First of all some background...
Having spent a good 2 years playing about with an Skywalker, Ursus and a Canon camera running CHDK, and designing my own uav, which actually flew recently ,I have come to the conclusion that flying wings may just be the best type of platform for short range aerial mapping tasks to create DEM, DSM models for GIS purposes.
The Skywalker was okay (but quite fragile, and now in pieces!), but I think it is too small to fit a roll gimbal on it. And I've found that if pictures are taken on a slight angle, it is very difficult to use software to tile them up nicely. this is my best effort, but far from perfect. The roads on the right do not line up as the camera must have been on a 45 degree angle when the picture was taken. (click for larger resolution) - It was taken using an ixus80 attached to an URSUS Airframe
Realizing that I need to use an airframe that can accommodate a stabilized roll gimbal, i started to design and build my own twin boom design. It took 6 months from initial design, to first test flight. It has a wingspan of 2.4m - AUW of 5kg, and a flight duration of around 30 minutes with 2 x 5000mah packs. However it needs a heck of a lot of room to take off and land, something i don't have in the areas i need to take photos.
Picture of twin boom plane...
What are peoples experiences with using flying wings for this reason? I have the following types of flying wings, and wondering which one is the best to begin with?
I have been using the 60" wing to test the APM2 and 3dr radios. And was using the URSUS (now in pieces after a nasty crash!) as a test platform to practice with the Canon CHDK Kit.
Here's a few pictures of the wing and camera....(click images for larger version.)
My question is how straight forward do you think it is to fit a roll stabilized gimbal to any of the above airframes?
Great name by the way.
Used a Sony Nex5 for the collection. 1/2000 shutter speed. Aperture 5.4(I think), ISO 400. How are you finding the X8? We are very pleased with its performance but we want to modify the airframe by flattening out the top and rounding out the bottom to put the COG under the wings. Then perhaps create a mold of the modified frame and start making our own. Anyone out there that can do this?
We did not use Pix4D. We have never found Pix4D to work well. We are beta testers of a new software and I can't really put the name out there yet. Sorry. But we use a variety of software to produce the final product not just one. I don't think that there is any single software solution out there that can meet true mapping specifications yet. I have not seen one anyway.
These look great. I was wondering if you would be able to post a full resolution version of one of these images or a portion of one. I would really like to see what the ground items look like at full resolution.
I have no idea how to post the entire image as it is 1.6 gig. If you have way for me to send the image to you I would be happy to share it. Is there a section in particular that you would like to see? I could also crop an area or two and place it with higher resolution.
Hi Bill, There is about 120m relief to the bottom of the river.
Hi John, Cool orthos! Looks like some serious relief in the upper left corner of the first image.
That's great thank you. I'm looking at doing something similar for aerial surveys of vegetation. It will hopefully allow us to monitor the management of some invasive species on a nature reserve. Could you tell me what altitude you were flying at for the images of the trees? Thanks again :)
We were flying quite high with this one at 250m because the terrain varied by as much as 120m. The area of the farmhouse was at the highest elevation and got the best resolution. Using the Sony Nex5 with a 16mm pancake lens at 120m will give you just under 4cm resolution. We have flown some missions at 75m and we get around 2cm resolution. The problem will be terrain at such a flying height. If it is a flat area it will be no problem but any major undulation in the terrain and you must either fly higher with a better camera/lens combination or do terrain following. ArduPlane does not have terrain following but there are ways to get around that. Your first consideration must be what objects you want to see on the ground and plan your mission from there.