9 replies to this topic

[D.Lafon]

Hello everyone,

Thank you for welcoming me as a member of the ultraviolet photography forums. I enjoy and use many types of photography, from film to digital, in my personal and academic pursuits; although I am far from mastering the craft of picture making, and I am content to remain an eternal student of this world. I have recently returned to college to continue my degree in anthropology, and I plan to incorporate multispectral imaging into my graduate work in archaeological studies. Lately, my son and I have also taken up an interest in UV imaging of various insects, arachnids, and other local wildlife. My greatest joy in life comes from being a father, which lead me to start teaching after school science programs at his elementary school. I have been honored by this opportunity to help out our younger generations for over five years now.

Last year, my 4th through 6th grade students spent afternoons throughout the school year building and testing a high altitude research balloon that included instrumentation for collecting atmospheric data and that used three separate cameras. I taught my students how to modify one of the cameras to image the Earth’s surface in infrared, and they handled the task wonderfully. Our research balloon collected some very valuable data and video on its journey to over 18.8 miles above the surface of the Earth. It was an amazing accomplishment by our students, and it will always be one of the most rewarding experiences of my life as well. Here is a link to some of the footage captured by our school's research balloon. The last few minutes of the video shows the infrared video captured by the camera that our students modified, and it is certainly one of my favorite parts of the project.
EECS high altitude balloon...

I look forward to learning a lot from the members on this forum, and I hope to also be of some assistance to other members as well. I currently experiment with and modify my own cameras and lenses, but I love reading about the exploits of others most of all.

Warmest regards,
D. Lafon

Edited by D.Lafon, 20 September 2017 - 18:44.

[Andy Perrin]

This is quite a project! Very successful outcome. Did you get any color infrared footage or was your filter cutoff too high for that?

[OlDoinyo]

And you had to retrieve it from the middle of Lake Michigan. That must have been a challenge all its own. Did you use hydrogen or helium for buoyancy?

[D.Lafon]

Andy Perrin, on 20 September 2017 - 18:55, said:

This is quite a project! Very successful outcome. Did you get any color infrared footage or was your filter cutoff too high for that?

Hello,

Thank you for the reply. If I remember correctly, we used a 950nm filter for the infrared camera, so it was meant to be viewed as black and white footage. We were fortunate to be able to partially adjust the white balance in the camera, and then tweak it further in post production using iMovie. I was pretty happy with the results since the camera was a rather inexpensive copy of the popular action type waterproof cameras. You may notice that there appears to be some faint, grid-like reflections of the circuitry that surrounds the cameras imaging sensor ghosted onto our infrared footage, presumably from internal reflections off of the back element of the lens. In the future, we may try applying some type of non-reflective covering over the shiny circuitry surrounding the image sensor to prevent that anomaly from appearing in the future.

The infrared video footage that we captured is proving to be a great teaching tool with plenty of potential. It is a wonderful way to introduce and demonstrate aspects of the electromagnetic spectrum to students. It can also be used to illustrate many other topics of scientific and environmental concern such as vegetation densities over various parts of the landscape, the trophic status of local lakes and rivers, or the phenomenon of urban "heat islands".

[Andy Perrin]

Well, the reason I asked about the color was because apparently the health of the vegetation can be judged by color using the "IRG" (Infrared-Red-Green) type images, or so I'm told.

How can you tell the heat islands from the infrared video? Is it from the effects of the heat on the vegetation?

[D.Lafon]

OlDoinyo, on 21 September 2017 - 03:17, said:

And you had to retrieve it from the middle of Lake Michigan. That must have been a challenge all its own. Did you use hydrogen or helium for buoyancy?

Hello,

We used helium for our weather balloon, and it was about 2 meters in diameter at the time of launch. The volume of helium that we needed was predetermined by our target values of lift and ascent rate; the students' calculations worked out perfectly. We knew that the balloon was going to land in the lake before we launched, due to predictions that we made based on the weather patterns for that morning. The fate of our entire mission rested in the hands of three very gracious officers from the Milwaukee Police Harbor Patrol who we had contacted prior to the launch. We were tracking the ballon remotely from our school classrooms, and we were allowed to phone the patrol officers with our last known GPS coordinates sent from the balloon shortly before splash down. The officers made a 32 mile trip to the middle of the lake for us via speedboat, and they recovered the balloon rig less than 100 yards from the coordinates that we had given them. In the footage of the recovery, taken by the officers aboard the patrol boat, notice that Lake Michigan was unusually calm that afternoon. I will never forget that feeling of disquiet; holding the hopes of some 90 students in suspense for a few hours before we received word that our balloon rig was safely aboard the patrol vessel. We are so very fortunate that everything worked out so well with this project.

[D.Lafon]

Andy Perrin, on 21 September 2017 - 04:24, said:

Well, the reason I asked about the color was because apparently the health of the vegetation can be judged by color using the "IRG" (Infrared-Red-Green) type images, or so I'm told.

How can you tell the heat islands from the infrared video? Is it from the effects of the heat on the vegetation?

Thanks for the reply. We are not able to delineate urban heat islands directly from our video footage as one might be able to do using infrared thermography, but what we do see is indirect evidence that can lend itself to discussions of such phenomenon. As we drift from Eagleville towards Milwaukee County, the vast expanses of white vegetative cover gradually give way to darker shaded areas of lower albedo, indicating parking lots, rooftops, roadways and other urban structures that are prone to infrared absorption. Vegetation limits the amount of infrared absorption at the surface, and also aids in cooling the surrounding environment through evapotranspiration. Rooftop gardens, expanding vegetation cover within cities, applying various high reflectivity paints and coatings to structures and asphalt, or using construction materials with a higher albedo are just some of the options that our future generations will have to continue to develop to help counter the urban heat island effect.

[Andrea B.]

Hello D.Lafon and welcome to UVP. I hope you find our website useful in some way. We are a slow little corner of the internet.

Your project was fascinating to read about. And it must have been very interesting to the students. Kudos for such wonderful work!!

A project you and your student groups might enjoy regarding UV would be an investigation of animal and insect vision. We have had some interesting posts here about modeling bees' UV/Blue/Green vision with certain kinds of filters or via difference stacks made in Photoshop. Here is a link about using filters: UV+Blue+Green Filters: 3 Examples
And here is a link about Photoshop stacks: Simulation of Bee-Colours I

[D.Lafon]

Thank you Andrea,

That information is very much appreciated, and I look forward to sharing some of it with my students in our science projects this year.

[nfoto]

Most welcome, nice to have a keen experimentalist on board