Howdy - Multirotors for tropical forest research and conservation

Mactadpole

Member
Howdy All,

As requested I will fill you guys in on my background and intended uses for multirotor copters. Currently, I am a PhD candidate at Texas State University in the Department of Biology. My primary interest is in Batrachology (study of amphibians). I have been doing amphibian research in Amazonia since 2000. I am also Founder and President of a non-profit research organization for tropical amphibian research and conservation (www.tadpoleorg.org). My dissertation focuses on amphibians living in the high canopy tree tops of the Amazon. I am focused on the ecology, molecular ecology, and the affects of habitat degredation on the canopy amphibian communities that live in large epiphytic plants called bromeliads that are capable of holding large volumes of water. These plants literally create wetlands in the sky between 50-150+ feet up in the canopy. My main avenue for conducting these studies have been ground-based surveys and climbing these trees to sample the bromeliads using single-rope tree climbing techniques. For the longest time I have been wondering about how much easier it would be to do some of this work from an aerial platform. I have taken airplane flights over the forest to do some survey work and acquired satellite imagery but both have major limitations, primarily cost. That's what led me to multirotors a little over a year ago. For more on my research you can visit my little homepage, www.shawnmccracken.net.

I have never done anything RC before, but after discovering multirotor copters on the internet I realized they had serious potential for tropical forest canopy research. I purchased my first used quad flying the QP FC a little over year ago. I have now built a couple quads, hexas, and now an X8. My my intended use for this platform is to collect aerial imagery of tropical forest that can then be geo-rectified and used for GIS analyses. I would also like to collect HD video for amateur/scientific and possibly professional presentation of my work. I need a platform that is easily transported because of international travel and in-country transportation such as bus, hiking, canoe, etc. I also desired as small a frame diameter as possible since I will often be launching/landing from trees or canopy towers in forested areas. This is why I have chosen the X8 (coax octo) platform. I also wanted/needed redundancy since I won't have a backup. I am hoping I can get enough flight time out of it so I can shoot several hectares in a flight. I plan to use a Panasonic GH2 for much of the work, but will also be flying a modded Canon t2i for NDVI imagery (multispectral) and in the future a full-blown multispectral scanner and FLIR system.

I currently fly the X8 with the HoverflyPro board which does fairly well. I want a silky smooth X8 with full gps navigation abilities so at the end of the month I will be purchasing a full MK electronics setup to install. I look forward to getting all the help I can from this great community.

Here is an example of an image I took this past summer in Amazonian Ecuador flying my QP hexacopter from a canopy tower. Look near the upper center of the pic for a white square, that was my launch pad and I am standing just above it. This tower is 150' up in the tree.

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Here are some pics of my current X8. I have a build log over at RCG in the Hoverfly forum (hope you mods don't mind me linking to there): http://www.rcgroups.com/forums/showthread.php?t=1380528

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Thanks in advance to all! Shawn
 

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Crash

Defies Psychics
Very interesting Shawn.

BTW, On your downlink, I can see a filter from OMM/Rusty and an inverted V antenna. The particular V antenna you have is poorly designed. Talk to the guy who brought those into the FPV world - IBCrazy on RCgroups. He's going to say that the antenna lead should come out the back of the V at an angle. Then he may tell you to get a circular polarized antenna.

Here's his new site: http://videoaerialsystems.com/products/transmitter-antennas/

Good luck and welcome to the site.

PS. Your hood looks just like an old helmet I use to wear. ;)
 
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Mactadpole

Member
Hey Crash,

Ya, I am not happy with my video downlink performance at the moment. I am using an LM 1.3ghz 1000mW vtx with two LM vrx's (stock antenna's) through the Eagle Tree EagleEyes ground station with diversity and I have flown a max of ~500-700' away and it can get glitchy at times. I really want the BluBeam set from Alex's site but they are sold out right now. I have tried the stock LM vtx antenna too and it is worse. I think that might have to do with CF blockage.

That hood is from Hobby Lobby. It is a kid's army helmet that was camo when I got it. It's super light, tall, provides good protection, and I think looks pretty good. Glad you like it!

Shawn
 

Droider

Drone Enthusiast
Welcome Mactadpole.. this site is getting as diverse as your studies.. Great to have you on board and I am sure there will be questions from members on here to you about your set up. As soon as I saw your ground station I thought of a few. I have to get off to work now.bummer! but will jump back on later as ask you a few..

Dave

PS as soon as I saw that dome I thought of Crash! strange that..
 


Crash

Defies Psychics
Hey Crash,

Ya, I am not happy with my video downlink performance at the moment. I am using an LM 1.3ghz 1000mW vtx with two LM vrx's (stock antenna's) through the Eagle Tree EagleEyes ground station with diversity and I have flown a max of ~500-700' away and it can get glitchy at times. I really want the BluBeam set from Alex's site but they are sold out right now. I have tried the stock LM vtx antenna too and it is worse. I think that might have to do with CF blockage.

That hood is from Hobby Lobby. It is a kid's army helmet that was camo when I got it. It's super light, tall, provides good protection, and I think looks pretty good. Glad you like it!

Shawn

It's raining in VA so he's probably hard at work making new antennas. It looks like they are in stock now. He also makes them for ReadyMadeRC btw.

I ground tested my Skew-planar antennas to 1/2 mile in terrible conditions. Well outside of radio range for my Futaba 2.4Ghz.

In your case, you may want to consider an omni and a helix antenna on the diversity box. That way you get the best of both worlds. Omni coverage and directional range. Ask Alex though. He knows his stuff and does the real world testing (or playing depending on how you look at it). For longer range, two helix antennas on the ground station would be better. For short range, two omnis spaced apart at different heights would be better.

Either way, your Vee and panel antenna WILL collect dust. I don't think a panel antenna will work very well in a tree anyway. I think they need a ground plane to work well. I'm not sure about the helix antennas.

Oh, there seems to be some 'conflict' with the lawmate radios. OMM says they work with the Skew-planar wheels but Alex hasn't had much luck. I'm not sure if that was ever resolved.
 

Mactadpole

Member
It's raining in VA so he's probably hard at work making new antennas. It looks like they are in stock now. He also makes them for ReadyMadeRC btw.

I ground tested my Skew-planar antennas to 1/2 mile in terrible conditions. Well outside of radio range for my Futaba 2.4Ghz.

In your case, you may want to consider an omni and a helix antenna on the diversity box. That way you get the best of both worlds. Omni coverage and directional range. Ask Alex though. He knows his stuff and does the real world testing (or playing depending on how you look at it). For longer range, two helix antennas on the ground station would be better. For short range, two omnis spaced apart at different heights would be better.

Either way, your Vee and panel antenna WILL collect dust. I don't think a panel antenna will work very well in a tree anyway. I think they need a ground plane to work well. I'm not sure about the helix antennas.

Oh, there seems to be some 'conflict' with the lawmate radios. OMM says they work with the Skew-planar wheels but Alex hasn't had much luck. I'm not sure if that was ever resolved.

I really want to get the Blubeam's because they are a little cheaper and I know someone who has them and they are really well built. These are the ones that are out of stock everywhere. Alex posted that the problem he found with Lawmate was his OSD and he fixed it with a resistor I believe. He posted that he thinks it should work fine for others and a couple people have posted that they work fine with their Lawmate's.

I am really interested in thoughts from others about what antennas they would use if they had my particular setup. As I said, I am using the Lawmate 1.3ghz 1000mW vtx with two Lawmate 1.3ghz vrx's hooked up to my ET EE ground station for diversity. Since this is a multirotor and for my work I don't see needing to go further than 1-1.5 kilometers. What I most concerned about is multipath resistance due to trees.

My current plan was to try the Blubeam cloverleaf on the copter, Blubeam skew-planar on one rx and a "virevent" or cloverleaf at different angle on the other rx. Any thoughts?

thanks, Shawn
 

Crash

Defies Psychics
My current plan was to try the Blubeam cloverleaf on the copter, Blubeam skew-planar on one rx and a "virevent" or cloverleaf at different angle on the other rx. Any thoughts?

thanks, Shawn

I almost forgot about that CP antenna that Hugeone came up with. I was waiting for the build specs but I missed that thread. Thanks. That's what I will build.
 

Mactadpole

Member
Welcome Mactadpole.. this site is getting as diverse as your studies.. Great to have you on board and I am sure there will be questions from members on here to you about your set up. As soon as I saw your ground station I thought of a few. I have to get off to work now.bummer! but will jump back on later as ask you a few..

Dave

PS as soon as I saw that dome I thought of Crash! strange that..

Fire away when you have a chance. I have made a few changes to it recently but still looks the same. I purchased one of these: http://www.geeks.com/details.asp?InvtId=BLK-VRD-MC6-FB-R
It's awesome! WAY better than the EasyCAP.

Shawn
 

Shawn,
Have to admit I don't envy u on phd thesis writing, btw wanted to ask u if u considered fixed wings as well ( apologies if me asking this questions upsets any one). One could fly, and stitch then possibly geotag as well :).
 
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rcmike

Member
Cool! I have been into dart frogs for about a year now. So far I have some D. Leucomelas and 4 D. Ventrimaculatus. Never thought of the connection between frogs and multirotors.
 

Mactadpole

Member
Cool! I have been into dart frogs for about a year now. So far I have some D. Leucomelas and 4 D. Ventrimaculatus. Never thought of the connection between frogs and multirotors.

Love dart frogs! Used to keep D. leucomelas myself. I regularly find ventrimaculatus with tadpoles in bromeliads at 150+ feet up in the canopy where I currently do research.

Shawn
 

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