Public Lab Wiki documentation


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"The Infra-whatnow?"

The Infragram is a simple, affordable infrared camera platform -- developed collaboratively, by the Public Lab community -- for measuring plant health and geeking out on gardening. It's for farmers, gardeners, DIY scientists, hikers, makers, farmers, teachers, kids, artists, and you!


It was originally developed to assess damage to wetlands in the wake of the BP oil spill; but it's also a simple, easy-to-modify, open-source hardware and software tool that anyone who's curious about plant physiology and health can use.

What is it good for?

  • Take pictures to examine plant health in backyard gardens, farms, parks, and nearby wetlands
  • Monitor your household plants
  • Teach students about plant growth and photosynthesis
  • Create exciting science fair projects
  • Generate verifiable, open environmental data
  • Check progress of environmental restoration projects
  • Document unhealthy areas of your local ecology
  • See the world through the infrared-sensitive eyes of birds or bugs


Vineyards, large farms, and NASA all use near-infrared photography for assessment, usually by mounting expensive sensors on airplanes and satellites. Infragram brings this technology to average citizens, enabling them to monitor their environment through quantifiable, citizen-generated data.


Just as photography was instrumental to the rise of credible print journalism, DIY data collection technologies like Infragram democratize and improve reporting about environmental impacts.

Remote infrared imaging

The study of Earth's environment from space got its start in 1972 when the first Landsat satellite was launched. The multispectral scanner it carried, like the scanners on all subsequent Landsat satellites, recorded images with both visible and near infrared light. Remote sensing scientists quickly learned that by combining visible and infrared data, they could reveal critical information about the health of vegetation. For example, the normalized difference vegetation index (NDVI) highlights the difference between the red and infrared wavelengths that are reflected from vegetation. Because red light is used by plants for photosynthesis but infrared light is not, NDVI allows scientists to estimate the amount of healthy foliage in every satellite image. Thousands of scientists, including landscape ecologists, global change biologists, and habitat specialists have relied on these valuable satellite-based NDVI images for decades.

Up-close infrared imaging

The goal of the Infragram project is to bring the power of NDVI and other infrared vegetation images back to earth where everyone can now take close-up images of plants or landscapes and instantly learn about their health and vigor.

There are public sources of infrared photography for the US available through the Department of Agriculture -- NAIP and Vegscape -- but this imagery is not collected when, as often, or at useable scale for individuals who are managing small plots. By creating a low-cost camera and working with farmers and environmental activists, we hope to explore grassroots uses for this kind of technology. What could farmers or activists do with leaf-scale, plant-scale, lot-scale, and field-scale data on plant health if the equipment costs as little as $10 or $35?


Screenshot from 2011-09-10-colorado-boulder-foothills-community-park-NRG. See how clearly plants are identifiable from bare earth or pavement. The unique colors in this photo will be explained below, keep reading!

Why does it work? (quick science)

Though we cannot perceive it with our eyes, everything around us (including plants) reflect wavelengths of light in red, green, blue and beyond into infrared, ultraviolet, and more. Our colorful world is created by varying amounts of particular wavelengths being absorbed and reflected. This also means that everything has a recognizable "spectral signature". Whoa.

Why do plants reflect a lot of infrared?

Plants use visible light (mainly blue and red light) as 'food' -- but not so much green light, which is why they reflect green away, and thus look green to our eyes. They also happen to reflect near infrared light (which is just beyond red light, but not visible to the human eye). This is because they chemically cannot convert infrared into usable food, and so they just bounce it away to stay cool. The illustrations show what colors of light plants absorb versus reflect away.

Public Laboratory: filtering infrared and visible light

By using this unique property of plants, plus our ability to take near-infrared photos we can create composite images which highlight where plants are and how much they are photosynthesizing.


Figure above: Normal color photo (top) and normalized difference vegetation index (NDVI) image. NDVI image was derived from two color channels in a single photo taken with a camera modified with a special infrared filter. Note that tree trunks, brown grass, and rocks have very low NDVI values because they are not photosynthetic. Healthy plants typically have NDVI values between 0.1 and 0.9.



  • NDVI
  • Image


How do we do it? (prototypes, links)