Help save net neutrality! A free, open internet is once again at stake—and we need your help. Learn more »

Public Lab Research note


  • 6

Review/Overview of the Public Lab Pole Mapping Kit

by Ecta64 |

Ecta64 was awarded the Video Documentation Barnstar by natalie for their work in this research note.


POLE_SMALL_-_Copy.jpg

Pole aerial photography has been a very popular means of gathering elevated imagery for some time. The advantages of such systems are extreme low cost, much better coverage than if you just held the camera yourself, very rapid setup and take down times when compared to most other forms of aerial imaging and are rather independent of weather conditions (the biggest exception to this would be electrical storms which could cause problems if a pole is made of conductive material).

When it comes to Public Lab, pole aerial imaging offers a simple and low-cost means of mapping a location that would otherwise be difficult due to any number of various restrictions that might be related to weather, regulations, shortage of materials (Helium) or physical constraints of the site.

The pole mapping kit, as I received it, consisted of a 11 m carbon fiber carp pole as well as a mounting bracket for my camera.

DSC00647_-_Copy.JPG

DSC00637_-_Copy.JPG

The pole itself is split into a number of sections that are stacked vertically. While the pole is 11 m tall it only weighs 1100 g. This is exceedingly light for such a large instrument. When collapsed the pole is only 158 cm tall. When it comes to using such poles as camera platforms, realistic heights that can be attained are typically 6 to 8m. If one has a light enough micro camera it may be possible to attain the full height.

Using the pole in a field environment is surprisingly easy. One simply pulls off the bottom and top rubber caps, pulls out the various sections and simply stacks them. This horizontal construction method necessitated by the need of the various sections to be stacked one atop the other, is a bit cumbersome in that it requires everything to be lofted once the camera is attached but offers great security in that it is nearly impossible to have a sudden collapse of the pole. Depending on the weight of the camera there will be some degree of flexibility with the pole. I do recommend that first-timers be mindful of this until they get the hang of the system. Once you understand how the pole flexes and moves at various angles it is possible to attain some quite interesting shots. If you would like to cover a large area, basically anything you cannot get within the footprint of the pole, it may be necessary to image while you are walking or pick up the pole and move to a different place while everything is fully assembled. This takes some practice but is by no means difficult. The main issue is one of situational awareness. The pole is more than tall enough to reach power lines and carbon fiber is electrically conductive. This is where having another person would be great on a large area pole mapping session. Having extra help also makes it extremely easy to get the pole up in the air. Disassembly and storage is very rapid and I do believe that if one was to do a comparison between the various means of getting a mapping system more than 20 feet into the air, the Public Lab pole mapping kit would win out every time in terms of quick set up and take down.

The methods of attaching the camera to the pole have a nearly infinite number of possibilities. I myself decided to utilize a method I outlined in some earlier notes in which I used a flexible tripod that is rubber-banded and slipped over the top the pole. There is a much more professional system sold in the Public Lab store (http://publiclab.myshopify.com/collections/aerial-camera-mounts/products/juno-pole-bracket) that I will have to get and test at some point in the future but it looks really exceptional.

vlcsnap-2017-01-21-21h24m00s347_-_Copy.png

Once imagery is gathered it must be processed into a map. My favorite workflow thus far is to put the various images into Microsoft image composite editor also known as ICE. This program works amazingly well as long as you were good in getting a sufficient overlap between the images. In terms of the amount of area one can cover I can say that in a 1 min. session of imaging while moving, I was easily able to cover somewhere around 20 or 30,000 ft.² of a local creek.

IMG_0981_stitch_-_Copy.jpg

Structure-from-motion software can also be used with fascinating results. Below is an screenshot of 123D Catch (http://www.123dapp.com/catch) with images of the same creek as above.

Capture_(1)_-_Copy.JPG

The disadvantages of the Public Lab pole mapping kit are endemic to any pole aerial photography set up that is of a similar height. Covering extremely large areas is less efficient than other aerial systems and if one wants to cover something that is far into a body of water the most that a pole system could do is get a nice oblique. The vertical stacking can be a bit tedious and I do recommend finding some kind of a bush or section of grass to lay out all the sections in so you do not get grime in the joints. That said the cost of this system is fractional of most other means of getting a pole this high. Some photographic tripods that attain similar heights are well over USD700. Some painter poles can reach similar heights but their closed length is usually unmanageable unless you own a SUV or truck. The safety factor of a vertical stacked pole is also something to consider. There is no way to damage the camera through vertical collapse unless a section was to break.

All in all I recommend this kit as a very effective means of gathering mapping imagery. A surprising amount of ground can be covered in a short time and stitched imagery looks as if it was taken from 100 feet rather than 25. Quick setup time, no reliance on wind or helium and lack of regulation issues make this a great system for those looking to get into mapping.



polemapping pole-mapping

barnstar:video-documentation


5 Comments

Nice tips. Good use of the animated GIF.


Thanks


that bubble level is a real slick addition!


Honestly while it does help I likely need a better model that is more sensitive. Useful but a more accurate survey bubble level would give far better results. It does fantastic for oblique imagery where the pole is or is close to vertical.


On using a gorilla tripod. Not a bad idea. Would be cool to have cameras at different heights together. I wonder if the pole could support them all? As a side note we will be offering different size mounts as an upgrade/bundle pack through the Public Lab store. We want to encourage folks to use smaller cameras and get the maximum height with the pole. The mount that is included in the kit I think works best at the base of the section that is second from the top (2A). This way the clamp is actually secured around 2 sections, the inner and outer parts of the put over. At this location it gives you a camera height of about 30ft. That being said, some will want to use a larger or heavier camera, such as a compact or a super zoom. That is why we are going to offer the various sizes.

Is this a question? Click here to post it to the Questions page.


You must be logged in to comment.