textbooks usually say that the gamma ray will produce secondary...
  10. S

    Anomaly detection in cybersecurity

    This question is primarily directed to @bapowell, but I encourage others to please add any thoughts or suggestions. Brian, I just saw your bio while reading the CMB primers, and thought you may have some ideas on cybersecurity data analytics. Some background: I've been in cybersecurity since...
  11. wolram

    I No detection of gravitational radiation

    Is none detection evidence of no gravitational radiation?arXiv:1707.06755 [pdf, other] Reanalysis of the BICEP2, Keck and Planck Data: No Evidence for Gravitational Radiation J. Richard Gott III (Princeton University), Wesley N. Colley (University of Alabama in Huntsville) Comments: LaTeX (MNRAS...
  12. Demystifier

    A Detecting Single Phonons: Is It Possible?

    Is it possible to detect a single phonon? If yes, can it be detected at a well-defined position?
  13. ORF

    Zoology -- How a mosquito's CO2 detection system works?

    Hello How mosquito CO2 detection system works? I found that the detection is made by npa neurons, but nothing is said about how the detection occurs (so, CO2 enters the neuron, and what happen next?) https://www.nih.gov/news-events/nih-research-matters/how-mosquitoes-detect-people Thank you...
  14. M

    Lie Detection: Testing Truth or Falsehood?

    Homework Statement A crime has been committed and the police have only captured a suspect, although he obviously claims to be innocent. To give a verdict the judge authorizes the use of the lie detector. The manufacturer of the device warns the authority that the lie detector in 10% of the...
  15. T

    I New Gravitational Wave Detection question

    This latest observation of gravity waves has brought up a question with me.. Since gravity is a mass-caused distortion in space-time aren't these waves wave distortions of the space-time? I know there is no such thing as ether but for this analogy and my simple mind I'll use it to illustrate...
  16. M

    Derivation of motion equations for collision detection

    Dear all, I am working on a car-accident prediction model. I found the following equations here that worked in my model. However, I could not figure out how the equations were derived. Could anyone help me in understanding the derivation of the mintime and mindist equations (Steps 3 and 5...
  17. Andy_K

    B Double Slit Experiment: Detection around slit?

    Dear All, I have a question on the double slit experiment. From the references I've read so far, they are focusing on the results of the detector AFTER the 2 slits. Let's say when photons are fired, how many % actually pass through the slits and get detected at the end? Would some (and how...
  18. ervays

    What's inside a gas detection Station?

    Good Morning guys! I'm trying to understand more about gas sensors. I know a lot about electrochemical and metaloxide sensors. I've faced all the limits that those sensors presents when you are using them outdoors. Now I'm wondering how the gas sensors stations can measure different gases...
  19. N

    Infrared Detection Range Up to 20m - TSOP38238 & TSAL 6100 LED

    Hi, I made the following circuit for 38kHz infrared receiver TSOP38238 to increase the detection range above 10 meters. i was quite happy to see the range is more than 20 meters with TSAL 6100 LED. but i am facing a problem, my circuit works like a relay circuit. i have to wave my hand in...
  20. J

    B How does sideband detection work in a Penning trap?

    http://depts.washington.edu/uwptms/research.html I'm having a hard time understanding how the sideband detection works. They say that they use an rf drive to observe the particle in the trap. But what is an rf drive and how does it observe the particle? Also, when this rf drive is put into the...
  21. N

    Harris Corner Detection Highlighting all edges not corners

    I need to implement Harris corner detection, which should only have positive R values, if i use threshold of R>0, it highlights nothing, if R<0 however, from even -0.00001 to -1000000 it outputs perfect edge detection, but no corners, ANY help appreciated. Input and...
  22. F

    Does a working underground tunnel detection technology exist?

    from what i readed in news articles about smuggling tunnels in the US-mexico border and terrorists tunnels in the israel-gaza border it seems that there is no technology that can detect deep(few dozens of meters) underground tunnels and that there is only technology for detecting underground...
  23. D

    I Trigonometry problem for collision detection and reflection

    A particle moves from point 0 to point 2. Both positions are known. The center of the circle and it's radius is also known. I am trying to work out the position of 1 where the particle strikes the circle. This is for a 2D astronomy simulator to work out where a particle will strike a 2D...
  24. phyzguy

    A Another detection of the 3.5 KeV line

    This link is yet another detection of a 3.5 KeV line in long exposure X-ray astronomy observations. It seems that this line is really there, since it has been seen in multiple objects with multiple instruments. I haven't seen any convincing explanations of this line as being due to atomic...
  25. jdawg

    RapiTest Kit Detection: Nitrates & Ammonia in Clay Soil

    Homework Statement I'm writing a few paragraphs for an assignment on the RapiTest soil test kit. Considering what happens in clay soil, can the Rapitest kit detect nitrate, ammonia, both, or neither? And what is really being tested for when it comes to nitrogen in the kit? I've already done a...
  26. Michael27

    Statistics on social media bot use and detection

    I am currently doing some research on the impact of social media bots. I am looking into the social and cultural aspects of bot use in social media. The technology I have under wraps but I do not have much information on the social aspect and impact of bot use. I also like to find some...
  27. Chronos

    I Dark Energy detection strategy

    This paper; https://arxiv.org/abs/1701.03418, Direct Probe of Dark Energy through Gravitational Lensing Effect, addresses a potential means to measure dark energy over cosmological distances. Perhaps I am a bit slow, but, I found the basic idea sufficiently simple and obvious that I am surprised...
  28. P

    A Detection limits for Raman spectroscopy

    This may be a completely terrible question, but does someone have an idea on the detection capabilities for raman spectroscopy of a bulk sample like human tissue (hair, blood, skin, anything)? I thought it might be fun to see if it were possible to use raman to identify exposures to chemicals...
  29. khelzor

    I Pion Detection: Finding a Film for Interference Experiment

    I'm a student in high school asking for suggestions for an experiment proposal. So far, our idea has been to recreate Young's interference experiment, but instead of using electrons, we will use a heavier particle. Charged pions have been the first choice so far. Aluminum is the current delegate...
  30. M

    Why Does the J/psi Meson Detection Show Large Standard Deviation in CMS Graphs?

    Homework Statement See Image The bit about Spectral lines, I couldn't explain why[/B] Homework Equations ΔEΔt≈h The Attempt at a Solution I expected the histogram to peak at the given mass in question and to have a width of about 0.08 MeV calculated as ΔE from the Energy-time uncertainty...
  31. R

    Pulsing an LED during muon detection

    Homework Statement For my lab physics class I was in a group doing the classic muon detection assignment. We ran the equipment for about two days and during the time we had a pulsing (100 Hz) LED inside the scintillator chamber. This gave some measurements that were extremely low (about 0.6 μs)...
  32. E

    250VDC Line, Transient detection

    Any of you guys know of any instrument to record both the DC and at the same time the AC transient of a DC line. Thanks.
  33. bbbl67

    I Understanding Neutrino Detectors & All-Neutrino Detection

    Now my understanding of neutrino detectors is that there are two common fluids used in the detectors, either Tetrachloroethylene (C2Cl4) aka "dry-cleaning fluid", and heavy water (D20). Why were these substances chosen specifically? Is there something about the elements within these substances...
  34. Newtonfalls

    B Detecting Smartphone Waves Using Toy - VIDEO

    Hi, i came across this video on BBC yesterday: <link to video deleted> Now I wonder how this stuff works in detail? Is it the carrier wave or the multiplexer signal of the phone? best regards
  35. Avatrin

    What Are the Methods for Detecting Gases in a Room?

    Hi I am not sure if this is the correct forum to post this on, but I guess it can be moved if it is not. I just want to know what methods exists to detect gases in a room. Smoke alarms use ionization or electromagnetic light. What other technologies exist on the market? What technologies are...
  36. M

    THz radiation detection with a conductor

    Hello! Is it possible to detect THz radiation (300 GHz - 1 THz) with conductor or dipole antenna used to detect radio waves? I know that THz radiation may be detected in spectroscopic set-ups with a photoconductive antenna based on the semiconductor. In this case, the light from laser create...
  37. V

    B LIGO Detection Question: Why Lighter Masses Mean More Time

    Re: the second LIGO detection, from Symmetry: “Because of their lighter masses compared to the first detection, they spent more time—about one second—in the sensitive band of the detectors.” As an absolute (albeit deeply fascinated) novice here, I'm unclear as to why lighter masses would allow...
  38. kolleamm

    Object detection for other specific objects, possible?

    How would I get started in object detection of specific objects? I know about OpenCV, it can perform face detection, but what about other objects? I've seen talks on the web of training the program, but I'm not exactly sure how I would do that. I would like to give my software, written in C#...
  39. R

    A GWs energy and aLIGO detection

    In a recent campus talk by one of the LIGO memebers authoring the last february announced GW detection paper(and that was very proud because her small team's analytical data had actually made it to the finally published paper) explained to the audience something I didn't fully get. She said that...
  40. JustinHolmik

    I Neutrino Detection: Theories & Improvements

    Disclaimer: I am a novice. I am wondering if anyone knows if there has been any improvement in detecting any of the three types of neutrinos? I would also be interested in hearing any theories as how we can improve detection? I guess, since I did my research I'm more interested in picking...
  41. P

    Light Collection Efficiency for Liquid Scintillation Detecto

    How do I calculate the light yield and light collection efficiency of a liquid scintillation detector? Couls someone give me a formula for that? What data do I need to calculate it? THanks a bunch!
  42. P

    Liquid Scintillation Counter w/ fast neutron detectin isotop

    I'm trying to make a LSC with U-238 (non-aqueous form) dipped in the scintillating cocktail to detect fast neutrons (no thermals or epithermals, only fast) from a Cf-252 source. How do I calculate the wavelength emerging from the cocktail (assuming U-238 does not react with the cocktail)? Also...
  43. P

    I Material detection with radiation sources

    How are radiation sources like neutron or gamma/x-ray emitters used to detect materials? In particular illicit explosives and nuclear material and the such?
  44. secur

    I Dark Matter Detection Experiment Results?

    In 2011 Dr. Gerald Guralnik of Brown University was involved in an ongoing Dark Matter Detection experiment, perhaps LUX? It was an international collaboration involving underground detectors. He was certain DM would be detected in 5 years - i.e., now. I was dubious, so we bet "bragging rights"...
  45. J

    I How Do Orbiting Black Holes Generate Gravitational Waves?

    I am probably missing something, but it seems to me that the only way gravitational waves could be generated would be if the center of gravity of a massive body or system began oscillating somehow. The detection of such waves was recently reported and were supposedly generated by a pair of black...
  46. Anton Alice

    How can crevasses be detected in alpine solo tours?

    Hello there, I want to do a alpine solo tour at the beginning of april. Crevasses, which are covert by snow are very insidious. This is why solo tours are more of a gambling game. The basic idea is: Using a detector which can make a differentiation between a solid subsoil of ice, and a...
  47. G

    GW Detection Confirmation: Time, Rate, & GRB?

    I understand that the LIGO experiment was very lucky to find a very strong signal of a very energetic event (binary black hole merger). Having into account the non-negligible possibility that the signal may be spurious or some problem in the data adquisition, how much time must pass before we...
  48. Dr. Courtney

    A Experimental detection of gravitational waves confirmed

    http://news.mit.edu/2016/ligo-first-detection-gravitational-waves-0211
  49. M

    Human Body and Frequency detection

    Is the Human body capable of creating any type of frequency ? Of course vocally but beyond that ... . What devices are in existence that can measure or see frequencies of living things ? Have there been experiments with documented results that shows frequencies created by the human body ?
  50. A

    Antibodies to test Microfludic device for antigen detection

    Hello. Sorry in advance for my ignorance, but I am looking for a reaction that will yield a colorimetric signal when an antigen and an antibody meet. Similar to a one-step ELISA. My plan was to use HRP-conjugated BSA and anti-BSA. Will this work, and in how many steps? Any kits out there for...
Back
Top