We’ve had some success using the iPhone for aerial imaging from kites, balloons, and quads, so I’ve been looking for a way to mount one to our new Phantom’s GoPro mounting base plate. A quick search of http://thingiverse.com returned this GoPro-compatible iPhone case created by N3W0NE (CC BY-NC-SA). I printed it out on our new Printrbot, and while it technically fits, it needs a little adjustment to be ideal for our situation. Most GoPro and iPhone users want to mount cameras facing forward, but ours needs to be pointing straight down, which sometimes doesn’t quite work – various mounts and housings get in the way. For this model to work correctly for our needs, it needs to be tweaked so that the GoPro mount bit is on the short edge of the iPhone. Not a big deal, and I’m grateful that communities like Thingiverse exist, and that folks are willing to share their work.
The new quadcopter arrived, and it flies like a dream right out of the box. We’ve been looking for a stable, predictable (some would say boring) flyer, and this machine seems to fit the bill. Excited to put it through its paces in the next few weeks!
Thanks to the very responsive team at Publiclab.org – Stewart, Jeff and Liz! – MapKnitter is back up and running exports. Here’s a before and after version of one student’s work with the balloon photos:
Overall, a fine result, but a few anomalies might bear some experimentation. For instance, the dropouts toward the top of the north/south path on the left-hand side, and a small faded out area near the bottom left, just above where the east/west and north/south paths join. If I had to guess, I’d say these were the result of too many overlapping images in those particular sections. I think I’ll see about thinning out some of the overlaps to see if I can’t get a cleaner export.
Here’s a screenshot of one of the many photo composites that students are working on with the data gathered from the balloon flight a couple of weeks ago:
MapKnitter is being finicky about exports, but hopefully that will resolve itself before long, and students will be able to get their hands on the stitched photos for further analysis.
November 3, 2014. Clear and cool with a light breeze – a perfect morning for field work. Students from Professor Pittman’s GEOG 331 – Exploring Maps and Geographic Technologies course gathered in the parking lot at the north end of campus for some balloon aerial photography. Jason explained some of the basics and gave a safety orientation. Rule #1: Anyone handling the line must glove up!
As we filled the balloon, we realized that we had miscalculated the helium required. The tank wasn’t quite full, and the balloon wouldn’t pull the picavet with the Canon SX130. Forced to improvise, we clipped a much lighter iPhone rig (running the TimeLapse app) directly to the string attachment point, and we were ready to fly.
With the lighter camera setup, the balloon flew fine, and students walked the trails that run through the wetlands.
We uploaded the photos to Google Drive, and over the next week, students will use Map Knitter to stitch the photos together and georeference them.
For Folsom Lake College’s 10th anniversary celebration, we rigged up the balloon to stream video to a monitor on the ground, using a custom rig with a POV camera, battery, and transmitter, all housed in an apple juice bottle rig.
Never having tried the setup before, we launched the balloon, and streamed the video to a little field monitor. Everything worked perfectly, and on the first try besides! Children seemed to appreciate the balloon’s eye view of the college.
We had to pull the balloon down and hide it from the falcons that were flown once or twice throughout the day. Apparently balloons are used in training the birds, and we were concerned that they would go after it.
After the falcons had finished their flights, we launched the balloon again, now streaming to a much bigger monitor stationed at our table. Once again, things worked exactly as planned. The video was surprisingly clear and the stream stable, save a few transmission hiccups from time to time.
Next steps include building a dual rig, with a camera for still images, and the streaming gear to aid in positioning the balloon. We also need to explore fins or other means of stabilizing the streaming rig, as it got to swinging pretty severely at times. It was attached directly to the string attachment point, so it’s entirely possible that hanging it from a picavet will take care of the swing.
With the easing of the helium shortage, we finally acquired a tank or two of the noble gas, and headed up to the El Dorado Center yesterday to launch our new imaging platform. First flights are always a little nerve-wracking, with safety considerations and weather variables and unknowns, but we drafted a protocol, filled the balloon, and sent it up.
We had used half the tank the other day on an aborted attempt – the balloon popped – so we ran out of gas a little short of the balloon’s capacity. While it lifted the picavet, it wasn’t especially enthusiastic about it. We brought it back to the ground, changed the 300# line to 100#, removed the bucket, and sent it back up. These weight tweaks worked well, and the balloon pulled the load gently but definitively.
A balloon is quite a different animal than a kite, and flying it took some getting used to. All in all, quite a bit less stressful than kites or quadcopters, as the helium counteracts (most of) the drop-out-of-the-sky, camera crushing effects of gravity. We were able to capture this nice image of the El Dorado County Master Gardeners Demonstration Garden, a work in progress, and one that we can hopefully document over time with additional flights.
Overall, a satisfying success. Next steps include constructing a new, lighter picavet specifically for the balloon, and finalizing the POV streaming rig we plan to fly over the crowd at a college event in October.
~5 hrs. 45 mins. of work in ~7 mins.
On Friday, April 4th, Jason and I went out to Cronan Ranch Regional Trails Park to do some recon, his new puppy in tow (and eventually in the pack when she tired of hiking). Though we brought kites, rain and lack of wind kept us out of the air. We were able to formulate a flight plan for the following Friday, and met a group of students for some hands-on learning.
Students paired up and took to the trails armed with Trimble GPS units, gathering data for the American River Conservancy.
After a few hours of trail mapping, the group met at the rendezvous point, and we got out the kites. The maiden voyage of the 12′ delta ended up with the kite atop an oak tree, but a quick climb freed it for another go. Though there seemed to be plenty of wind at ground level, the kite just wouldn’t stay up, so we switched it out for the 9′ delta. Despite valiant efforts by a couple of students, we weren’t able to get up into any stable air, so we didn’t end up with any photos.
It’s been pretty quiet on the flying front this winter, but we’ve got a field day planned for Cronan Ranch tomorrow, so I took a few minute to mod the picavet. In the prior incarnation, the bucket was not attached to the picavet cross, but was instead sandwiched between the cross and the camera mount. As such, every time the camera mount had to be changed, the bucket came with it, making for some annoying alignment issues.
To remedy, I cut away the middle of the top of the bucket (to make camera attachment a little easier, and to make the camera screen visible from outside of the bucket – the camera is always pointed straight down, and without access to the screen it’s sometimes difficult to tell if the camera is firing ), and attached the bucket directly to the picavet cross via two machine screws. Much better. Let’s hope the predicted winds arrive tomorrow…