GaugeCam background set up in small irrigation channels in Bangladesh

The GaugeCam system was recently used in Bangladesh during experiments related to Arsenic dissipation in irrigation channels.  These experiments were conducted by Dr. Polizzotto, Mr. Lineberger and Dr. Birgand in December 2012.  These experiments were done to generate preliminary data to evaluate the ability of ecologically engineered systems to strip Arsenic from water in small irrigation channels.

One of the factors at play is the height of the water column above the substrate in the channels.  We thought it would be nice to use cameras and the GaugeCam system to measure the levels in the channels. So that is what we did!  The system set up can be seen in the picture to the right.

Our original GaugeCam camera is dedicated to transferring images on a real time basis to our server.  Our camera can also save images on an SD card.  The ratio quality/size of the images is outstanding and that is the reason for our preference.

Line detection of water level in irrigation channel in Bangladesh

For short term experiments, we only needed the SD card writing capabilities. In fact we believe this might be the case for many people!

We have explored the capabilities of using hobby type of equipment (Arduino based systems) to build a camera able to take time lapse pictures.

Thanks to Dr. Kyle Aveni-Deforge, we have built such a camera, which we now call ‘mini-GaugeCam’ for a cost of about $150 for parts.

Obviously, the quality is not nearly as good as our original camera, but one can still obtain some very decent images.  In fact, we had no problem finding water lines (see picture above).

As it turns out, our experiments lasted less than 30 min each and at constant flow.  So in the end we decided to read the water heights directly on the gauge staff.

Thanks to our ‘mini-GaugeCam’, we were able to very easily set up the camera, the background and the gauge staff and obtain 1-min interval pictures and verifiable measurements!  This, we think, should interest a lot of people!  More on the mini-Gaugecam later.

The problem:  We measure fine when the target is stable relative to the camera, but if the camera gets bumped, the target sinks down or tilts in the water, or anything else happens to alter the geometric relationship between the camera and the target, measurements come out wrong.

The solution:  Adjust the calibration to accommodate some of the changes between the camera and the target.  We cannot handle big changes, but we can handle those that most commonly occur in the field.

The next step will be to integrate this in to our GRIM software folllowed by integration into our web service.

Figure 1.  Reference image

Figure 2.  Target find of moved image

Figure 3.  Unaligned images

Figure 4.  Adjusted image overlayed on the reference image

Dark Image

Dirty Image 1

Dirty Image 2

Dirty Image 3

• The real-time web interface – This is the movement of images from the camera to the webserver, the application of the algorithm to create measurements, and the presentation of graphics and measurments on the internet.  You can see some of the results of this work on this web page that shows the water level in a tidal marsh on the North Carolina coast as measured by one of our cameras.  Andrew is responsible for our software systems and infrastructure.
• Camera, remote power, mounting, and target hardware – One of our hardest tasks is to develop a truly remote camera system that generates its own power, withstands the weather, provides its own light at night, is phsically stable, etc., etc.  François is responsible for this in addition to his maintenance of the lab and our test cameras.  Up until now, his improvements to the hardware have taken place behind the scenes, but expect to see a dramatically improved set of hardware on this blog in the very near future as we move to our first prototype camera production run.
• Vision algorithms – Up until the marsh camera was put into place and started shoveling images out to our web site, the requirements of the image processing software were not really well known because there were no images with which to work other than what we gathered in the lab.  Therefore, we made our best best a what was required, wrote the algorithms and deployed them.  They really work quite well, but now that we have a “real” and continuing stream of images, we know a lot more about what the vision algorithms will have to handle.  I (Ken) am responsible for making the improvements to handle things like fog (See Image 1 below) and dirty high water marks (See Image 2 below).  I will write about these and other improvements to the vision algorithms as they are developed and deployed.

Image 1.  Fog

Image 2.  High water line

The College of Agricultural and Life Sciences (CALS) at NC State was hosting a conference: “Stewards of the future: Research for Human Health and Global Sustainability“.  Along with the conference, CALS hosted its Innovation Fair.  GaugeCam had its booth entitled: ‘Hydrology for all: measuring water level using webcams’.

Our booth had posters, videos, a slide show of how the system works and of results, live data streaming from the field and a display of the GaugeCam hardware.

We must admit that few people did stop by but we did obtain some true interest and that was good.  Thanks to the conference, we did make quite a bit of progress on the live web site.

We have a variety of micro-controllers that work with GaugeCam cameras and to control light position on some of our lab setups.  When Dr. Birgand saw this, he wondered whether we could use the much less expensive micro-controllers to run some pumps and other equipment both in the lab and out in the field.  He put one of the lab assistants to work learning to program the equipment and now, several months later, they have developed a couple of solutions that are more flexible, smaller, lighter, and more capable, not to mention much cheaper than the previous solution.

This is an example of one of several synergies that has occurred as a result of the collaboration between GaugeCam and the NCSU BAE department.  Even though we do not plan to use Arduinos as actuators on our remote camera products (we are several months away from an exciting announcement in that regard), still, the research has contributed the effectiveness and capability of the lab in the performance of their on-going research.