UAS II - Mission Planning

Introduction

     Advances in technology have allowed for people to significantly increase the amount of data and its accuracy.  This is especially true with the growing use of unmanned aerial systems (UAS).  There are many things to consider prior to field work and during field work that will help and UAS study successful.  The work that is done before going out into the field is called "mission planning" as you need to know ahead of time all aspects of your area of interest and how your equipment will effectively cover the entire area.  Knowing your equipment inside and out is essential in conducting a study with a UAS.  The Geog 336 class went to the Eau Claire Indoor Sports Center grounds (Figure One) on Monday, April 14, 2014 to learn about UAS mission planning.  We use a three armed, six propeller fixed wing aircraft can travel at about 5 meters per second (Figure Two).

Figure One - At the center of this map is the grounds for the Eau Claire Indoor Sports Center.

Figure Two - Joe Hupy's fixed winged UAS that can travel at about 5 meters per second.  The unit has a typical battery life of about 15 minutes.  A simple Canon digital camera is attached to the bottom of the unit which is set to swivel so it is always pointing downward.

Planning Methods

     Before flying a UAS in the field, it is important to remember a couple things.  First of all, it is very important to make sure that the batteries are fully charged and that the transmission is working.  The weather should be checked before a UAS flight.  Obviously if it is raining, you may want to consider changing the flight day so to avoid damage to any of your equipment.  Also, it is important to note that if it is a particularly cold or windy day, this will drain the batteries faster on the UAS.  Understanding the topography and foreign objects (such as buildings) in your mapping area is essential.  If either of these factors are at a high enough elevation, it may be possible that the UAS would collide with them.  The user needs to plan to fly above or around these objects.  Elevation data (z-coordinate) is not very very good with many GPS units, but a good average altitude to fly a UAS at is about 100 feet.  Since z-coordinates are not high in accuracy, it would be a good idea to give yourself enough of a buffer to go around objects that have a relatively high elevation.  The user can decide if they want the UAS to loiter within that polygon or if they want the UAS to visit certain points during its flight.  A survey grid or footprint should be used to make sure there is a correct amount of overlap across imagery scans.  

Figure Three - Joe Hupy watches the software as
the UAS is in flight to make sure all the vitals of
the equipment is in check. 

     A checklist should always be made for a UAS flight.  The UAS will land wherever you tell it to land, despite what objects may be in that spot when the UAS is supposed to land. The user can set up the UAS so that it returns to the same place it took off from.  The whole process should not be done by one person alone.  One person should be at the computer the whole time watching the battery life and making sure the UAS stays on the proper course (Figure Three).  One person should be the commander pilot that knows how to fly the UAS manually, for those "just in case" scenarios.  One person should be the engineer that is able to deal with any software issues if they were to occur.  The one manning the computer should make sure that auto pilot is working at all times during the flight (green light).  When the battery power is at about 60%, it is a good idea to start bringing the UAS to its landing point.  The flight will have to be interrupted and the UAS will have to be commanded to forget about the remainder of the mission and go directly to the landing point.  Something to keep in mind when the user goes to retrieve the UAS is that the engine should be turned off before picking it up.

     Free software is available for download for unmanned aerial system flights.  Within this program, a polygon can be drawn around the area of interest and weigh points can be added depending on where the user wants the UAS to travel to.  An exact flight plan can be executed, or the UAS can be set to loiter within that polygon that was drawn around the area of interest (Figure Four).  The software for these kinds of applications are being updated fairly often, so it is uncommon for manuals to be written for this kind of program.  Discussion forums and blogs are the more common way to communicate comments and issues about software packages.

Figure Four - This shows a quick look at what the planned flight path of the UAS was in the software program.  The green dots represent the weigh points the UAS is set to go to and the yellow line is the planned flight path of the UAS.

Results

     Figures Five through Eight are a few images that were collected during the UAS flight conducted by Joe Hupy.  The images turned out to be a little dark because the weather was slightly overcast that day.  Images could be brightened up with Photoshop, but I wanted to show what the raw data looked like that was collected from the Canon camera that was attached to the bottom of the UAS.

Figure Five - Image over a neighborhood house nearby the Eau Claire Indoor Sports Center grounds.

Figure Six - An image of a road near the Eau Claire Indoor Sports Center.  It is apparent just from doing a short exercise like this that the roads in the area are in less than perfect shape.  This could be one of many applications of these methods.

Figure Seven - This is an image the UAS took while it was returning to its launch site after flying over a nearby neighborhood.  This photo must have been captured right when the UAS changed direction, because the camera did not get a chance to point itself downward.  

Figure Eight - This is a photo of the top of the main pavilion of the Eau Claire Sports Center.  This is towards the end of the UAS flight as the unit is returning to its launch location.

Conclusion

     Advances in unmanned aerial systems have made imagery applications much easier and more efficient.  Mission planning of the flight of a UAS is almost more important that knowing how the unit flies.  There are so many factors that could make a flight fail, that it is important to consider all the possibilities before even beginning a flight.  The more knowledge and experience the user has, the more effective and efficient a UAS flight can be.