Think of a pulsed laser. It is projected from an aircraft onto a rocky outpost below. It sweeps the rock, recording the waves reverberating from the surface. What follows is a science: the construction of those waves into a topographical map. This is LiDAR and this is why it’s important.
LiDAR stands for light detection and ranging and is a remote sensing method used to analyze the Earth. The example above is an illustration. LiDAR laser instruments, when combined with GPS systems and a scanner, create a detailed map of the world it is targeting, and the uses are vast.
It is often combined with photogrammetry to create measurements between objects. Photogrammetry is the science of measuring distance within photographs. In other words, LiDAR creates the picture of the world, while photogrammetry measures the distance.
What are the applications of LiDAR surveying and photogrammetry? Here are five industries that these technologies are utilized in surprising ways.
Agriculture
Think of that farmer with little understanding of the topography of their farm. They don’t know the slopes, where water and fertilizer runs off, where crops are being deprived of nutrients, or where they’re being over-saturated.
LiDAR surveying and photogrammetry changes that. LiDAR creates an elevation map of the farmland, which the farmer can convert to a sunlight exposure and slope map. From there, a farmer knows where their high crop production areas are. This saves money on fertilizer.
Energy
Fossil fuel companies search rigorously for new oil and natural gas deposits. A new deposit can mean hundreds of millions of dollars in revenue. With LiDAR, they have a better chance at finding the next deposit.
LiDAR, when combined with a new technology called Differential Absorption, detects trace amounts of gases above the hydrocarbon energy level. Fossil fuel companies use these trace amounts to find the next oil or natural gas deposit.
Forest Planning and Management
Think of a forest. Hundreds of trees. Their branches everywhere. The leaves overhead skewing all vision. This is the challenge of forestry employees. How do you measure something which seems to go on forever, with few resources?
The answer is LiDAR surveying and photogrammetry. An aircraft with a LiDAR instrument will fly above the canopy and pulse a laser. The reverberations will show the canopy. Photogrammetry will then show the distance of the canopy. The same can be done for the trees in the forest.
River Survey
You’re a scientist trying to study streams. You have all the training in the world and understand the physics behind the movement of the water. But it’s too fast for you to measure and to complex. That’s where LiDAR surveying and photogrammetry come in.
LiDAR surveying puts together all the information: The flow rate of the stream, the depth, the strength, and the width of the stream. Photogrammetry does the rest, applying distances to all those measurements. With LiDAR, there is a general idea. With photogrammetry, there are concrete units.
Mapping
This seems fairly straightforward. LiDAR and photogrammetry are used to create maps, after all, right? The answer, of course, is not that simple.
We all have our GPS. It has a map of the city or the state or the country. But that is surface area. The real trick, with both LiDAR surveying and photogrammetry, lies in their ability to penetrate underground; this creates a layering in Earth models, which is useful for geographers, miners, and others.
Geotechnical engineering firms use LiDAR technology and phogrammetry. As do the biggest civil engineering companies in the world.
Industries use these technologies because they get something they cannot get through other methods: a detailed view of the Earth with concrete measurements, from just a few instruments
Here are just five industries. There are many, many more.