The University of California Cooperative Extension sponsored Dr. Maggi Kelley in a fascinating talk on the uses of LiDAR in forestry.
LiDAR (Light Detection And Ranging) is an emerging technology that hold the promise of completely revolutionizing the way forests are measured. The use of LiDAR can greatly facilitate gathering the data for timber cruises and stand structure. This data can be used for metrics like growth rates and stand complexity determinations.
LiDAR works a lot like radar in that a laser is pulsed out of the emitter and the reflection coming back is gathered and recorded. These “light echoes” can be used to generate a three-dimensional picture of the topography being measured, including not only the canopy of the forest, but also its understories and the topography of the land itself. The granularity of the data is proportional to the density of the outgoing pulses, with experimentation showing that low density collection can still provide sufficient information for many inventory purposes.
This technology is coming on fast, but it’s not quite ready for prime-time. Data collection remains expensive; the data is collected by airplane and then processed through any number of data processing packages, depending on what the user wants as an end result. There is also a ground-based method that can map the tree trunks within its circumference of view, providing a fast inventory containing a count of the trunks and their dbh’s. (Unfortunately, I expect this works better on flat ground. Anyone using this on my land will get mostly pictures of the cliffs or the tree tops, depending which way it’s pointing.) It may be possible to reduce some costs by having neighboring properties work together to hire a plane for data collection over all of their properties.
Check out the current state of this really interesting technology by visiting Current Research at U.C. Berkeley and looking for Dr. Maggi Kelly.