My project is still in the nebulous planning (can I afford it, can I build it) phase and I've noodled out alot of info on air frames and autonomous flight but I'm missing an important part of the puzzle. My goal is to fly lawnmower patterns over ~90 acres for mosaic mapping and possible wildlife spotting. With this as the goal, I'm wondering about flight altitude vs camera resolution. I know that if I fly higher (300m vs 100m), I'll need a higher resolution to get the same quality image. I don't think I'm saying that right but I bet you get my point.
So, are there any calculators or trial and error experience that says for example: 7 Mega Pixels is good for 100m altitude stills if I want 4cm/per pixel resolution (pulled this number out of thin air as I don't know what is good enough yet)? How does that scale if I want to fly at 300m? 9MP camera? I guess I'm asking, for a given altitude, and given pixel=X centimeters, what resolution camera do I need? Is it more complex than this? Lens diameter?
On the fantasy end of this project, the future may bring low light or infrared cameras into the mix. Has anyone flown them? Good results? Thoughts?
Provided you can stop any vibration from the camera, a major job, we have found you can barely identify people from 100m with a 10M pixel camera.
I would go for the highest pixel camera you can afford, 10M minimum, but 16M is readily available now for low cost.
If you have a look at Finch Surveying Consultants Camera Tests the first images are from 80m with a 10M pixel Ricoh.
We are working on his camera mount and frame at the moment to get rid of as much of this vibration as possible, but it will give you an idea of the res at that height.
The low light cameras are good, except the frame rate drops with the light level after a certain lux level is passed.
Have a great starlight camera good down to .001lux but unfortunately it's frame rate is 6seconds, yes that's a frame every 6 seconds. Just something to be aware of.
Infra red is easy as all CCD's can pick it up, just remove the IR filter from the lens and block the light. Some very good DIY methods out there just do a Google.
Ok. Some one do some killer math for me. If a low light cam could give me a still every 6 seconds, then for a given field of view and altitude, how slow would I need to fly to still be able to stitch the images together for the mosaic.
Another thing; it occurs to me that you may be getting one frame every 6 seconds because it takes that long of an exposure to get the image. If this is the case, a moving camera (like flying on a UAV) would only give very blurry unusable images from this setup. Thoughts?
What kind of animals are you looking for? That will help determine how good of a camera/lens you need. If you're looking for elephants that doesn't require as much resolution as if you're looking for squirrels.
Deer, Pig, Coyote, Bobcats & Humans. Central Texas game animals. I'd like to get a feel for the game travel patterns around the property by running a repeating route several times at a specific time each day for several days. Then move to a new time slot and do it again to extend the pattern.
The property is densely wooded so I might see nothing but I have always been interested in RC flight as a hobby but never enough to actually try it. I've been looking at alot of domestic civilian drone info and got bit by the bug again. I looked at another of my hobbies, hunting, and wondered what I could come up with.
I'm shy to even mention hunting because I'm afraid someone will take offense on general premise or think I'm building kill-bots to track down poor defenseless Bambi and slaughter autonomously. I assure you this is not the case. Several members of my family maintain the land and are into conservation. We're building Owl houses, planting food plots, setting up wetland grasses for migratory birds, just general outdoors conservation type things. I'd love to be able to map this dense property accurately, and as a bonus, photograph game. Any hunter knows that a real time update of a deer's location is almost useless. It is very difficult to approach a deer and that is why most hunts are done by sitting quietly and waiting for the deer to come to you.
Knowledge of wildlife's normal travel patterns on the property would certainly aid a hunter in setting up appropriate blind locations, but:
I realize I've gone far off the "aerial photography" track this section of the board is for, and way over into political/philosophical/moral quandary territory for some people, and for that I apologize. I'd welcome a discussion on any part of this topic on any other more appropriate section of this forum if some one wants to talk it out.
It is surprising to me how little notice wildlife take of the copters.
I usually have Kangaroos or Wallabies grazing in the back paddock where I test fly my Hexa's.
They are a bit nervous of me but seem totally oblivious of the copters, even when flown over their heads in a typical auto mission. Height is usually 20m to 30m so it is not that far up.
And it seems Kangaroo protocol is to turn your back, so when I turn my back to them they will graze up to about 15m from me, so you would think when I take off they might be startled, but no, even when it lands as close to 5m from them, they might be curious but not scared.
That's not how the game works :-)
I found Waldo!
I don't think you would ever find him from 100M.
Stupid question from someone up north... How big is a wallby??? :)
(I found it)
"The whiptail wallaby is distinguished by its paler colouring and white stripe under its face. Their faces have a chocolate-brown fur covering their muzzle. They are black and white on its chest and the rest is grey to brown fur. Males weigh from 14 to 26 kilograms and stand at a height from 70 to 93 cm. Females weigh from 7 to 15 kilograms and stand at a height from 65 to 75 cm."
Comparable to a kid in size then. Nice to know if one are involved in SAR. :)
What kind of camera was used / lens zoom? A wide angle 10mm would take a picture of half the world, but be totally useless for wildlife or SAR use...
It s a Ricoh GR Digital 10 Mpixel.
Not a choice I would have made as there are much higher res cameras for much less out there now.
We have also had one failure of a camera 'out of the box' and for a $900 camera that not really encouraging.
Getting it to focus has always been an issue.
We use a CHDK cable to trigger the shutter.