Measuring Plumes Occluded by Vegetation

We often get asked if we can see a plume if it is behind solid objects. Generally yes, due to the well-known ability of lidar to be able to “poke through” otherwise visibly occluded scenes (like forest canopies), we can image plumes as they ooze through complex obstructions, as the example below illustrates. Here we’ve released gas deep inside some tomato bushes, and taken an image with the QLM gas imaging lidar camera. By imaging over a few minutes, the gas moves around so we eventually measure nearly the entire plume. Also, there is a lot of depth in our image, as the range image at right shows – we are seeing deep into the tomato bushes – getting lidar returns from the leaves at the surface (at 5.4m from the camera) all the way inside the bush with some leaves a meter inside (at 6.4m). You can see the silhouette of the nearest leaf in the range image.