What is Multispectral Imaging?

If you’ve been looking into implementing precision agriculture practices in the fields this year you’ve probably come across this term more than once.

So, basically, when we do a multispectral scan with a drone we fly over some plants and take a bunch of pictures with a bunch of little cameras, each which is tuned to pick up specific wavelengths of light. Then we take that data and apply some fancy math magic to it and the result is a map that can show us how healthy the aforementioned bunch-of-plants are, and fertilize them accordingly.

Yup, thats pretty much it. Thanks for coming to my Ted-Talk.

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Buuuuut if you wanna know more of what’s going on in slightly more technical terms, keep reading.

We take the pictures with separate cameras because that allows us to add and subtract their values in post. For example, one of the cameras gathers data in the Near Infrared (NIR) spectrum and another gathers data in the Red (R), if we apply the formula (NIR - R) / (NIR + R) we will get the Normalized Difference Vegetation Index (NDVI) which we can use to assess how green the plants are, thus we can see how healthy they are.

“… but can’t we just look at the plant and see if it’s green?…”

Yes! But actually, no!

I mean, yes, you can see how green a plant is by looking at it, but not at this level.

Unless you can see in infrared. And could see 500 acres of land in 4K resolution all at once. In which case, you probably wouldn’t be using that super power to assess crop health.

Hmm.

Anyway, a healthy plant is going to be producing lots of chlorophyll so it can soak up that yummy sunlight, and with these specialized algorithms we can assess the amount of chlorophyll in the plant’s leaves. Yes, you read that right. My little drone, flying 150 feet over your field, scanning hundreds of acres in minutes, can assess the health of every plant by snapping a few photos, tell me which plants are doing alright and which ones need a boost, prescribe a variable rate application map for fertilizer spraying (this is the part that saves you thousands of dollars, btw), all by seeing the CHLOROPHYLL CONTENT IN THE LEAVES.

How. Freakin’. Neat.

If you wanna learn more about the whole process or get in touch with me about this service, check out this page.