Infrared Training Center

Monday, January 16, 2012

Infrared Wildlife and Black Ice Detector - Looking for Feedback

by Rosaele Tremblay

Hello, I am a high school student writing a paper for my science project and I would like any feedback from the InfraMation readers (scientists or thermographers to see if I am on track with this idea or if anyone has suggestions as to how we can make this work. Thank you for any input.

You can provide comments and suggestions for Rosaele by leaving a comment on this post - Editor

Introduction
The electromagnetic spectrum includes gamma rays, X-rays, ultraviolet, visible, infrared, microwaves, and radio waves and each of them has a different wavelength and frequency. Infrared radiation is between visible light and the microwave portions of the electromagnetic spectrum and it is not visible to the human eye. Some animals do exist which see in infrared such as a few different snakes. Three categories exist in infrared: near, mid and far-infrared. Near-infrared is the closest to visible light and far-infrared is closer to the microwave portions. Infrared radiations are all around us every day coming from sunlight, a fire, radiator, a warm sidewalk and the TV remote. Everything on earth gives off heat when molecules begin to move and the higher the temperature of an object, the more the atoms and molecules will be moving which will produce a greater amount of infrared radiation. Objects with a temperature above absolute 0 radiate in infrared including the objects we perceive to be cold or freezing such as ice cubes or objects which are hot but do not visibly appear to be hot emit heat.

These shots of a coffee mug are in three different palettes to show that we assign the colors to gray steps. Human eyes see ten gray steps so to see the colors in definition we can assign 10 colors to them like in these shots. In these, white is hot and black is cool, but we can also invert these so that white is cool and black is hot, this is up to the thermographer.

image image

The real Infrared, note not the colors but the reflection in the foreground which is the heat that is being emitted from the cup and reflected into the camera lens, some of that heat is being absorbed into the table and some of that heat is being transferred through the table and the camera is seeing the radiation portion off the table. This is due to emissivity and is called T reflection.

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Black Ice
Black ice is like a glaze that forms on surfaces in the winter such as roads, sidewalks and driveways. It forms around freezing point and happens usually because of a light freezing rain, due to the melting and re-freezing of snow, water or ice on certain surfaces or sometimes it is even due to the heat of the tires on the road which quickly then cools and freezes again. Usually it forms at night or early in the morning when the temperature are low and the sun is not yet present. The air and surface temp of the road could be significantly different by at least 20 degrees F but when the road temp goes down to 37 degrees F one should be cautious and watch out because black ice is clear, not visible and undetectable to the naked eye. Almost always forms in very smooth, very glossy sheets but black ice patches are usually not longer than 6 m and patchy so some traction is available for the tires but not much. Roads are usually made out of asphalt and or concrete which emit energy very well. With an infrared camera, it can measures the amount of energy emitted by the road and can also measure its surface temperature. A camera with a refracted lens can detect radiation from different specific points from the road. These cameras can be used to tell workers where to apply salt or sand on highways and municipal roads. Infrared light or thermography is using a camera to see and measure the amount of thermal energy being radiated from an object. The infrared camera can detect heat and quickly convert it into an image or video and precisely measure the amount of heat coming from an object. The warmer the object the more heat it emits. These cameras can be used to prevent damage related to heat in pipes in homes for example but since infrared can detect anything that radiates heat, this technology could be used to detect any wildlife close by when driving. According to WARS (Wildlife Accident Reporting System) there have been approximately 4,700 car accidents including wildlife in North America since 1993. Weather conditions in North America, especially winters are hash and the roads are extremely treacherous with black ice causing many accident. The technology to detect wildlife on roads or nearby when driving has already been tested and used on some cars but adding the element of detecting black ice at the same time adds more protection and reassurance to drivers driving in bad road conditions. Using a flip down screen cover or an alarm, we could warn the driver when a patch of ice was coming up or when wildlife was close by. We would have to use emissivity and T reflection when looking for black ice, because the ice is going to be a smooth surface, therefore it is going to reflect whatever is in the background. We will even have to consider the reflection of the sky and or trees and anything in the surroundings because black ice is highly reflective. The angle of the camera and the speed of the car have to be considered so that we can get the information to the LCD or alarm to warn the driver so that they can have enough time to slow down and so that we don’t miss the ice or do not have the time to react to it. First off by finding the angles of field of view using the formula: 2 x the tangent of ½ the angle x distance and then finding the speed of the car in feet pr second. Finding the speed is only the first step of the formula which will show how this camera will work to detect not only wildlife but black ice as well. By using the formula of absorption, transmission and radiation, we have a good start to the end formula.

19 comments:

  1. Found an article about a company who has done some work on the black-ice part, but without revealing much about how it was done: http://www.photonics.com/Article.aspx?AID=6204
    The text suggests they don't detect actual black ice, but detect the RISK of black ice formming based on surface temperature.
    One method off the top of my head to detect ACTUAL ice would be to aim a sensor stright down below the engine. When driving over ice, the apparant temp would rise as the sensor picks up infrared radiation emitted by the hot engine and reflected by lower-emissivity ice. This method has a serious drawback, in that you are already on the ice before you get a warning.

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    1. Thank you for that link!
      I was thinking if we could somehow place the camera just on the mirrors or somewhere on the front of the car, the infrared could detect upcoming ice and send an image to a screen inside to warn the driver but all this would depend on the angle of the camera and the speed of the car.

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  2. The general theory for use is discernable here, I think some field work has to be done to prove the theory of use first before you get any further into the formulas as to how to utilize the technology properly in a vehicle.
    Something to note is that ALARMS and or NOTIFICATION to the driver may simply cause the driver to panic and slam on the brakes which is the worst possible measure to counteract black ice. The ability to SAFELY USE the information received by the user is what will be paramount in the viability of this safety device.

    PTC
    L1 Thermographer 10yr experience

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    1. Is there any way we can test this before we continue on with this theory? The way the driver will be warned is definitely something to be considered. It depends on how far ahead the camera can detect the ice from and if its a long enough time an alarm can be used to warn the driver that ice is coming up and to slow down but if its too quick a notice the driver may lose control of the car and the warning wont have helped. Just having a screen where the driver has to check may work too without an alarm.

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  3. I think that the emissivity of ice the will be important, therfore an emissivity test for a baseline would be a good idea. This should be coupled with the changing atmospheric conditions, the speed of the car/truck with the angle of the camera, along with the delta T, should get you close to your quontitative IR portion. Keep in mind that the emissivity of ice will give reflection and the background through your angles will move.Quolitative IR this may be a good thing for a comparitive. Once this is proven you may wamt to take the isotherms and set them to your paramitors that way you may be able to conect the isotherms to your alarm.Im no scientist so please correct me if I am wrong or add too.

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    1. How can you do an emissivity test? Thank you for this, especially the part about quantitative and qualitative infrared. Since the IR camera can only see the radiation what else needs to be added so that everything gets calculated?

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    2. See this page

      http://irinformir.blogspot.com/search?q=emissivity

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  4. Please see the images of black ice I took this morning at:
    http://irinformir.blogspot.com/2012/01/black-ice-thermal-images.html

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    1. Thank you for those pictures. Its nice to actually see how well the infrared camera can detect the ice. Now we just have to add the element of movement and speed and see if it would still work just as well to detect the ice compared to when the camera was not in motion.

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  5. In my opinion this would be fairly difficult to adapt this to the situation you are trying to apply it to. Emissivity is going to change rapidly as you approach the ice sheet. Would it not simplify things to look for variances along the edge of the sheet at distance, and then show it's shape and distance on a heads up display. Even this approach would require more systems than just infrared due to the fact your camera is going to see reflections at distance on a flat road.

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  6. Having the shape of the ice and its distance from the car would already be a great step because that would already be a great warning to the driver to watch out. The infrared could look for surface temperature changes but wouldnt it need to be closer to the ice or can it to that from a distance away?

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  7. Wildlife detector - this is a little off topic - but I'm looking for an IR viewer that I can attach to a motorbike for night riding so I can have it help me detect wildlife on the road and verges up ahead. Does anyone know if such a device already exists? Ideally it would have an alarm when it detects an animal ahead? Many thanks, Lucas

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    1. Try the FLIR Pathfinder systems. I have seen it applied to motorcycles.

      http://www.flir.com/cvs/americas/en/transportation/

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  8. that looks like what I'm after - many thanks.

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  9. Hi! I am trying to detect to detect ice accerated on different metal structures like poles to make a automatic de-icing system. By using Infrared camera i can get the temperature of any structure but how I can distinguish between metal, water contents and ice?
    I was thinking I can distinguish ice from other materials by knowing emissivity and temperature distribution of whole structure. But I am not able to find the emissivity distribution from IR image.
    Can any one help me? I'll be grateful to you

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    1. Presumably, the temperature of the metal, water condensation, and ice will all be at the same temperature? If that is true, the only way I can think of distinguishing between them is by the amount of IR energy they emit vs reflect from the surroundings.

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    2. Yes The temperature will be same. But how I can measure the IR energy they emit vs reflect from the surroundings?

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    3. I'm using IRControl software with FLIR A615 camera for this purpose. The software can calculate Emissivity Map of an IR image (which is not delivering proper information) but it doesn't give the emissivity at a certain pixel or location. Can you please suggest me how I can do that by using any other tool?

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    4. The differing emissivities of the ice vs no ice will be visible in the image. See http://irinformir.blogspot.com/2012/01/black-ice-thermal-images.html

      This link will introduce you to emissivity measurement techniques; http://irinformir.blogspot.com/2012/02/thermographic-measurement-techniques.html

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