Public Lab Research note


2-24-12 KAP Livermore CA development

by patcoyle | February 25, 2012 08:33 25 Feb 08:33 | #851 | #851

I flew a Sutton FF16 this afternoon in 12-13 mph winds with a two-camera juice-bottle rig. The session covered part of a new development under construction near the airport in Livermore CA. I deliberately stayed at relatively low altitude, since the location is near the pattern for the airport. I didn't contact the airport tower, based on recent reports about experience with FAA and NOTAMs. There were a number of planes taking off toward me, typically all well above me in the pattern, some are visible in the videos. As I've previewed the images, I recall Stewart Long's advice that higher is generally better in terms of mapping and minimizing distortion. The session resulted in photos from two Canon cameras: A1200 visible (recent Fry's acquisition, on sale for $59.99): 2,601 images; A490 (modified by Jeff Warren) IR: 2,082 images (about an hour of shooting, obviously not all at altitude).

I've been trying to carry the kit in my car and practice setting up flying more quickly. Lot's of room for improvement.

I noticed:

  • The A1200 visible camera was canted significantly. More care to rigging the camera is indicated (I used the rubber band cradle with mini-bungee with one sided connection to bottle, but I think the pure rubber band rigs with connections on both sides will mitigate this issue. I realized I didn't have the bottle caps to simply do this technique, though I could have also brought the rubber bands out the top and connected them to slits in the bottles. See Mathew Lippincott post, http://publiclaboratory.org/wiki/pet-bottle-rubber-band-rig)
  • my iphone wouldn't quite fit in the Ocean Spray juice bottle with enough depth for reasonable crash protection ( I have the insurance that supposedly covers everything.). Mathew Lippincott and Stewart Long mapped the bottle space nicely at http://publiclaboratory.org/wiki/pet-bottle-rubber-band-rig.
  • So, I'll try one of the more suitable ones identified there, or perhaps cut and put in a spacer for the one I have, so I can retain the flat surface side-by-side 2-camera set up.
  • One motivation for that is to use the iPhone with apps like Sensor Data or xSensor Pro to capture yaw. pitch and roll as well as gps data for sites like the cloud based stitching services like http://pix4d.com/ which require this information (still have to post-process the images to tag them or make a companion file that has the required information). One can also use apps like InterCam and PhotoTimer as intervalometers to simultaneously take photos (which should already have the lat/long gps data encoded, making it easier to post-process the rest of the sensor data.)
  • I used Brooxes Hangups™ on the line, but they got "scrunched" together so that they did not provide a separation along the kite line. I may need to take more wraps around the line to mitigate this. It reduced the effectiveness of the looped line-two-point attachment scheme, which, when it works, acts a bit like a 2-D Picavet.
  • I notice, that while focused on horizon at beginning, the balance of the IR images appear soft, not crisp. Need to troubleshoot this. Did I stop and start it inappropriately?
  • I felt a general awkwardness rigging the cameras from scratch - my rubber band and found-pebble triggers for continuous shooting seemed awkward. The A490 batteries were low and needed to be changed, I didn't get the rubber band for shutter control triggering in place first, so had to remove the cradle rubber band, add it, etc.

Links to videos of the image sequences and video of the flight are coming at at:

https://www.youtube.com/playlist?list=PL3E6406180913DA3F

I haven't tried to stitch them yet.


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