Steven Sexton is Technical Consultant at Aerial Imaging Services, LLC (Ephrata, WA). With broad availability of new UAVs and high-performance hyperspectral imaging sensors, Steven's business is a good one. 'Remote sensing' is the study of agriculture, climatology, geology, and infrastructure from airborne platforms. The amount and quality of image data the sensors collect is amazing, allowing scientists to make important decisions about crops, plant health, mineral deposits, and environmental trends.
Recently, Steven teamed up with Precision Hawk (Raleigh, NC) and Headwall Photonics to put one of these 'flying laboratories' into the air. Because the combination of UAVs and specialized sensing instruments is still 'new' to many users, ease of integration and great customer support from Precision Hawk and Headwall allowed Steven to get into the air collecting data-rich images of the ground below. Precision Hawk took care of many of the airborne issues while Headwall addressed the hyperspectral side of the application. Together, both companies helped Aerial Imaging Services reach a very impressive level of differentiation in a still-emerging business. The myriad of mechanical, electrical, optical, and aerodynamic considerations can be daunting, and Steven took to LinkedIn on June 28, 2016 to tell his story:
I am going to shift focus to sensors today. I recently acquired a Nano-Hyperspec Sensor from Headwall Photonics and PrecisionHawk. This sensor is absolutely amazing, and is configured to just plug right onto the Lancaster Rev 4 and the Lancaster 5. This Plug and Play setup is how all of the sensors PrecisionHawk sells. Making it extremely easy to do a visual scan, land, change to a BGNIR sensor and fly. They sensors scan at much higher resolutions then most multispectral sensors. Around here being at a higher altitude means not running into the trees lining fields, silos, buildings etc. I get 1.5cm per pixel at 100m or 329 feet AGL. I go lower for Lidar and thermal to 60m or 196 feet AGL.
Now this may seem a little high but with the higher resolution sensors I got from PrecisionHawk, it just made sense, less worry and more time to just watch the Lancaster do its thing. It also means I don't have to make as many passes over a field like I would at lower altitudes. Now I haven't heard anyone say the resolution of some of the newer multispectral sensors that recently have come out or those that I may not know of. If you use one of these, and it gets as high of resolution, please, either leave a comment and share your results or message me so I can add that information to this article. I want to give everyone a fair shake here.
Now back to the Headwall Photonics Nano-Hyperspec® sensor. This unit is a little heavier than most of my other sensors, The LiDaR is about as heavy. The reason for the extra weight is a 500gb SSD drive attached to it. It also has a network cable interface to hook to your computer or laptop. Please read the manuals that come with it, it will save you a lot of headaches trying to figure out how to access the SSD on the sensor. You can find general information at the Headwall site here.
The customer service from Headwall is absolutely amazing. I decided to update the Nano driver software and missed one step and wound up not being able to access the data. Now this was totally my fault, I kind of went in blind to do the update.
Greg Chenevert from Headwall was extremely helpful and had me try a few things. These didn't work, but Greg spent time trying to help me get things going and guaranteed that they would get it back up. He put me in contact with one of the companies programmers, I gave him remote access to my system with the Nano hooked up and running and he had it all set up, reconfigured and doing imaging within probably 15 minutes at the most. Now I don't know about the rest of you, but most companies don't even come close to the customer service of Headwall and PrecisionHawk. They went way above and beyond to get the sensor working so I could do my job.
The unit itself is not that big, it is the bracket and connectors for the plug and play that make it seem larger. On average I can swap out a sensor and battery in about 30 to 45 seconds. The battery only lasts for about 35 minutes with the heavier load, but I get some pretty amazing images with it.
Headwall has software that accompanies the sensor that are very useful and allow you to transfer the files to a local drive on your computer or laptop. You could even transfer it to a USB drive if you have one that can hold the amount of data you get. There is also an option to view the data in NDVI, now this can be done in the field if you so desire. I usually just bring it back to the office and process it there and add it to other data sets I have gathered on that particular job. It does make the farmer happier if you can show it in the field.
When I first started I was unsure of which sensors I should purchase. I imagine several of you have or had the same issue. I determined that if I only get the sensors for agriculture then I am going to be very poor during the winter months. I decided to add the LiDaR, thermal, and the HeadWall Nano-Hyperspectral sensor. This gives me the ability to do other types of work during the non growing season. I also don't mind travelling to a location or even going to another area for several weeks at a time so this also opened up income opportunities.
The data is only as good as your sensors are. Sure the higher quality imagery costs a bit more, but, it also means the data is going to be more precise. Combined with the DataMapper Algorithms you get a very complete package from one source.