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EasyStar Vertical Format Aerial Photography with CHDK

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Re: EasyStar Vertical Format Aerial Photography with CHDK
« Reply #10 on: 08 / August / 2011, 07:35:33 »
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The Multiplex EasyStar is in my opinion the easiest plane to fly for aerial photography. The brushless motor mod helps add extra power to be able to fly on slightly windy days. The plane is very forgiving and simple to control. After your get the plane balanced on the ground with a few metal washers and add little trim after takeoff, the FMA Co-Pilot flight stabilizer is able to keep the plane pretty much level all the time. I can even take my hands off the RC radio joysticks for a few moments to fiddle with my head mounted display controls and the plane will keep flying straight and level.
Canon SD780IS

Re: EasyStar Vertical Format Aerial Photography with CHDK
« Reply #11 on: 01 / November / 2011, 22:27:15 »
I ordered an EasyStar yesterday - already have Phoenix flight simulator software that lets me practice flying that model a bit.  Looking forward to the learning curve.

Found this - probably the most inelegant mounting of a Canon Powershot possible - but it worked :
http://www.wired.com/geekdad/2007/03/worlds_cheapest/
Ported :   A1200    SD940   G10    Powershot N    G16

Re: EasyStar Vertical Format Aerial Photography with CHDK
« Reply #12 on: 02 / November / 2011, 05:38:47 »
Hi Waterwings.

I found it really helpful when I started learning how to fly model airplanes to have my R/C Radio connected to the flight sim software with a USB trainer port device.

The hardest part for me was getting used to the model airplane 'orientation'. When the plane is flying away from you control is easy but when the plane is coming towards you you have to map in your brain the correct control response to the left or right wing tip leaning downwards.

When preparing your plane for aerial photography make sure your propellor is balanced or it will induce vibrations into your camera.

The most important thing about carrying cargo on an EasyStar is to have the CG (Center of Gravity) balanced, even if this means adding something as a counterweight on the tail of the plane.

I found the upgrade to a 3S Lipo battery and a brushless motor really adds to the cargo carrying potential on an EasyStar. I went with a Hobby King 2200kv Brushless Inrunner motor HXT 2835 (380S) because it is a drop in replacement for the typical brushed speed 400 motor. With a standard 2200mAh 3S1P 11.1Volt Lipo batery I get about 20 minutes of flying time.

A shaft adapter (with a collet made for a 3.175mm motor shaft) is also required to connect a propellor to the brushless motor. I have had good success with APC 6x4 props on my EasyStar. Metal gear servos are also good to have. They are less likely to fail after a hard landing.

Camera Mounts

During my flight experiments I have experimented with all sorts of camera mounts.

My first camera mount was quite hackneyed - I cut a slot in the foam canopy and used electrical tape to hold the camera onto the plane.





Next I tried using plastic cable ties to attach the camera to the wing so I could take vertical format aerial mosaic images.





Then I tried using a 1/4 nylon bolt run through the canopy and screwed into the tripod thread on the camera. I also used a piece of corrugated plastic as a washer to reinforce the bottom part of the foam canopy. I used large rubber bands to hold the canopy on.

Later on I experimented with sticking a large piece of industrial velcro on the front of the camera and using a wide velcro strip to affix the camera to the plane. This works for sideways camera mounts and vertical camera mounts. Just make sure to put the "soft" side of the velcro on your camera for easy handeling!












CHDK Settings

As far as CHDK camera settings I typically use ND Filter "out" and set the camera to manual exposure mode using as high of a shutter speed override as I can on the day. A speed of 1/1000th of a second is typical on a sunny day. I then bump the ISO up and down a bit to adjust the exposure. I also set the focus mode to infinity and set the review mode to off.

If you want to take lots of photos I typically go with the non-stop CHDK intervalometer route because I find the more photos I take the better odds of capturing something interesting.

Some people like the idea of using an R/C "switch" to enable / disable their intervalometer in CHDK. There are a few manufacturers like Gentles Limited who make these types of remote switch products.

Good Luck!

P.S. I noticed that the Forum software has removed some of the photos and text from previous messages on this thread.
Canon SD780IS

Re: EasyStar Vertical Format Aerial Photography with CHDK
« Reply #13 on: 02 / November / 2011, 09:11:04 »
I found it really helpful when I started learning how to fly model airplanes to have my R/C Radio connected to the flight sim software with a USB trainer port device.
My sim does just that.  I'm hoping it will save me some tree climbing and wing gluing time.   Thanks for the rest of the tips - I figured I'd need a motor upgrade at some point.

As for your photos - probably another casualty from acseven recently switching the ISP he uses to host the forum.

Ported :   A1200    SD940   G10    Powershot N    G16


Re: EasyStar Vertical Format Aerial Photography with CHDK
« Reply #14 on: 16 / February / 2012, 23:57:48 »
The weather has been nice enough the last few days to get out and take some aerial photos using my trusty Multiplex EasyStar model airplane. The photos were taken at noon on Feb 14th, 2012 around the old ruins at Polly Cove, West Dover, Nova Scotia. To take the photos I used CHDK + the UBASIC Countdown Intervalometer script on my Canon Powershot SD780IS camera with the shutter speed set to 1/1500th second.













Waterwings,

How is your model airplane project going? Have you flown with a camera yet?
Canon SD780IS

Exploring Aerial Photogrammetry
« Reply #15 on: 14 / March / 2012, 07:29:47 »
This weekend I started exploring aerial photogrammetry using Bundler and Meshlab. The first few Google searches I did while researching aerial photogrammetry discussed KAP (Kite Aerial Photography) enthusiasts who have used free photogrammetry tools like Microsoft PhotoSynth and Synth Export or the open source program Bundler (SfM) to create surveys of archeological sites.

My goal was to use aerial photos my brother & I captured with our EasyStar model airplane to create DEMs (digital elevation models) of our local scenery. The aerial photos I used to test Bundler were taken at a 400 foot altitude with a model airplane flying at 35 kilometers per hour. I used a Canon Powershot SD780IS camera with CHDK and the countdown intervalometer script to trigger the photos.

I wrote a blog post about my first experiences processing CHDK shot aerial photos into a digital elevation model:
Exploring Aerial Photogrammetry using Bundler and Meshlab


Here is a tutorial I created that shows how to convert the Bundler point cloud data into a polygon mesh:
http://www.youtube.com/watch?v=uB-TeEF0TSY#ws
Canon SD780IS

Re: EasyStar Vertical Format Aerial Photography with CHDK
« Reply #16 on: 14 / March / 2012, 20:39:11 »
Temperature here today is more like what you  would expect in June,  there is no wind but my EasyStar is still in pieces in my workshop.  Keep up the posts Andrew - its really nice to see somebody doing something like this.

Ported :   A1200    SD940   G10    Powershot N    G16

Re: EasyStar Vertical Format Aerial Photography with CHDK
« Reply #17 on: 28 / March / 2012, 21:53:25 »
Last week I got out during the unusually warm spring weather and got in some CHDK aerial photography above Privateers Island in West Dover, Nova Scotia, Canada. The model airplane carried a Canon PowerShot SD780IS digital camera, a Garmin eTrex Legend GPS, and a wireless video camera.

We launched several flights that day starting around 11am in the morning. This is the first year that I can remember wearing a t-shirt and getting a sunburn in March!

During the vertical aerial photo flight we took several hundred photos. The main thing we noticed when we reviewed the aerial photos of Privateers Island was evidence of significant hurricane damage in the forest. There are large areas in the forest canopy that are now open clearings with a lot of fallen trees.



This is a photo of me holding a ready-to-launch EasyStar model airplane. The plane is fully loaded with camera gear and has a total weight of 1.3kg.


The hurricane damage is really visible on the southern part of Privateers Island.




There are hundreds of trees down in the center of the island.


A slow cleanup process is underway on parts of the island.






On the nose of the EasyStar plane is a homemade camera mount that lets us pan the wireless video camera using a large servo.


This is a top view of the fully loaded EasyStar model airplane. The eTrex GPS is on the left and the Canon Powershot is on the right.


I used the CHDK Countdown intervalometer script to take the photos. To manually control the exposure I used a CHDK shutter speed override with a 1/4000th second exposure. The fast shutter speed reduces motion blur that can often be an issue when taking low altitude vertical aerial photos. The GPS indicated the EasyStar's average flying speed was 36 km / hr.




This is the EasyStar doing a low flyover of the launch site just after takeoff.


The weather was absolutely perfect for flying.


Here is a Google Earth view of the flight path.

I used Microsoft ICE to create a mosaic image of the lower part of Privateers Island. A few years ago the large open areas on the island used to be fully forested. In the full resolution version of the mosaic an incredible amount of detail is visible. It is possible to notice flotsam and jetsam washed up on the shoreline, and stacked piles of cut wood.


This is a mosaic image of the southern part of Privateers Island. The mosaic image was created by stitching together 15 aerial photos in Microsoft ICE.
You can view a medium resolution version of the mosaic image here: Privateers_Island_Mosaic_5K_x_2K.jpg
Canon SD780IS


Re: EasyStar Vertical Format Aerial Photography with CHDK
« Reply #18 on: 28 / March / 2012, 22:00:57 »
Hi Andrew.  Once again - nice project.

A couple of questions ?   

Did you actually fly this with the wireless camera ?  Looking at the map,  it seems like you must have flown out of visual range from the ground ?

Also,  you've switched to shooting "straight down" from your previous "side shooting".  Was this just for this project or for some other reason ?

Finally,  is the GPS module just something that records your flight path for later playback ?
Ported :   A1200    SD940   G10    Powershot N    G16

Re: EasyStar Vertical Format Aerial Photography with CHDK
« Reply #19 on: 28 / March / 2012, 22:31:21 »
On March 21st we did three flights by FPV control using a 900 MHz video link and a fatshark HMD (head mounted display). The first two flights were to test all of the systems and get the plane trimmed nice and level. Most of the flying was within visual range and consisted of circling around the island.

For the last flight we put on the Canon Powershot camera and did the photo mission. After the plane got some altitude we did a quick trip across the cove and took some photos of the barren tundra in East Dover. There are some really interesting glacially deposited boulders in the area.

I have been taking straight down photos recently to experiment with creating aerial photomosaic maps and using open source photogrammetry tools to try extracting terrain elevation maps from the photos. The GPS was used so I could try georeferencing the images in Google Earth and also to feed the photos into the beta version of the dronemapper.com website.
Canon SD780IS

 

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