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Permalink Reply by Matt on July 31, 2012 at 8:41pm

Well, I found out I will need to find a platform with a greater wing area to accomodate that high of an operational altitude. But I also have to make it backpackable into very remote areas that are at least 10 miles from the nearest road. I also want it to have both a visual spectrum camera and a FLIR onboard to help detect ground temperature variation. But FLIR modules are very expensive, so will start off with just a regular digital camera.

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Permalink Reply by Jeff Taylor on July 31, 2012 at 11:36pm

Matt, I would recommend any camera supported by CHDK for this kind of hacked mapping. The SX230 HS is great for automatically georeferencing your images. The E382 is designed for this kind of work but to be perfectly honest I'm not sure how well it would perform at such high altitudes!

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Permalink Reply by Matt on August 1, 2012 at 9:18am

Thanks for the link! I am checking out the SX230 also.

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ModeratorPermalink Reply by Gary Mortimer on August 1, 2012 at 12:45am

How hot will it be at your 13,000' obviously not too hot but the density altitude will be impressive if say it plus 10.

I quite easily have a DA of 8000' here in the summer and I live at 5000' I have a 1.2m wing that can carry my 100gm Canon IXUS camera fairly easily but I would not want to go much higher. A lightly build X8 ought to do the job but that won't fit in a backpack.

The machine will be flying pretty quick at those altitudes so you will need a big space and a deal of skill to operate it. Keep the AUW down, you might even consider building a balsa wing which will be way more fragile to keep the weight down.

I'm going to say it again so you get it. Keep the weight down. Anything over 2kg in weight will be very hard to chuck at 13,000' You will probably need an assistant to do that as I can forsee it getting away at some un predictable angles.

Oh if there is a slope to launch from chuck it from that, it will give you height straight away.

Staying close to the ground will give you very little overlap have a look at KB's book Secrets of Photomapping  and make a sea level smaller craft to learn to fly on and experiment with mapping, its easy but you have to think a little.

If you want FLIR and professional sensors you will be spending way more than a Sensefly costs. The biggest problem I can see is charging batteries, if its cold at your location you can count on the flight time being halved from sea level. You will need pockets full of SD cards as well along with a laptop to check the images were crisp.

For all the effort, making a sensor pod and hanging it out of a Cessna might be easier. You can lift all you need and then head home for post production. We aim on 2 days post to one days shooting BTW and sometimes that's too little.

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Permalink Reply by Matt on August 1, 2012 at 9:11am

I don't think a cessna could fly slow enough and low enough to get the kind of resolution I am after. And there are limits to how low to the ground you can fly in the San Juan National forest with planes.

 

With regard to overlap, I will have plenty of time to run as many passes as I want, so I will just fly a bunch of them close together to compensate for the low altitude.

I do appreciate your input though, and I'm thinking of designing a special wing for use by a small RC airplane at that altitude. I need it to fly as slow as possible, but as you pointed out the thin air at that altitude requires a higher velocity than at lower elevations. But if I build a wing with adjustable angle of attack, or some special flaps, maybe I could do some test flying with dummy payloads and see what the right wing/flap angle would be to accomodate those goals at that altitude.

 

Keep the suggestions and input coming!

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Permalink Reply by Matt on August 1, 2012 at 8:22pm

http://www.stenulson.net/rcflight/index.htm

Take a look at this site. This guys flies his RC planes at 13,000 all the time. I think it is just a matter of customizing a plane appropriately.

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Permalink Reply by Marcus VTM on August 2, 2012 at 8:33am

Depending on how low you want to go, light planes flying slowly will have a harder time to generate steady images while compensating for winds, mainly when flying inside moutain turbulance wake.

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Permalink Reply by Matt on August 9, 2012 at 9:05pm

After doing some research, I would like to use the X8 fling wing for a platform. There are of course other platforms, but its high payload and large wing span should help alleviate some of the challenges associated with high elevation flying. If anyone knows of reasons why this would not be a good idea, I am always open to hear them.

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Permalink Reply by Matt on August 15, 2012 at 10:19am

I got my new X8  platform delivered yesterday, and can't wait to start adding goodies.

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Permalink Reply by Jeff Taylor on August 15, 2012 at 3:18pm

Let us know how well it flies at that altitude, I am interested!

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Permalink Reply by m00se on August 16, 2012 at 6:36am

me too :)

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Permalink Reply by Matt on August 21, 2012 at 6:57am

I am up in CO prospecting this week, and I gotta say that Google Earth really sucks when to comes to accurately depicting how things are on the ground. I am more convinced than ever that GE needs competition in the form of higher resolution aerial coverage. What they have now for the national forests is a joke, especially considering the level of technology currently available.

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