Touche' - I can't believe I mixed up AGL and MSL - especially since I live at 5400 feet MSL!
-Eric -=--=---=----=----=---=--=-=--=---=----=---=--=-=- Eric B. Wolf 720-209-6818 USGS Geographer Center of Excellence in GIScience PhD Student CU-Boulder - Geography On Thu, Apr 16, 2009 at 6:23 AM, Chris Hill <[email protected]> wrote: > A local man used a radio-controlled glider tp photograph our village and an > archaeological dig a couple of miles away. One problem with RC planes is > that they are unstable in the air because of their short wing-span, so the > camera points left and right wildly. A glider has much longer wingspan and > is more stable laterally. The glider used has a small electric motor to get > it into the air and worked quite well for general shots of the area but to > use it to systematically photograph a wide area is an unthinkable difficult > task for any usefully big area. > The height restriction is AGL, not MSL or you could never fly slope soarers > in the Pennines. :-) > > Cheers, Chris > > Eric Wolf 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 <[email protected]> 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 <[email protected]> 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 >>>> [email protected] >>>> http://lists.openstreetmap.org/listinfo/talk >>>> >>> >>> _______________________________________________ >>> talk mailing list >>> [email protected] >>> http://lists.openstreetmap.org/listinfo/talk >>> >>> >>> >> >> _______________________________________________ >> talk mailing list >> [email protected] >> http://lists.openstreetmap.org/listinfo/talk >> >> > > _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
