3D Robotics

T3, Round 4: Map a quarter-kilometer!

Welcome to the Time Trust Trial contest, Round 4 (T3-4)! This round is an aerial imaging task. Here is your assignment: Program your UAV to take photos from an altitude of ~400 feet that you then stitch together to make a single image showing an area of 500mx500m (a quarter square kilometer). Somewhere in that image, a Santa (or replica of a Santa, poster of a Santa, just you wearing a Santa hat, etc) must be seen. NO PHOTOSHOP (ie, the sample above would be disqualified)--you actually need to bring something Santa-ish to the field so your UAV can capture it in its shots (yes, I know it will be very small. Just circle the location in your image so we can enlarge and inspect--don't make us do "Where's Wally"!) This is to prove that the shots aren't actually taken from Google Earth ;-) You can use any path strategy you want: "lawnmower", spiral, concentric circles, etc... For stitching software, I use the free PTGui, but you're welcome to use whatever software you prefer. And for your camera, may I suggest you hack up some cool way to trigger the shutter with our cool ServoSwitch? KML tracks must be provided. Video is not required, but is suggested. We've now switched to a six-week cycle, so the deadline is 12:00 midnight PST on Sunday, January 17, 2010 now Monday, January 18th due to the Martin Luther King holiday in the US. The overall winner will be the best quality image, as decided by the judges (based on a combination of resolution, stitch quality and overall coolness--a clever Santa will win you brownie points, and a pretty area is no bad thing [note: snow is lovely, but be warned that it can confuse stitching software]), but everyone who completes the challenge will win a prize. Enjoy!
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  • T3
    Hi, somehow my post from yesterday was not updated.
    I made 2 stiches,

    White one is straighforward pattern just after the 1st snowfall this winter and has 2 traces of Santa Claus Global Services travelling north-south during dec 21th.


    Green one a few days later when the snow melted, uses 'cropscan' similar to lentsika flight planner.
    The green map is incomplete as the battery died too early (too many pre-flights).

  • brakar- yes I noticed you used the same flying pattern. I call it the "zamboni" pattern, you know the machine that cleans the ice on a hockey rink. It makes a lot of sense for small areas with narrow strips. Making smooth gentle turns into the lines helps a lot with tracking and maintaing GPS lock. With the classic meander pattern, you end up spending half the line recovering form or preparing for the turns. Of course at some altitude/spacing, a meander becomes more efficient.

    I should add that the mosaic generation was done with photogrammetric software that can do a block adjustment and project the images into geographic coordinates so it can be displayed in google earth or GIS software directly. There was no extra stretching or scaling of the result, it fits that well from the accuracy of the GPS on the plane and the camera calibration. All 289 photos are used, and it runs automatically. I would have liked to make a better mosaic with color balancing and seam blending, but I didn't have time.

    Brian- I used a CHDK-enabled Canon Ixus70 (SD1000). An old camera, but they are very good for the purpose.

  • Nice stitch Steve, and cool (familiar looking ) track ;-)

    Btw, what software did you use for stitching?
  • T3
    They are nice tracks Steve. What was the camera and lens?
  • Can't you tell just from looking at that precision flight track Gary?
  • Moderator
    And the autopilot Steve??
  • 3D Robotics
    Very nice, Steve!

  • I just have to get in on the fun. The location wasn't so interesting, but it was -18C and I didn't want to go too far from home. The flight was uneventful and photos turned out nice. The mosaic could have been better, but it is tricky with low altitude flights. I usually fly around 200m.

    A snapshot of the flight log:

    There are some more details in there like the photo locations in the kmz file. Unfortunately the image quality is pretty poor when you display it int GE.

    Some flight stats are reported during data processing:

    Santa was spotted in several overlapping images:

    And finally a picture of the setup: A flying wing, 1.2m wingspan, covered EPP, ~1.1kg. 868Mhz radio link.

  • T3
    Yea, our stitches look a little stark and alien (yours looks a bit like a moon scape when you zoom in) but we know Santa has traveled to other planets as can be seen in this 1964 film Santa Claus Conquerors the Martians (a film that consistently makes the worst films ever made lists). So who's to say we don't have a Christmas themed image.

  • T3
    I used Microsoft ICE to stitch the photos into the following image: StitchedImage.zip (67 MB). I had to zip it as 5 attempts at uploading the .jpg failed.

    Yeah Gary, that dam does look a bit like a manta from above. It has a bit of water in it from the rain on the previous day. Thanks for arranging the competition. It's been an interesting exercise.

    Cheers, Mark
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