I see. Thanks for the clarification. On Thu, Apr 16, 2009 at 10:47 AM, Eric Wolf <ebw...@gmail.com> wrote:
> RC airplanes aren't cheaper for two reasons: > > 1. RC airplanes (and any civilian-operated UAV) has significant flight > restrictions - distance and altitude. Flying at low altitude (under > 500 feet MSL), you end up with a higher spatial resolution but you > have to stitch together many more images to cover the same extent as a > single image taken from an aircraft flying at, say, 2000 feet MSL. > Selecting good shots and correcting the imagery for hundreds of images > ends up costing more than the difference in operating an RC plane and > a regular aircraft. > > 2. RC airplanes crash - often - and they aren't cheap. Sure, regular > airplanes are more expensive but they don't crash as often. A decent > RC rig will set you back $1000+ - not counting the camera. > > I used balloons and blimps to do low-altitude aerial photography in my > MS thesis. They are much cheaper than RC planes to operate because > they don't crash (as easily). But you also don't have as much control. > They work really well for taking low-altitude obliques for general > documentation processes. But for creating a basemap of aerial > imagery, you need to get above the 500 ft MSL barrier put in place by > the FAA. To do this, you have to be in an airplane piloted by a > licensed pilot. > > Surprisingly, hiring a light aircraft - like the one used in this > study - is not really all that expensive. > > -Eric > > -=--=---=----=----=---=--=-=--=---=----=---=--=-=- > Eric B. Wolf 720-209-6818 > USGS Geographer > Center of Excellence in GIScience > PhD Student > CU-Boulder - Geography > > > > > On Wed, Apr 15, 2009 at 6:25 PM, Keith Ng <khensth...@gmail.com> wrote: > > Couldn't the process of obtaining aerial photographs be made much cheaper > > with RC planes? I am not sure if it would work but setting the RC plane > on > > auto pilot and attaching a camera with continuous shooting mode might > make > > the process simpler. > > > > Also refering to this link, a commentator said:"Just wanted to make it > clear > > that we (Pict'Earth) are willing to help anyone from the DIYDrones group > to > > get their UAV imagery processed and published in OAM, just let us know. > If > > you can fly with a logging GPS and a digicam, our Win32 software will get > > you part of the way and we can help with the rest of the manual bits > until > > we get it truly automatic." > > > > > > On Thu, Apr 16, 2009 at 4:06 AM, Blumpsy <blum...@yahoo.co.uk> wrote: > >> > >> There is an interesting paper from our dear friends over in Redmond: > >> > >> http://research.microsoft.com/apps/pubs/default.aspx?id=75312 > >> > >> From the article: > >> "Our mission, in contrast, involved an ordinary four seat Cessna > >> ($160/hour rental, including pilot), three feet of PVC pipe, a consumer > >> digital camera ($300), and two people: one pilot and one to operate the > >> camera shutter and change the batteries (Figure 2). In post-processing, > >> we identified 25 ground reference pairs, and used 60 photos to produce a > >> 208 megapixel image at a resolution of 0.15 m/pixel" > >> > >> The camera in Figure 2 looks exactly like the one I have sitting right > >> next to me: a Canon Power Shot A640 with 10MP. > >> > >> I found it rather entertaining to have an operator to press the trigger > >> and swap batteries. For this, there is surely a more elegant solution > >> (PSU and gphoto2) > >> > >> Anyhow, maybe one or the other finds this interesting and inspiring. > >> > >> Cheers > >> > >> Blumpsy > >> > >> > >> _______________________________________________ > >> talk mailing list > >> talk@openstreetmap.org > >> http://lists.openstreetmap.org/listinfo/talk > > > > > > _______________________________________________ > > talk mailing list > > talk@openstreetmap.org > > http://lists.openstreetmap.org/listinfo/talk > > > > > > _______________________________________________ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk >
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