Unmanned Aerial Systems (UAS) is a very broad topic.
Part of my role as a student innovation fellow is to build and experiment with UAS, with the goal of developing a “Manual” for UAS use at Georgia State.
The manual will include both safety and technical information, as well as some basic flight instruction and guidelines for use.
To that end, my post today will consist of a pretty “stream of consciousness” discussion of what is available and what is possible with unmanned aerial systems in a University setting. I will also go over the differences in the various types of UAS and their pros and cons. The reason I ask this is, is that I have a somewhat narrow focus when it comes to the use of these aircraft. I want to know what sort of ideas you can come up for using Unmanned Aerial Systems in a University setting.
Aerial Photography or Videography is the primary use of most UAS in academic or research settings. There are many different variations on this role. Cinematographers and photographers have been using UAS to achieve an airborne perspective with low cost in many fields including journalism, entertainment and real estate. Other Colleges and Universities are using them on sports fields to analyze athletic performance from a new perspective. Governments and utilities have used cameras in the air to perform critical infrastructure inspections, and still others have used small unmanned aircraft to survey large swaths of land with high resolution aerial imagery.
It’s by changing the actual imaging sensor used to take images that the capabilities of unmanned aerial systems start to diversify. Simple photography uses a Red-Green-Blue color representation in “Natural Color” imagery, but the electromagnetic spectrum is very wide and visible or natural colors only make up a small portion of that. NIR or Near-Infrared imagery is one of the simplest to acquire. NIR light is that band immediately adjacent to red but beyond the human visual spectrum. NIR reflectivity can be used to help assess plant type or health, and is widely used in environmental and agricultural research. Typical off the shelf consumer cameras are often capable of recording the NIR band with the removal of a simple filter, however the inconsistencies from one model to the next and one filter to the next make these less than ideal for scientific research. A small cottage industry in NIR modified cameras has developed, targeting scientific researchers with inexpensive but consistently and correctly modified cameras.
Moving further away from visible/natural light you come to Thermal IR. Even though its still Infrared, Thermal IR cannot be easily captured by a consumer camera. Thermal IR is also known as Thermal Radiation or just “Heat”. Thermal IR sensors are much more expensive than NIR. These cameras allow the operator of a UAS to view temperature differences. This is useful in a number of fields, such as wildlife management or infrastructure inspection. Other than the cost of the sensors, these capabilities are essentially just specialized applications of aerial photography.
Mapping can also take on another dimension, when the aerial imagery is used not only to build an orthophoto mosaic of the land being mapped, but also to reconstruct a 3D model of the terrain. This is the primary use of Unmanned Aerial Systems for me, however I realize that many of you will have many more ideas for how to use these systems to further interesting projects that you come up with.
As for the types of systems, there are two primary types of aircraft in use for UAS, and their capabilities, advantages and disadvantages are similar to their full size manned counterparts. Fixed wing UAS look like a traditional plane or “drone” with a propeller for thrust and wings for lift. Like a traditional helicopter, a multirotor spins a propeller in order to generate thrust. A multirotor then changes the vector of that thrust to generate motion, both horizontally and vertically.
A fixed wing UAS is the go to solution for any application where any of the following are of overriding concern: Flight time, Power efficiency, Range, and straight line speed. For large aerial surveys or other long range, long duration missions a fixed wing provides a significantly more robust platform. Because the wing generates lift through forward motion, fixed wing UAS are generally unable to hover, but because that forward motion is what keeps the vehicle in the air, they are much more efficient than multirotors when it comes to power use/flight time.
A multirotor is going to be most useful where extremely accurate and precise maneuverability are needed over all else. Because a multirotor uses thrust to move both horizontally and vertically, it’s possible to ascend vertically as well as hover and strafe from side to side. This allows for extremely accurate and precise camera control in 3D space.
So, there you have it.
I’d love to hear what ideas you all have for using these systems.