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Thread: help me to take a thermal image

  1. #1

    Default help me to take a thermal image

    hai everyone,
    i am woking on a project, that takes thermal images of a location and shows the heat distribution of that particular location. i have tried searching for IR cameras in chennai, but could not find one.
    i need help in finding out a IR camera or how to convert a RF cam to take thermal image.......... or any other idea to take the thermal image.
    please anyone who has worked or has the knowledge please let me know about it ............
    looking forward for help

  2. #2
    Super Moderator T-1000 docel's Avatar
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    ALL webcams are Thermal cameras.......
    Just that he gain is less, due to subdued IR response.
    There is a IR filter inside the Lens housing. Just remove the blue colored filter and you have an IR response far exceeding the Visual.
    Then, replace this with a Visible light filter.

    Besides you must find a CCD cam ( translate= expensive). Or use a USB/AV output digcameras. All of them are CCD.
    Normal cheap cams are CMOS types and are unsuitable to modify easily. They are inherently lo gain compared to CCD, but still usable, if you can change the exposure.

    A lot of Webcams are thrown away, even the CCD types, due to lost or incompatible drivers......What a pity!
    docel
    ^Anything is possible..
    after YOU prove it!!

    http://bangalorerobotics.tripod.com

  3. #3

    Default

    i thank for ur reply sir. but i think as i get deep into the matter, i happento come across various doubts.
    though overhauling the ccd cam may be tedious, i am curious enough to spare one..........
    sir, in ur post u mentioned the below
    "There is a IR filter inside the Lens housing. Just remove the blue colored filter and you have an IR response far exceeding the Visual.
    Then, replace this with a Visible light filter. "
    i cannot visualise the thing . i would be thankfull if u canguide me thruogh by giving some step by step procedure or some sort of tutorial.
    hoping to get some help ..........
    guys and gals anyone else help me on this.......
    thank you

  4. #4
    Senior Member T-1000 debu's Avatar
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    Default

    I think, now would be a good time to establish the difference between a thermal image and an infrared image.

    An Infrared image is an image which show the IR radition reflected off an object. This can be achieve, (as docel explained), by :

    -Adding a filter lens at the end of your existing camera, this lens filters out all visible light and UV light, which just leaves the IR reflected light, to be captured. This method does not work with all cameras as some of them have an inherent IR filter. This method is illegal in most countries, (except in labs), due to the fact that you can see things which other people cover, so as to not be seen. :wink: See here (clickie)

    -By focusing an IR light source on the object, after removing the IR filter from the lens of the camers. This method is very common, and is found on every camcorder in the market.

    Now, a thermal image (also called a heat signature), shows you the IR energy or heatenergy being transmitted by an object. (Not reflected, transmitted!)

    These in design are very different from the above, these dont have a CCD or a CMOS array to detect the image, these have an array of IR sensors, (each similar to those that we use in line detecting, exept one thousandths the size). These require very special lenses to focus the IR image, they also require severe cryogenic cooling. They are used in missiles and military equipment. These cost several hundered thousand dollars each (an exaggerated figure).

    There are DIY methods of making both of the above, but the questioin is; Which one do you want?

  5. #5

    Default

    debu thanks forur valuable time and comments. what i need is the second type, to take the thermal image(heat signature) of the body. i found some DIY for the first type........ but coudnt find for device to take the heatignature. would u please add me some of the links or give me the site that contains some sort of tutorial.

  6. #6

  7. #7

    Default

    hai debu,
    thanks a lot for ur links and sure i wil make it worth for the time u spared.
    but i think i should post the entire details of my project, so that all kind hearts would spend their valuable time in giving comments.
    the project is to detect the landmine effectively with lesser time when compared to the contempory methods. the property of metal is to get hotter than the soil during day and colder than soil during night. this is the bait used to locate the mine. i have planned to use an UAV(some sort of aerial vehicle that can be controlled with joystick) fitted with a camera to take THERMAL IMAGE. with the thermal image and after post processing using transforms in image processing the exact location can be calculated(some intermediate position can be tagged to the position). this intermediate points are correlated to the orginal lat and long of the location.
    these lat and long are given to an UGV for ponit to point navigation. the UGV if fitted with the deminning mechanism that drills the plug into the mine and burns the explosive gradually. this can be followed by mannual deminning or lest as such because it does not threatens the human life.
    this is the detail of my project. anyone who is intrested in giving some valuable ideas and suggestions are whole heartedly welcomed. the main area in which i need help is that taking the THERMAL IMAGE FOR FINDING THE LANDMINES.

  8. #8
    Super Moderator T-1000 docel's Avatar
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    Hari!!
    These guys have become smart.!!
    LandMines are not metallic since quite a long time.

    A metallic landmine is quite easy to detect and hence not profitable. They can be easily detected and mapped from half a kilometer.

    The present day LandMine is VERY difficult to detect and are made from funny composites. They are designed leave very little or no thermal signatures.

    The technology is quite advanced, hence the great problem!!

    Added:
    1. IR images are not instantaneous like the visible photography.
    2. ...and an UAV?? That may be too far fetched.

    All the links by debu are good. I hope you read them throughly before you continue with your project.

    3. It would have saved a lot of breath , if you had stated your purpose at the beginning of the thread.
    docel
    ^Anything is possible..
    after YOU prove it!!

    http://bangalorerobotics.tripod.com

  9. #9

    Default Thats a great project hari

    But it's not feasible in the way u see it. Try building something like ground penetrating radar.hang it below a helium drigible ballon.put a wifi link upto the drigible or u can can control it by wire.
    Try something with spectroscope coupled with airsampling machinery.
    Spectroscope can analize the vapours in the air(as they are made of composite they loose certain amount through air as they get heated.)
    thats how dogs find'em.
    or I have an extreme idea. Use infrasonics to trigger the mines.

    Now dont ask whats infrasonics... try googling it. :arrow:


    BTW :you could always poke them with a stick. :idea:

    :twisted:

  10. #10
    Super Moderator T-1000 docel's Avatar
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    Default Re: help me to take a thermal image

    techraptor:

    Your reply does not address the OPs problem.

    Quote Originally Posted by hari3838
    hai everyone,

    i need help in finding out a IR camera or how to convert a RF cam to take thermal image.......... or any other idea to take the thermal image.
    please anyone who has worked or has the knowledge please let me know about it ............
    looking forward for help
    Suggesting such unreachable solutions will only put him off his idea and enthusiasm. I doubt if he has the resources of a half-a-million dollar research Lab as you do.

    Please do'nt discourage him outright! :roll:

    Now, if you could provide Hari the necessary resources for HIS idea, it will be very much appreciated. I know someone was doing this at TEPP, or was it NRDC?
    docel
    ^Anything is possible..
    after YOU prove it!!

    http://bangalorerobotics.tripod.com

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