I am 2nd year PhD student in Physics.
Can you think of any UAV project which won't contribute to army? UAV designing is a career of my dream, but I want to serve the greater good. However, all advances are developing in military field.
Here are a few non-military ways in which drones have been used:
One would be the Aurora Flight Sciences Perseus, which started as an unmanned instrument carrier for flights into the south polar vortex, in order to study ozone depletion.
But guess what: Development took much longer than initially expected, and funding gaps could only be filled with DARPA money. In the end, military contracts keep many high-tech companies alive which could not support themselves exclusively with civilian money.
If your field of interest has military applications, it will be very hard to stay true to your ethical standards.
I would dispute your claim, however, that all advances take only place in the military field. Apart from GPS, many advances which make UAVs practical are connected to civilian-driven technological progress. Only when it comes to issues like reserving airspace for UAV operations, the military is in a much easier position than civilian operators which must wait for slow-moving government bureaucracies to adapt to progress. The discussions we had with the FAA in 1990 on how to operate UAVs were surreal.
Of course, there's also a growing field in selling them for retail.
While other countries have better regulatory processes right now, the FAA is preventing much progress in the US.
If you come up with your own idea, then why not start your own business? There are lots of possibilities.