UAS Demo

Introduction:

The purpose of this lab was to demo the use of a UAS. This was done at the UW-Eau Claire Priory, as have the previous few exercises. The demo included running through the preparation, setup, and execution of a UAS survey. The first UAV (unmanned aerial vehicle) used was an IRIS equipped with a GoPro.

Methods: 

After arriving to the Priory, Professor Hupy got out the IRIS UAV the controllers and the base station computer and tablet. The first step to prepare for a mission is to go through a series of checks. These are held in a spreadsheet, and include things like checking weather, making sure the UAV's hardware is secure, that the rotors are tight, that all of the necessary connections are made. A part of this checklist is verifying battery life, and this was an issue. The IRIS's battery short circuited during the process. A student was sent home to get another one, and to get some AA batteries for the controller. In the meantime, Professor Hupy explained a little bit about the base station, and the mission planning software. We each were able to try drawing routes on a tablet, and we compared the strengths and weaknesses of using the laptop vs the tablet for mission planning. Basically, the laptop allows for more in depth setup, but the tablet is quite convenient for drawing routes etc after setup.

Once Michael returned with the batteries, checking continued. This included verifying connections between the UAV base station and transmitter, and verifying satellite connections. Once these were done, we were ready to fly. Professor Hupy manually did takeoff, and then switched to autopilot at 40m to run the mission previously drawn on the computer. Another student was at the base station. Afterwards, they used the autoland functionality to bring the UAV back to the starting point.

Professor Hupy was hesitant to use the next UAV because of the weather conditions. The wind had picked up, with gusts up to 20mph, and sprinkling rain seemed possible. The class also took some ground points with the TopCon GPS system (see the Survey Methods post for more info on this). After re-checking the same things as above, this was ready to fly. This UAV is considerably more powerful than the IRIS, so Professor Hupy cautioned us to stay back in case the gusts blew it towards us. After the flight began, the UAV was put on auto, and began its route. However, the wind quickly began a problem, and a gust nearly flipped it for a second. This was due to the combination of a relatively sharp turn (where the UAV has to tilt) and the wind. The UAV couldn't right itself to get back on course properly. Michael at the base station noted this, and called for a return to launch to avoid a crash. This was a lesson on how important PIC (Pilot in Command) and PAC (Pilot at Controls) communication is. Professor Hupy couldn't see the UAV's planned route, so he wouldn't necessarily know why it was operating incorrectly. Michael at command quickly realized what was going on, and told Professor Hupy, who then called it back to launch. 

Discussion:

This exercise was very interesting, because we were finally able to see a UAS in action. It is important to understand that a UAS (unmanned aerial system) really is a system rather than just a unmanned or unpiloted vehicle. There is extensive planning and preparation that must be done to properly carry out a UAS mission, and it was very interesting to see this first-hand. I was also impressed at how effective the UAV's were in the wind. They were very steady and stuck to their routes really well. It was really useful to see the PIC - PAC interaction, because if they hadn't been on the same page, things could have gone wrong. This is important in any UAS mission. 

Navigation with GPS

Introduction:

The purpose of this exercise was to set up a navigation course for future students using points plotted on a GPS. Each group was required to map five points, then navigate to them using a Trimble GPS unit to mark them. At each point, flags were installed, marking them for use by future groups. An important aspect of this exercise was setting up a proper map for navigation on the GPS. The same navigation map that was used in the previous navigation exercises was imported onto the GPS.  For more information on the navigation map's creation refer to this post.

This is an image of the map used for navigation. This was also used on the Trimble GPS unit.

The Trimble Juno GPS device used for navigation and point storing. 

Methods: 

Upon arriving at the priory, members from each group convened to plan areas to cover with each course. My group's course was set for the Northwestern corner of the Priory. The GPS, along with the navigation map and compass were used to navigate to this area. Once there, points were selected based on their relative locations to one another- we didn't want to make it too easy or too difficult. Their locations were also determined based on accessibility with respect to elevation change, vegetation and such factors. Trees were used as points, so they were flagged with fluorescent surveying tape and labelled. GPS points were also taken. However, our group experienced a temporary issue with this. Before going out into the field, the GPS unit was set up without a feature class to be edited. This means that the map that the Trimble unit had loaded didn't allow for adding any features. Because of this,  a new quick project had to be created, and points taken on that. This made the GPS unit useless for navigation purposes.

After collecting the field data and returning to campus, the five points had to be checked back in, and mapped. The results are shown below.

Results:

One of the points in the navigation course

One of the points in the navigation course

One of the points in the navigation course

A basic map of the locations of the points marked in the UWEC Priory

Discussion:

As mentioned above, the inability to edit any feature classes in the Trimble GPS map rendered the GPS useless for navigation. We were then forced to rely on map and compass navigation, as was done in previous exercises. This is just another lesson about how technology can fail, so it is important to have the background knowledge to be able to subside without it. The rest of the process went smoothly, and favorable weather conditions made the exercise very enjoyable. 

Conclusion:

Navigation methods today have shifted more and more towards GPS, so being able to properly set them up, use them to navigate, and collect data on them is a very important skill. We learned the lesson that overlooking just one little element of the data check-out process can render the GPS more or less unusable. However, building upon previous exercises, we had the skills to be able to navigate through our assigned section of the Priory and set up our course and return to our beginning point without any major issues. 

Navigation With Map and Compass

Introduction:

The purpose of this lab was to use simple distance / azimuth measurements to navigate UW-Eau Claire's land at the Priory. This involves simply using a compass, pace measurements, and the navigation maps we created earlier in the semester. For more information on the navigation map's creation refer to this post.

Before going out into the field, it was vital that to do some background research on the basic principles of orienteering. The professor and a classmate compiled some resources to facilitate this. They also printed the navigation maps referenced above for each group, and provided us with compasses.

The object of this lab was to navigate to a number of different points given to us by the instructor using just our distance / azimuth tools and pace counts in groups of three. For more information on distance / azimuth surveying, refer to this post.

This is a compass similar to the one used in this exercise. The general idea is that first, the compass is lined up from the starting point, to the desired point. The red circle can be spun in order to line up with North on the navigation map, then the whole compass is spun so that the actual North arrow is within the red outline pointing north. Finally, the arrow at the top of the image is followed as the direction of travel.

Methods: 

Upon arriving at the priory, each group convened to plot coordinates given to us by the instructor. There were 5 points total given to us in a UTM coordinate system. The first step was to plot these on each map. Next, our compasses were used to calculate the azimuths that would be needed to follow to go from one point to the next. The instructor and a classmate also gave the class important advice on proper methodology to follow to maintain a valid course.

Groups planning for the navigation exercise

To find the proper bearing, the compass must be laid on the map on a flat surface. It must then be lined up from the starting point (the location in the Priory parking lot) to the first point marked by the instructor. Then, North must be lined up with North on the map. This is done by spinning the red circle (see above image for details). Next, the whole compass can be picked up and spun so that the actual North arrow falls exactly within the outline. This is commonly called "putting red in the shed." Being sure to maintain red in the shed, the arrow at the other end of the compass is followed. This is the direction of travel.

Another important step before heading out, is calculating the approximate number of paces to expect before reaching the desired point. The navigation map that was used had a pace count for a group member, so the scale bar had to be used to calculate approximate number of his paces between each point. Note: we calculated this along with the bearings for each point before heading out into the field. This ensured that we had a flat space to calculate them on, and was ultimately less trouble than attempting to figure it out in the field.

A snapshot of the field navigation map that was used. Note the measurements taken on the map. This was done before surveying. 

Groups of three are ideal for this type of surveying. One person is in control of the compass, and directs another group member to a landmark that falls within the proper bearing, then the pace counter can walk to that person. Only after this is done can the compass-holder follow. This ensures that if there is some error, that reference point can always be returned to, and measurements can be retaken from that spot.

There were a total of five points to find using this methodology, and each group had a different order assigned. 

Results:

The first point that this group was assigned to. This particular point was the hardest one to find, as it was down in a ravine 10 to 20ft, and because we hadn't solidified our methodology yet. See the discussion section for more information on this.

The second point assigned to this group.

The third point

The fourth point assigned

The fifth and final point

Discussion:

There was some difficulty in finding the first point. Our azimuth measurement must have been a little bit off, because we ended up considerably East of the desired point. This was exacerbated by the fact that this was the farthest distance between points in the entire study. There came a point, that having little success with our three person survey method (described above), that we all grouped together looking around the nearby area for the point. This is a natural human response to being lost, but it only makes the problem worse. This means that we lost our points of reference, and no longer had any way of knowing where our bearing was. Luckily, we stumbled upon the point, and were able to continue the activity, being sure to be more careful in following our azimuth. The rest of the points were found relatively easily. To find the third point assigned, (point 1) it was advised that we first make a bee line towards the parking area in which we started, then following an azimuth a short distance to the point. This allowed for easy measurements, and less difficulty traversing difficult (sometimes impassable terrain). 

Conclusion:

Knowing how to navigate using simple tools is essential for field work, because as is well known: technology can and will fail. It is very plausible that a GPS wouldn't have reception under the heavy tree-cover and in the ravines of the Priory, so using a compass and navigation map was very possibly the only way to navigate the land there.