Demonstration of Drone Aerial LiDAR Mapping
What is LiDAR?
Seeing With Lasers
LiDAR is an acronym for “light detection and ranging,” (sometimes Light Imaging, Detection, And Ranging). Like sonar and radar, LiDAR relies on the same principle: echolocation.
Although it sounds like Star Wars space science, echolocation has been around for millions of years and happens to be a critical tool for a little flying mammal – the humble bat. Bats use sound waves — issuing a squeak that bounces off an object that returns to their ears sooner or later depending on how far away the object is. Tracking how long it takes to come back tells the bat the distance and location of prey—or death by tree.
Fast forward to naval sonar, which sends a bigger click into the surrounding water and listens for echoes. Knowing how fast sound travels in water, operators can tell exactly how long it took to hit something and come back, telling them precisely how far away it is.
Radar, the next big advance, does much the same thing with radio waves. The familiar radar dishes we’ve all seen fire out a beam of radio waves. When those waves hit something solid they bounce back and the dish detects them. Since we know the exact speed of light we can calculate the distance of the object hit. But radio waves have limitations. They don’t detect some objects, and don’t work well below an elevation of 100 feet.
What is the Value of LiDAR?
High Precision Optical Distance Measurement
LiDAR systems use lasers to send out pulses of light outside the visible spectrum and measure how long it takes each pulse to return. When it does, the direction of and distance to whatever that specific pulse hit, is recorded as a point in a 3D map with the LiDAR unit at the center. Starting in the early 1960s, laser-focused imaging (with the ability to calculate distances by measuring the time for a signal to return) and data acquisition electronics were combined.
Today, thanks to shrinking electronics and the great speed of computers, a LiDAR imaging system may send out and receive millions of pulses and complete hundreds of revolutions per second. The resulting “point cloud,” a collection of coordinates from returning laser pulses, can be extraordinarily detailed showing all the contours of the environment and objects within it.
LiDAR, which provides rapid, remote data sensing solutions, is popularly used to make high-resolution maps with applications in geomatics, archaeology, geography, seismology, forestry, atmospheric physics, laser guidance, and airborne laser swath mapping (ALSM), to name a few. This is just the beginning.
LiDAR and Drones for Commercial Use
LiDAR technology has been available for commercially for about 20 years. Only recently with miniaturization and the increased awareness of drones, LiDAR has become a cost-effective tool for capturing 3D representations of assets, vegetation, and elevation models. LiDAR scanning is a rapid and accurate data modality, making it more efficient than traditional photogrammetric methods. Hundreds of uses in a variety of industries are being developed. The benefits of using LiDAR and drones vary depending on the application.
Today, the value of LiDAR and all its known applications are widely recognized by government agencies, engineering firms, surveyors, energy, environmental and natural resource entities. LiDAR can be mounted on almost anything that moves, typically weighing less than 4-7 pounds. Consequently, Unmanned Aerial System (UAS) uses have skyrocketed.
What would you use it for? Talk to our Industrial Engineering Specialists for a collection process that fits your needs and gets you decisional data when you need it.
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The Benefits of LiDAR – Changing the Paradigm of Terrain Mapping
LiDAR provides a wealth of data and offers distinct advantages over traditional methods for aerial mapping and Graphic Information Systems (GIS). Applications from forest inventory, floodplain mapping, hydrology, geomorphology, urban planning, landscape ecology, coastal engineering, survey assessments, and volumetric calculations are all benefiting from LiDAR. Every day new applications are discovering how to can take advantage of LiDAR to analyze, manage, visualize, and disseminate LiDAR data.
A few key advantages of LiDAR include the following:
Quickly collect data with very high accuracy
Provides the ability to collect data in a dense vegetation, where photogrammetry cannot reveal the accurate terrain surface.
Day or night usage available compared to traditional photogrammetric techniques.
Eliminates geometric distortions.
Can be integrated with other data sources.
Many data products are possible from a single LiDAR mission.
LiDAR General Workflow
It has never been easier to collect large amounts of high definition terrain data. If you are new to drones or have your remote piloted aircraft license some simple flight planning can make all the difference.
First, check your airspace and make sure you obtain the right to fly.
Next, Calculate your Desired Point Density and Flight Profile. See Point Cloud Planning Section Below.
Finally, Set up your flight plan in a mission planner to observe flight profile, terrain, and obstacle avoidance. We like UgCS Pro.
Here at Modus Robotics, we look at drone data collection as an industrial process. As a pilot’s confidence and skill increases so do their awareness to use the best tools. Beginning pilots tend to want to fly by hand, which reduces battery life, adds positional error, increases collection time, and increases flight risks. Many of our customers try using photogrammetry apps, only to discover they can only fly flat terrain well above obstacles. What is more frustrating is most apps do not allow modification of the flight plan to make the most of LiDARs unique collection characteristics. We know, we have tried dozens of applications. Finally, our advanced clients adopt a full smart automation system, that allows loading of current terrain data, update obstructions, precise terrain following, loading of previous LiDAR Digital surface maps. Many of these pilots are paid by the kilometer or acre and the more ground they cover the higher the margin.
Professionals know even on good day conditions change. Monitoring LiDAR point cloud density ensures you get the data quality your analysts needs to build a decision-making product. Sometimes you may miss a checklist item and not turn on your LiDAR or the vegetation is different requiring you to change your flight profile. For the professional, getting this information while in flight and making a change is critical.
This is where LiDAR becomes useful.
There are a variety of packages and tools available for visualizing and manipulating LiDAR data in innovative ways. Our Data Analysis Team has review dozens of platforms for ease of use, functionality, and applicability.
Need to know what software to use, talk to our experts.
If you just want to get started and obtain results, we can help you there too. Our staff of remote sensing specialist, data scientist, and certifying agents can work with you to get you and your client the products they need.