sUAS news recently spoke with Dr Patrice Carbonneau a Durham University geographer who has surveyed the mini grand canyon that opened up in a field close to the university during flooding
A brief resume of yourself and what drove your interest in sUAS
I’m a fluvial geomorphologist focusing on the remote sensing of rivers. My main research interest is in fact aquatic habitat surveyed at large scales. I’ve been working for several years on using very high resolution image data (below 10cm on the ground per pixel) to measure river habitat properties like water depth and bed material grain size. My interest in sUAS is mainly data driven. I want continuous information on river systems at the largest possible scale. I do work with a aerial survey firm here in the UK (APEM ltd). They do great work but there are cases when you need imagery at a lower cost and with a quicker deployment. That’s where sUAS could fill a niche.
How long have Durham University been using sUAS for research purposes.
Our department bought a first SmartPlane 3 years ago. Initially, a colleague of mine (Prof Danny Donohugh) was interested in forestry applications which was the specific focus of the initial SmartPlane design.
Its a flying wing is there a good reason for that? Did you try many airframes before reaching the flying wing?
This is our second system from SmartPlanes but they have all been flying wings. The designers chose the wing for stability and level flight. The airframe was designed with photography in mind.
Was the Houghall College job handy as its right on you doorstep, what other tasks have you undertaken?
The Durham Canyon was ideal. This was in fact our first survey. Our current system is new and we spent last week on training. So the chance to make the first real survey at the end of the week was ideal. In the past, we have used a UAV for algal bloom mapping. I had a Student, Steve Dugdale, who used the old system to survey a large of Seal sands on the Tees estuary in order to estimate the total mass of algae.
How to you capture images from your sUAS?
The PAMS (Personal Airborne Mapping System) controls the camera from the autopilot. The (human) pilot specifies a rectangular area of interest on a ground map or georeferenced image with a size ranging from 100X100m to 400X400m. The system then automatically plans a flight path to cover the area. Once in the air, the system flies the survey lines and triggers the camera in order to achieve an overlap of at least 80%. Alot of redundancy is thrown in to insure complete coverage and plenty of overlap for the mosaicking. Manual intervention is needed at takeoff and landings, but once in the air every aspect of the survey can be managed automatically. This makes the whole system a lot easier for people who aren’t accomplished model plane pilots.
What takes longer capturing the images or post production?
I’d say that flight preparation and maintenance is by far the time consuming element. Smartplane offers a webservice for postproduction so for a price we could eliminate post-processing time. Alternatively, we could use the photogrammetry software that we have here in the department. That would obviously be longer in post-processing.The image capture is actually quite short. If the weather is good and everything works, you can be in and out of the site in an hour.
How to you see sUAS aiding research in the future?
sUAS still don’t match the image quality you can get from professional survey firms. In the next year or so, the advances in CCD size for professional cameras will allow these firms to get imagery with a ground resolution below 3cm (maybe even below 2) from a fixed wing aircraft platform. The optical properties of these cameras are obviously better than those of the small format cameras used by most UAV systems. Add to that the use of proper dGPS and sometimes even INS in aircraft and you usually end up with a better level of data quality. But, at 1.1kg our system definitely has an edge in terms of cost, ease of deployment and response time. A key point here is monitoring and repeat fly-overs. We are already discussing the possibility of monitoring the Durham Canyon on a regular basis. In normal circumstances, we’d have to contract a survey company on a yearly basis and thus find the funding to pay for the acquisition. With our sUAS, we can simply do the aerial survey ourselves. That’s where these systems will benefit research.
Might using sUAS become part of every student geographers life?
Given the low-cost and ease of deployment, I am definitely hoping that this tool will be used by my remote sensing M.Sc. and Ph.D. students.
If you had the ear of the regulators what would like seen put in place?
I’d say clear weight specific regulations. I’ve seen the range of NASA UAS and I’m quite worried that my aircraft will be lumped into a set of regulations designed for a UAV with the capacities of a combat aircraft.