Headwall Photonics Blog

UAVs and Hyperspectral Imaging Unite

Posted by Christopher Van Veen on Tue, Mar 25, 2014

One of the things we’re seeing at Headwall is the proliferation of airborne applications. Multispectral suffers a bit with respect to hyperspectral (a handful of bands versus hundreds), which is why hyperspectral is winning the day.

UAV choicesOne reason is instrument affordability. Multi-million-dollar hyperspectral sensor programs might have flown (literally and figuratively) in the military world, but not in precision agriculture or with universities. Budgets are smaller, and that money has to be spread among not only the sensor but the UAV and everything in between. This is where small, entrepreneurial companies like Headwall shine, because everything in between can mean LiDAR, GPS/IMU technology, application software, data processing, and so much more. We understand hyperspectral imaging better than anyone, and our focus has always been to better that technology while driving costs lower. This is the essence of commercial-off-the-shelf (COTS), where highly specialized military instrumentation finds a home all across industry and academia. With respect to Headwall, COTS implementation means smaller, lighter and more affordable sensors that are easier to use yet just as optically precise as their multimillion-dollar military counterparts.

Second, you cannot go a day without seeing stories about UAVs. Fixed-wing designs like those from AGX and PrecisionHawk are crowding the skies along with multi-rotor helicopters like Infinite JIB and AIBOTIX. These are much more than hobbyist playthings and are perfect for scientific reasearch duties. They have excellent range and payload-carrying characteristics, and they are stable aloft.  From mineral exploration and agriculture to petroleum and pollution control, UAVs are everywhere it seems. And everyone takes notice when household names like Facebook, Google and Amazon decide that the UAV is going to be instrumental to their future success. Much of this might sound fanciful and far-off, but it is happening now. Court challenges are being won, and while care needs to be taken on how regulations are drafted and enforced, no one doubts that the UAV is not only here to stay but will become commonplace.

Obviously, UAVs simply take up airspace unless they are doing good work. And largely, we seem to hear about bad things happening when mention of UAVs (and drones) is made. But stop and consider for a moment how a famine-stricken area can be made crop-fertile thanks to hyperspectral data that a UAV-mounted sensor can collect. A scientist will know about disease conditions with enough time to prevent damage by skimming the treetops and looking for anomalies that become ‘visible’ through hyperspectral imaging. A farmer will know where to plant and harvest…and where not to. Crop stress will be seen long before it becomes a worry, and the amount of wholesome and nourishing food planted in areas once thought impossible will blossom. In short, small and light UAVs are affordable for the people who need to use them. They can be flown in areas that vehicles and humans cannot yet reach, providing a window of research never available to scientists before.

As we see the proliferation of UAVs capable of carrying sensor payloads, it is important to understand how everything goes together. Here, Headwall is taking a leading role. Many mistakenly believe that slapping a sensor onto an octo-copter is all they need to do. But making sure everything works the way it should aboard a flying, unmanned vehicle is another challenge altogether. How much ground do you need to cover, and do you have enough battery power to do it? How much hyperspectral data do you need to collect, and do you have the computing and storage horsepower to make that happen? What are you looking for, and what spectral ranges are those things in? How do you ortho-rectify the data during post-processing? And how do you use the science of ground-truth as it relates to airborne hyperspectral imaging? This last consideration is hugely important, because the collaboration of airborne hyperspectral and ground-truth delivers the best possible accumulation of data. Headwall and ASD have even authored a 12-page whitepaper on the relationship between airborne hyperspectral data and ground-truth techniques.

Tags: hyperspectral imaging, Airborne, Remote Sensing, UAV, precision agriculture