Photo Interpretation and Remote Sensing Module 8

Another fun lab this week! After learning about thermal energy, how to work with thermal infrared imagery in both ArcMap and Erdas (as well as how to compile multiple image bands into a single image in both programs), and some applications for thermal image analysis, such as identifying forest fires, we were asked to use the thermal band in one of the lab images to identify a feature of our choice.

I looked at the image from Ecuador using a panchromatic display of the thermal band in comparison to a true color composite and a panchromatic display of the near-infrared band. There were several things in the image that intrigued me (some of which I actually wasn't able to identify with certainty), but I eventually noticed this pair of bridges that only popped out at me when looking at the thermal band--in the visible and near-infrared bands, the one on the left is subtle and the one on the right is almost invisible, because their coloring isn't that far off from the water and both pavement and water absorb strongly in the near-infrared. But pavement certainly gives off thermal energy after warming up in the sun!

Anyway, I thought it was really interesting, because I wasn't expecting such a stark difference in what seems like it should be a prominent feature. There are certainly benefits to comparing multiple image bands.