Striving to be the person my dog thinks I am.

I’m pleased to introduce a new topic to butzi.ca/tech; Low Altitude Aerial Surveys.  This category will cover items and issues related to a project to capture aerial images from an Unmanned Aerial Vehicle (UAV), precisely geocode them, and montage them on a platform such as Google Earth (GE).

In my work to deliver petroleum well data for the Western Sedimentary Basin (WSB) through GE — see www.intellog.com/blog — I’ve found the aerial imagery on GE is excellent — particularly when you consider what you pay for it (nothing).  It does have two significant limitations; 1) it’s only updated periodically and over fairly long intervals, and 2) the resolution is pretty much what you would expect for an image captured from either satellite or high altitude aircraft.  Both of those issues would seem to be the result of the extremely high cost of gathering the image information in the first place.

There is a confluence of several technologies that makes much higher resolution and much more timely images a distinct possibility;  digital photography, Geographic Positioning System (GPS), solid-state position sensing, radio control and battery technologies are all on curves of increasing quality & performance and decreasing cost.  In short, by putting a relatively high quality digital camera on a electrically-powered radio controlled aircraft, stabilizing the camera using solid-state position sensing technology, and using GPS to geocode the images, you have the necessary ingredients for a high quality image.  This data can be presented using tools like GE and ArcGIS, and will be achievable at at very low relative cost.   The motto of this project could well be “bringing the lens to the terrain, rather than the terrain to the lens“.

The use of an electrically-powered aircraft is considered important in that many areas of interest for survey are likely inhabited, or at the very least, noise-sensitive enough to prohibit the use gas-powered aircraft.  Electric aircraft are virtually silent, and it is anticipated survey missions could be flown within proximity of populated areas without significant disturbance to the human or wildlife populations.  This is to say nothing of the obvious environmental benefits of using electric, as opposed to internal combustion power.

Beyond putting the vehicle in the air, collecting the images and geocoding them, the most immediate challenge is to automate the montaging of the images.  It is anticipated that if the geocoding is sufficiently accurate, it will be possible to build application software that will take the raw data collected in the air, and make it available on GE (or equivalent) with minimal, if any human inspection.  Assuming this is achieved, information gathered during the survey mission could potentially be available for viewing within hours, or even minutes, of its collection.

One of the future challenges of this work will be the ability to scale up the image collection process.  Close proximity of the aircraft to its survey subject, and the attendant very high resolution images, comes at a price; the area that can be surveyed within a given unit of time is relatively limited.  How this problem could potentially be solved in the future is not currently known, but it’s felt the relatively low unit cost of the image collection vehicles will be such that increasing their number will be cost effective.   A more difficult problem may be the sourcing and training of crews that can reliably deploy them in the field.

In the future, it will be valuable to support fully autonomous flight — flight without the the intervention of a ground-based pilot — but it is not considered to be an immediate objective, given the emerging regulatory issues with this mode of flight.  Therefore, it’s assumed the UAV will achieve its mission objectives within line-of-sight of a ground-based pilot and/or spotters.

Anybody who is even mildly conversant with current technological trends could spot this potential opportunity, but their still remains an as yet unknown number of details in the execution on this objective.  The work related to this project will be conducted on an experimental, iterative basis.  The intention is to sequence the problems in the order in which they must be solved, and then experimentally deal with each one in turn, and publish results as they are obtained.  Lessons learned from one iteration of development will flow into the next iteration of development.