This is my first post so I wasn't to sure where to put this, this looked like the best place.
Anyway, I have a project I want to do where I use an Arduino to detect insects, specifically whiteflies.
My problem is I'm not sure what type of sensor would be best suited for this application, since whiteflies are extremely small, I wanted to make use of a sonar setup to detect them when they swarm, but I am unsure if the resolution on a sonar module would be enough to detect them. This will happen in a closed greenhouse area so I'm not concerned about picking up unknowns and things.
Edit: I would like to be able to detect them at a range of about 500mm and they measure around 1-2mm each, at the bear minimum I would like to know that there are a couple flying around.
Sonar modules in this case would be like blasting a cannon to shoot a mouse. The return signal reflected would be insufficient to be detected especially at 500mm.
Yes that is what I was thinking as well, that is why I am asking around to see if people have other ideas, I could reduce the range to say 100mm but I feel that it will still not be able to pick up the insects. I'm not after individual insects I just want to know more or less if they are in the area, I was thinking of perhaps some sort of PIR, but being insects and so small as well that is also out of the question.
A diode laser beam and photodetector of some sort might work, but certainly only if the flies were to cross the beam. The most sensitive detection would probably be using scattered laser light, with the detector(s) at right angles to the beam. A filter (red for red beams) in front of the detector would help by reducing background light intensity.
The flies will most probably make some noises when flying (most probably ultra sonic). Depending on the number of the flies you might be able to detect them and their position using some microphones.
I know that there was a project to detect mosquitos using microphones and stop them from reaching a villages using laser beams (to prevent malaria infections). They shot at the mosquitos using the microphones for aiming. Therefore the technique should work.