Lab 11: HABL Launch

Introduction:

A significant section of this course in geographic field methods has been that of balloon mapping, an inexpensive way to obtain fairly high quality imagery of the earth that can be used to provide more up to date images to detail areas where recent satellite imagery has not been taken, specifically the University of Wisconsin Eau Claire campus. A previous blog post detailed the use of a balloon mapping rig, using a Panasonic Lumix eight-megapixel camera on continuous-shot mode, and incorporated those images to create a mosaic of campus, using the software programs MapKnitter and ArcGIS. This is not the only use for a balloon mapping project, however. In addition to the tethered balloon, the rig can be let go and fly into the sky, equipped with a tracking beacon and insulation to keep the camera from freezing up at high altitudes. This blog will detail the processes involved in the flight of the HABL, and the subsequent recovery and post-processing imagery that was obtained through the flight.

Methodology:

Figure 1: Construction of the mapping rig.

Figure 2: Taking the fully inflated balloon to be released

The most important part about preparing for this activity was the construction of the HABL rig itself, which was done mostly in Lab 3. Taking a styrofoam container and modifying the lid so that the FlipCam could point its lens downward in the right direction was important to produce quality images that would be clear, despite the high winds that day. This was done by securely attaching  the FlipCam to the lid by using Velcro pads, with the final product seen in Figure 1. Teamwork was a critical step in getting the camera packed into the rig and getting the rig secured to the balloon.
The materials inside of the rig included a waterproof case for the camera with hand-warmers packed around it to prevent freezing at high altitudes, and a GPS tracker to allow for recovery of the unit. The rig was hung from rope on each of the four corners; about 3 ft. in length, and then the pieces are tied together at the top so that the carriage can swing in flight. Pieces of packaging tape were used to secure the lid on the bottom of the rig, so that the camera would not fall out during the course of the flight. The camera carriage was fastened to the balloon by a series of carabiners.. With the rig already built, the only real preparation that needed to be done on the day of launch was to fill up the balloon to be used. This balloon was significantly bigger than the one used in the previous balloon mapping activities, and made of stronger latex to withstand the amount of pressure that would be bearing down on it as the balloon gained altitude. The balloon was 8 feet in diameter, roughly 3 feet larger than the first one, with the sheer size of it visible in Figure 2. Being bigger meant that more helium would be required to fill it up, taking approximately one hour to fill the balloon up fully and ensure that the mapping rig was securely fastened. We did not want to fill it to the max as the balloon would need room to expand as it rises, so it was not fully inflated for this particular activity. Once the balloon was filled to the desired level, the neck of the balloon was secured with a few zip ties and then folded it over, using a liberal amount of duct tape to ensure that the balloon was closed up. The camera carriage and parachute were then fastened and the rig itself was then ready to fly.

Discussion:

It was roughly two hours when we found out that the balloon had landed in Spencer, WI, with the path of the balloon being visible in Figure 3. The balloon had actually landed in a tree, seen in Figure 4, on a private landowner's property. Negotiations were held to allow us to go on the recovery mission to get mapping rig. After consent was given, the tracking device was followed to lead the retrievers to the selected tree where the parachute had delivered the remains of the balloon and the mapping rig. 

Figure 3: Map showing the path of the balloon rig

Figure 4: The tree in which the HABL rig was found in Spencer, WI, close to 80 miles away from Eau Claire.

Figure 5: Recovery of the balloon, parachute, and mapping rig.

 The entire apparatus was in surprisingly good condition, as demonstrated in the picture in Figure 5. After recovery, the process of getting the data off of the camera could finally be done, and we could then see just what kind of imagery we had collected throughout the course of the balloon's 78 mile flight. Figures 6, 7, and 8 show some frames of the video shot with the camera, in fairly good quality imagery. Haas Fine Arts Center on the UWEC campus is clearly visible in Figure 6, and the same goes with the higher altitude image of the Chippewa River in Figure 7. The balloon eventually got high enough so that the curve of the earth was seen, visible in Figure 8. The video of the entire trip, which was limited to just under an hour due to the amount of memory on the FlipCam, can be seen just below Figure 8. The end of the video, where the flight starts at 7:24, is a little unstable, due the rig just being attached to the balloon by a string, and the winds bombarding the rig. It is the presence of this wind, however, that is the reason the shots of the curve of the Earth in Figure 8 can be visible at all.

Figure 6: Aerial footage of Haas Fine Arts Center, at the beginning of the HABL flight

Figure 7: Aerial image of the Chippewa River, seen from the balloon

Figure 8: Picture demonstrating how the rig captured the curve of the Earth

Conclusion:

The HABL launch was the conclusion of a nearly semester long process of trial and error in the balloon mapping field. Balloon mapping hasn't become widely used in the mainstream geography community yet and we're already on the forefront of it at UW-Eau Claire, demonstrating just how ahead of the curve we are. It is very unique that as undergraduate students we can be a part of the small percentage of people who are using this technique. The technical aspect of this course has given us the opportunity to be hands on with our education, and has given us a vested interest in seeing the success of our project. The teamwork aspect was critical, as this project would not have been completed without the input of the entire class. Delegation of responsibilities created manageable jobs for everybody involved, and covered all of the necessary aspects in preparation for the flight. Throughout the course, the importance of ensuring that all is done before going out in the field was stressed, and the conduct of our class throughout this activity exemplifies our understanding of this crucial step in the field methods process.

The article put out by the UWEC News Bureau for the HABL can be seen here.