What I want to do
I want to successfully complete all steps of a grassroots mapping workflow in order to put together a demonstration for prospective partners in a project that monitors impacts of Invasive Green Crabs in Coastal Maine. (see http://publiclab.org/notes/code4maine/05-08-2014/mobilizing-data-to-combat-the-evil-green-crab)
My attempt and results
While I've been working throughout the winter with students at the Harpswell Coastal Academy on everything from mini-quadrotors to a touchscreen-enabled Raspberry Pi-camera, we wanted to collect something tangible to show for all our work. We have multiple camera options including a touchscreen-enabled Raspberry Pi+ Camera module and two Canon Powershots flashed with CHDK (from a DIY Book Scanner project outlined at- http://publiclab.org/notes/code4maine/10-07-2013/diy-time-machine). However, the PiCam is a ways away from the point where it will be easily deployable in field conditions, and we didn't want to risk losing a +$100 Powershot until we were a little more confident in our technique.
One of the Quadrotors we experimented with over the Winter, the Blade QX-180, came with a detachable mini-HD Camcorder (http://www.e-fliterc.com/Products/Default.aspx?ProdID=EFLA800) and any sacrifice made iin image quality (unavoidable when capturing stills from a video feed) seemed more than justified by the onboard battery and overall weight. Most importantly, it wouldn't be the end of the world if anything happened to it. At barely over 2 inches long, the camera also meant I could use my Printrbot Simple, which has a maximum build volume of 4"x4"x4", to 3D print parts of the rig. The result was the teeny-tiniest bottle-KAP rig you'll ever see!!!
I made a total of three flights of which only the first was successful, though all three yielded valuable information.
####Attempt Number 1 The first attempt was made on June 14th 2014 on a tiny peninsula called Potts Point in South Harpswell Maine. Parts used included- a small HQ Power Sled Kite w/ stabilizer tail, 100 yards of 50ibs test Dacron Line on a standard spool, and the micro-bottle rig pictured above with a 3D Printed Picavet attached to two carabiners with 100Ibs test Kevlar Line (used as the belt on the Printrbot Simple).
While the winds were more than strong enough to lift the kite immediately, they soon became so strong that it snapped the plastic spool reel in two! The picture shown below is as good an endorsement of the Dacron line that I can think of as Nylon line would surely have snapped in such conditions and I'd have no such view!
I was able to get a few good shots of the peninsula but the broken spool resulted in an early landing before adequate altitude was reached.
That evening I made some modifications to the bottle rig by adding some stabilizer "fins", and I transferred the Dacron line to my autowinding reel pictured below-
Attempt Number 2
Unfortunately, the auto reel didn't fare much better in the high winds as the mechanism that guides the line came loose almost immediately and resulted in some tangling evident in the photo below-
Despite all this, I managed to get some good altitude this time while the stabilizing "fins" worked wonders on the steadiness of the Mini-Bottle rig-
The satisfaction of a successful flight and camera retrieval was soon to be dashed howeveras I plugged in the camera and found nothing on the SD Card! Even though the same card had worked the previous day, subsequent recording comparisons using different SD Cards revealed the camera simply refused to write to the card I was using for no apparent reason! So on to attempt #3...
####Attempt Number 3 Having assured myself that my new SD Card would behave, I spent the next few days trying to improve performance in the always unpredictable afternoon wind conditions. I untangled the line on the automatic reel and got a hold of a 6 foot Delta Coyne Kite (http://www.amazon.com/gp/product/B00C9T4HDG/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1) in the hopes that it would prove more stable in the variable wind conditions. The fact that I have no photos for this attempt hints at the outcome... While the Delta Coyne certainly took off with ease, it handled the wind like a bucking bronco! By the time I got my bottle rig hooked up it not only snapped off the guide reels completely, but started on a slow-motion decent into the water by sharply banking to its left unless I let out more slack. I desperately tried to reposition it so at least the camera would crash on dry land, but it wasn't long before I found myself reeling in the worlds most awkward fishing lure with a bobber that used to be a camera... Once again, the one piece of equipment that performed heroically was the Dacron line, which didn't seem to strain or even fray despite the fact that the Delta Coyne was now doing its best to collect what had to be over 50 Ibs of Kelp! **(EDIT: After recovering the SD Card from the waterlogged cam, it appears that, like the previous day, it didn't capture the video anyway,.. So final analysis is that that camera pretty much ended up where it belongs- In my box of e-scraps!)**
Questions and Next Steps
The lesson learned on the third day is that the Delta Coyne is clearly the better option for calmer days while the Power Sled handled itself much better in windier conditions. I'll always use Dacron line forever after, and I have a lot more research to do about strengthening kite reels. Despite its tiny size, the Mini-Bottle Rig performed surprisingly well, though v2.0 might be a little larger to accomodate the Mobius Action Cam I finally broke down and ordered (along with a waterproof case...). I might also look into adding a foam "life vest"to the bottom of the bottle rig to either cushion the landing or keep the camera from fully submerging should another water landing occur. (Edit: This note on a styrofoam version of the PET Bottle Rig seems to be perfect!- http://publiclab.org/notes/eustatic/03-12-2014/floating-camera-rig)
There was enough material from the first day however, to meet my initial goal of completing a full mapping workflow demonstration.
The screen capture utility on VLC seems to offer the highest resolution possible, while also eliminating the time consuming step of sorting through bad images. I tried further sorting the captured stills through MapMill, but I can never get Ruby to play nice with Ubuntu, so my attempts at compiling a local deployment failed.
On the other hand, I discovered the Linux-based DigiKam to be perfectly suited to the image sorting needs of grassroots mapping. The same endlessly customizable features that make it so frustrating as a desktop photo manager, makes it perfect for the high volume meta-tagging necessary before uploading to Mapknitter.
As for Mapknitter itself, I managed to stitch together a layer covering a small area on this map- http://archive.publiclaboratory.org/leaflet/?tms=https://mapknitter.org/tms/pottskaptest2/&lat=43.7323905685&lon=-70.024710949, however, as of this writing the export process does not seem to be working. I can see all the photos in edit mode, and it seems to go through the export without error. Yet, it still gives me the "This Map has not been exported yet" dialog... I'm guessing it has something to do with the resolution, but my knowledge ends there...
Despite all the bumps in the road, I have undoubtedly gained some valuable insights into how to successfully deploy a grassroots mapping effort amidst certain local conditions. "thy wind shall giveth and thy wind shall taketh away"
Field testing has been delayed due to the necessity of redesigning a camera rig that is
A.Waterproof and B.capable of accommodating the impressive Mobius Action Cam.
This is proving to be quite a challenge as the camera would need to be mounted in a somewhat vertical position. Initially, I was hoping to 3D Print a custom mount design but my Printrbot Simple decided it wanted to be completely rebuilt from the ground up... A task I'm not exactly jumping in anticipation for...
So my next idea was to use a transparent plastic dry-bag, in combination with the floating KAP rig design by PLOTS contributor eustatic- http://publiclab.org/notes/eustatic/03-12-2014/floating-camera-rig. That way I could just use the dry-bag to simultaneously waterproof and suspend the camera inside the foam shell-
The immediate problem was aligning the lens with the plastic covering tightly enough so as to not interfere with the pictures... Again, the vertical shape of the Mobius proved challenging as there was no way to make it fit flush within a flat dry-bag. I tried using multiple tube shapes to form a kind of scaffold that the plastic could wrap around smoothly but nothing worked... Ultimately, I settled on the tapered-flat shape of a medicine bottle from Target.
Its possible this could've done the trick with enough tweaking but before I got too far I discovered a purpose-built weather-cover for the wide-angle Mobius cam is actually for sale by the official US distributor for Mobius. Hence, as of Sunday July 6th, flight gear redesign is on hold pending delivery by USPS... I suppose this'll give me some time to rebuild and upgrade my Printrbot... whomp whomp...
After a lengthy design process which was documented in its own research note and even spun off into an exciting underwater photography rig, I was finally able to get back into the air! The wind was way too strong that day, so with previous disasters in mind, I made sure to make it a short, low altitude flight to test the new rig, camera and reel.
The new setup yielded some fantastic photos! Unfortunately, none will likely be of much use for aerial mapping due to the low altitude limit and the wide angle lens distortion. Nevetheless, it confirmed that I'm indeed ready to fly again!
The full sequence can be found at https://picasaweb.google.com/107186102357963872918/KAP?authuser=0&feat=directlink